地球科学进展  2018 , 33 (2): 189-205 https://doi.org/10.11867/j.issn.1001-8166.2018.02.0189

研究论文

北祁连西段熬油沟组玄武岩地球化学特征及构造意义

刘懿馨1, 侯克选2, 沙鑫1, 马蓁1, 王金荣1*

1.兰州大学地质科学与矿产资源学院 甘肃省西部矿产资源重点实验室(兰州大学),甘肃 兰州 730000
2.河北省众联能源环保科技有限公司,河北 石家庄 050000

Geochemical Characteristics and Tectonic Significance of Aoyougou Group Basalts in Western North Qilian

Liu Yixin1, Hou Kexuan2, Sha Xin1, Ma Zhen1, Wang Jinrong1*

1.School of Earth Sciences, Lanzhou University, Key Laboratory of Mineral Resources in Western China, Lanzhou 730000, China
2.Zhong-Lian Environmental Protection and Scientific Technology Co. Ltd., Shijiazhuang Hebei 050000,China

中图分类号:  P588.145

文献标识码:  A

文章编号:  1001-8166(2018)02-0189-17

通讯作者:  *通信作者:王金荣(1958-),男,福建莆田人,教授,主要从事构造地质学的教学科研工作.E-mail:jrwang@lzu.edu.cn

收稿日期: 2017-07-20

修回日期:  2017-12-18

网络出版日期:  2018-02-20

版权声明:  2018 地球科学进展 编辑部 

基金资助:  甘肃省矿产资源补偿费项目“甘肃省肃南卡瓦铁矿综合研究”(编号:甘财建【2014】99号)中央高校基本科研业务费(编号:lzujbky-2016-197)资助

作者简介:

First author:Liu Yixin(1988-),female,Qin’an City,Gansu Province,Ph.D student. Research areas include petrotectonics.E-mail:liuyx16@lzu.edu.cn

作者简介:刘懿馨(1988-),女,甘肃秦安人,博士研究生,主要从事岩石大地构造研究.E-mail:liuyx16@lzu.edu.cn

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摘要

北祁连造山带是一典型的板块缝合带,其中镶嵌着众多大小不一的由前震旦系变质岩系组成微陆壳残块,为解析北祁连前造山构造过程提供了重要的研究载体。北祁连西段卡瓦—祁青一带分布有较为完整的中元古界长城系朱龙关群熬油沟组火山岩—碎屑岩—碳酸盐岩建造。岩石地球化学研究表明,熬油沟组玄武岩主量元素含量变化较为稳定,具高K2O(4.27%~6.07%),TFe2O3(10.49%~13.01%),TiO2(1.96%~2.90%)以及中等的MgO(5.37%~6.71%,Mg# 48~51),CaO(2.57%~ 5.51%),为钾玄碱性玄武岩。岩石Cr和Ni含量随着Mg#降低而减小、CaO与CaO/Al2O3呈正相关,明显富集轻稀土元素(LREE)和大离子亲石元素(LILE),轻微正Eu异常,高含量的高场强元素(Nb,Ta,Ti),以及元素对Gd/Yb(2.5~3.0),Zr/Y(8.6~10.2),Ta/Yb(0.96~1.23),Ti/Yb(5 074~6 021),Zr/Yb(81~97),Ce/Nb(1.87),Zr/Nb(6.41)值均揭示了熬油沟组玄武岩具有洋岛玄武岩(OIB)地球化学特征。结合区域地质背景研究表明,熬油沟组碱性玄武岩源于类似于OIB的深部富集地幔,在岩浆作用过程中发生过橄榄石和单斜辉石的分离结晶作用以及一定程度的大陆地壳物质的混染作用,形成于大陆裂谷背景,并认为其是对中元古代Columbia超大陆裂解的响应,进一步为中元古代华北克拉通裂解与Columbia超大陆裂解事件的关系提供了重要的岩石学证据。

关键词: 玄武岩 ; OIB ; 富集地幔 ; 分离结晶 ; 大陆裂谷

Abstract

The North Qilian orogenic belt is a typical plate suture zone, which is studded with numerous different sizes of fragments of micro-continental crust consisting of pre-Sinian metamorphic rocks and the North Qilian orogenic belt provides important study carrier for studying the pre-orogenic tectonic process of the North Qilian. The relatively complete volcanic-clastic-carbonate rocks formation of Zhulongguan Group, Changchengian System, Mesoproterozoic are distributed in the Kawa-Qiqing area, Western North Qilian orogenic belt. Geochemical characteristics of the Aoyougou Group basalts in the North Qilian indicated that the contents of major element were relatively stable, high K2O contents(4.27%~6.07%), TFe2O3(10.49%~13.01%),TiO2(1.96%~2.90%)and middle MgO(5.37%~6.71%,Mg# 48~51), CaO(2.57%~5.51%)content. Thus, the Aoyougou Group basalts belong to potassium alkaline basalt. The contents of Cr and Ni of the basalts decreased with the decreasing of Mg#, and there was a positive correlation between CaO and CaO/Al2O3, Furthermore, the Eu anomaly of samples was slightly negative, high contents of high field strength elements (HFSE, Nb, Ta, Ti), and the ratios of Gd/Yb(2.5~3.0), Zr/Y(8.6~10.2), Ta/Yb(0.96~1.23), Ti/Yb(5 074~6 021), Zr/Yb(81~97), Ce/Nb(1.87), Zr/Nb(6.41)indicated that the Aoyougou Group basalts had obvious OIB-type magmatic affinity. In combination with the regional geological background, the study results showed that Aoyougou Group alkaline basalt generated from deep enrichment mantle similar to the source of OIB, with fractional crystallization of olivine and monoclinic pyroxene and a certain degree of contamination of continental crust in the process of magmatism, formed in the background of continental rift, might response to the Proterozoic Columbia supercontinent rifting, which further provides important petrological evidences for the relationship between North China Craton rifting events and Columbia supercontinent rifting during Proterozoic.

Keywords: Basalts ; OIB ; Enriched mantle ; Fractional crystallization ; Continental rift.

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刘懿馨, 侯克选, 沙鑫, 马蓁, 王金荣. 北祁连西段熬油沟组玄武岩地球化学特征及构造意义[J]. 地球科学进展, 2018, 33(2): 189-205 https://doi.org/10.11867/j.issn.1001-8166.2018.02.0189

Liu Yixin, Hou Kexuan, Sha Xin, Ma Zhen, Wang Jinrong. Geochemical Characteristics and Tectonic Significance of Aoyougou Group Basalts in Western North Qilian[J]. Advances in Earth Science, 2018, 33(2): 189-205 https://doi.org/10.11867/j.issn.1001-8166.2018.02.0189

1 引言

位于青藏高原东北部的北祁连造山带是一典型的板块缝合带,记录了从新元古代到早古生代的大陆裂解、洋盆扩张、大洋俯冲、大陆闭合拼贴的完整的威尔逊旋回[1~15],其最大的特点是在早古生代增生杂岩中镶嵌着众多大小不一的由前震旦系变质岩系组成的陆壳残块[16],故被认为是一条典型的增生型造山带[17~20]。长期以来,国内外学者主要侧重于新元古代—早古生代祁连古大洋形成与演化的研究,并取得较为一致的认识[5~8,13~15,17,20~25],但对于前震旦纪北祁连的研究则显得相对薄弱且分歧较大,主要集中在中祁连地块基底地层格架的讨论方面[26~35]。少数学者对陆壳残块中的元古宙火山岩系及变质岩系做了初步研究,左国朝等[16]认为北祁连造山带西段陆壳残块可分为裂谷型残块、活动大陆边缘型残块及海底孤岛型陆壳残块,是华北古大陆西南缘阿拉善地块在早古生代裂解后残留的块体,并以此认为早古生代北祁连构造格局表现为洋、海峡(裂谷)、岛屿(陆壳残块)及海底高原并存的局面;冯备战等[36]通过北祁连西段古元古代北大河群斜长角闪岩年代学和地球化学特征研究认为,斜长角闪岩(原岩为玄武岩)形成于与地幔柱有关的大陆裂谷环境,但付国民等[28]则认为其是古元古代华北克拉通与柴达木克拉通之间存在的古洋盆俯冲消减作用的产物;王忠良[37]根据中祁连西段的托赖岩群岩石组合、岩石地球化学和年代学等的研究认为,祁连地块的基底主体起始于太古代—古元古代,形成于中元古代;徐晓春等[38]认为走廊南山朱龙关群玄武岩(Sm-Nd等时线年龄为1 770.9 Ma)形成于大陆板内环境;毛景文等[39]在熬油沟地区朱龙关群下部辉绿岩墙获得的锆石年龄为1 840~1 784 Ma;夏林圻等[9]研究认为在北祁连西段镜铁山矿田镜铁山群下部铁矿层中碧玉岩的Sm-Nd等时限年龄为(1 309±80)Ma,上部(东水峡地区)碱性玄武岩Sm-Nd等时限年龄为(1 032.7±64.9)Ma,并认为后者形成于大陆板内环境,源于地幔柱岩浆作用的产物,是北祁连新元古代—寒武纪洋盆打开的前兆;张招崇等[40]认为北祁连西段早元古代变质火山岩形成于裂陷槽构造背景,分布在熬油沟地区的蛇绿岩之辉绿岩锆石高灵敏度高分辨率离子探针质谱法(Sensitive High Resolution Ion Microprobe,SHRIMP)年龄为1 777 Ma,并被认为其所代表的洋盆闭合于中元古代早期(1 466 Ma)[41],但近年来的研究认为,祁连山西段熬油沟蛇绿岩是新元古代—早古生代北祁连大洋演化的产物,形成于早古生代,熬油沟蛇绿岩中的辉长岩和二只哈拉蛇绿岩中辉长岩LA-ICP-MS锆石U-Pb年龄分别为480~504 Ma和(497±3.2)Ma[42~44]。由此可见,北祁连西段元古宙火山活动广泛发育从下元古界北大河岩群的变质火山岩系、中元古界朱龙关岩群下部熬油沟组和上部桦树沟组基性火山岩,到新元古代大陆溢流玄武岩,不同学者从不同角度开展了研究,取得了许多重要的认识,但也存在许多亟待解决的科学问题,特别是北祁连造山带内部镶嵌着众多大小不一的前震旦系变质岩系,其构造属性存在较大的分歧。许志琴等[17]认为其是中祁连地体推覆而来的飞来峰;冯益民[45]将其视为外来移置的滑覆体;左国朝等[16]则认为其是早古生代时期华北古大陆裂解的陆壳残留体。若是陆壳残留体其构造含义是什么?北祁连古—中元古代构造岩浆演化过程仍缺乏高精度的年代学及岩石地球化学的系统研究,且认识存在分歧;祁连地块的构造属性是与华北克拉通还是与扬子克拉通更具亲缘性?同时,对北祁连前寒武纪变质岩系的构造属性与中祁连的对比研究缺乏系统性。因此,本文通过对北祁连西段卡瓦—祁青地区中元古界长城系朱龙关岩群熬油组中的玄武岩岩石学及岩石地球化学的研究,查明熬油沟组玄武岩性质、成因、构造动力学过程,为构建北祁连前寒武纪构造演化体制及确定祁连地块的构造属性提供重要的地质依据。

2 地质背景

研究区位于北祁连造山带西段南部的祁青—卡瓦一带(图1),区内分布有熬油沟—卡瓦蛇绿岩带[27,42,44],其代表着祁连古大洋南向俯冲形成的弧后盆地的残留体[44]。除了蛇绿岩分布外,其最大的特点是在早古生代岩系中镶嵌着前震旦系变质岩系组成陆壳残块[16],主要由下元古界北大河岩群、中元古界朱龙关岩群、蓟县系、上元古界青白口系等组成(图1),表现为较完整的元古宙沉积层序,其中北大河岩群中的斜长角闪岩原岩为玄武岩,Sm-Nd等时线年龄为1 980 Ma[39],被认为是古元古代晚期柴达木与华北克拉通之间古洋盆俯冲消减的产物 [28],但从其岩石组合(玄武岩—石英岩—石英片岩—碳酸盐岩—黏土岩)来看,并不支持其形成于岛弧环境的认识。

朱龙关岩群由下部熬油沟组和上部桦树沟组组成,主要出露于祁青、卡瓦、牛毛泉子、头道沟、小柳沟及镜儿泉—九个青羊一带,层位及横向延伸相对稳定,与下伏北大河岩群及上覆桦树沟组均呈断层接触 。熬油沟组下部以变石英砂岩和粉砂质千枚岩,粉砂质板岩夹泥钙质板岩,夹透镜状赤铁菱铁矿体为主,自下向上岩石粒度变细,化学沉积物含量增加,在夹皮沟铁矿一带,在岩性上变化很大,除了夹多层厚层火山岩,碳酸盐型变质岩(灰岩和硅质岩)增加外,且产有数层透镜状赤铁矿;上部岩性变化较大,火山岩发育程度不一致,由下而上具有火山岩逐渐减少、碳酸盐岩逐渐增多的变化规律。碳酸盐岩中发育有数层赤铁矿层,含矿层位稳定,延伸达数十公里。总体上表现为一套中低级变质的碎屑岩—海相碳酸盐岩(含赤铁矿层)—火山岩(玄武岩)建造。毛景文等[39]分别对朱龙关群下部侵入的辉长岩和辉绿岩进行单颗粒锆石测年,年龄分别为(1 784±2)Ma~(1 840±2)Ma和(1 777±28)Ma[41];徐晓春等[47]在北大河地区朱龙关群中获得的玄武岩Sm-Nd等时线年龄为1 770.9 Ma;夏林析等[9]测得3个泉朱龙关群下部基性熔岩年龄为(1 780.7±50)Ma;俞伯达[48]获得了肃北县大泉一带的玄武岩Sm-Nd同位素年龄为1 529 Ma,并以此年龄作为熬油沟组与桦树沟组之界线。故可以初步认定熬油沟组玄武岩年龄应在1 784~1 529 Ma,形成于中元古代早—中期,这与区域地层年代的归属吻合。桦树沟组岩石类型主要由一套浅变质碎屑岩、碳酸岩盐夹中基性火山岩构成,是区域上沉积变质型铁矿、层控再造型铜矿的赋矿地层。

图1   研究区地质简图(据参考文献[15,46]修改)
(a)北祁连西段卡瓦地区大地构造纲要图(据参考文献[15]修改);(b)卡瓦一带地层分布图(据参考文献[46]修改).1.中新生界;2.古生界;3.第四系;4. 青白口系;5.长城纪桦树沟组;6.长城纪熬油沟组;7.古元古代北大河岩群;8.基性—超基性岩;9.中酸性侵入岩体;10.地质界线;11.图2剖面位置(采样位置见图2)

Fig.1   Geology sketch of the research area(modified after references[15,46])
(a)Structure outline map of Western North Qilian (modified after reference [15]). (b) Stratigraphic map of Kawa region (modified after reference [46]).1:Middle Cenozoic. 2:Paleozoic. 3:Quaternary. 4:Qingbaikou System. 5:Huashugou Group, Changcheng Period. 6:Aoyougou Group, Changcheng Period. 7:Paleoproterozoic Beidahe terrain. 8:Mafic-ultramafic rocks. 9:Neutral-acid intrusion. 10:Geology boundary. 11:Samples and geological section location of Fig.2

3 样品采集与分析方法

玄武岩样品位于熬油沟组顶部,采自北祁连西段古浪峡以北、卡瓦铁矿区II矿段南,与上下凝灰质砂岩为整合接触关系(图2),样品新鲜蚀变弱。在野外地质调查和岩石薄片鉴定的基础上,选取新鲜玄武岩岩石样品,经过表面杂质清洗粗碎,在无污染玛瑙研钵中将样品研磨至200目以下,送实验室进行测试。全岩主量元素、微量元素和稀土元素的测试在西安地质矿产研究所实验测试中心进行。主量元素利用荷兰帕纳科公司生产的Axios4.0kw 顺序式-X射线荧光光谱仪(XRF)测试,测试结果利用曲线法校正,精度一般优于1%。稀土元素的测定使用Series II型电感耦合等离子体质谱仪(ICP-MS) (美国热电公司生产)完成,微量元素分析仪器为等离子体质谱仪(ICP-MS)和Xios4.0kw X-荧光光谱仪(XRF),分析精度优于5%。样品处理的详细方法、流程及分析参见参考文献[49]。

图2   熬油沟组—桦树沟组地质剖面图及采样点(剖面位置见图1)

Fig.2   Aoyougou-Huashugou Group geological sectionmap and sample position (the position of section map are shown in Fig.1)

4 岩石学特征

熬油沟组火山岩与地层为整合接触,岩石类型主要为辉石玄武岩、玄武岩,少量安山玄武岩及火山碎屑岩。玄武岩的风化面为浅灰色,新鲜面为灰黑色,隐晶质和间粒结构,致密块状构造。玄武岩矿物组成主要为斜长石(约 55vol.%)(vol.%为体积百分数)、单斜辉石(约 43vol.%)及少量角闪石(图3),副矿物主要为磷灰石、磁铁矿等。其中斑晶约25%,主要为斜长石,半自形—自形长板状结构,粒径为0.6~2 mm,聚片双晶发育少数发生绿泥石化,基质约75%,具间粒结构,多为细板条状斜长石,粒径为0.02~0.5 mm,双晶发育,分布杂乱,呈多角格架状,其间分布着约20%的单斜辉石颗粒,粒度小于0.2 mm,以及少许磁铁矿、钛铁矿石颗粒,粒度小于0.05 mm,偶见的杏仁体为方解石和石英,呈圆形、椭圆形,大小为0.2~0.5 mm。

图3   玄武岩及其镜下特征(正交5X)
Cpx.单斜辉石;Pl.斜长石

Fig.3   Basalts with its microscopic photasl (perpendicular 5X)
Cpx:Clinopyroxene. Pl:Plagioclase

5 地球化学特征

5.1 主量元素

岩石主量元素分析结果见表1。熬油沟组玄武岩样品的烧失量(Loss On Ignition,LOI)为6.05wt.%~7.27wt.%(wt.%为重量百分含量),表明岩石遭受到了蚀变作用。经烧失量剔除后进行百分化重新计算后,岩石中SiO2含量为44.87wt.%~48.31wt.%,TiO2含量为2.01wt.%~2.91wt.%, Al2O3为15.43wt.%~16.26wt.%, CaO为2.58wt.%~3.91wt.%(样品14-KW-H33达5.98wt.%),富钾贫钠,Na2O为1.09wt.%~2.76wt.%,K2O为4.35wt.%~6.11wt.%,MgO含量中等(5.67wt.%~6.74 wt.%),Mg#值(Mg#= 100×Mg/(Mg+Fe2+))为48~51,平均为49。Fe含量较高,TFe2O3=10.86wt.%~13.08 wt.%,P2O5为0.49wt.%~0.61wt.%。在全碱分类(TAS)图(图4a)上,样品主要投入碱玄岩、碧玄岩域中。在 Zr/TiO2-Nb/Y图(图4b)和SiO2-K2O图解(图5)中,所有样品均投于碱性玄武岩和钾玄岩系列,故认为其为钾质碱性玄武岩。

图4   火山岩分类图
(a)火山岩TAS分类图(据参考文献[50]修改); (b)Nb/Y-Zr/TiO2图解(据参考文献[51]修改)

Fig.4   Classification diagrams for volcanic rocks
(a)TAS classification of volcanic rocks(modified after reference [50] ). (b)Nb/Y-Zr/TiO2 diagram (modified after reference [51])

图5   熬油沟组玄武岩SiO2-K2O图解[50]

Fig.5   SiO2-K2O diagram for Aoyougou Group Basalts[50]

5.2 微量元素

岩石微量元素分析结果见表1。玄武岩稀土元素(Rare Earth Element,REE)总量较高,为192×10-6~241 ×10-6,轻稀土元素(Light Rare Earth Element,LREE)的含量为139×10-6~184×10-6,重稀土元素(Heavy Rare Earth Element,HREE)的含量为46×10-6~58×10-6。在稀土元素球粒陨石标准化配分图(图6)上,岩石中等富集LREE、LREE/HREE=2.60~3.53,(La/Yb)N=6.92~9.44,弱的正Eu异常(δEu=1.02~1.12),配分曲线整体呈右倾分布,表明REE之间发生了分馏作用,其配分模式与洋岛玄武岩(Ocean Island Basalt,OIB)的一致(图6)。在微量元素原始地幔标准化蛛网图(图7)上,玄武岩富集大离子亲石元素(K,Rb和Ba),除了Ba,K和Sr元素外,在微量元素标准化蛛网图上的所有元素的分布均类似于OIB(图7)。Ba,K和Sr为活动性强的元素,其配分异常部分可能与岩石后期蚀变作用或地壳混染作用有关。

图6   熬油沟组玄武岩REE球粒陨石标准化配分图(标准化值来自参考文献[52])

Fig.6   Chondrite-normalized rare earth element patterns diagram of Aoyougou Group Basalts (normalized value from reference[52])

表1   北祁连西段熬油沟组玄武岩主微量元素(%)、微量元素(×10-6)分析结果

Table 1   The contents of major (%) and trace elements (×10-6)of Aoyougou Group Basalts in the Western North Qilian

样号14-KW-H3014-KW-H3114-KW-H3214-KW-H3314-KW-H3414-KW-H3514-KW-H36
SiO244.8644.5645.6445.5648.0746.7846.64
Al2O315.6416.1515.7215.1615.4715.7115.59
TiO22.902.432.502.301.962.552.39
TFe2O313.0110.9911.3010.5810.4911.5311.04
MnO0.650.850.720.460.460.630.55
MgO6.716.355.685.995.375.805.75
CaO2.572.993.225.513.562.743.67
Na2O1.911.081.721.611.602.072.57
K2O4.336.075.365.136.014.954.27
P2O50.490.560.540.510.470.560.52
LOI6.417.277.016.406.056.126.59
Total99.4899.3099.4199.2199.5199.4499.58
Mg#48514850484848
Ba1 2803 8102 3801 7902 0401 8901 290
Rb42.8067.2083.0068.4086.8064.6040.00
Cs2.993.493.322.893.183.212.75
Th3.123.193.653.133.373.713.30
U0.800.730.780.940.770.800.79
Nb43.9036.2036.9042.0036.9037.9039.00
Ta3.552.752.783.022.862.882.98
Pb4.273.814.033.193.816.153.08
Sr211.00275.00312.00307.00250.00257.00236.00
Zr272.00236.00236.00264.00238.00248.00252.00
Hf6.815.595.966.275.806.046.19
P2 1402 4462 3582 2272 0522 4462 271
Cr246.00165.00181.00223.00123.00170.00207.00
Ni134.0096.1093.30107.0054.8094.9091.10
Co50.2039.6038.8037.4028.0045.0034.60
V274.00229.00220.00204.00169.00236.00213.00
Sc24.9020.6021.8015.5016.7024.2020.60
Ga24.0021.2021.2022.3020.7021.5021.30
La27.9029.0036.9035.8033.9036.8031.10
Ce61.6063.8081.2079.4075.9078.2067.20
Pr7.858.5310.409.829.2510.208.28
Nd31.2035.6042.8040.2037.1041.2032.40
Sm7.438.249.158.698.479.407.46
Eu2.543.303.333.102.963.282.66
Gd7.237.568.768.177.628.757.07
Tb1.181.191.381.291.231.451.11
Dy6.586.447.306.536.367.395.96
Ho1.231.201.341.231.221.351.11
Er3.243.063.423.063.123.562.90
Tm0.460.420.470.430.440.480.42
Yb2.892.602.912.722.752.962.60
Lu0.430.380.420.380.400.410.38
Y30.1027.5031.0026.4025.5031.8024.80
∑REEEE191.86198.82240.78227.22216.22237.23195.45
LREE138.52148.47183.78177.01167.58179.08149.10
HREE53.3450.3557.0050.2148.6458.1546.35
LREE/HREE2.602.953.223.533.453.083.22
δEu1.021.121.061.051.051.041.05
δCe0.860.860.870.870.880.870.87
(La/Yb)N6.928.009.109.448.848.928.58
Nb /U54.8849.5947.3144.6847.9247.3849.37

注:Mg#=100×Mg/(Mg+Fe2+)(原子数), FeO=0.899×TFe2O3,δEu=EuN/(SmN×GdN)1/2,δCe = CeN/(LaN×NdN)1/2;测试单位:西安地质矿产研究所实验测试中心

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6 讨论

6.1 岩石成因

熬油沟组碱性玄武岩最突出的特点是富钾贫钠以及具有较高的高场强元素含量(TiO2 为2.01wt.%~2.91wt.%,Nb为 36×10-6~43 ×10-6,Ta为 2.75×10-6~3.55 ×10-6),岩石在REE球粒陨石标准化配分图(图6)上表现为明显富集LREE,其配分曲线完全与OIB的一致;在微量元素原始地幔标准化图上(图7),除了活动性元素Ba,K和Sr等元素外(应该与岩石后期蚀变作用或地壳混染作用有关),其他亦与OIB的一致,提示其源区应为类似于OIB的富集地幔。众所周知,分配系数接近、化学性质类似的元素之间的比值不受部分熔融程度和结晶分异作用的影响,能够有效地反映岩石源区的地球化学特性以及岩浆作用过程。岩石具有高Gd/Yb(2.5~3.0),Zr/Y(8.6~10.2),Ta/Yb(0.96~1.23)值,揭示其源区应为富集地幔,较高的Ce/Nb均值1.87(OIB为1.63~2.11)、Nb/U均值49(OIB为48)、Hf/Nb均值0.16(OIB为0.14~0.19)、Zr/Nb均值6.41(OIB为5.80~8.08)[53]与典型的OIB微量元素比值一致,显示出熬油沟组玄武岩具有明显的OIB亲缘性。玄武岩石中Nb,Zr和Y的丰度可区分富集地幔源区、过渡型地幔源区和亏损地幔源区。在Zr/Nb-Ce/Y图解(图8)和TiO2/Yb-Nb/Yb图解(图9)及Zr-Nb和Zr-Y图解(图10)上,熬油沟组玄武岩样品全部落入了OIB区域和富集型地幔区域,表现为OIB的地球化学特征。另外,Ta/Yb-Th/Yb和Ta/Yb-Nb/Yb图解常用来判别地幔源区和岩浆上升过程中流体或熔体对微量元素的贡献,未遭受后期影响的岩石应落入地幔序列。地幔柱是洋岛玄武岩浆的重要动力学背景之一[55,57]。利用δNb值能够较好地区分地幔柱、亏损地幔和壳源基性岩浆,前者大于0,后两者小于0[58]。熬油沟组玄武岩样品的δNb(0.31~0.51)大于0,表明北祁连熬油沟组玄武岩可能与地幔热柱岩浆作用有关。

图7   熬油沟组玄武岩微量元素原始地幔标准化蛛网图(标准化值来自参考文献[52])

Fig.7   Primitive-mantle-normalised multi-element diagram of Aoyougou Group Basalts (normalized value from reference [52])

图8   玄武岩Zr/Nb-Ce/Y变异图[54]

Fig.8   Zr/Nb-Ce/Y variation diagram of basalts[54]

图9   玄武岩Nb/Yb-TiO2/Yb变异图[55]

Fig.9   Nb/Yb-TiO2/Yb variation diagram of basalts[55]

图10   玄武岩源区判别图
(a)熬油沟组玄武岩Zr-Nb图;(b)Zr-Y图解[56];直线为原始地幔

Fig.10   Resource discrimination diagrams of basalts
(a)Zr-Nb. (b)Zr-Y diagram of Aoyougou Group basalts[56]. Straight line represents the PM

微量元素Yb相对石榴子石是相容元素,而La和Sm是不相容元素,因此La/Sm-Sm/Yb图解可以很好地区分石榴子石相橄榄岩和尖晶石相橄榄岩源区的玄武岩[59]。熬油沟组玄武岩在La/Yb-Sm/Yb图解(图11a)上可以看出,该玄武岩样品落入接近于石榴石二辉橄榄岩熔融演化曲线上,并且其熔融程度为3%~5%。在La/Sm-Sm/Yb图解中,全部样品同样落在石榴石二辉橄榄岩熔融演化曲线之间,并表现出富集地幔洋岛玄武岩的演化趋势,部分熔融的程度在10%左右(图11b)。

在Nb/Th-Nb/La变异图(图12)上,玄武岩样品呈正相关关系,说明在岩浆演化过程中加入了少量的地壳物质[62],推测北祁连西段熬油沟组玄武岩在形成过程中遭受了一定程度的地壳物质混染。

熬油沟组碱性玄武岩主量元素含量变化范围较为稳定,具有中等的Al2O3含量以及正常大洋玄武岩的Mg#值,但CaO及相容元素(Cr,Ni和V)含量较低、TFe2O3含量较高,且样品Cr和Ni含量与Mg#哈克图解、CaO vs.CaO/Al2O3图解上具有良好的正相关性,表明在玄武岩浆作用过程中发生过橄榄石及单斜辉石的分离结晶作用。然而,轻微的正Eu异常指示了在玄武岩浆作用过程中没有发生斜长石分离结晶作用。

综上所述,熬油沟组碱性玄武岩源于深部富集地幔(类似于OIB源区),深部地幔物质在上升过程中通过减压导致源岩发生部分熔融,熔融程度应在10%以下,在岩浆作用过程中早期发生过橄榄石、单斜辉石的分离结晶作用,但没有斜长石的分离结晶。此外,玄武岩浆在上侵过程中受到一定程度的大陆地壳混染作用。

图11   岩石部分熔融演化图
(a)熬油沟组玄武岩La/Yb-Sm/Yb[60];(b) La/Sm-Sm/Yb图解[61]

Fig.11   Partial melting evolution diagram
(a)La/Yb-Sm/Yb diagram[60]. (b) La/Sm-Sm/Yb[61] diagram of Aoyougou Group basalts

图12   Nb/La-Nb/Th变异图(据参考文献[55]修改)

Fig.12   Nb/La-Nb/Th variation diagram(modified after reference[55])

6.2 岩石形成的构造背景

玄武岩浆类型、性质与其源区、部分熔融深度及程度密切相关,而岩浆作用过程又受到板块构造背景所控制。碱性玄武岩的形成可以发生在多种大地构造背景下,即板内环境(包括裂谷、洋岛环境)、大陆弧、大洋弧和碰撞后弧环境[63]。上文已明确得出北祁连熬油沟组玄武岩类似于OIB,源于深部富集地幔的部分熔融。研究表明板内玄武岩(Within Plate Basalt, WPB)、过渡型洋中脊玄武岩(Transitional-Middle Ocean Ridge Basalt, T-MORB)和富集型洋中脊玄武岩(Enriched-Middle Ocean Ridge Basalt, E-MORB)的Nb丰度大于12×10-6,Ta大于0.7×10-6,Nb/La>1,Hf/Ta<5,La/Ta<15,Ti/Y>350。而岛弧玄武岩(Island Arc Basalt, IAB)和部分亏损型洋中脊玄武岩(Normal-Middle Ocean Ridge Basalt, N-MORB)则表现为相反的地球化学特征[63]。由于不相容元素在岩浆演化过程中比较稳定,且受后期地质作用过程的影响比较小,因而常被运用到岩浆源区的示踪、判断火成岩形成的大地构造背景。熬油沟组玄武岩Nb丰度为36.2×10-6~43.9×10-6,Ta丰度为2.75×10-6~3.55×10-6,Nb/La(1.02~1.57)>1,Hf/Ta(1.92~2.14)<5,La/Ta(7.86~13.27)<15,Ti/Y(461~578)>350,表明熬油沟组玄武岩可能形成于板内环境(WPB)[64]。在Th/Yb-Ta/Yb(图13a)、Zr-Zr/Y(图13b)、Hf/3-Th-Ta(图13c)和Ti/100-Zr-Y*3构造环境判别图(图13d)也指示了熬油沟组玄武岩形成于板内构造环境。

板内构造环境主要包括大陆内的正常地壳和衰退地壳及大洋岛[69]。熬油沟组玄武岩与凝灰岩、凝灰质砂岩呈整合产出,为一套陆源碎屑岩—碳酸盐岩—火山岩建造,其特征提示应形成于大陆环境,不是洋岛环境。在MgO-Al2O3-TFeO和Ce/Nb-Th/Nb图解中,玄武岩样品也全部落入大陆玄武岩序列和大陆溢流玄武岩域中(图14),同时上文认为熬油沟组玄武岩岩浆演化过程中发生过一定程度的大陆地壳混染作用进一步佐证了这一认识。前人对该地区同一时期的火山岩研究结果表明,朱龙关群在长城系早期发生了裂陷并形成多条裂谷,北祁连西段古元古代北大河群斜长角闪岩年代学和地球化学特征研究认为,它们形成于与地幔柱有关的大陆裂谷环境[69]。中祁连西段的托赖岩群岩石组合、岩石地球化学和年代学等特征表明祁连地块的基底主体萌起始于太古代—古元古代,形成于中元古代[36,37]且走廊南山朱龙关群火山岩形成于陆内裂谷环境;张招崇等[40]认为北祁连西段北大河群中元古代变质火山岩形成于裂陷槽构造背景。由此可见,熬油沟组玄武岩形成于陆内裂谷环境与区域大地构造背景是一致的,符合地质实际。

6.3 构造意义

在地质发展史中,地球经历了多次超大陆旋回,2.9~2.2 Ga的Kenorland超大陆、1.9~1.2 Ga的Nuna 或Columbia超大陆、1.1~0.7 Ga的Rodinia超大陆及300~200 Ma的Pangea超大陆假说[70]。其中Columbia超大陆假说认为在中元古代早期(1.9~1.5 Ga)由Nena,Ur和Atlantic等3个大陆块体群汇聚形成了Columbia超大陆,于中元古代中期(约1.5 Ga)再次发生裂解,并在新元古代(约1.0 Ga)这些破裂的大陆块体又重新汇聚形成Rodinia超大陆[71~74]

前人对中国华北古大陆做了大量研究,陆松年等[73]通过对吕梁—中条造山运动(2.0~1.8 Ga)和大规模裂解事件(1.8~1.6 Ga)的性质、特点和同位素年龄数据的研究,认为哥伦比亚超大陆汇聚峰期与吕梁—中条造山运动的时限相一致, 在造山及裂解事件的性质、特点和时代等特征上,华北与北美、西伯利亚和西北欧有更大的相似性,故此华北古大陆应属于哥伦比亚超大陆的组成部分, 并可能是Nena大陆块体群的一员。此后,地质学家[75~79]通过同位素年代学、地层学、岩石地球化学、地球物理学等方法对华北板块元古宙岩石组合的研究认为,华北板块隶属于哥伦比亚超大陆构造演化过程的一部分。扬子板块是我国前寒武纪最大的三大板块之一,起源于古太古代[80],其广泛存在的1.8~2.0 Ga的构造热事件[81~89],可能与Columbia超大陆再造有关[90,81]

图13   熬油沟组玄武岩构造背景判别图
(a)玄武岩Th/Yb-Ta/Yb[65];(b)Hf/3-Th-Ta[66];(c)Zr-Zr/Y[67];(d)Ti/100-Zr-Y*3[68]

Fig.13   Tectonic setting discrimination diagrams for Aoyougou Groups Basalts
(a)Th/Yb-Ta/Yb diagram[65]. (b)Hf/3-Th-Ta diagram[66]. (c)Zr-Zr/Y diagram[67]. (d)Ti/100-Zr-Y*3 diagram[68]

图14   熬油沟组玄武岩构造背景判别图
(a)玄武岩MgO-Al2O3-TFeO[67];(b) Ce/Nb-Th/Nb构造判别图[12];PM.原始地幔;DMM.亏损地幔端员;N-MORB.N型洋中脊玄武岩;E-MORB.E型洋中脊玄武岩;OIB.洋岛玄武岩;BC.平均大陆壳;UCC.大陆上地壳;GLOSS.全球俯冲沉积物组成;Iceland plume.冰岛地幔柱;ECFB.峨眉山大陆溢流玄武岩

Fig.14   Tectonic setting discrimination diagrams for Aoyougou Groups basalts
(a) MgO-Al2O3-TFeO diagram[67]. (b) Ce/Nb-Th/Nb diagram[12]. PM: Primitive Mantle.DMM: Depleted mantle. N-MORB: Normal mid-ocean ridge basalt. E-MORB:Enriched mid-ocean ridge basalt. OIB: Oceanic island basalt.BC:Average continental crust. UCC:Upper continental crust. GLOSS:Global subducted sediments. ECFB: Emei Mountain continental flood basalt

关于祁连山地块构造属性有2种不同的认识:①祁连地块在新元古代末由华北板块裂解出来,与华北克拉通有很大亲缘性[4,5,91,92];②祁连地块与扬子板块有较大的亲缘性[29,36]。但是,目前许多学者更倾向于由Rodinia超大陆裂解事件导致祁连—柴达木地块是从华北克拉通裂解出来的[15,26]认识。北祁连造山带最大的特点是在早古生代岩系中镶嵌着众多大小不一的由前震旦系变质岩系组成的陆壳残块[16],研究区位于由中—上元古界组成的镜铁山—托勒山北坡陆壳残块上,下元古界代表性地层为北大河群、中元古界长城系的朱龙关群和蓟县系花儿地组和海原群。北大河群斜长角闪岩形成于与地幔柱有关的大陆裂谷环境[67]或裂陷槽构造背景[38],认为北祁连造山带的基底从克拉通向大陆裂谷构造体制转换大致发生在早—中元古代的分界时限(约1 777 Ma)[41,93,94]。之后,北祁连山西段火山作用明显加强,范围扩大,主要分布在朱龙关岩群的熬油沟和桦树沟组,位于北大河岩群之上的朱龙关岩群中下部的基性熔岩Sm-Nd等时线年龄为1 770~1 840 Ma[9,47],在岩性、层序及时代上相当于朱龙关群上部的镜铁山岩群碧玉岩Sm-Nd等时线年龄为(1 309±50)Ma[9]。此外,位于塔里木克拉通的东南缘大红山一带A型花岗岩(锆石LA-ICP-MS测年,获得二长花岗岩的w(207Pb)/w(206Pb)加权平均年龄为(1 732.3±7.4)Ma,形成于岩石圈伸展的构造背景[95],柴北缘的欧龙布鲁克微陆块中发现有环斑花岗岩((1 776±33)Ma)和基性岩墙((1 852±15)Ma)[96],上述构造岩浆事件均反映了中元古代早期祁连地块及其邻区处于伸展的构造背景,提示大陆进入裂解的演化阶段。赵国春等[97]研究表明全球规模的造山事件可能发生在古元古代末期,部分克拉通可能在中元古代早期就开始大陆裂解,华北克拉通1.7~1.8 Ga侵位的基性岩墙群记录了该超大陆的裂解事件[98,99]。因此,北祁连西段中元古代早—中期熬油沟组碱性玄武岩所指示的大陆裂谷岩浆作用与Columbia超大陆裂解事件的时限[71~74]以及华北克拉通裂解事件[71]相吻合,是对Columbia超大陆裂解事件的响应,进一步为华北克拉通在中元古代裂解事件[98,100,101]与Columbia超大陆全球性的裂解事件之间的联系提供了重要的岩石学依据。

7 结论

北祁连西段中元古界长城系朱龙关岩群熬油沟组碱性玄武岩具有OIB的地球化学特征,是深部富集地幔(类似于OIB源区)上升、减压过程中发生部分熔融的产物,熔融程度应小于10%,在岩浆作用过程中发生过橄榄石、单斜辉石的分离结晶作用,但没有斜长石的分离结晶。

熬油沟组碱性玄武岩与凝灰岩、凝灰质砂岩、碳酸盐岩呈整合产出,为一套陆源碎屑岩—碳酸盐岩—火山岩建造,形成于大陆裂谷环境,其是对Columbia超大陆裂解事件的响应,进一步为中元古代早—中期华北克拉通裂解事件[96,98,99]与Columbia超大陆裂解事件之关系提供重要的岩石学证据。

致 谢:感谢甘肃省地质矿产开发局第四勘查院丁书宏院长,陈世强、付强、胡小春等工程师在野外工作期间给予大力的支持和帮助,参加野外工作的还有研究生霍永豪、边鹏等;感谢2位匿名评审人认真细致的审阅,并提出许多建设性的建议和意见。

The authors have declared that no competing interests exist.


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In the North Qilian subduction-zone complex (suture zone), two sub-belts of high-pressure (HP) metamorphism have been distinguished in terms of mineral assemblages, i.e., the low-grade blueschist belt and high-grade blueschist–eclogite belt. The low-grade blueschist belt consists of lawsonite–pumpellyite–glaucophane schist, lawsonite–glaucophanite and minor lawsonite-bearing felsic blueschist with a typical mineral assemblage of Lws02+02Pmp02+02Gln02+02Ab02+02Chl02±02Arg. This assemblage constrains the metamorphic conditions of T 02=0265250–35002°C and P 02=020.6–1.102GPa. Protoliths of the lawsonite-bearing mafic blueschist are similar to present-day N-type MORB. The high-grade blueschist belt occurs as three slices within the island-arc volcanic complex and consists of blueschist- to eclogite-facies metamorphosed greywacke, basite, serpentinite, meta-pelite, chert and marble. Lawsonite and Mg-carpholite occur in eclogites and meta-pelites, respectively. P 61 T estimation yields peak metamorphic conditions of P 02=022.2–2.602GPa and T 02=024606154002°C for eclogite and carpholite meta-pelite. Geochemical data suggest that protoliths of mafic blueschist and eclogite in both belts have features of present-day MORB or OIB. These observations indicate that the North Qilian HP metamorphic rocks have experienced a history of seafloor subduction in a cold subduction-zone with a geotherm of 656–702°C/km in the early Paleozoic before exhumed at the Late Silurian and Devonian in response to continental collision.
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北祁连走廊南山加里东火山岛弧带前缘为弧前俯冲杂岩增生地体。它由多重的增生火山岛弧、复理石增生楔、高压变质滑脱带及蛇绿岩残片组成,为早古生代古祁连洋壳自SW往NE俯冲于阿拉善地块之下的结果。俯冲过程的高压变质阶段经历了中温高压的初期、降温增压的主期而进入降压增温的驰后期。提出了450-500Ma期间,中祁连地块向北俯冲、阿拉善地块向南增生的海沟后退的俯冲动力学模式。
[18] Hou Rongna,Wang Shuhua,Zhang Xiang,et al.

Geochemical characteristics and tectonic significance of the granotoids in the western section of the Mid-Qilian

[J]. Advances in Earth Science,2015,30(9): 1 034-1 049.

[侯荣娜,王淑华,张翔,.

中祁连西段花岗岩类的地球化学特征及构造意义

[J].地球科学进展,2015,30(9):1 034-1 049.]

DOI      URL      摘要

中祁连西段石板墩地区北部及南部发育有辉长岩、闪长岩及花岗岩. 北带岩体的LA-ICP-MS锆石U-Pb年龄为(469.3±2.8)Ma,(461.2±3.3)Ma和(470.0±2.5) Ma;岩石Si02质量百分含量为53.2%~66.11%,高Al,Ti,Mg,Fe,Ca,K,Na,A/CNK<1.1;富集大离子亲石元素 Rb,K和Pb,亏损高场强元素Nb,Ta,Ce,Sr,Hf,Ti;REE总量较高,LREE富集、HREE近平坦型分布,中等的负Eu异 常,δEu=0.6;此外,在构造判别图中,样品落于岛弧环境.南带岩体LA-ICP-MS锆石U-Pb年龄为(470.9±2.8) Ma和(472.3±4.2)Ma,岩石Si02质量百分含量较高(67.13% ~70.73%),高Al,Mg,Fe,Ca,富Na贫K,A/CNK<1.1;岩石表现为明显的高Sr低Yb,Y的特点,富集大离子亲石元素 R,K,Sr等,亏损高场强元素Nb,Ta,P,Ti等;REE总量较低,LREE富集、HREE亏损,轻重稀土分异明显,轻微的负Eu异常至正异 常,δEu=0.74~1.18.研究表明,北带岩体为地幔楔部分熔融产生的,形成于岛弧环境;南带岩体为消减的大洋岩石圈板块部分熔融产生的埃达克岩, 是北祁连向南俯冲导致的岩浆作用的产物,“中祁连西段”是早古生代时期在“残留的微陆块”基础上形成的一个岛弧增生杂岩地体.
[19] Zhang Jianxin,Xu Zhiqin.

North qilian middle caledonian dive hyperplasia complex/volcanic arc belt and its deformation characteristics

[J]. Acta Geoscientica Sinica,1995,16(2):153-163.

[张建新,许志琴.

北祁连中段加里东俯冲—增生杂岩/火山弧带及其变形特征

[J].地球学报,1995,16(2):153-163.]

[20] Yang Jingsui,Song Shuguang,Xu Zhiqin.

Early Paleozoic in northern Qaidam basin shearing section at high pressure metamorphic belt were found in a typical ultrahigh pressure minerals:coesite

[J]. Acta Geologica Sinica,2001,75(2):175-179.

Magsci      [本文引用: 2]     

[杨经绥,宋述光,许志琴.

柴北缘早古生代高压—超高压变质带中发现典型的超高压矿物——柯石英

[J].地质学报, 2001,75(2):175-179.]

Magsci      [本文引用: 2]      摘要

从都兰北带榴辉岩的片麻岩围岩的锆石中发现了柯石英包裹体和石墨包裹体,说明该超高压带的峰期变质作用已达柯石英稳定区间(>2.8GPa)但小于金刚石的稳定区间(<3.5GPa),从而确定柴达木盆地北缘存在早古生代超高压变质作用和陆-陆碰撞作用,为中国中部存在一条横贯东西的早古生代(大致500-400Ma)高压超高压变质带的推断提供了新的关键性证据。
[21] Wang Jinrong,Guo Yuansheng,Zhai Xinwei,et al.

Gansu Baiyin mines field:Early-Middle Cambrian volcanic tectonic environment

[J].Geological Journal of China Universities,2003,9(1) :89-98.

[王金荣,郭原生,翟新伟,.

甘肃白银厂矿田早—中寒武世火山岩形成的构造环境

[J].高校地质学报,2003,9(1): 89-98.]

DOI      URL      摘要

白银厂矿田早-中寒武世火山岩主要由钙碱性玄武岩和流纹岩及少量的安山岩组成,被认为是大陆 裂谷环境下的产物.本文的地球化学分析结果显示:玄武岩具有低Ti,Nb和Ta负异常、富集LREE,相对亏损HFSE,Th/Ta比值高(介于 9~15),La/Nb>1.4,低Ni,Th/La为0.32~0.56; 低Zr/Nb(<16),(87Sr/86Sr)i为0.704~0.707,εNd(t)=-6.46,δEu≈1的地球化学特点;流纹岩同样具 有低Ti,Nb和Ta负异常,Th/Ta为6~12,低Ti/Zr比值(介于6.1~53)之间;稀土元素配分为MREE负异常,δEu为 0.5~1.1,(87Sr/86Sr)i为0.7026~0.7048,εNd(t)为+5.60~+6.14.综合两类岩石的地球化学特征,可以推测 它们是陆缘弧岩浆作用的产物,但并非同源岩浆演化的结果.玄武岩源于富集的岩石圈地幔,在岩浆上升过程中发生明显的陆壳混染作用,而流纹岩应为镁铁质下地 壳部分熔融与地幔物质混合作用的产物.
[22] Wang Jinrong,Dong Ningfang,Chang Huajin,et al.

Ductile shear zone volume loss and composition variation of Xiaotie Mountain Baiyinchan Gansu

[J]. Journal of Lanzhou University (Natural Sciences),2005, 41(6):1-5.

[王金荣,董宁芳,常华进,.

甘肃白银厂小铁山韧性剪切带体积亏损与成分变异

[J].兰州大学学报:自然科学版,2005,41(6):1-5.]

[23] Wang Jinrong,Wu Chunjun,Cai Zhenghong,et al.

Early Paleozoic high-Mg adakite from Yindongliang in eastern section of the North Qilian:Implications for geodynamics and Cu-Au mineralization

[J]. Acta Petrologica Sinica,2006,22(11):2 655-2 664.

[王金荣,吴春俊,蔡郑红,.

北祁连山东段银洞粱早古生代高镁银洞粱埃达克岩:大陆动力学及成矿意义

[J]. 岩石学报,2006,22(11):2 655-2 664.]

[24] Hu Wanlong,Hou Rongna,Zhang Cheng,et al.

Geochemical characteristics and tectonic implications of basaltic porphyry in the western segment of the central Qilian Mountains

[J].Journal of Lanzhou University (Natural Sciences),2016,52(3):287-294.

[胡万龙,侯荣娜,张铖,.

中祁连西段玄武玢岩地球化学特征及其构造意义

[J].兰州大学学报:自然科学版,2016,52(3):287-294.]

[25] Hu Wanlong,Jia Zhilei,Wang Jinrong,et al.

Geochronology and geochemistry characteristics of the granites from the Huashigou area,South Qilian and their tectonic significance

[J].Geological Journal of China Universities,2016,22(2):242-253.

[本文引用: 1]     

[胡万龙,贾志磊,王金荣,.

南祁连化石沟花岗岩年代学、地球化学特征及其构造意义

[J]. 高校地质学报,2016,22(2):242-253.]

[本文引用: 1]     

[26] Chen N S,Gong S L,Sun M,et al.

Precambrian evolution of the Quanji Block,northeastern margin of Tibet:Insights from zircon U-Pb and Lu-Hf isotope compositions

[J].Journal of Asian Earth Sciences,2009, 35:367-376.

DOI      URL      [本文引用: 2]      摘要

The Quanji Block, a cratonic fragment, has been discovered between the north Qaidam HP-UHP metamorphic belt and the Qilian orogenic belt in northwestern China. This fragment has a pre-Neoproterozoic crystalline basement overlain unconformably by Neoproterozoic, Paleozoic and Mesozoic sedimentary strata. Pervasive anatexis of the basement produced extensive leucosomes in mafic and felsic migmatites. Zircons from the leucosomes yielded upper intercept and weighted mean 207Pb/ 206Pb ages of 651950 Ma, indicating that anatexis occurred in the late Paleoproterozoic, during regional high-grade metamorphism. Hf model ages ( T DM2) for these zircons suggest that protoliths of the felsic and mafic migmatites had crustal residence time of 652.80 and 652.65 Ga, respectively. The basement rocks of the Quanji Block are compositionally similar to those of the Yangtze Craton, and may have been involved in assembly of the late Paleoproterozoic global supercontinent, Columbia.
[27] Zhang Z C,Zhou M F,Robinson P T,et al.

SHRIMP dating of the Aoyougou ophiolite in the west sector of the north Qilian Mountains and its geological significance

[J].Acta Petrologica Sinica,2001,17:222-226.

DOI      URL      [本文引用: 1]      摘要

The SHRIMP U Pb zircon data of a diabase from the Aoyougou ophiolite in the west sector of north Qilian Mountains are reported in the paper. It shows that the Aoyougou ophiolite was formed in the early middle Proterozoic (about 1777Ma), and proves that it is the earliest ophiolite that has been reported in China. In addition, the dating implies that two geological events occurred about 1466 Ma, and 507 Ma, respectively. The former one probably represents the least closure age of the ocean basin of the early middle Proterozoic whereas the latter one represents the Caledonian regional metamorphism. Moreover, Late Archean crystallized basement (about 2561 Ma) may present in the area although it did not outcrop.
[28] Fu Guomin,Su Jianping,Hu Nenggao,et al.

The geochemical characteristics and tectonic setting of Beidahe Group amphibolites of the Paleoproterozoic of the western Qilian Mountain

[J].Geology in China, 2006, 22(12):2 910-2 922.

[本文引用: 2]     

[付国民,苏建平,胡能高,.

祁连山西段古元古代北大河岩群中斜长角闪岩的地球化学特征及构造背景

[J].中国地质,2005,32(4):541-547.]

[本文引用: 2]     

[29] Zhang Hongfei,Chen Yuelong,Xu Wangchun, et al.

The origin and tectonic significances of Yinzhi period granitoid in Qinghai Gonghe Basin

[J]. Acta Petrologica Sinica,2006,22(12):2 910-2 922.

[本文引用: 1]     

[张宏飞,陈岳龙, 徐旺春,.

青海共和盆地周缘印支期花岗岩类的成因及其构造意义

[J].岩石学报,2006,22(12): 2 910-2 922.]

DOI      URL      [本文引用: 1]      摘要

本文对青海共和盆地周缘印支期黑马河岩体、温泉岩体、大河坝岩体和同仁岩体花岗闪长岩进行了主量元素、微量元素和 Pb-Sr-Nd 同位素地球化学研究,并对黑马河岩体和温泉岩体进行皓石 U-Pb LA-ICP-MS 年代学研究。结果表明, 黑马河岩体的岩浆结晶年龄为235±2Ma,属印支早期,而温泉岩体的岩浆结晶年龄为218±2Ma,属印支晚期。这些印支期花岗闪长岩的 SiO_2=63.34~68.06%,K_2O/Na_2O=0.82~1.36,岩石均为准铝质(A/CNK=0.9~1.0),并属中钾到高钾钙碱性岩系。它们总体上具有相似的微量元素组成特征,并有着极为相似的稀土元素组成模式,(La/Yb)_N 值主要介于10~15之间,存在微弱到中等程度的负 Eu 异常(Eu/Eu~*=0.5~0.8)。岩石初始 Sr 同位素比值 I_(Sr)=0.70701-0.70952,ε_(Nd)(t)=-3.8到-8.4,指示它们的岩浆物质主要来自于地壳物质的部分熔融。这些岩石以高放射成因 Pb 同位素组成为特征,其全岩初始 Pb同位素比值为:(~(206)Pb/~(204)Pb)_t=18.068~18.748、(~(207)Pb/~(204)Pb)_t=15.591~15.649、(~(208)Pb/~(204)Pb)_t=38.167~38.554。地球化学特征指示共和盆地周缘印支期花岗岩类的原岩为下地壳变玄武岩类,并且这类原岩可能派生于元古宙富集地幔,但在不同区段,下地壳变玄武岩类存在着一定程度化学组成的不均一性。根据花岗岩类对深部地壳物质的地球化学示踪及其区域对比,共和盆地周缘的西秦岭、柴达木(包括东昆仑)和欧龙布鲁克块体具有统一的地壳基底组成,并具有扬子型块体的构造属性。结合区域地质背景的分析,共和盆地周缘印支早期花岗岩类(以黑马河岩体为代表)可能形成于俯冲陆壳断离的地球动力学背景,而印支晚期花岗岩类(以温泉岩体为代表)形成于中央造山带在地壳加厚作用后岩石圈拆沉作用的地球动力学背景。
[30] Guo Jinjing,Lu Songnian.

China Neoproterozoic continental collage with Rodinia supercontinent

[J].Geological Journal of China Universities,1999,5(2):29-37.

[郭进京,陆松年.

中国新元古代大陆拼合与Rodinia超大陆

[J].高校地质学报,1999,5(2):29-37.]

[31] Guo Jinjing,Zhang Guowei,Lu Songnian,et al.

Discussion on the stratigraphic framework of the Proterozoic basement in the Eastern Middle Qililian block

[J].China Regional Geology,1999,2(4): 379-396.

[郭进京,张国伟,陆松年,.

中祁连地块东段元古宙基底地层格架讨论

[J].中国区域地质, 1999,2(4):379-396.]

DOI      URL      摘要

中祁连地块东段元古基底一般认为由3套地层组成,即古元古代湟源群、中元古代长城系湟中群和蓟县系花石山,三者之间皆为平行不整合关系。但新的研究表明:(1)花石山 与下伏的湟源群为角度不整合,结合新近发现的化石资料分析,认为药石山 是震旦纪--寒武纪稳定盖层沉积,不应归于基底组成部分;(2)湟源群与湟中群为同一构造层,统称湟源群。
[32] Guo Jinjing,Zhao Fengqing,Li Huaikun.

Geological significance of the Jinning period collision type granite in the Eastern Middle Qilian

[J].Acta Geoscientica Sinica,1999,20(1):10-15.

[郭进京,赵凤清,李怀坤.

中祁连东段晋宁期碰撞型花岗岩及其地质意义

[J].地球学报,1999,20(1):10-15.]

DOI      URL      摘要

对中祁连地块东段西宁西部近S-N向展布的元古宙花岗岩带地质地球化学和年代学研究表明:它侵位于元古宙基底中浅变质岩系湟源群中,具有同碰撞S型花岗岩的性质;(917±12)Ma的单颗粒锆石U-Pb年龄记录了其侵位的时代为新元古宙晋宁期,这一新元古宙晋宁期碰撞型花岗岩带具有重要的地质意义.
[33] Guo Jinjing,Zhao Fengqing,Li Huaikun,et al.

The new evidence and geological significance of Huangyuan Group in the Eastern Middle Qilian

[J].China Regional Geology,2000,6(1):27-32.

[郭进京,赵凤清,李怀坤,.

中祁连东段湟源群的年代学新证据及其地质意义

[J].中国区域地质,2000,6(1): 27-32.]

DOI      URL      摘要

根据新近获得的中祁连地块东段湟源群中变质火山岩(910±6.7)Ma和侵位于湟源群中的响河尔花岗岩(917±12)Ma的单颗粒锆石U-Pb年龄,结合区域地质背景分析认为:(1)湟源群时代不时古元古代,而是中晚元古代,上限在900Ma左右;(2)响河尔花岗岩是晋宁期花岗岩而非中条期花岗岩;(3)湟源群及侵位于其中的晋宁期花岗岩代表了中祁连晋宁施回结晶基底,并非中条旋回结晶基底。湟源群时代的重新厘定使
[34] Gao Xiaofeng,Li Wenyuan,Ye Meifang, et al.

Geochemical characteristics and tectonic significance of Hualong Group amphibolites in the Eastern Middle Qilian

[J]. Acta Petrologica et Mineralogica,2010,29(5):507-515.

[高晓峰,李文渊,叶美芳, .

中祁连东段化隆群中斜长角闪岩地球化学特征及构造意义

[J].岩石矿物学杂志,2010,29(5):507-515.]

DOI      URL      摘要

中祁连东段化隆群中斜长角闪岩岩相学特征及主、微量元素地球化学分析结果显示,其原岩为碱性玄武岩。斜长角闪岩表现出轻稀土元素富集、Nb-Ta不亏损,与典型洋岛玄武岩(OIB)的微量元素分布模式和特征元素比值(Nb/La=1.24~1.48,Th/Ta=1.19~1.40)类似,但与典型OIB相对亏损高场强元素(如Th、Nb)不同,且在大地构造环境判别图上落入板内大陆玄武岩区,反映了化隆群斜长角闪岩原岩来源于软流圈地幔交代大陆岩石圈地幔熔融源区,为Rodinia超大陆在新元古代汇聚过程中局部裂解或Rodinia大陆整体上汇聚未完成局部地区就开始裂解的产物。
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[冯备战,王晓伟,曾俊杰,.

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[张招崇,毛景文.

北祁连山西段早元古代变质火山岩的地球化学特征及其构造背景

[J].矿物岩石, 1998,18(4):22-30.]

DOI      URL      [本文引用: 2]      摘要

产于北大河群的早元古代火山岩是北祁连山西段最主要的三期火山岩之一。其地球化学特征表明,该期火山岩的原岩为具有双峰式组合的拉斑玄武岩和中酸性凝灰岩。两者具有完全不同的稀土分布型式,前者以极低的富集轻稀土为特征,而后者则以强烈富集轻稀土为特征:基性火山岩的微量元素分布曲线指示了其形成于裂陷槽环境。结合Nd同位素特征以及区域背景得出本区早元古代变质火山岩形成于裂陷槽环境。
[41] Zhang Zhaochong,Zhou Meifu,Robinson P T,et al.

SHRIMP dating of the Aoyougou ophiolite in the west sector of the North Qilian Mountains and its geological significance

[J]. Acta Petrologica Sinica,2001, 17(2):222-226

Magsci      [本文引用: 3]     

[张招崇,周美付, Robinson P T,.

北祁连山西段熬油沟蛇绿岩 SHRIMP 分析结果及其地质意义

[J].岩石学报,2001,17(2):222-226.]

DOI      URL      Magsci      [本文引用: 3]      摘要

本文通过对北祁连山西段熬油蛇绿岩中辉绿岩岩墙的锆石SHRIMP法年龄 的测定,确定出熬油的沟蛇绿岩形成于中元古代早期(约1777Ma),这是迄今为止我国发现的最古老的蛇绿岩。该年龄测定的结果还暗示了本区在1466Ma和507Ma各有一次地质事件,前者可能代表了中元古代早期的洋盆闭合的下限年龄,后者代表一次加里东期区域变质事件,并且本区可能还存在未出露的新太古结晶基底(2561Ma)。
[42] Xia Xiaohong,Sun Nan,Song Shuguang,et al.

Age and tectonic setting of the Aoyougou-Erzhihaladaban ophiolite in the Western North Qilian Mountains,NW China

[J].Acta Scientiarum Naturalium Univeisitatis Pekinensis,2012,48(5):757-769.

[本文引用: 2]     

[夏小洪,孙楠,宋述光,.

北祁连西段熬油沟二只哈拉达坂蛇绿岩的形成环境和时代

[J].北京大学学报:自然科学版,2012,48(5):757-769.]

[本文引用: 2]     

[43] Xiang Zhenqun,Lu Songnian,Li Huaikun, et al.

SHRIMP U-Pb zircon age of gabbro in Aoyougou in the western segment of the North Qilian Mountains,China and its geological implications

[J].Geological Bulletin of China,2007,26(12):1 686-1 691.

[相振群,陆松年,李怀坤,.

北祁连西段熬油沟辉长岩的锆石Shrimp U-Pb年龄及地质意义

[J].地质通报,2007,26(12):1 686-1 691.]

[44] Sha Xin.

Study on the Diagenesis and Tectonic Implications of Mafic-ultramafic Rocks in the Western Sector of The Northern Qilianshan[D].

Lanzhou:Lanzhou University,2017.

[本文引用: 3]     

[沙鑫.

北祁连西段镁铁质—超镁铁质岩的成因与构造意义的研究[D]

.兰州:兰州大学,2017.]

[本文引用: 3]     

[45] Feng Yimin.

Allochthones along the west section of the North Qilian Orogenic Belt

[J]. Geological Review, 1998, 44(4):365-371.

Magsci      [本文引用: 1]     

[冯益民.

北祁连造山带西段的外来移置体

[J]. 地质论评, 1998, 44(4):365-371.]

Magsci      [本文引用: 1]      摘要

北祁连造山带西段发育有许多外来移置体,本文论述了其物质组成,构造样式、运动学及动力地征。揭示了研究外来移置体对正确重造山带构造演化的重要意义。
[46] Qi Ruirong,Chen Shiqiang,Hu Xiaochun.

The exploration practice of Jingtieshan iron ore deposit in the Western North Qilian, Gansu:An example of mining breakthrough in the rich area of Kawa iron ore

[J].Gansu Geology,2015,24(1):11-18.

[齐瑞荣,陈世强,胡小春.

甘肃北祁连西段镜铁山铁矿外围勘查实践——以卡瓦铁矿富集区找矿突破为例

[J].甘肃地质, 2015,24(1):11-18.]

URL      摘要

张新虎等人在区域成矿地质背景研究过程中,通过对比研究甘肃北祁连西段镜铁山铁矿外围成矿条件和物化探异常特征,认为祁连山西段具有形成沉积变质型铁矿的地质条件,镜铁山铁矿外围是最有利找矿靶区,建议在其东延带部署"丰乐河—西插山地区1∶5万矿产远景调查"。通过该项目实施,进一步理清了"镜铁山式"铁矿含矿岩系空间展布,先后发现了卡瓦铁矿、沙梁铁矿、光滑岭铁矿等一批铁矿点,实现了铁矿勘查新突破,成为甘肃北祁连西段找矿战略突破行动典型实例。通过前期勘查,目前已获铁矿石资源量达5亿吨。本文从区域成矿背景、含矿层位对比、勘查找矿成果及工作部署思路等方面进行初步总结,对该区铁矿勘查规划和找矿部署具有指导意义。
[47] Xu Xiaochun,Yue Shucang,Liu Yin,et al.

The era and petrochemical characteristics of Zhulongguan Group volcanic rocks in Zoulang Mountian,Gansu

[J].Anhui Geology,1996,6(4):1-6.

[本文引用: 2]     

[徐晓春,岳书仓,刘因,.

甘肃走廊南山朱龙关群的时代及其火山岩的岩石化学特征

[J].安徽地质,1996,6(4):1-6.]

URL      [本文引用: 2]      摘要

甘肃走廊南山朱龙关群是一套以发育大量基性火山岩为特征的浅变质火山沉积岩系,分布于托来山北坡刘口峡山至热水大坂一带以及朱龙关河北侧小柳沟和古浪峡等地。本文在前人工作的基础上,对区内地层的分布提出了新的见解,认为沙龙地区和北过龙至金龙河地区出露的一套浅变质火山-沉积岩石应划归来龙关群,并运用同位素年代学方法测定了该地层中火山岩的成岩时代,首次较确切地给出了这套浅变质岩系的时代归属,从而进一步确定了朱龙关群的时空分布。同时根据火山岩岩石化学特征研究,认为朱龙关群火山岩的成岩大地构造背景为陆内裂谷。
[48] Yu Boda.

New understanding of Changcheng Period stratigraphic division,Gansu

[J].Gansu Geology, 1997,6(1):1-15.

[本文引用: 1]     

[俞伯达.

关于甘肃长城纪地层划分的新认识:甘肃地质

[J],1997,6(1):1-15.]

[本文引用: 1]     

[49] Govindaraju K.

Compilation of working values and sample description for 383 geostandards

[J].Geostandards Newsletter,1994,18(Suppl.1):1-158.

DOI      URL     

[50] Le Maitre R W B,Dudek P,Keller A,et al.

A Classification of Igneous Rocks and Glossary of Terms:Recommendations of the International Union of Geological Sciences,Subcommission on the Systematics of Igneous Rocks

[M].London:International Union of Geological Sciences,1989.

[本文引用: 2]     

[51] Winchester J A,Floyd P A.

Geochemical magma type discrimination:Application to altered and metarnorphosed basic igneous rocks

[J]. Earth and Planetary Science Letters,1976,28:459-469.

DOI      URL      摘要

Five minor and trace elements, known to be chemically stable during alteration and metamorphism, have been combined in a set of binary diagrams that distinguish fresh tholeiites from alkali basalts. Of the five elements: Ti, P, Zr, Y, Nb, only P shows slight mobility during metamorphism, which is not sufficient to alter greatly the point distribution on the binary diagrams. Using these stable elements altered basaltic rocks: greenstones, spilites and amphibolites may be distinguished in the same way as fresh basalts, and their original magma may be identified as tholeiitic or alkaline basalt. All five elements are readily and rapidly determined, using XRF, thus this method may be applied as a rapid, easy way of discriminating the magma types of altered basaltic rocks. Using this method it can be demonstrated that alkali basalt magma was produced in minor quantities in the Precambrian.
[52] Sun S S,Mcdonough W F.

Chemical and isotopic systematics of oceanic basalts:Implications for mantle composition and processes

[J].Geological Society London Special Publications,1989,42(1):313-345.

DOI      URL     

[53] Wilson M.

Igneous Petrogenesis:A Global Tectonic Approach

[M].London:Unwin Hyman,1989.

[本文引用: 1]     

[54] Goncuoglu M C,Sayit K,Tekin U K.

Oceanization of the northern Neotethys:Geochemical evidence from ophiolitic melange basalts within the Izmir-Ankara suture belt, NW Turkey

[J].Lithos,2010,116:175-187.

DOI      URL      [本文引用: 2]      摘要

The remnants of the Neotethyan Izmir–Ankara Ocean, the main branch of Neotethys in the eastern Mediterranean are represented by the Dagküplü Melange Complex in Central Sakarya, NW Turkey. It comprises several blocks or tectonic slices of pillow lavas, some of which include mudstones and radiolarian cherts as intra-pillow-fillings or interlayers. In the Igdecik area, a huge basaltic block has been studied in detail. Geochemical data reveal three distinct basalt types separated by sheared contacts. The first of these groups is an enriched mid-oceanic ridge basalt (E-MORB) type which is enriched in the most incompatible trace elements relative to normal MORB (N-NORB) in addition to having heavy rare earth elements (HREE) depletion, suggesting the influence of residual garnet in their mantle source region. The second is back-arc basin basalt (BABB) type with relatively depleted trace element compositions with respect to N-MORB together with a negative Nb anomaly, suggesting generation above an intra-oceanic subduction zone where partial melts are derived from a depleted (MORB-like) mantle. The final group is island-arc tholeiite (IAT) type, displaying the most depleted trace element abundances among the studied groups in addition to marked Nb depletion, reflecting intra-oceanic supra-subduction zone (SSZ) signatures similar to the BABB-type but requiring a depleted mantle source which has experienced a previous melt extraction. Combined with a previously ascribed Late Triassic age of Tekin et al. (2002) (221 Ma, Late Carnian; based on the radiolarian fauna found in a chert layer alternating with mudstones), the associated basalts with E-MORB-type geochemical signatures, suggest formation of oceanic crust as early as Late Carnian. This age is the oldest thus far obtained from the basalts of the Izmir–Ankara Ocean. This new data provides constraints on tectonic models for the opening the Izmir–Ankara Ocean and its relationship to other branches of the Neotethyan ocean in the Eastern Mediterranean area.
[55] Pearce J A.

Geochemical fingerprinting of oceanic basalts with applications to ophiolite classification and the search for Archean oceanic crust

[J]. Lithos,2008,100:14-48.

DOI      URL      [本文引用: 3]      摘要

Two geochemical proxies are particularly important for the identification and classification of oceanic basalts: the Th–Nb proxy for crustal input and hence for demonstrating an oceanic, non-subduction setting; and the Ti–Yb proxy for melting depth and hence for indicating mantle temperature and thickness of the conductive lithosphere. For the Th–Nb proxy, a Th/Yb–Nb/Yb projection demonstrates that almost all oceanic basalts lie within a diagonal MORB–OIB array with a principal axis of dispersion along the array. However, basalts erupted at continental margins and in subduction zones are commonly displaced above the MORB–OIB array and/or belong to suites with principal dispersion axes which are oblique to the array. Modelling of magma–crust interaction quantifies the sensitivity of the Th–Nb proxy to process and to magma and crustal compositions. For the Ti–Yb proxy, the equivalent Ti/Yb–Nb/Yb projection features a discriminant boundary between low Ti/Yb MORB and high Ti/Yb OIB that runs almost parallel to the Nb/Yb axis, reflecting the fact that OIB originate by melting beneath thicker lithosphere and hence by less melting and with residual garnet. In the case of volcanic-rifted margins and oceanic plume–ridge interactions (PRI), where hot mantle flows toward progressively thinner lithosphere (often becoming more depleted in the process), basalts follow diagonal trends from the OIB to the MORB field. Modelling of mantle melting quantifies the sensitivity of the Ti–Nb proxy to mantle potential temperature and lithospheric thickness and hence defines the petrogenetic basis by which magmas plot in the OIB or MORB fields. Oceanic plateau basalts lie mostly in the centre of the MORB part of that field, reflecting a high degree of melting of fertile mantle. Application of the proxies to some examples of MORB ophiolites helps them to be further classified as C (contaminated)-MORB, N (normal)-MORB, E (enriched)-MORB and P (plume)-MORB ophiolites, which may add a useful dimension to ophiolite classification. In the Archean, the hotter magmas, higher crustal geotherms and higher Th contents of contaminants all result in widespread crustal input that is easy to detect geochemically with the Th–Nb proxy. Application of this proxy to Archean greenstones demonstrates that almost all exhibit a crustal component even when reputedly oceanic. This indicates, either that some interpretations need to be re-examined or that intra-oceanic crustal input is important in the Archean making the proxy less effective in distinguishing oceanic from continental settings. The Ti–Yb proxy is not effective for fingerprinting Archean settings because higher mantle potential temperatures mean that lithospheric thickness is no longer the critical variable in determining the presence or absence of residual garnet.
[56] Roex A P L,Dick H J B,Erlank A J,et al.

Geochemistry,mineralogy and petrogenesis of lavas erupted along the Southwest Indian ridge between the bouvet triple junction and 11 degrees east

[J].Journal of Petrology,1983,24(3):267-318.

DOI      URL      [本文引用: 2]      摘要

Abstract Basaltic lavas from fracture zones and ridge segments were sampled systematically along the Southwest Indian Ridge from the Bouvet triple junction to 11oE. Major- and trace-element analyses and isotopic variations serve to distinguish three compositional groups: 1) a group with typical 'depleted' N-type MORB characteristics (Zr/Nb > 20, Y/Nb > 8 and LREE depletion with La/YbN 0.35-1.1), 2) a relatively enriched group with typical 'plume' characteristics or P-type MORB (Zr/Nb 5.8-6.8, Y/Nb 0.9- 1.2 and strong LREE enrichment with La/YbN 4.8-6.8), and 3) an intermediate group with a transitional composition or T-type MORB (Zr/Nb 7.7-11.0, Y/Nb 1.3-3.0 and slight LREE enrichment with La/YbN 1.7-4.3). N- and T-type lavas are the most abundant.-R.A.H.
[57] DePaolo D J,Bryce J G,Dodson A,et al.

Isotopic evolution of Mauna Loa and the chemical structure of the Hawaiian plume

[J].Geochemistry, Geophysics, Geosystems, 2001,2(7):223-235.

DOI      URL      [本文引用: 1]      摘要

[1] New He isotopic data from the HSDP pilot hole core, lava accumulation rate models, and data from the literature are used to develop a 200,000 year isotopic record for the lava erupted from the Mauna Loa volcano. This record, coupled with an analogous record from Mauna Kea from the Hawaii Scientific Drilling Project (HSDP) pilot hole project and other literature data from the GEOROC database, are used to construct a 090008map090009 of lava isotopic compositions for the island of Hawaii. The isotopic map is converted to a map of the He and Nd isotopic compositions of melts from the mantle plume, which can be compared with a published melt supply map derived from geodynamic modeling. The resulting map of the plume indicates that values of helium 3He/4He &gt; 20 Ra are confined to the core of the plume (radius 090908 2009000925 km) and correspond to potential temperatures &gt;156500°C, suggesting the He isotopic signal is derived from deep in the mantle. The 3He/4He map has closed contours down to 10 Ra; the contours are teardrop-shaped and elongated in the general direction of plate motion. The closed contours indicate that most of the plume He signal is lost during the early stages of melting, which is consistent with helium behaving as a strongly incompatible element (KHe 0909¤ 0.001). The 0208Nd contours (and by inference the contours for Sr, Pb, Hf, and Os) do not all close on the scale of the island of Hawaii but instead partially follow material flow lines within the plume beneath the lithosphere. The plume signal for Nd extends circa 100 km in the direction of plate motion, which is consistent with the moderately incompatible behavior of Nd (KNd 090908 0.02). Downstream from the plume core epicenter, plume Nd occurs with asthenospheric He; this could be mistaken for an additional plume component, whereas it may be only a manifestation of differing incompatibility. Data from Mauna Loa suggest the presence of a low-3He/4He plume component that has low 0208Nd and high 87Sr/86Sr. The plume map suggests that this component may be a blob (circa 20 km scale), located between Mauna Loa and Hualalai and separated from the main plume core by a zone of more asthenosphere-like material. The HSDP data preclude a proposed model where this material represents a ring of entrained material from the lower mantle. The orientation of the elongation of contours on the plume He and Nd isotope maps (090804N4500°W) does not match the modern plate motion as measured by GPS (N6500°W) nor does it match the trend of the ridge axis between Maui and Loihi (N3000°W). The geochemical evidence, as well as the locations and growth histories of the Hawaiian volcanoes, suggest that the plume, as well as the Pacific plate, has been moving at a velocity of several centimeters per year over the past 1 to 2 million years.
[58] Hawkesworth C,Scherstén A.

Mantle plumes and geochemistry

[J].Chemical Geology,2007,241(3):319-331.

DOI      URL      [本文引用: 1]     

[59] Xu Y G,Ma J L,Frey F A,et al.

Role of lithosphere-asthenosphere interaction in the genesis of Quaternary alkali and tholeiitic basalts from Datong,western North China Craton

[J].Chemical Geology,2005,224(4):247-271.

DOI      URL      [本文引用: 1]      摘要

The geochemistry of Quaternary volcanic rocks from Datong provides important constraints on the petrogenesis of continental alkali and tholeiitic basalts and lithospheric evolution in the western North China Craton. Alkali basalts in north Datong have trace element compositions similar to oceanic island basalts (OIB). They show nearly homogenous isotopic compositions ( 07 Nd = 5.4–6.8 and 87Sr / 86Sr = 0.7035–0.7037) that resemble the nearby Hannuoba Miocene basalts, indicating that the two lava suites share a similar asthenospheric source. However, Datong basalts have conspicuously lower Al 2O 3 and CaO, higher SiO 2 and HREE contents and Na / Ti ratios, compared to Hannuoba lavas at comparable MgO. This compositional difference is attributable to the combined effect of source difference and temporal decrease in melting depth. The latter reflects Cenozoic lithospheric thinning of the western North China Craton. Tholeiitic basalts in southeast Datong have incompatible element ratios that differ from OIB; they have lower 07 Nd (1.3–3.7) and higher 87Sr / 86Sr (0.7039–0.7046) compared to alkali basalts. These moderately evolved rocks (MgO < 7%) display unusually high Cr concentrations (> 200 ppm), a nearly flat LREE pattern and a fractionated HREE with the “kink” occurring at Gd. A shallow melting depth (< 60 km), suggested by their Q-normative composition, is in conflict with the residual garnet in the source (> 75 km) as required by REE modeling. This paradox, which is reminiscent of that for Hawaiian tholeiites, can be reconciled if garnet lherzolite melts react with refractory peridotites during which orthopyroxene is dissolved and olivine precipitates. The diagnostic consequence of this melt–rock reaction includes increases in SiO 2 and Cr, decreases in Al 2O 3 and CaO, and formation of “kinked” REE patterns. Involvement of lithospheric mantle in the genesis of Datong tholeiites may be related to the Cenozoic lithospheric thinning/erosion in the western North China Craton. The spatial distribution of Datong alkali and tholeiitic basalts may be related to enhanced extension along the lithospheric boundary between the Western Block of the North China Craton and the Trans-North China Orogen.
[60] Zhu Yusheng,Hou Guangshun,Yang Jinhui.

The origin and genesis of the Cenozoic basalts in Hebi: Evidence from geochemistry and Sr-Nd-Hf isotope

[J].Acta Petrologica Sinica,2012, 28(12):4 064-4 076.

[本文引用: 2]     

[朱昱升, 侯广顺, 杨进辉.

鹤壁新生代玄武岩源区及成因:地球化学和 Sr-Nd-Hf 同位素证据

[J].岩石学报,2012,28(12):4 064-4 076.]

URL      [本文引用: 2]      摘要

大陆碱性玄武岩是研究大陆地幔、软流圈和岩石圈、壳幔相互作用的窗口。鹤壁碱性玄武岩为华北中部新生代玄武岩重要组成部分,其源区和成因对了解新生代期间华北克拉通中部岩石圈地幔改造提供了重要依据。鹤壁新生代玄武岩主要为碱性玄武岩,贫硅(SiO2=45.0%~47.8%)富镁(MgO=7.3%~8.5%)和全碱(Na2O+K2O=4.6%~6.3%),富集轻稀土元素,轻、重稀土元素强烈分馏[(La/Yb)N=15.1~21.2],无明显Eu异常。富集大离子亲石元素(LILEs)和高场强元素(HFSEs)。在原始地幔标准化蛛网图上,具有明显的Nb、Ta正异常,其中Nb/U=35~48、La/Nb=0.4~0.7、Ba/Nb=3.6~11。全岩的Sr、Nd、Hf同位素比值分别为87Sr/86Sri=0.7036~0.7044,εNd(t)=+0.4~+5.4,εHf(t)=+5.0~+9.7,显示鹤壁新生代玄武岩具有洋岛玄武岩(OIB)的地球化学特征和同位素组成。岩相学特征和地球化学特征表明鹤壁新生代玄武岩是软流圈地幔(80km)小程度部分熔融形成的熔体与富集的岩石圈地幔相互作用后的结果,地壳物质混染和结晶分离作用不显著。
[61] Dilek Y,Furnes H.

Ophiolite genesis and global tectonics:Geochemical and tectonic fingerprinting of ancient oceanic lithosphere

[J].Geological Society of America Bulletin,2011,123(3/4):387-411.

DOI      URL      [本文引用: 2]      摘要

No abstract available.
[62] Rudnick R L,Fountain D M.

Nature and composition of the continental crust:A lower crustal perspective

[J].Reviews of Geophysics,1995,33(3):267-310.

DOI      URL      [本文引用: 1]      摘要

Geophysical, petrological, and geochemical data provide important clues about the composition of the deep continental crust. On the basis of seismic refraction data, we divide the crust into type sections associated with different tectonic provinces. Each shows a three-layer crust consisting of upper, middle, and lower crust, in which P wave velocities increase progressively with depth. There is large variation in average P wave velocity of the lower crust between different type sections, but in general, lower crustal velocities are high (&gt;6.9 km s0908081) and average middle crustal velocities range between 6.3 and 6.7 km s0908081. Heat-producing elements decrease with depth in the crust owing to their depletion in felsic rocks caused by granulite facies metamorphism and an increase in the proportion of mafic rocks with depth. Studies of crustal cross sections show that in Archean regions, 5009000985% of the heat flowing from the surface of the Earth is generated within the crust. Granulite terrains that experienced isobaric cooling are representative of middle or lower crust and have higher proportions of mafic rocks than do granulite terrains that experienced isothermal decompression. The latter are probably not representative of the deep crust but are merely upper crustal rocks that have been through an orogenic cycle. Granulite xenoliths provide some of the deepest samples of the continental crust and are composed largely of mafic rock types. Ultrasonic velocity measurements for a wide variety of deep crustal rocks provide a link between crustal velocity and lithology. Meta-igneous felsic, intermediate and mafic granulite, and amphibolite facies rocks are distinguishable on the basis of P and S wave velocities, but metamorphosed shales (metapelites) have velocities that overlap the complete velocity range displayed by the meta-igneous lithologies. The high heat production of metapelites, coupled with their generally limited volumetric extent in granulite terrains and xenoliths, suggests they constitute only a small proportion of the lower crust. Using average P wave velocities derived from the crustal type sections, the estimated areal extent of each type of crust, and the average compositions of different types of granulites, we estimate the average lower and middle crust composition. The lower crust is composed of rocks in the granulite facies and is lithologically heterogeneous. Its average composition is mafic, approaching that of a primitive mantle-derived basalt, but it may range to intermediate bulk compositions in some regions. The middle crust is composed of rocks in the amphibolite facies and is intermediate in bulk composition, containing significant K, Th, and U contents. Average continental crust is intermediate in composition and contains a significant proportion of the bulk silicate Earth's incompatible trace element budget (3509000955% of Rb, Ba, K, Pb, Th, and U).
[63] Wang Jian,Li Jianping,Wang Jianghai,et al.

The geology implication of inclusion of the Cenozoicshoshonite series in Jianchuan-Dali region

[J]. Acta Mineralogica Sinica,2002,22(2):113-125.

[本文引用: 2]     

[王建,李建平,王江海,.

滇西剑川—大理地区新生代钾玄岩系中深源包体的地质意义

[J].矿物学报,2002, 22(2):113-125.]

[本文引用: 2]     

[64] Condie K C.

Geochemical changes in baslts and andesites across the Archean-Proterozoic boundary:Identification and significance

[J].Lithos,1989,23(1):1-18.

DOI      URL      [本文引用: 1]      摘要

To identify accurately changes in rock composition across the Archean-Proterozoic boundary, it is necessary to compare rocks from similar lithologic associations to constrain the effect of tectonic setting. Most basalts and andesites from the greenstone association (volcanic-dominated submarine supracrustal rocks) possess a geochemical subduction-zone component similar to their counterparts from modern arc systems. Basalts with island arc geochemical affinities dominate in Archean greenstones while those with calc-alkaline affinities are most abundant in Proterozoic greenstones. Basalts with MORB or oceanic within-plate geochemical characteristics are rare in Precambrian greenstones of all ages. Preserved early Archean greenstone basalts (猢3500 Ma) reflect mantle sources less depleted than late Archean greenstone basalts (2500鈥3500 Ma). Proterozoic greenstone basalts are derived from relatively enriched mantle sources compared to all Archean sources, a feature which may be due to recycling of continental sediments into the mantle following rapid late Archean continental growth. Precambrian andesites are geochemically similar to andesites from modern arcs, but Archean andesites are unique in that they are depleted in heavy REE and Y. Results are consistent with Archean andesite production by partial melting of descending mafic crust with amphibole/garnet remaining in the residue, while Proterozoic (and younger) andesites are produced by fractional crystallization of basalts.
[65] Rudnick R L,Fountain D M.

Nature and composition of the continental crust: A lower crustal perspective

[J].Reviews of Geophysics,1995,33(3):267-310.

DOI      URL      [本文引用: 2]      摘要

Geophysical, petrological, and geochemical data provide important clues about the composition of the deep continental crust. On the basis of seismic refraction data, we divide the crust into type sections associated with different tectonic provinces. Each shows a three-layer crust consisting of upper, middle, and lower crust, in which P wave velocities increase progressively with depth. There is large variation in average P wave velocity of the lower crust between different type sections, but in general, lower crustal velocities are high (&gt;6.9 km s0908081) and average middle crustal velocities range between 6.3 and 6.7 km s0908081. Heat-producing elements decrease with depth in the crust owing to their depletion in felsic rocks caused by granulite facies metamorphism and an increase in the proportion of mafic rocks with depth. Studies of crustal cross sections show that in Archean regions, 5009000985% of the heat flowing from the surface of the Earth is generated within the crust. Granulite terrains that experienced isobaric cooling are representative of middle or lower crust and have higher proportions of mafic rocks than do granulite terrains that experienced isothermal decompression. The latter are probably not representative of the deep crust but are merely upper crustal rocks that have been through an orogenic cycle. Granulite xenoliths provide some of the deepest samples of the continental crust and are composed largely of mafic rock types. Ultrasonic velocity measurements for a wide variety of deep crustal rocks provide a link between crustal velocity and lithology. Meta-igneous felsic, intermediate and mafic granulite, and amphibolite facies rocks are distinguishable on the basis of P and S wave velocities, but metamorphosed shales (metapelites) have velocities that overlap the complete velocity range displayed by the meta-igneous lithologies. The high heat production of metapelites, coupled with their generally limited volumetric extent in granulite terrains and xenoliths, suggests they constitute only a small proportion of the lower crust. Using average P wave velocities derived from the crustal type sections, the estimated areal extent of each type of crust, and the average compositions of different types of granulites, we estimate the average lower and middle crust composition. The lower crust is composed of rocks in the granulite facies and is lithologically heterogeneous. Its average composition is mafic, approaching that of a primitive mantle-derived basalt, but it may range to intermediate bulk compositions in some regions. The middle crust is composed of rocks in the amphibolite facies and is intermediate in bulk composition, containing significant K, Th, and U contents. Average continental crust is intermediate in composition and contains a significant proportion of the bulk silicate Earth's incompatible trace element budget (3509000955% of Rb, Ba, K, Pb, Th, and U).
[66] Wood D A.

The application of a Th,Hf,Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary Volcanic Province

[J].Earth and Planetary Science Letters,1980,50(1):11-30.

DOI      URL      [本文引用: 2]     

[67] Pearce J A,Norry M J.

Petrogenetic implications of Ti,Zr,Y,and Nb variations in volcanic rocks

[J].Contributions to Mineralogy & Petrology,1979,69(1):33-47.

DOI      URL      [本文引用: 5]      摘要

Data from experimental runs, coexisting phases in ultramafic rocks and phenocryst-matrix pairs in volcanic rocks have been used to compile a table of mineral-liquid distribution coefficients for Ti, Zr, Y, and Nb for basic, intermediate and acid melt compositions. These values have then been used to interpret variations of these elements, first in basalts and second, during fractional crystallization from basic to acid magmas. For basalts, petrogenetic modelling of Zr/Y, Zr/Ti, and Zr/Nb ratios, when used in conjunction with REE, Cr and isotopic variations, suggests that: (1) the increase in Zr/Y ratio from mid-ocean ridge to within plate basalts and the low Zr/Nb ratios of alkalic basalts are due to (fluid controlled) source heterogeneities; (2) the low Zr and Zr/Y ratio of volcanic arc basalts results from high degree of partial melting of a depleted source; and (3) the high Zr and similar Zr/Y ratio of basalts from fast spreading relative to slow spreading ridges results from open-system fractional crystallization. Modelling of fractionation trends in more evolved rocks using Y-Zr, Ti-Zr and Nb-Zr diagrams highlights in particular the change in crystallizing mafic phases from island arcs (clinopyroxene-dominated) to Andean-type arcs (amphibole卤biotite-dominated). These methods can be applied to altered lavas of unknown affinities to provide additional information on their genesis and eruptive environment.
[68] Pearce J A,Cann J R.

Tectonic setting of basic volcanic rocks determined using trace element analyses

[J].Earth and Planetary Science Letters,1973,19(2):290-300.

DOI      URL      [本文引用: 2]      摘要

Analyses for Ti, Zr, Y, Nb and Sr in over 200 basaltic rocks from different tectonic settings have been used to construct diagrams in which these settings can usually be identified. Basalts erupted within plates (ocean island and continental basalts) can be identified using a Ti-Zr-Y diagram, ocean-floor basalts, and low-potassium tholeiites and calc-alkali basalts from island arcs can be identified using a Ti-Zr diagram (for altered samples) and a Ti-Zr-Sr diagram (for fresh samples). Y/Nb is suggested as a parameter for indicating whether a basalt is of tholeiitic or alkalic nature. Analyses of dykes and pillow lavas from the Troodos Massif of Cyprus are plotted on these diagrams and appear to the tholeiitic ocean-floor rocks.
[69] Sun Shuqin,Zhang Chengjiang,Zhao Songjiang.

The trace elements determination of intra-plate tectonic setting

[J].Geotectonica et Metallogenia,2007,31(1):104-109.

[本文引用: 2]     

[孙书勤,张成江,赵松江.

大陆板内构造环境的微量元素判别

[J].大地构造与成矿学,2007, 31(1):104-109.]

[本文引用: 2]     

[70] Xiong Lijuan.

The Tectonics Evolution and Collage of the Western North Proto-Tethys[D].

Qingdao:Ocean University of China,2014.

[本文引用: 1]     

[熊莉娟.

原特提斯北界西段构造演化与拼合方式[D]

.青岛:中国海洋大学,2014.]

[本文引用: 1]     

[71] Rogers J J W,Santosh M.

Configuration of Columbia,a Mesoproterozoic Supercontinent

[J].Gondwana Research,2002,5(1):5-22.

DOI      URL      [本文引用: 3]      摘要

A supercontinent, here named Columbia, may have contained nearly all of the earth's continental blocks at some time between 1.9 Ga and 1.5 Ga. At that time, eastern India, Australia, and attached parts of Antarctica were apparently sutured to western North America, and the eastern margin of North America, southern margin of Baltica/North China, and western margin of the Amazon shield formed a continuous zone of continental outbuilding. Fragmentation began at 鈭1.6 Ga, when rifting occurred in North China. Rifting continued until about 1.4 Ga in most of Columbia, and a similar age of rifting north of the Zimbabwe craton of southern Africa suggests that an entire continental block stretching from Australia to South Africa separated from Columbia at this time. Further separation of North America from South America/Africa and rotation of the different blocks ultimately resulted in their reattachment during the Grenville orogeny to form the supercontinent Rodinia.
[72] Lu Songnian,Yang Chunliang,Li Huaikun,et al.

Northern China and Colombia supercontinent

[J].Geoscience Frontiers,2002,9(4):225-233.

[陆松年,杨春亮,李怀坤,.

华北古大陆与哥伦比亚超大陆

[J].地学前缘,2002,9(4):225-233.]

DOI      URL      摘要

由Rogers和Santosh等 (2 0 0 2 )提出的哥伦比亚超大陆 ,是约从 1.9~ 1.5Ga由Nena ,Ur和Atlantic等 3个大陆块体群 ,通过逐步汇聚而形成的一个超级大陆。它是前罗迪尼亚古 -中元古时期的超大陆。从 1.5Ga开始的裂解作用使哥伦比亚超大陆逐步破裂 ,并在 1.0Ga左右这些破裂的大陆块体又重新汇聚形成罗迪尼亚超大陆。文中除介绍Rogers等提出的哥伦比亚超大陆的概念、组成和古大陆重建图外 ,重点阐述了中国华北古大陆 2 .0~ 1.8Ga期间吕梁—中条造山运动和 1.8~1.6Ga时期大规模裂解事件群的性质、特点和同位素年龄数据。文中提出哥伦比亚超大陆汇聚主要峰期与吕梁—中条造山运动的时限相一致 ,华北古大陆属于哥伦比亚超大陆的组成部分 ,并可能为Nena大陆块体群的一员 ,在造山及裂解事件群的性质、特点和时代等特征上 ,华北与北美、西伯利亚和西北欧有更大的相似性。
[73] Lu Songnian,Li Huaikun,Xiang Zhenqun.

A review on the research progress of isotope geochronology during the Paleoproterozoic,China

[J].Geology in China,2010, 37(4):1 002-1 013.

[本文引用: 1]     

[陆松年,李怀坤, 相振群.

中国中元古代同位素地质年代学研究进展述评

[J].中国地质,2010,37(4):1 002-1 013.]

DOI      URL      [本文引用: 1]      摘要

本文较全面地总结了自2000年第三届全国地层大会以来,中国中元古代地层和热-构造事件同位素地质年代学研究工作所取得的主要进展,讨论了这些进展所具有的重要意义,指出确立中国中元古代上部地层标准剖面,重新厘定中元古界地质年表,是当前最迫切需要解决的课题.
[74] Chen Nengsong,Wang Qinyan,Chen Qiang,et al.

The preliminary discussion on the relationship between composition and metamorphism of the Qaidam and Olongbluk continental block basement and the evolution of ancient continent in West China

[J].Geoscience Frontiers,2007,14(1):43-55.

[本文引用: 2]     

[陈能松,王勤燕, 陈强,.

柴达木和欧龙布鲁克陆块基底的组成和变质作用及中国中西部古大陆演化关系初探

[J].地学前缘,2007,14(1):43-55.]

DOI      URL      [本文引用: 2]      摘要

中国西部的柴达木陆块和欧龙布鲁克陆块的基底岩系虽然在地球化学上与扬子陆块具有亲缘性,但 它们之间的组成和变质作用历史却显著不同。欧龙布鲁克陆块下部基底德令哈杂岩和达肯大坂岩群于~1.95Ga发生了角闪岩相一麻粒岩相区域变质作用并克拉 通化,响应了全球Columbia超大陆汇聚事件;随后又与中元古代万洞淘岩群一道于~1.0Ga发生绿片岩相变质作用,共同响应了全球Rodinia超 大陆汇聚事件;新元古代中晚期裂解后于中奥陶纪受原特提斯洋关闭影响而隆起。柴达木陆块基底主体由中元古代金水口岩群白沙河岩组(柴南缘)和沙柳河岩群鸟 龙滩岩组(柴北缘)组成,以S型花岗岩的侵入活动和相应的变质作用响应了全球Rodinia超大陆汇聚事件。晚泛非期(520-480Ma)柴达木陆块与 冈瓦纳主大陆俯冲碰撞,发生中压角闪岩相-麻粒岩相和高压超高压变质作用,经短暂拼贴后很快进入到原特提斯洋域,随460-420Ma的大洋关闭而发生变 质叠加。区域对比表明,在基底组成和地壳演化史上,欧龙布鲁克陆块与阿拉善陆块和塔里木陆块(包括扬子陆块)相似,柴达木陆块则与北秦岭陆块以及祁连陆块 相似,因而分属两个陆块群。塔-欧陆块群记录的~500Ma热事件与塔-欧和柴-秦陆块群共同记录的~450Ma热事件是两个性质不同的构造热事件。
[75] Tang Dongjie,Shi Xiaoying,Liu Dianbo,et al.

Termianl Paleoproterozoic ooidal ironstone from North China: A sedimentary response to the initial breakup of Columbia supercontinen

[J].Earth Science—Journal of China University of Geosciences, 2015,40(2):290-304.

[本文引用: 1]     

[汤冬杰,史晓颖,刘典波,.

华北古元古代末鲕铁岩:Columbia 超大陆裂解初期的沉积响应

[J].地球科学——中国地质大学学报,2015,40(2):290-304.]

DOI      URL      [本文引用: 1]      摘要

铁建造和鲕铁岩是地史上两类主要的富铁沉积,不仅记录了地球大气与海洋氧化还原状态和化学条件演变,而且也反应了构造运动、岩浆活动和生物的相互作用过程.过去对铁建造已有深入研究,而有关前寒武纪铁岩成因与古海洋和构造背景研究甚少.运用扫描电镜(scanning electronic microscopy,简称SEM)、X射线衍射(X-ray diffraction,简称XRD)、能谱(energy dispersive spectroscopy,简称EDS)技术分析铁鲕的微组构、矿物成分和化学组成,讨论华北串岭沟组(1.65~1.64Ga)鲕铁岩的成因环境及其与Columbia超大陆裂解的关系.研究表明,铁鲕主要由赤铁矿和少量高岭石组成,贫陆源碎屑和Al2O3;鲕包壳由微片状赤铁矿构成的致密和疏松纹层交互组成;Fe-Al呈明显的负相关性,表明铁主要源于缺氧富铁深海水体而非陆源风化.鲕铁岩集中在快速海进和低陆源输入引起的沉积饥饿期,发育于氧化还原界面附近的潮下贫氧环境.与超大陆裂解伴生的岩浆活动、基底沉降和快速海侵是促进鲕铁岩形成的重要因素.串岭沟组底部铁岩是华北地台响应Columbia超大陆裂解而发生构造与环境转化的重要沉积记录.
[76] Wu Hailin,Zhu Wenbin,Shu Liangshu,et al.

The record of the Columbia supercontinent polymerization in the North Tarim Craton

[J].Geological Journal of China Universities,2012,18(4):686-700.

[吴海林,朱文斌,舒良树,.

Columbia 超大陆聚合事件在塔里木克拉通北缘的记录

[J].高校地质学报,2012,18(4):686-700.]

URL      摘要

塔里木克拉通北缘库鲁克塔格地区广泛出露古老基底的岩石组合。对于这些老的基底岩石的研究将会加深对塔里木前寒武纪地壳演化的认识。本研究对来自库尔勒前寒武纪4个变沉积岩中碎屑锆石进行U-Pb和Lu-Hf同位素研究,目的是为了限定变沉积岩的最大沉积年龄及其源区的地壳演化信息。结果表明,其中3个变沉积岩中碎屑锆石经历了强烈的~1.85 Ga变质热事件,记录了塔里木克拉通对Columbia超大陆聚合的极度热响应。而另一样品T1既记录到该期热事件的年龄,还有部分未改造的碎屑锆石的残留,未改造碎屑锆石的最年轻峰值年龄为~2.0 Ga,判断这套变沉积岩的沉积作用发生于2.0~1.85 Ga之间,并于1.85 Ga发生变质。锆石的Hf同位素研究表明,塔里木克拉通库鲁克塔格地区在3.32~2.92 Ga(古太古代—中太古代)和2.56~2.46 Ga(新太古代末—古元古代初)发生两期地壳增生事件,且太古代地壳在2.65~2.50 Ga,2.20 Ga和1.90~1.80 Ga发生地壳再造,而年轻一期地壳在新元古代再造形成该时期的花岗岩类。此外本研究中还发现一颗tDM2为3.64 Ga的锆石,说明该区还可能存在≥3.64 Ga的老的地壳物质残留。
[77] Xu Huiru,Yang Zhenyu,Zhu Rixiang.

Paleo-position of the North China Craton within Supercontinent Columbia

[C].Chinese Geophysics Proceedings of the Fifth Conference,2013.

[徐慧茹,杨振宇,朱日祥.

华北克拉通在Columbia超大陆的古位置

[C].中国地球物理第五分会场论文集,2013.]

[78] Pei Junling,Yang Zhenyu,Zhao Yue.

New results of the Palaeoproterozoic ancient geomagnetic testing in North China and reseacch of Columbia supercontinent

[J].Geological Bulletin of China,2005,24(6):496-498.

[裴军令,杨振宇,赵越.

华北中元古界古地磁测试新结果与 Columbia 超级大陆研究

[J].地质通报,2005,24(6):496-498.]

DOI      URL      摘要

华北地块中元古代杨庄组的古地磁研究提供了一个同时通过褶皱检验 和倒转检验的古地磁极,极位置为经度190.4°、纬度2.4°.通过与Laurentia、Baltica和Siberia可靠的古地磁数据对比,支持 了古-中元古代可能存在Columbia超级大陆的假说.华北地块与Laurentia、Baltica和Siberia视极移曲线的对比表明华北地块与 Baltica在古-中元古代可能长期相连.
[79] Zhang S B,Zheng Y F,Wu Y B,et al.

Zircon isotope evidence for ≥3.5 Ga continental crust in the Yangtze craton of China

[J].Precambrian Research,2006,146(1):16-34.

DOI      URL      [本文引用: 1]      摘要

The presence or absence of Paleoarchean crust in different continents provides an important basis for a comparison of their growth histories. Since the finding of ca. 3.8 Ga detrital zircon in the North China craton by means of SHRIMP U–Pb dating, it has been a question whether the Yangtze craton, one of the two major blocks constituting the basement of China continent, also contain Paleoarchean crustal relicts. It is generally accepted that the basement of the Yangtze craton mainly formed in the Paleoproterozoic, with only minor Archean rocks in ages of 2.5–3.3 Ga. A combined study of zircon U–Pb dating and Hf isotope analyses for the Kongling migmatite and gneiss from this craton reveals the existence of ca. 3.5 Ga rocks. The zircon U–Pb ages are divided into three groups: 653.2 Ga in cores, 652.9 Ga in most grains and 652.0 Ga in rims. Both 653.2 Ga cores and 652.9 Ga grains have negative 07 Hf( t) values of 611.6 and 614.0, respectively. Mantle-like δ 18O values of 5.6–5.8‰ were obtained for the zircons, precluding a significant input by sedimentary source component for the magmas that are responsible for protolith of the Kongling metamorphic rocks. From the Hf model ages of these zircons, about 3.5 Ga crustal relicts are speculated to occur in the Kongling rocks. This provides the first demonstration for the existence of Paleoarchean rocks in the Yangtze craton. Thus the early evolutionary history of the Yangtze craton may resemble the North China craton that has crustal relicts with the minimum ages of 3.5 Ga. These Paleoarchean rocks resided in the crust of the Yangtze craton for at least several hundreds of million years before remelting, probably leaving some clues to be traced and verified. Paleoproterozoic U–Pb ages of 1.8–2.0 Ga are identified in magmatic and metamorphic rocks in the Yangtze craton, providing a likely connection of this craton with the North China craton with respect to assembly and breakup of the supercontinent Columbia during the late Paleoproterozoic.
[80] Peng Min.Paleoproterozoic Magmatism of Yangtze Craton:Timing and Geological Implications[D].Wuhan: China University of Geosciences(Wuhan),2010.

[本文引用: 1]     

[彭敏.

扬子板块古元古代岩浆事件年龄及其地质意义[D]

.武汉:中国地质大学, 2010.]

[本文引用: 1]     

[81] QiuY M,Gao S,McNaughton N J,et al.

First evidence of ≥3.2 Ga continental crust in the Yangtze craton of South China and its implications for Arehean crustal evolution and Phanerozoic tectonics

[J].Geology, 2000,26(1):11-14.

[本文引用: 2]     

[82] Ling Wenli,Gao Shan,Zhang Benren,et al.

The Paleoproterozoic tectonic heat events and evolution of the Yangtze Craton

[J].Chinese Science Bulletin,2000,45(21):2 343-2 348.

[凌文黎,高山,张本仁,.

扬子陆核古元古代晚期构造热事件与扬子克拉通演化

[J].科学通报,2000,45(21):2 343-2 348.]

DOI      URL      摘要

对扬子克拉通太古宙高级区域变质岩系变质事件进行了Sm-Nd同位素定年(1 939~ 1 958 Ma), 综合区内同类岩石的SHRIMP锆石U-Pb等相关年龄数据和地质事件, 确认这一时期构造热事件的存在并对其地质意义进行了解析. 通过与扬子克拉通其他地区早期基底岩系形成时代的对比分析, 表明古元古代晚期在整个扬子克拉通范围内存在一次重要的构造热事件, 并导致了扬子陆块统一基底的形成.
[83] Lei Hengcong,Xiang Hua,Zhang Zeming,et al.

Paleoproterozoic UHT granulite in the Sulu orogen and its tectonic implications

[J].Acta Petrologica Sinica,2014,30(8):2 435-2 445.

[雷恒聪,向华,张泽明,.

苏鲁造山带古元古代超高温麻粒岩及其构造意义

[J].岩石学报,2014,30(8):2 435-2 445.]

URL      摘要

本文报道了在苏鲁超高压变质带北端威海地区识别出的古元古代超高温泥质麻粒岩.泥质麻粒岩与大理岩、钙硅酸盐岩和片麻岩等变质表壳岩伴生.这些表壳岩以透镜体的形式产于经历了三叠纪超高压变质的新元古代正片麻岩中.泥质麻粒岩由石榴石、夕线石、斜长石、钾长石、反条纹长石、石英、黑云母、白云母和金红石组成.黑云母和白云母呈石榴石和夕线石的冠状体产出,为退变质矿物.相平衡模拟结果表明,麻粒岩峰期变质的温度和压力条件为~ 940℃和~ 1.2GPa.泥质麻粒岩中的锆石近等粒状或椭圆形,具有扇状或冷杉状分带,大多数具有平坦甚至亏损的重稀土配分模式,并有Eu负异常,为典型的麻粒岩相变质锆石.锆石的LA-ICP-MS U-Pb定年结果给出了1845 ±9Ma的207 pb/206 Pb加权平均年龄,表明超高温麻粒岩形成于古元古代.结合现有的其他研究结果,我们推测扬子板块北缘经历了古元古代的增生造山作用.
[84] Compston W,Williams I S,Kirschvink J L,et al.

Zircon U-Pb ages for the Early Cambrian time-scale

[J].Journal of the Geological Society,1992,149(2):171-184.

DOI      URL      摘要

Single zircons from two Early Cambrian volcanic horizons have been analysed using the SHRIMP ion microprobe. Full details of the analytical procedures and data reduction are given. Zircons from tuff within the Lie de Vin Formation, near Tiout, Morocco, show little spread in U-Pb age and have a mean value of 521 ± 7 Ma (2σ). Those from a bentonite within unit 5 of the Meishucun section near Kunming, southern China, show relatively dispersed U-Pb ages, revealing the presence of both detrital or xenocrystic grains as well as areas within grains that have lost radiogenic Pb. The main population has a mean age of 525 ± 7 Ma, but a mean ^(207)Pb/^(206)Pb age of 539 ± 34 Ma which is a maximum estimate for the bentonite age. These results conflict with previous Rb-Sr whole rock ages of c. 580 Ma for overlying Cambrian shales at Meishucun, and c. 570 Ma for Atdabanian shales from the E. Yangtse Gorges area.
[85] Zheng J,Griffin W L,O'Reilly S Y,et al.

3.6 Ga lower crust in central China:New evidence on the assembly of the North China craton

[J].Geology,2004,32(3):229-232.

DOI      URL      摘要

U-Pb and Hf isotope analyses of zircons from felsic granulite xenoliths in Mesozoic volcanics reveal Early Archean (鈮3.6 Ga) lower crust beneath the younger (<2.85 Ga) southern margin of the North China craton, and suggest that the eastern part of the craton formed a coherent block by 3.6 Ga. Hf model ages indicate extraction of protoliths from the mantle ca. 4 Ga or earlier, followed by remelting at 3.6 3.7 Ga. Hf isotope data require both recrystallization of magmatic zircons, and growth of new zircon, up to ca. 1.9 Ga. One sample records 2.1 1.9 Ga remelting of a 2.5 Ga protolith. If large parts of the exposed upper continental crust elsewhere also are underlain by older lower crust, estimates of crustal growth rates through time will require revision.
[86] Wu Yuanbao,Chen Daogong,Xia Qunke,et al.

SIMS U-Pb dating of zircons in granulite of Huangtuling from Northern Dabieshan

[J].Acta Petrolog ica Sinica,2002,18(3):378-382.

Magsci     

[吴元保,陈道公,夏群科,.

北大别黄土岭麻粒岩错石U-Pb离子探针定年

[J].岩石学报,2002,18(3):378-382.]

DOI      URL      Magsci      摘要

阴极发光显微结构分析表明 ,北大别黄土岭麻粒岩中存在三种类型的锆石 :原岩锆石、麻粒岩相锆石和残留锆石。对它们分别进行离子探针定年 ,得到黄土岭麻粒岩的原岩年龄约为 2 70 0 Ma、麻粒岩相变质事件的年龄为 2 0 5 2± 10 0 Ma、残留锆石的年龄为约 3.4 Ga。以上研究表明黄土岭麻粒岩为残存的扬子板块的结晶基底 ,而约 3.4 Ga残留锆石的发现 ,则首次证明大别山地区存在古太古代的陆壳物质
[87] Yin Congyu,Liu Dunyi,Gao Linzhi,et al.

The age of the Nanhua Period foundation and the Gucheng ice era: Evidence from SHRIMP Ⅱdating

[J].Chinese Science Bulletin,2003,48(16):1 721-1 725.

[尹崇玉,刘敦一,高林志,.

南华系底界与古城冰期的年龄:SHRIMP Ⅱ定年证据

[J].科学通报,2003,48(16): 1 721-1 725.]

DOI      URL      摘要

报道南华系候选层型剖面--湖南石门壶瓶山镇杨家坪剖面的同位素年代学研究结果.锆石 SHRIMP定年研究表明, 南华系下统渫水河组(相当于莲沱组)上部凝灰岩的锆石定年结果为758±23 Ma, 可限定南华系古城冰期的下限.其下青白口系老山崖组为809±16 Ma, 采样点距顶界12 m, 根据沉积速率估算, 其顶界的时限大致为800 Ma.这一组年龄结果使我国南方前寒武纪长期争论的"莲沱组"是否等于"板溪群"的重大地层对比问题得以澄清.
[88] Peng Touping,Wang Yuejun,Fan Weiming,et al.

Zircon U-Pb dating and its tectonic significance of Early Mesozoic acid igneous rocks in southern part of Lancang River

[J].Science in China (Series D),2006, 36(2):123-132.

[彭头平,王岳军,范蔚茗,.

澜沧江南段早中生代酸性火成岩SHRIMP锆石U-Pb定年及其构造意义

[J].中国科学:D辑,2006,36(2):123-132.]

DOI      URL      摘要

应用SHRIMP方法对澜沧江南段临沧花岗岩体和云县忙怀组流纹岩代表性样品进行了精确的SHRIMP锆石 U-Pb定年研究. 临沧岩体北段黑云母二长花岗岩(02DX-137)锆石年龄为229.4±3.0 Ma, 南段景洪地区黑云母二长花岗岩(20JH-10)锆石年龄为 230.4±3.6 Ma, 两者在误差范围具有一致的年龄, 可能代表了临沧花岗岩体主体的形成年龄. 云县棉花地忙怀组上段的流纹岩样品(02DX-95)给出了231.0±5.0 Ma的SHRIMP锆石U-Pb年龄. 这些资料为理解滇西古特提斯构造演化提供了重要信息. 临沧岩体南段黑云母花岗岩中存在1977±44 Ma锆石年龄, 表明区内可能存在着早元古代结晶基底.
[89] Zhang Shaobing.

Geoehemistry of the Yangtze Continental Nucleus and Its Anatectic Granitoids

[D].Wuhan: China University of Geosciences(Wuhan),2008.

[本文引用: 1]     

[张少兵.

扬子陆核古老地壳及其深熔产物花岗岩的地球化学研究[D]

.武汉:中国地质大学,2008.]

[本文引用: 1]     

[90] Li Jianghai,Hou Guiting,Huang Xiongnan,et al.

Precambrian geology of North China Block

[J]. Acta Petrologica Sinica,2001,17(2):177-186.

Magsci      [本文引用: 1]     

[李江海,侯贵廷,黄雄南,.

华北克拉通对前寒武纪超大陆旋回的基本制约

[J].岩石学报,2001,17(2):177-186.]

DOI      URL      Magsci      [本文引用: 1]      摘要

全球大陆克拉通在前寒武纪至少记录了3次超大陆聚合-裂解的构造旋回。不同大陆前寒武纪地质的研究证明,板块的构造模式可以前推至新太古代。超大陆的聚合表现为大规模造山带的穿时性发育,而裂解则表现为大陆裂谷系、非造山花岗岩及巨型基性岩浆岩省的同期快速发育。广泛的区域地质研究揭示华北克拉通前寒武纪地质构造演化具有明显的阶段性差异特征,克拉通主体形成于新太古代陆壳增生与碰撞造山过程。华北克拉通在太古宙末期首次经历强烈的裂解作用,在古元古代晚期涉及强烈的陆缘再造作用。在古元古代末期发生第二次大规模的裂解活动,随后以中元古代末期的造山带拼合为Rodinia超大陆的组成部分。详细的区域构造对比证明,华北克拉通长期以来与波罗的地质、东南极克拉通、印度南部克拉通、巴西克拉通等具有构造亲缘关系。
[91] Hou G,Liu Y,Li J.

Evidence for ~1.8Ga extension of the Eastern Block of the North China Craton from SHRIMP U-Pb dating of mafic dyke swarms in Shandong Province

[J].Journal of Asian Earth Sciences,2006,27(4):392-401.

DOI      URL      [本文引用: 1]      摘要

A large mafic dyke from the NNW-trending dyke swarms in the Eastern Block of the North China Craton was dated by SHRIMP U-Pb age analysis. This dyke occurs near Mt. Taishan in Shandong Province; it cuts Neoarchean tonalite, adamellite and diorite plutons. Two types of zircons were found in the dyke. Type 1 zircons were inherited from the host rocks and gave a SHRIMP U-Pb age of 2544±2402Ma with a weighted mean 207 Pb/ 206 Pb age of 2523±1802Ma. Type 2 zircons were crystallized from the dyke magma and yielded a concordant SHRIMP U-Pb age of 1830±1702Ma with a weighted mean 207 Pb/ 206 Pb age of 1837±1802Ma, indicating that the large dyke at Taishan was emplaced at 65183002Ma. The mafic dyke swarm provides evidence of a phase of extension in the Eastern Block of the North China Craton at 651.802Ga. This dyke has a similar age to dyke swarms in the Western Block and in the Central Orogen Belt of the North China Craton. This lithospheric extension, led to the opening of the Yanliao and Zhongtiao aulacogens. The similar ages and orientations of 651.802Ga dyke swarms throughout the North China Craton demonstrate that at that time the Eastern and Western blocks were united and that the amalgamated craton experienced widespread extension.
[92] Peng P.

Reconstruction and interpretation of giant mafic dyke swarms: A case study of 1.78 Ga magmatism in the North China craton

[J].Geological Society London Special Publications,2010,338(1):163-178.

DOI      URL      [本文引用: 1]      摘要

姝hort-lived giant mafic dyke swarms are keys to the interpretation of continental evolution and tectonics,reconstruction of continental palaeogeographical regimes,and petro-genesis of volcanism.The 1.78 Ga Taihang-Lvliang dyke swarm,one of the most significant and best-preserved Precambrian swarms in the central part of the North China craton(NCC),is reviewed and discussed.It is interpreted to have a radiating geometry that is compatible with the Xiong'er triple-junction rift,in which the Xiong'er volcanic province is proposed to be the extrusive counterpart of this swarm.It resulted in significant extension,uplift and magmatic accretion of the NCC,and it is comparable with the Phanerozoic large igneous provinces(LIPs) in areal extent(c.0.3 Mkm~2)and estimated volume(c.0.3 Mkm~3),short lifespan(20Ma), and intraplate setting.This North China LIP is unique in that it comprises large volumes of both mafic and intermediate components.It could have resulted from extensive mantle-crust interaction, probably driven by a large-scale mantle upwelling.A plume tectonic model is favoured by several lines of supporting evidence(i.e.massive volcanic flows correlated over large areas and a giant fanning dyke swarm with plume-affinitive chemistry).It could responsible for massive sulphide(Pb-Zn)and gold(Au-Ag)ore deposits in the Xiong'er volcanic province. Dismembered remnants of this magmatism in other block(s),with potential candidates in South America,Australia and India,could identify other cratonic blocks that were formerly connected to the North China craton.
[93] Gao Shanlin,Lin Jinyan,Lu Yanjun.

Formation epoch and its geological implications of Paleoprotozoic A-type granite in Shizuizi of Jingyuan County,Ningxia Province

[J].Acta Petrologica Sinica, 2013,29(8):2 676-2 684.

[本文引用: 1]     

[高山林,林晋炎,陆彦俊.

宁夏泾源石咀子古元古代A型花岗岩的形成时代及其地质意义

[J].岩石学报,2013,29(8):2 676-2 684.]

URL      [本文引用: 1]      摘要

对华北克拉通西缘贺兰坳拉谷南段泾源县石咀子花岗斑岩进行了岩石地球化学和年代学研究结果表明,石咀子花岗岩体具有高硅(SiO2=72.28%~76.69%)、富钾特征,Na2O+K2O平均值7.61%,K2O/Na2O为2.17~7.39,Al2O3=10.59%~11.84%,A/CNK为0.86~1.11(平均为1.01),低钙镁,岩石为高硅准铝质-弱过铝质A型花岗岩;稀土元素总量较高,为340.4×10-6~468.9×10-6,轻稀土富集,具有中等的负Eu异常,配分曲线呈典型的右倾"海鸥型";高场强元素Ta、Nb、Ti具有明显的负异常,大离子亲石元素Rb、Ba、Th等相对富集,花岗岩具有造山后岩石地球化学特征。锆石的LA-ICP-MSU-Pb年龄为1803±15Ma,为古元古代晚期,表明贺兰坳拉谷形成于古元古代晚期,其形成与华北克拉通古元古代晚期大陆裂解过程有关。
[94] Lu Songnian,Yuan Guibang.

Geochronology of early Precambrian magmatic activities in Aketashitage,east Altyn tage

[J].Acta Geologica Sinica,2003,77(1):61-68.

Magsci      [本文引用: 1]     

[陆松年,袁桂邦.

阿尔金山克塔什塔格早前寒武纪岩浆活动的年代学证据

[J].地质学报,2003,77(1):61-68.]

Magsci      [本文引用: 1]      摘要

在阿尔金山阿克塔什塔格曾测得3605±43Ma的单颗粒锆石U-Pb年龄数据,获得了古老地壳存在的同位素年代学信息。近年来根据野外的实际资料,建立了早前寒武纪岩浆活动的相对序列,这些热事件序列可分为早期花岗岩和二长花岗岩侵入体、英云闪长岩侵入体(赋存有斜长角闪岩的包体)、奥长花岗岩、基性岩墙群和石英二长岩脉等。目前除斜长角闪岩包体和基性岩墙群尚未获得同位素年龄外,其他各期侵入体均已获得单颗粒锆石U-Pb测年数据。在野外建立热事件相对序列的基础上,通过单颗粒锆石U-Pb法测年和Sm-Nd同位素示踪研究,初步建立了该区早前寒武纪岩浆活动的年代格架:石英二长岩(脉):1825±23Ma,T_(DM)=2920Ma;奥长花岗(片麻)岩:2374±10Ma,T_(DM)=3460Ma;英云闪长(片麻)岩:2604±102 Ma,T_(DM)=3063Ma;二长花岗(片麻)岩:3096±17Ma,T_(DM)=2978Ma;花岗(片麻)岩:3605±43Ma,T_(DM)=3528Ma。根据上述年代学和钕同位素地球化学资料,证明阿克塔什塔格是我国西部最古老的地壳出露区,在太古宙3.5~3.6Ga和3.0~3.1Ga时期各有一次造壳活动,而太古宙末约2.6Ga则表现为地壳的活化再造。阿尔金山阿克塔什塔格不仅是我国西部最老地壳出露区,也是早前寒武纪岩浆事件序列保存最完整的地区。该区早前寒武纪岩浆活动序列和年代格
[95] Wang Yuxi,Wang Jinrong,Zhou Xiaoling,et al.

The cracking of Columbia Supercontinental:Evidence from the Dahongshan A-type granite in the southeastern Tarim Craton

[J].Acta Geologica Sinica,2017,91(11):2 369-2 386.

[本文引用: 1]     

[王玉玺,王金荣,周小玲,.

Columbia超大陆裂解:来自塔里木克拉通东南缘大红山A型花岗岩的证据

[J].地质学报,2017,91(11):2 369-2 386.]

[本文引用: 1]     

[96] Xiao Qinghui,Lu Huanxiang,Wang Fei,et al.

Geochronological studies of rapakivi granites in North of Qaidam Basin and its geological implications

[J].Science in China (Series D),2003,33(12):1 193-1 200.

[本文引用: 2]     

[肖庆辉,卢欣祥,王菲,.

柴达木北缘鹰峰环斑花岗岩的时代及地质意义

[J].中国科学:D辑,2003,33(12):1 193-1 200.]

DOI      URL      [本文引用: 2]      摘要

柴达木北缘鹰峰环斑花岗岩是继北京密云沙厂及吉林宽甸等元古宙环斑花岗岩之后,在我国发现的又一典型的元古宙环斑花岗岩体,它出露于秦岭-昆仑造山带与华北板块结合带的北侧,对其进行锆石U-Pb和角闪石、钾长石Ar-Ar同位素测年,结果表明,锆石U-Pb上交点年龄(1776±33)Ma,代表了岩体的形成时代;下交点及矿物的^40Ar/^39Ar年龄则反映了岩体形成后曾受到区域强烈的加里东-海西构造运动的影响,鹰峰中元古代环斑花岗岩的发现,为中国西部大陆地壳基底及华北板块基底的克拉通化时间及其在中元古代发生的裂解事件提供了岩石学依据,说明中国古大陆在早中元古代之交的吕梁运动时曾发生过大陆的拼合。
[97] Zhao Guochun,Sun Min,Wilde S A.

The research progress of the Early-Middle Proterozoic Columbia super-continental

[J].Chinese Science Bulletin,2002,47(18):1 361-1 364.

[本文引用: 1]     

[赵国春,孙敏,Wilde S A.

早—中元古代Columbia超级大陆研究进展

[J]. 科学通报,2002,47(18):1 361-1 364.]

[本文引用: 1]     

[98] Hou Guiting, Li Jianghai, Qian Xianglin.

Geochemical characteristics and tectonic setting of Mesoproterozoic dyke swarms in northern Shanxi

[J]. Acta Petrologica Sinica,2001,17(3):352-357.

Magsci      [本文引用: 3]     

[侯贵廷,李江海,钱祥麟.

晋北地区中元古代岩墙群的地球化学特征和大地构造背景

[J].岩石学报,2001,17(3):352-357.]

DOI      URL      Magsci      [本文引用: 3]      摘要

晋北地区发育大规模的中元古代北北西向岩墙群,未变形和未变质,是华北克拉通前寒武纪构造演化研究的最显著标志,根据本区岩墙群的岩石学和地球化学研究,这些岩墙群的岩石属于板内大陆裂谷玄武岩系列,形成于大陆裂谷拉张的构造环境,与东侧的燕辽-中条拗拉槽内的火山岩岩石化学对比分析,本区岩墙群的基性岩浆可能来自拗拉槽深部,这些基性岩浆从拗拉槽的深部向北西方向侵位于晋北地区先存的构造裂隙中形成了基性岩墙群。
[99] Peng Suxia,Yin Chuanming,Liu Jianchao,et al.

The analysis and review of nature of Cambrian basement, origin of volcanic rocks and the prospecting problems in Northern Qilian Orogenic Belt

[J].Geology and Prospecting,2012,48(2):250-258.

[本文引用: 2]     

[彭素霞,尹传明,刘建朝,.

对北祁连造山带前寒武纪基底物性, 火山岩的源区性质及找矿问题的分析和综述

[J].地质与勘探,2012,48(2):250-258.]

URL      [本文引用: 2]      摘要

本文主要在先前一些研究者对北祁连山加里东造山带的构造、海相火山岩和块状硫化矿床研究所获 成果和认识的基础上,重点从造山带的前寒武纪基底的物性特征,来分析和讨论所见不同时代地层中的变火山岩类的物源区及形成机制,进而提出一些区域找矿思 路。所得结论主要包括:(1)北祁连山加里东造山的真正基底应是从阿拉善或华北地块分裂出来的一套绿岩类型火山沉积建造,并以古元古宙的北大河群和龙首山 群为代表;(2)北祁连造山带的基底从克拉通向大陆裂谷构造体制转换大致发生在早一中元古宙的分界时限(约1777Ma),并普遍以一套大陆裂谷型双峰式 火山岩组合为典型特征;(3)不同时代或不同构造体制下形成的火山岩,各有其不同的物源区和成岩模式。具体说,在元古宙绿岩类型的火山岩的源区可能是克拉 通早期由原始玄武质下地壳转变来榴辉岩或基性麻粒岩相,进入大陆裂谷构造体阶段,便转换为一种幔-壳双层岩源区模型,而晚期的次火山岩类的源岩明显是已经 过先期大量改造或改变了中上地壳物质作为物源;(4)按大陆裂谷成矿体系并结合以往一些区域调查资料,提出托莱山西段的小龙口-九个青羊地段可能是个与海 相火山岩有关的块状硫化物矿床潜在远景找矿地段。
[100] Li Jianghai,Qian Xianglin,Huang Xiongnan,et al.

Tectonic framework of North China Block and its cratonization in the early Precambrian

[J].Acta Petrologica Sinica,2000,16(1):1-10.

Magsci      [本文引用: 1]     

[李江海,钱祥麟,黄雄南,.

华北陆块基底构造格局及早期大陆克拉通化过程

[J].岩石学报,2000,16(1):1-10.]

DOI      URL      Magsci      [本文引用: 1]      摘要

依据区域构造分析及同位素年代娄数据库,华北克拉通普质基底主要可以区划为以处构造单元:1)鄂尔多斯陆块新太古代被动边缘沉积;2)恒山--承德太古代末期构造带;3)太古代末期五台--登封岛弧带杂岩及构造缝合带;4)鲁西--冀东-辽吉新太古代活动大陆边缘岩浆杂岩带;5)胶辽陆块;6)冀北--固阳古元代初造山带及内蒙-=东再造麻粒岩要带;7)吕梁--中条古元古代裂谷带;8)辽南古元古代裂谷带。华北克拉通早
[101] Liu Chaohui,Liu Fulai.

The Mesoproterozoic rifting in the North China Craton:A case study for magmatism and sedimentation of the Zhaertai-Bayan Obo-Huade rift zone

[J].Acta Petrologica Sinica,2015, 31(10):3 107-3 128.

[本文引用: 1]     

[刘超辉, 刘福来.

华北克拉通中元古代裂解事件:以渣尔泰—白云鄂博—化德裂谷带岩浆与沉积作用研究为例

[J].岩石学报,2015,31(10):3 107-3 128.]

URL      [本文引用: 1]      摘要

华北克拉通存在三个主要的中元古代裂谷带,从南到北分别为熊耳裂谷带、燕辽裂谷带以及渣尔泰-白云鄂博-化德裂谷带.其中熊耳群中火山岩的峰期年龄为1780~1750Ma,其上还有形成于被动大陆边缘的五佛山群、汝阳群以及官道口群.中北部的燕辽裂谷带包括长城系、蓟县系和青白口系,其中长城系团山子组和大红峪组火山岩的年龄分别为~1640Ma和1626~1622Ma,蓟县系高于庄组、雾迷山组和铁岭组凝灰岩的年龄分别为1560Ma、1485Ma和1437Ma,而下马岭组凝灰岩年龄为1366~1380Ma.北缘渣尔泰-白云鄂博-化德裂谷带中渣尔泰群书记沟组玄武岩年龄为1743Ma,阿古鲁沟组酸性火山岩年龄为~810Ma,白云鄂博群尖山组中基性火山岩年龄为1728Ma,化德群比鲁特组火山碎屑岩年龄为1515Ma.中元古代岩浆事件除了裂谷带中的火山作用外,还包括三期基性岩墙群(~ 1780Ma太行-吕梁岩墙群、~1730Ma密云岩墙群和~1620Ma泰山岩墙群)以及1.76Ga到1.65 Ga非造山岩浆组合(斜长岩-环斑花岗岩体-A型花岗岩).中元古代中期,华北克拉通北缘发育了基性岩席(墙)、A型花岗岩以及碳酸岩脉,双峰式岩浆作用说明华北北缘在中元古代中期经历了裂谷作用,与哥伦比亚超大陆的最终裂解有关,并且与白云鄂博巨型REE-Nb-Fe矿床的形成具有成因上的联系.华北克拉通北部两个裂谷带中的地层具有可以对比的层序以及时代,而中元古代中期辉绿岩墙、A型花岗岩以及碳酸岩脉可以与其它克拉通同时期的非造山岩浆作用对比,证明华北克拉通经历了哥伦比亚超大陆的最终裂解.古地磁数据已经证明在哥伦比亚超大陆时期Siberia、Laurentia、Baltica、Amazion以及华北克拉通是连接在一起的,而北缘中元古代中期大陆裂谷相关岩浆岩的发现也说明它是与另一个古大陆相连的.华北克拉通南缘熊耳火山岩的构造背景到底是大陆裂谷还是大陆边缘弧则关系着其是与另一个克拉通相连还是面向大海,这需要我们进一步深入研究.