远喷口型
  <strong>SEDEX</strong>铅锌矿床最新研究进展及发展趋势

doi:10.11867/j.issn.1001-8166.2021.067

远喷口型SEDEX矿床是全球铅锌矿产的主要来源，但是，长期以来有关其成因及判别的标志一直存在争议。最近全球几个典型的此类铅锌矿床成矿研究取得了一些重要进展： $①$ 海底喷流沉积作用不是该类矿床成矿的唯一方式，纹层状矿化也不是其成因的直接诊断标志； $②$ 与传统上认为该类矿床一般形成于封闭、还原的海底低洼沉积环境不同，远喷口型SEDEX矿床赋矿围岩可以形成于开放、氧化沉积环境； $③$ 甲烷厌氧氧化作用和海底热液交代作用可能是该类矿床纹层状、条带状矿化形成的主要机制。这些认识不仅对该类矿床传统成因模式提出了挑战，而且也将引起传统找矿勘查评价准则的改变。因此，借鉴已有研究经验，加强该类矿床成矿研究是当前矿床学的迫切任务之一。

关键词: 远喷口型SEDEX矿床, 诊断标志, 沉积环境, 成矿机制

Vent-distal Sedimentary-Exhalative（SEDEX）ore deposits are the main source of lead-zinc minerals worldwide，however，their genesis and diagnostic marks are yet controversial. Recently，some important discoveries have been made in the study of typical vent-distal SEDEX ore deposits in the world， including： $①$ Submarine exhalative sedimentation is not the unique way of mineralization， and laminated mineralization is not an exclusive diagnostic signature of the genesis of such deposits； $②$ Contrary to the traditional view given that vent-distal SEDEX deposits are generally formed in a closed，reduced and down-warped submarine sedimentary environment，the host rocks of these deposits can be formed in an open and oxidized sedimentary environment； $③$ Methane anaerobic oxidation and submarine hydrothermal alteration may be the main mechanisms for the formation of laminated and layered mineralization of this type of deposits. These understandings not only challenge the traditional genetic model of SEDEX deposits but also lead to the change of traditional prospecting and exploration evaluation criteria. Therefore，it is one of the urgent tasks to strengthen metallogenic research of this type of deposits learnt from the existing research experiences.

Key words: Vent-distal SEDEX deposit, Diagnostic signature, Sedimentary environment, Mineralized mechanism

中图分类号:

P618.4

图1 SEDEX型Pb-Zn矿床成因模式对比^{［

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（a）近喷口型成因模式；（b）远喷口型成因模式；（a）和（b）成因模式中成矿均受海底喷流沉积作用及封闭、还原沉积环境控制；（c）热液交代成因模式，成矿受压实成岩地层热液交代作用控制，沉积环境为开放、氧化环境

Fig. 1 Genetic model comparison of SEDEX Pb-Zn deposits^{［

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（a）Vent-proximal genetic model；（b）Vent-distal genetic model； Both of （a） and （b） are controlled by submarine sedimentary exhalative and enclosed and reduced sedimentary environment；（c）Hydrothermal altered genetic model of SEDEX Pb-Zn deposits. Notably， mineralization is controlled by hydrothermal alteration within the diagenetic strata and formed in the open and oxidation environments

图2 海底硫酸盐—甲烷过渡带（a）及甲烷厌氧氧化作用（b）示意图^{［

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（a）上部硫酸盐还原带，下部甲烷带，二者之间为硫酸盐—甲烷过渡带；（b）粗黑色箭头代表上部SO

4 2 -

向下渗透，下部CH ₄向上渗透，二者渗透过程中出现甲烷厌氧氧化作用（AOM）及主要化学反应。此外，深部有机质分解形成的甲烷越向上 δ ¹³C越亏损，相反，硫酸盐还原形成的硫化物越向上 δ ³⁴S越富集

Fig. 2 Schematic figures for submarine sulphate-methane transition zone （a） and anaerobic oxidation of methane （b）^{［

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（a）Sulphate reduced zone in the upper level， methane forming zone in the lower level， sulphate methane transition zone between them；（b）Thicked black arrows denote that SO

4 2 -

infiltrates downward， whereas CH ₄ transfers upward， and anaerobic oxidation of methane occurs in the sulphate methane transition zone. In addition， in the upward stratigraphic sequences， it is the characteristics of depletion in δ ¹³C while enrichment in δ ³⁴S

4 2 -

4 2 -

图3 加拿大Selwyn盆地SEDEX型Pb-Zn矿床赋矿DLK组地层有机碳含量、黄铁矿δ³⁴S组成和自生碳酸盐矿物δ¹³C组成与层位变化关系图^{［

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Fig. 3 Correlation diagrams between organic carbon content，δ³⁴S of pyrites， and δ¹³C of autogenetic carbonate minerals and strata sequence in the ore-hosted DLK formation of SEDEX Pb-Zn deposit in Selwyn basin， Canada^{［

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图4 交代作用对溶液pH值改变及其对硫化物沉淀顺序影响的热动力学模拟图解^{［

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（a）黄铁矿稳定域pH值变化范围3~9；（b）闪锌矿稳定域pH值变化范围5~11； SEDEX型Pb-Zn矿床一般黄铁矿形成早于闪锌矿，闪锌矿形成与交代作用导致的溶液pH值升高有关

Fig. 4 Thermodynamic modeling diagrams illustrate how the pH value change， which is caused by the alteration between hydrothermal fluids and rocks， to effect on the precipitation sequence of sulfides from the hydrothermal fluids^{［

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（a）Stable area of pyrite ranges from 3 to 9 in pH；（b）Higher pH value of 5~11 for sphalerite. Which gives a reasonable explanation for the formation of pyrite before sphalerite， and the latter is the result of alteration triggering pH value increasing

1	HANNINGTON M D， DE RONDE C E J， PETERSEN S. Sea-floor tectonics and submarine hydrothermal systems ［J］. Economic Geology， 2005， 100： 111-141.
2	LEACH D L， SANGSTER D F， KELLEY K D， et al. Sediment-hosted lead-zinc deposits： a global perspective ［J］. Economic Geology， 2005， 100： 561-607.
3	SANGSTER D F， HILLARY E M. SEDEX lead-zinc deposits： proposed sub-types and their characteristics ［J］. Exploration and Mining Geology， 1998， 7： 341-357.
4	SATO T. The behaviours of ore-forming solutions in seawater ［J］. Mining Geology， 1972， 22： 31-42.
5	GOODFELLOW W D， LYDON J W， TURNER R J W. Geology and genesis of stratiform sediment-hosted （SEDEX） zinc-lead-silver sulphide deposits： mineral deposit modeling ［J］. Geological Association of Canada Special Paper， 1993， 40： 201-251.
6	LYDON J W. Genetic models for Sullivan and other SEDEX deposits ［C］//MIHIR Deb， GOODFELLOW W D. Sediment-hosted lead-zinc sulphide deposits， attributes and models of some major deposits in India， Australia and Canada. New Delhi， India： Narosa Publishing House， 2004： 149-190.
7	MAGNALL J M， GLEESON S A， CREASER R A， et al. The mineralogical evolution of the clastic dominant-type Zn-Pb±Ba deposits at Macmillan Pass （Yukon， Canada）—tracing subseafloor barite replacement in the layered mineralization ［J］. Economic Geology， 2020， 115： 961-979.
8	LARGE R， BULL S W， COOKE D R， et al. A genetic model for the HYC deposit， Australia： based on regional sedimentology， geochemistry， and sulfide-sediment relationships ［J］. Economic Geology， 1998， 93：1 345-1 368.
9	GU Lianxing. Advances in research on massive sulfide deposits： a review ［J］. Geological Review， 1999， 45（3）： 265-275.
	顾连兴. 块状硫化物矿床研究进展评述［J］. 地质论评， 1999， 45（3）： 265-275.
10	HAN Fa， SUN Haitian. Metallogenic system of SEDEX type deposits ［J］. Earth Science Frontiers， 1999， 6（1）： 139-162.
	韩发，孙海田. SEDEX 型矿床成矿系统［J］. 地学前缘， 1999， 6（1）： 139-162.
11	LIU Jiajun， ZHENG Minghua， LIU Jianming， et al. The geological features and prospecting marks of the exhalative type of stratabound gold deposits in western Qinling ［J］. Gold， 1997， 18（9）： 9-12.
	刘家军，郑明华，刘建明，等. 西秦岭喷流型层控金矿床的地质特征及其找矿标志［J］. 黄金， 1997， 18（9）： 9-12.
12	SANGSTER D F. The role of dense brines in the formation of ventdistal Sedimentary-Exhalative （SEDEX） lead-zinc deposits： field and laboratory evidence［J］. Mineral Deposita， 2002， 37： 149-157.
13	IRELAND T， LARGE R R， MCGOLDRICK P， et al. Spatial distribution patterns of sulfur isotopes， nodular carbonates， and ore textures in the McArthur River （HYC） Zn-Pb-Ag deposit， northern Territory， Australia ［J］. Economic Geology， 2004， 99： 1 687-1 709.
14	SPINKS S C， PEARCE M A， LIU W H， et al. Carbonate replacement as the principal ore formation process in the Proterozoic McArthur River （HYC） sediment-hosted Zn-Pb deposit Australia ［J］. Economic Geology， 2021， 116（3）： 693-718.
15	LEACH D L， BRADLEY D C， HUSTON D， et al. Sediment-hosted lead-zinc deposits in Earth history ［J］. Economic Geology， 2010， 105： 593-625.
16	MA G， BEAUDOIN G， ZHONG S， et al. Geology and geochemistry of the Dengjishan Zn-Pb SEDEX deposit， Qinling belt， China ［J］. Canadian Journal of Earth Sciences， 2007， 44： 479-492.
17	GADD M G， LAYTON-MATTHEWS D， PETER J M， et al. The worldclass Howard's Pass SEDEX Zn-Pb district， Selwyn Basin， Yukon. Part I： trace element compositions of pyrite record input of hydrothermal， diagenetic and metamorphic fluids to mineralization ［J］. Mineral Deposita， 2016， 51： 319-342.
18	RAISWELL R， BUCKLEY F， BERNER R A， et al. Degree of pyritization of iron as a paleoenvironmental indicator of bottom water oxygenation ［J］. Journal of Sedimentary Research， 1988， 58： 812-819.
19	GOLDHABER M B. Sulfur-rich sediments ［C］// MACKENZIE F T. Treatise on geochemistry. Amsterdam： Elsevier， 2003， 7： 257-288.
20	SANGSTER D F. Toward an integrated genetic model for vent-distal SEDEX deposits［J］. Mineral Deposita， 2018， 53： 509-527.
21	SLACK J F， FALCK H， KELLEY K D， et al. Geochemistry of host rocks in the Howards Pass district， Yukon-Northwest Territories， Canada： implications for sedimentary environments of Zn-Pb and phosphate mineralization ［J］. Mineral Deposita， 2017， 52： 565-593.
22	JOHNSON C A， SLACK J F， DUMOULIN J A， et al. Sulfur isotopes of host strata for Howards Pass （Yukon-Northwest Territories） Zn-Pb deposits implicate anaerobic oxidation of methane， not basin stagnation ［J］. Geology， 2018， 46： 619-622.
23	COOKE D R， BULL S W， LARGE R R， et al. The importance of oxidized brines for the formation of Australian Proterozoic stratiform sediment-hosted Pb-Zn （SEDEX） deposits ［J］. Economic Geology， 2000， 95： 1-18.
24	ELDRIDGE C S， WILLIAMS N， WALSHE J L. Sulfur isotope variability in sediment-hosted massive sulfide deposits as determined using the ion microprobe SHRIMP： II. a study of the H.Y.C. deposit at McArthur River， northern Territory， Australia ［J］. Economic Geology， 1993， 88：1-26.
25	GADD M G， LAYTON-MATHEWS D， PETER J M， et al. The world-class Howard's Pass SEDEX Zn-Pb district， Selwyn Basin， Yukon. Part II： the roles of thermochemical and bacterial sulfate reduction in metal fixation ［J］. Mineral Deposita， 2017， 52： 405-419.
26	GOODFELLOW W D， JONASSON I R. Ocean stagnation and ventilation defined by δ³⁴S secular trends in pyrite and barite， Selwyn Basin， Yukon ［J］. Geology， 1984， 12： 583-586.
27	KELLEY K D， LEACH D L， JOHNSON C A， et al. Textural， compositional， and sulfur isotope variations of sulfide minerals in the Red Dog Zn-Pb-Ag deposits， Brooks Range， Alaska： implications for ore formation ［J］. Economic Geology， 2004， 99： 1 509-1 532.
28	BOROWSKI W S. A review of methane and gas hydrates in the dynamic， stratified system of the Blake Ridge region， offshore southeastern North America［J］. Chemical Geology， 2004， 205： 311-346.
29	LASH G G. Pyritization induced by Anaerobic Oxidation of Methane （AOM）—an example from the upper Devonian shale succession， western New York， USA ［J］. Marine and Petroleum Geology， 2015， 68： 520-535.
30	LIN Z Y， SUN X M， PECKMANN J， et al. How sulfate-driven anaerobic oxidation of methane affects the sulfur isotopic composition of pyrite： a SIMS study from the South China Sea ［J］. Chemical Geology， 2016， 440： 26-41.
31	LIN Z Y， SUN X M， STRAUSS H， et al. Multiple sulfur isotope constraints on sulfate-driven anaerobic oxidation of methane： evidence from authigenic pyrite in seepage areas of the South China Sea［J］. Geochimica et Cosmochimica Acta， 2017， 211： 153-173.
32	BROADBENT G C， MYERS R E， WRIGHT J V. Geology and origin of shale-hosted Zn-Pb-Ag mineralization at the Century deposit， northwest Queensland， Australia ［J］. Economic Geology， 1998， 93： 1 264-1 294.
33	KELLEY K D， DUMOULIN J A， JENNINGS S， et al. The Anarraaq Zn-Pb-Ag and barite deposit， northern Alaska： evidence for replacement of carbonate by barite and sulfides ［J］. Economic Geology， 2004， 99： 1 577-1 591.
34	MAGHFOURI S， HOSSEINZADEH M R， CHOULET F， et al. Vent-proximal sub-seafloor replacement clastic-carbonate hosted SEDEX-type mineralization in the Mehdiabad world-class Zn-Pb-Ba-（Cu-Ag） deposit， southern Yazd Basin， Iran ［J］. Ore Geology Reviews， 2019， 113. DOI：10.1016/j.oregeorev.2019.103047. doi: 10.1016/j.oregeorev.2019.103047
35	DERAKHSHI M G， HOSSEINZADEH M R， MOAYYED M， et al. Geological， isotope geochemical and fluid inclusion constraints on the Mishu SEDEX-type Barite （Pb-Cu-Zn） system， NW Iran ［J］. Ore Geology Reviews， 2020， 121. DOI：10.1016/j.oregeorev.2020.103493. doi: 10.1016/j.oregeorev.2020.103493

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[7]	李岩峰,曲国胜,张进. 弧形构造研究进展[J]. 地球科学进展, 2007, 22(7): 708-715.
[8]	冯军;李江海;牛向龙. 现代海底热液微生物群落及其地质意义[J]. 地球科学进展, 2005, 20(7): 732-739.
[9]	屈建军; 代枫年; 康国定; 王远萍; 张伟民. 鸣沙研究及其展望[J]. 地球科学进展, 1993, 8(4): 59-61.
[10]	李任伟. 分子地层学[J]. 地球科学进展, 1992, 7(2): 78-.
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摘要

Advance and Trend of the Vent-Distal SEDEX Lead-Zinc Deposits