天山造山带中的侏罗纪地层、古环境与油气资源——以库米什盆地为例

自三叠纪以来,天山造山带在南—北向应力场的作用下,产生了一系列山间盆地,例如吐鲁番-哈密盆地、库米什盆地等。在这些盆地中广泛发育了中、新生代陆相碎屑岩沉积,特别是侏罗纪的沉积。侏罗系除上统为红层外,主要由暗色岩石组成。这些暗色岩石包括灰色、黑色泥、页岩,碳质泥岩和煤层,它们都具有较强的生烃能力。对沉积和植物、孢粉化石等材料的综合分析表明,在早、中侏罗世,天山区为低山—丘陵面貌和湿润的古气候环境。这种环境有利于煤的聚集和暗色泥岩的沉积。     

Scandium in the coals of Northern Asia (Siberia,the Russian Far East,Mongolia, and Kazakhstan)

We present new original data on the geochemistry of scandium in the coals of Asian Russia, Mongolia, and Kazakhstan. In general, the studied coals are enriched in Sc as compared with the average coals worldwide. Coal deposits with abnormally high, up to commercial, Sc contents were detected in different parts of the study area. The factors for the accumulation of Sc in coals have been identified. The Sc contents of the coals depend on the petrologic composition of coal basins (composition of rocks in their framing) and the facies conditions of coal accumulation. We have established the redistribution and partial removal of Sc from a coal seam during coal metamorphism. The distribution of Sc in deposits and coal seams indicates the predominantly hydrogenic mechanism of its anomalous concentration in coals and peats. The accumulation of Sc in the coals and peats is attributed to its leaching out of the coal-bearing rocks and redeposition in a coal (peat) layer with groundwater and underground water enriched in organic acids. The enrichment of coals with Sc requires conditions for the formation of Sc-enriched coal-bearing rocks and conditions for its leaching and transport to the coal seam. Such conditions can be found in the present-day peatland systems of West Siberia and, probably, in ancient basins of peat (coal) accumulation.     

Tien Shan,Pamir, and Tibet: History and geodynamics of phanerozoic oceanic basins

Geological and biogeographical data on the paleooceanic basins of the Tien Shan and High Asia are summarized. The oceanic crustal rocks in the Tien Shan, Pamir, and Tibet belong to the Tethian and Turkestan-Paleoasian systems of paleooceanic basins. The tectonic evolution of these systems in the Phanerozoic was not coeval and unidirectional. The sialic blocks of the future Tien Shan, Pamir, and Tibet were incorporated into the Eurasian continent during several stages. In the Late Ordovician and Silurian several microcontinents were preliminarily combined into the Kazakh-Kyrgyz continent as a composite aggregation. The territories of the Tien Shan and Tarim became a part of Eurasia after the closure of the Turkestan, Ural, and Paleotethian oceans in the Late Carboniferous and Early Permian. The territories of the Pamir, Karakorum, Kunlun, and most of Tibet attached to the Eurasian continent in the Triassic. The Lhasa and Kohistan blocks were incorporated into Eurasia in the Cretaceous, whereas Hindustan was docked to Eurasia in the Paleogene.     

Types,characteristics, and time–space distribution of molybdenum deposits in China

Molybdenum exploration activity in China has accelerated tremendously during the past decade owing to the continuous, increasing demand for Earth resources. China possesses the largest Mo reserves in the world (exceeding 19.6 Mt). The major ore deposits are of porphyry, porphyry–skarn, skarn, vein, and sedimentary types. Porphyry molybdenum deposits contain 77.5% of the Chinese Mo reserves, with lesser amounts in porphyry–skarns (13%), skarns (5.1%), and veins (4.4%). Exploitation of sedimentary-type molybdenum deposits thus far has been uneconomical. The six Mo provinces are in the Northeast China, Yanliao, Qinling–Dabie, middle–lower Yangtze River Valley, South China, and Sanjiang areas. We recognize six ore-forming periods: (1) Precambrian (>541 Ma), (2) Palaeozoic (541–250 Ma), (3) Triassic (250–200 Ma), (4) Jurassic–Early Cretaceous (190–135 Ma), (5) Cretaceous (135–90 Ma), and (6) Cenozoic (55–12 Ma). The abundance of Mo ore deposits in China reflects the occurrence of multiple periods of tectonism, involving interactions between the Siberian, North China, Yangtze, India, and Palaeo-Pacific plates. Precambrian molybdenum deposits are related to Mesoproterozoic volcanism in an extensional setting. Palaeozoic Cu–Mo deposits are related to calc-alkaline granitic plutons in an island arc or a continental margin setting. Triassic Mo deposits formed in the syn-collision–postcollision tectonic setting between the Siberian and North China plates and between the North China and Yangzi plates. Jurassic–Early Cretaceous molybdenum deposits formed along the eastern margin of Asia and are associated with the palaeo-Pacific plate-subduction tectonic setting. Cretaceous Mo deposits are related to high-K calc-alkaline granitic rocks and formed in a lithospheric thinning setting. Cenozoic molybdenum deposits formed in a collision setting between the Indian and Eurasian continents and the subsequent extensional setting.     

Episodic burial and exhumation of the southern Baltic Shield: Epeirogenic uplifts during and after break-up of Pangaea

Cratons are conventionally assumed to be areas of long-term stability. However, whereas Precambrian basement crops out across most of the Baltic Shield, Palaeozoic and Mesozoic sediments rest on basement in southern Sweden, and thus testify to a complex history of exhumation and burial. Our synthesis of published stratigraphic landscape analysis and new apatite fission-track analysis data reveals a history involving five steps after formation of the extremely flat, Sub-Cambrian Peneplain. (1) Cambrian to Lower Triassic rocks accumulated on the peneplain, interrupted by late Carboniferous uplift and exhumation. (2) Middle Triassic uplift removed the Palaeozoic cover along the south-western margin of the shield, leading to formation of a Triassic peneplain with a predominantly flat relief followed by deposition of Upper Triassic to Lower Jurassic rocks. (3) Uplift that began during the Middle Jurassic to earliest Cretaceous caused denudation leading to deep weathering that shaped an undulating, hilly relief that was buried below Upper Cretaceous to Oligocene sediments. (4) Early Miocene uplift and erosion produced the South Småland Peneplain with scattered hills. (5) Early Pliocene uplift raised the Miocene peneplain to its present elevation leading to reexposure of the sub-Cretaceous hilly relief near the coast. Our results thus provide constraints on the magnitude and timing of episodes of deposition and removal of significant volumes of Phanerozoic rocks across the southern portion of the Baltic Shield. Late Carboniferous, Middle Triassic and mid-Jurassic events of uplift and exhumation affected wide areas beyond the Baltic Shield, and we interpret them as epeirogenic uplifts accompanying fragmentation of Pangaea, caused by accumulation of mantle heat beneath the supercontinent. Early Miocene uplift affected north-west Europe but not East Greenland, and thus likely resulted from compressive stresses from an orogeny on the Eurasian plate. Early Pliocene uplift related to changes in mantle convection and plate motion affected wide areas beyond North-East Atlantic margins.     

Epithermal deposits in North Xinjiang, NW China

The North Xinjiang region (NW China) is an important part of the Central Asia Orogenic Belt, situated at the junction of Siberia, Tarim and Kazakhstan plates. It is an area characterized by multiple stages of Phanerozoic continental growth, during which several porphyry and epithermal systems were formed. The relationship of these mineral systems to the geodynamic evolution of the region has not yet been well understood. In this paper, we list the main geological characteristics of 21 significant epithermal precious and base metal deposits in North Xinjiang, and classify them into high-sulfidation and low-sulfidation styles, with the latter being predominant. We have selected seven epithermal deposits representing different styles formed under different tectonic regimes and discuss their geology and geochemistry in some detail. The deposit-scale geology and geochemistry of epithermal systems in North Xinjiang are essentially similar to those in other parts of the world. All epithermal deposits in North Xinjiang are hosted in volcanic rocks with ages ranging from Devonian to Triassic, with the Early Carboniferous volcanic sequences being the most important, followed by the Permian and Triassic. The Devonian–Early Carboniferous host rocks belong to the calc-alkaline series that developed in pre-collisional arc-back-arc basin systems; whereas the Permian–Triassic host volcanic rocks of shoshonite series formed in post-subduction regimes. Available isotopic ages of these epithermal systems cluster in two periods: Early Carboniferous (>320?Ma) and Late Carboniferous–Triassic (320–220?Ma), reflecting two metallogenic episodes that occurred during subduction-related accretion and post-subduction collision regimes, respectively. Accordingly, three groups of epithermal deposits in North Xinjiang can be recognized as (1) pre-collisional deposits without or with negligible collisional-related modification, (2) deposits formed in collision regime and (3) ore systems strongly overprinted by fluid flow in post-subduction collision regime.     

The Early Baikalian crystalline complex in the basement of the Dzabkhan microcontinent of the Early Caledonian orogenic area, Central Asia

Fragments of continental blocks or microcontinents are represented in the Early Caledonian orogenic area of Central Asia (or Early Caledonian superterrane); the largest of these are the Dzabkhan and Tuva-Mongolian microcontinents, with Early and Late Precambrian crystalline basements, respectively. In the linkage zone of these microcontinents, crystalline rocks of the Tarbagatai and Songino blocks that are considered as units of the Early Precambrian ensialic basement of the superterrane are also known. They are composed of strongly metamorphosed rocks formed during the Early Baikalian orogeny about 790 to 820 Ma. U-Pb zircon dating and Nd isotope studies revealed, within the northwestern Dzabkhan microcontinent, the Dzabkhan-Mandal zone of crystalline rocks associated with the Riphean crust-forming process. The age of the gneiss substrate of this zone is estimated as 1.3 to 0.86 Ga. An early episode of metamorphism is dated at about 856 ± 2 Ma. The data available so far indicate a heterogeneous structure of the Dzabkhan microcontinent basement represented by Early Precambrian and Early and Late Baikalian crystalline formations.     

蒙古国巴彦洪格尔铜金矿集区地质特征及成因

巴彦洪格尔地区位于蒙古国中部 ,由古生代俯冲体系构成。该体系包括前寒纪微板块 (白得拉格和伯得高尔构造带 )、逆冲蛇绿岩带、加积型沉积岩 (巴彦洪格尔和得扎格构造带 )和弧前沉积岩 (可汗盖构造带 )。巴彦洪格尔地区岛弧岩浆作用主要以早古生代钛铁矿系列和晚古生代磁铁矿系列花岗岩类为特征。许多诸如斑岩型、矽卡岩型及脉岩型等各种类型的热液矿床与这些花岗岩类伴生。该区四大矿床的 K Ar同位素测年显示 :南方 Cu Au斑岩型矿床、呼布金洪迪矽卡岩型 Cu Au矿床、罕乌尔含金剪切带和塔磁高尔伟晶岩 W Au矿床的形成年龄值分别为 2 40± 5 Ma、2 5 2± 5 Ma、2 83± 6 Ma、32 9± 7Ma。由此可见 ,前三个地区的矿床与二叠纪—三叠纪初期磁铁矿系列花岗岩类具亲缘关系 ,而塔磁高尔W— Au伟晶岩则与早石炭世钛铁矿系列花岗岩类具亲缘关系。斑岩型和矽卡岩型 Cu— Au矿化作用发生在二叠纪末期—三叠纪初期 ,此时紧随着安第斯型岛弧岩浆作用 ,发生了白得拉格和塔巴嘎泰微板块的碰撞。     

Geology and K-Ar Ages of the South, Huh Bulgiin Hundii, Saran Uul, Taats Gol and Han Uul deposits in the Bayankhongor Region, Mongolia

Abstract: The Bayankhongor region in central Mongolia consists of a Paleozoic subduction system including Precambrian microcontinents (Baidrag and Burd Gol zones), obducted ophiolites and accretionary sedimentary rocks (Bayankhongor and Dzag zones), and forearc sedimentary rocks (Khangay zone). Arc magmatism in the Bayankhongor region is characterized by dominance of Early Paleozoic ilmenite-series and Late Paleozoic magnetite-series granitoids. These granitoids accompany many hydrothermal deposits of such various types as porphyry, skarn and vein. K-Ar dating on four deposits in the region revealed that the South porphyry Cu-Au, Huh Bulgiin Hundii skarn Cu-Au, Han Uul shear zone-hosted Au and Taats Gol pegmatite W-Au deposits formed at 240±5 Ma, 252±5 Ma, 283±6 Ma and 329±7 Ma, respectively.
Thus the former three are related to the Permian to earliest Triassic magnetite-series granitoids, whereas the W-Au pegmatite at Taats Gol to the Early Carboniferous ilmenite-series granitoids. Porphyry and skarn Cu-Au mineralization occurred at latest Permian to earliest Triassic, when the Andean-type arc magmatism was immediately followed by the collision between the Baidrag and Tarbagatai microcontinents.     

库车坳陷三叠-侏罗纪烃源岩生气特征与生气模式

根据热解实验和动力学模拟计算结果,研究了塔里木盆地库车坳陷侏罗纪煤、煤系泥岩及三叠纪泥岩的生气特征与生气模式。结果表明,库车坳陷三叠-侏罗纪烃源岩具有良好的生气性,尤其在进入中、高热演化阶段,甲烷产率更高,且侏罗纪煤和煤系泥岩的甲烷产率要高于三叠纪泥岩。侏罗纪和三叠纪烃源岩均以生气为主,是库车坳陷的有效气源岩,但前者的生气贡献明显高于后者。      

The mesozoic evolution of the mino terrane, central Japan: A geologic and paleomagnetic synthesis

The Mino tectono-stratigraphic terrane, central Japan, underlain by Permian to Jurassic sedimentary and volcanic rocks of various origins, was formed through accretion processes associated with the Mesozoic sea-floor spreading. This conclusion has been reached mainly from the following reasoning:

1. (1) the entire boundary of this terrane is defined by tectonic belts with high-pressure metamorphic rocks and serpentinized ultramafic rocks,

2. (2) the chemistry and petrology of the Permian greenstones demonstrate their affinity with abyssal tholeiitic and alkalic basalts,

3. (3) the widespread, but chaotic, occurrence of Permian greenstones, Triassic cherts, and Jurassic siliceous shales in the younger Jurassic clastic rocks of this terrane suggests extensive post-depositional mixing of strata,

4. (4) the sedimentology of the Jurassic sandstones strongly suggests that they are turbidity-current deposits supplied from cratonic lands,

5. (5) the South-Pacific type fossil assemblage in the Mino terrane shows strong contrast with the North-Pacific type fossil assemblage of the adjacent terranes,

6. (6) the paleomagnetism of the Permian and Jurassic greenstones, the Triassic cherts, and the Jurassic siliceous shales implies long-distance northward drift in Cretaceous time of these rocks from their original low latitudinal regions.

Along with this northward migration, the Mino terrane was accreted with extensive internal deformation to northeast Asia including the present Hida terrane. Recent accumulation of paleomagnetic and paleontologic data in the Pacific peripheral regions appears to support the existence of many allochthonous terranes which migrated from the equatorial regions. The Mino terane may be regarded as one example of these Circum-Pacific allochthons.     

兴蒙造山带的基底属性与构造演化过程

为了解兴蒙造山带基底属性和多个构造体系演化与叠加历史,系统总结了近年来在基础地质研究中取得的新成果,并利用这些成果讨论了兴蒙造山带的基底属性与演化历史.兴蒙造山带是指我国东北地区古生代构造作用影响的地区,这些地区也遭受了中生代构造作用的叠加与改造.兴蒙造山带主要由微陆块和其间的造山带组成.虽然传统上认为属于前寒武纪结晶基底的地质体主要已解体为古生代和早中生代,但随着新太古代和古元古代地质体的相继发现,以及新生代玄武岩中幔源古元古代橄榄岩包体的发现,可以判定兴蒙造山带内微陆块应具有古老的前寒武纪基底,并且壳幔是耦合的.微陆块内部地壳增生以垂向增生为主,且主要发生在新元古代和中元古代,以及次要的新太古代和古生代.相反,陆块间造山带或岛弧地体的陆壳则以侧向增生为主,且主要发生在新元古代和古生代.额尔古纳地块与兴安地块的拼合发生在早古生代早期;兴安地块与松嫩地块的拼合发生在早石炭世晚期;松嫩地块与佳木斯地块的拼合发生在早古生代晚期,中生代早期又经历了裂解与再闭合的构造演化过程;华北克拉通北缘增生杂岩带与北方微陆块群的最终拼合发生在晚二叠世-中三叠世,古亚洲洋的最终闭合发生在中三叠世,且为剪刀式闭合.晚古生代晚期蒙古-鄂霍茨克大洋板块南向俯冲作用的发生以及早中生代(三叠纪-早侏罗世)的持续南向俯冲,控制了大兴安岭-冀北-辽西地区的岩浆活动,蒙古-鄂霍茨克大洋的闭合发生在中侏罗世,晚侏罗世-早白垩世主要表现为闭合后的伸展环境.古太平洋板块中生代的俯冲起始时间为早侏罗世,晚侏罗世-早白垩世早期东北亚陆缘主要表现为走滑的构造属性和陆缘地体从低纬度到高纬度的构造就位过程,早白垩世晚期-古近纪岩浆作用的向东收缩揭示了古太平洋板块的持续俯冲和俯冲板片的后撤过程,古近纪晚期日本海的打开标志着东北亚陆缘从活动陆缘已经转变为沟-弧-盆体系,并且标志着东亚大地幔楔的形成.     

Formation and evolution of the Eastern Kunlun Range,northern Tibet: Evidence from detrital zircon U-Pb geochronology and Hf isotopes

The Eastern Kunlun Range, as a high-elevation and granitoid-rich tectonic element in northern Tibet, records Paleozoic–Mesozoic amalgamation process of the East Asia continent and Cenozoic uplift of the Tibetan Plateau. However, Precambrian evolution of the Eastern Kunlun remains poorly understood and relations between Eastern Kunlun and adjacent terranes (e.g., Qaidam and Qilian) during the Phanerozoic accretion process are still highly controversial. We use detrital zircon U-Pb geochronological and Hf isotopic data of Proterozoic and Paleozoic metasedimentary rocks from the Eastern Kunlun Range, to reconstruct its origin and subsequent evolutionary history. Detrital zircons of the Proterozoic rocks are dominated by early–middle Neoproterozoic ages (700–1000 Ma), with two age peaks at ca. 800 Ma and ca. 920 Ma and εHf(t) values ranging from −10 to 5. The youngest detrital zircon ages (648–788 Ma) demonstrate that these investigated Proterozoic strata, which were previously mapped as Paleoproterozoic to Mesoproterozoic, were most likely deposited in the middle–late Neoproterozoic. Abundant 0.9–1.0 Ga detrital zircon crystals are consistent with those crystalline rocks of similar ages across the Kunlun-Qaidam and Qilian terranes, which are generally interpreted as the product of Grenvillian orogenesis. These findings support the hypothesis that these terranes were probably within a single continental landmass (named as KQQ block) during the Neoproterozoic. The high similarity of detrital zircon ages, Hf isotopes and Neoproterozoic lithostratigraphy between western Yangtze and KQQ blocks, supports a temporary connection of the KQQ block to western Yangtze in Rodinia supercontinent. Detrital zircons of the analyzed Paleozoic rocks are characterized by 390–490 Ma age populations. These results, in combination with published granitoids data of the northern Tibet, favor a scenario in which the Kunlun-Qaidam and Qilian terranes underwent separated subduction and accretion processes during the late Cambrian–Devonian, but together formed an upper plate to northward subduction of the Paleo-Tethys during the Permian–Triassic.     

The Karoo Basin of South Africa: type basin for the coal-bearing deposits of southern Africa

The coal-bearing sediments and coal seams of the Karoo Basin, Southern Africa are described and discussed. The Karoo Basin is bounded on its southern margin by the Cape Fold Belt, onlaps onto the Kaapvaal Craton in the north and is classified as a foreland basin. Coal seams are present within the Early Permian Vryheid Formation and the Triassic Molteno Formation.The peats of the Vryheid Formation accumulated within swamps in a cool temperate climatic regime. Lower and upper delta plain, back-barrier and fluvial environments were associated with peat formation. Thick, laterally extensive coal seams have preferentially accumulated in fluvial environments. The coals are in general inertinite-rich and high in ash. However, increasing vitrinite and decreasing ash contents within seams occur from west to east across the coalfields. The Triassic Molteno coal seams accumulated with aerially restricted swamps in fluvial environments. These Molteno coals are thin, laterally impersistent, vitrinite-rich and shaly, and formed under a warm temperate climatic regime.Palaeoclimate, depositional systems, differential subsidence and basin tectonics influence to varying degrees, the maceral content, thickness and lateral extent of coal seams. However, the geographic position of peat-forming swamps within a foreland basin, coupled with basin tectonics and differential subsidence are envisaged as the primary controls on coal parameters. The Permian coals are situated in proximal positions on the passive margin of the foreland basin. Here, subsidence was limited which enhanced oxidation of organic matter and hence the formation of inertinitic coals. The coals in this tectonic setting are thick and laterally extensive. The Triassci coals are situated within the tectonically active foreland basin margin. Rapid subsidence and sedimentation rates occurred during peat formation which resulted in the preservation of thin, laterally impersistent, high ash, vitrinite-rich, shaly coals.     

微陆块属性厘定的依据——以中亚造山带南缘中段为例

造山带中残存有许多前寒武纪地质体,其中一些被当作前寒武纪基底用于探讨所在微陆块的大地构造属性。由于微陆块属性对于造山带结构和演化具有重要意义,以及所讨论的前寒武纪地质体蕴含地球早期历史演化信息,对微陆块属性的厘定成为造山带研究的重点和难点问题之一。笔者等以中亚造山带南缘中段的微陆块为例,总结梳理了微陆块厘定的相关依据：岩石组合和变质变形特征,碎屑锆石谱峰显示的源区时代特征,地质事件序列,前寒武纪地壳演化信息,继承锆石、捕获锆石和古生代侵入体同位素显示的深源地壳信息,以及地球物理等方面的特征。由于不同学者采用的厘定依据不同,对微陆块属性认识争论不断,即使相同依据也有一定的差异,从而影响对造山带结构和演化的认识。基于以上原因,笔者等认为前寒武纪基底的亲缘性探讨不仅要注重岩石组合和形成时代,还要在精细野外解剖和高精度年代学工作基础上,注意其变质—变形特征、接触关系、源区时代特征、岩石成因和构造环境、地壳增生信息和深源地壳信息等的综合对比分析,以得到较全面依据,探讨其构造属性。当获得一组前寒武纪地质体信息时,可先进行同构造单元内对比,再与其他构造单元对比。当特征相异时则需进行构造单元拆分或考虑构造就位的可能（包括但不限于推覆体、走滑外来体、俯冲刮削的构造岩片）;当特征相似时,可能指示了相同微陆块的裂解或破坏或者不同的微陆块共同经历了相似的前寒武纪演化历程。     

大兴安岭中部乌兰浩特地区中生代花岗岩的锆石U-Pb年龄及地质意义

大兴安岭中生代花岗岩浆作用的时间和期次的确定对讨论东北地区中生代的构造-岩浆演化具有重要意义。本文采用激光ICP-MS技术进行锆石U-Pb年龄测定的结果表明,大兴安岭中部乌兰浩特-索伦地区的中生代花岗岩浆活动可以划分为3期:中-晚三叠世花岗岩岩浆侵位结晶年龄为235-225Ma;早-中侏罗世花岗岩岩浆侵位结晶年龄为182-175Ma;早白垩世花岗岩岩浆侵位结晶年龄为140-125Ma,与该区广泛分布的中生代火山岩时代一致。该区花岗岩的年代学格架与松辽盆地东缘的张广才岭-小兴安岭地区完全可以对比。花岗岩中的捕获锆石具有与额尔古纳地块新元古代花岗岩一致的的年龄信息(-800Ma),反映该区曾经具有前寒武纪结晶基底。结合岩石学特征和邻区的其它地质资料,该区三叠纪花岗岩的形成可能与古亚洲洋闭合造山后的岩石圈伸展体制有关,侏罗纪花岗岩可能是佳木斯地块西缘洋壳俯冲及与松嫩地块拼合作用的产物,而早白垩世花岗岩的形成则与板内拉张性构造体制有关。     

Mineral matter in triassic and tertiary low-rank coals from South Australia

The minerals and non-mineral inorganic constituents in Triassic and Tertiary low-rank coals from various coal deposits in South Australia were studied using selective chemical leaching and oxygen-plasma ashing techniques. Although gypsum may be present in some samples, most of the sodium, calcium and magnesium, as well as part of the sulphur, appears to occur as a combination of dissolved ions in pore water and exchangeable ions attached to carboxylate groups. Significant concentrations of iron and aluminium occur in acid-soluble form, probably as organometallic complexes within the hydrocarbon structure.Quartz is the dominant mineral in the Tertiary coal samples. It appears to be mainly detrital, but doubly terminated euhedral crystals suggest an authigenic origin in one of the deposits. Well crystallized kaolinite is common in the Triassic coals, while poorly crystallized kaolinite occurs in the Tertiary samples. Siderite, calcite and possibly collophane occur in the Triassic coals; sparse pyrite is present in both the Tertiary and the Triassic samples.The differences in minerals and other inorganic constituents between the Tertiary and Triassic deposits can be explained partly by variations in the composition of the pore waters permeating the strata, and partly by mobility of silica and alumina from different sources within the peat deposit. The relative mobility of the different inorganic constituents is also significant in beneficiation of the coal for use in combustion processes.     

青海聚乎更矿区侏罗纪含煤岩系层序地层研究

运用钻井岩心及层序地层学有关理论、方法，对木里煤田聚乎更矿区中侏罗统含煤岩系进行了层序地层学研究，共识别包括区域不整合面、河流下切谷及河道间6个层序界面，将侏罗系含煤岩系划分为5个三级层序。全区发育的厚煤层常横跨不同相区连续分布（如下．煤层），厚煤层的形成主要受控于可容空间的增加速率与泥炭堆积速率的关系。陆相含煤盆地三级层序湖侵体系域聚煤作用最好，煤层厚度的变化则与煤层下伏沉积相有一定关系。     

湖南省成矿地质事件纲要

[研究目的]湖南省矿产资源丰富,矿种及成因类型繁多,但对各类矿产形成的时代和构造背景尚缺乏系统归纳和总结.[研究方法]本文在既有区域矿产资料基础上,结合近些年区域构造演化、成岩成矿年龄、矿床成因机制等研究成果,对湖南省成矿地质事件及各期成矿事件的构造背景、矿床成因、矿产发育和分布特征等进行了系统探讨和总结.[研究结果]...