In this research,tectonics is integrated with coal geology to propose a new frontier,coal-forming tectonics.It is a science dealing with, from a tectonic point of view,the process of coal accumulation and the temporal and spatial distribution pattern of coal deposits.Tectonic coal-accumulating units are classified into three classes:domains,zones and basins.This research,taking China as an example,dwells upon problems related to coal-forming structures and has led to the following results.①According to tectonic settings,coal-accumulating basins and coal-bearing formations have been divided into three types:geosynclinal,platform and diwa.They may be subdivided into 10 genetic types(the former)and 15 genetic styles(the latter).②This research has revealed the control of paleotectonics on coal accumulation and confirmed that stable tectonic settings are favourable for coal accumulation.Of the total humic coal amount platform type accounts for 87%,diwa type for 13%,and geosynclinal type is almost barren of economically valuable coal beds.60% of China s and 70% of the world s coal resources concentrate on marginal troughs
of platforms.③From a global coal-forming tectonic point of view,this research has elucidated the coal-forming tectonic evolutionary history and the temporal and spatial distribution pattern of coal-accumulating basins of China from Late Proterozoic sapropelite to Tertiary lignite(including peat).Late Paleozoic,Meso-zoic and Cenozoic coal-forming tectonic structures have been divided into 4,2 and 1 coal-accumulating domains respectively.They have been further subdivided into coal-accumulating zones(subzones)and basins.In the Mesozoic Pal-Asiatic continental coal-accumulating domain,for example,the Juggar coal basin(including Turfan,J1-2) of the Northwest China coal-accumulating zone and the Ordos coal basin(C-O,T3,and J1-2)of the N-S coal-accumulating zone are the world-class giant coal basins.This research has also satisfactorily explained why sapropelite only occurs in the South China-Yangtze coal-accumulating domain.
④It has proposed for the first time the concept of marine tectonic coal-accumulating zone and put forward arguments in favour of occurrence of coal resources in China s sea areas.There are about 100 coal beds in the Tertiary of the East China Sea continental shelf,with a single coal bed attaining 3～4 m in thickness.
The metamorphic grade of coal increases with depth(peat within 600 m,lignite within 1 600 m,long-flame coal within 3 700 m,gas coal below 4 700 m and coke below 5 000 m).The gas field Ya 13-1 in the South-east Hainan Basin,the South China Sea,is the largest humic-type gas field in China s sea areas.⑤Four maps such as theDeep Structures and Meso-Cenozoic Tectonic Coal-accumulating Domains and Zones of China and Adjacent Areashave been compiled and control of deep structural pattern on coal-accumulating basins and its evolutionary mechanism have been discussed.⑥The term coal-forming tectono-geochemistry has been coined which indicates that different coal-bearing formations,folds,fractures and rock bodies differ from each other in coal-forming geochemical features.⑦According to the degree of tectonic destruction and origin,the structural superimposition and transformation of coal-accumulating basins have been divided into three types:geosyncline+transformation,platform+transformation and diwa+transformation.They may be further subdiveded into subtypes,weak,medium and trong.⑧Problems pertinent to coal-forming tectonic settings have been discussed.For example,it is believed from a catastrophic point of view that the large-scale catastrophic event occurring between P and T destroyed the paleoclimatic and paleofloral environments of Late Permian coal formation on Earth and resulted in a non-coal period lasting 20 Ma.⑨The theory has been applied to the prediction and evaluation of coal resources in the whole world,in a large region or in a coal basin.Coal-forming tectonics not only enriches the contents of tectonics,but also promotes the development of coal geology.