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 共查询到20条相似文献，搜索用时 31 毫秒
1.
《《地质学报》英文版》2007,81(5):M0004-M0004
UPPer Mantle Craek Zones in the Eastern Part of North China YANG肠，，c(，i，ZH八入7G Xie，，，in‘了nd YU Chaz老gqiog(j了]了) An Analysis of SuPerPosed Deformation and Tectonie Stress Fields of the Western Segment of Daba Mountains Foretland SHI肠i，DONG Shuwe，;，HU Jianznin，Z产L今NG Zhong夕1 and LIU Gang(]了27少Quaterna即Normal Faulting and Its Dynamies of the oiga Graben in South·Eastern Tibet WU Zjlongh‘之i，Z厅魂NG Yongsl了z亡ang，HU Daogong，ZH乃0 Xitao a…  相似文献   

2.
N0.1ANewPlaty一annoredW6rmfiDmtheEarlyC出nbrianChen幻iangLagers巨“七,SouthChina Hanjia几刀盖口ng芍nglia雌,劝angZh诉1 and Shu DeganlANewsyn””etrodontManuna】withFurllnPressions加mtheMesozoieofChina “.””””””.”‘”“’““‘’.””·’‘·’二”””’“.‘.”···……”’‘”·”…‘Gui“e门”OWRougie‘JIQ勿昭andMichaelJ.Ndvacek7A New Genus of Psittacosauridae(Dinosauria:ornitho详对a) and the origin and Early Evolution of MarginocePhalian Din0SaUrS ..................…  相似文献   

3.
NO.1.I’reface………’··’…………’…………‘…··‘…………………………………………Zhal Yu。lleng(l)bteletal btructures and Classlflcatlon of the Order Cystlpbylllda(Rugosa)…………………………………… Wang I4ongzhen,He Yuan-clang and Chen Jlanqlang(3)I。oramlnlfera Blostratl匡raphy and Paleogeography of the T。rtlary In Tibet Was X laoqiao(15)Trace Fossils In Ngar。l{eglon,Xlzang(tibet)and their Sedimentary Environments………………………………………··‘……………………………h…  相似文献   

4.
Petroliferous Provinces in China and the World: A Compaison from Tectonic Point of View REN Jishun, DENG Ping, XIAO Liwei, NIU Baogui and WANG Jun (Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037) The comparison of petroliferous provinces of China with those of the world indicates marked differences beween them. The world’s oil and gas regions, which, in general, experienced monocyclic evolution in the geological history, are dominated by marine, e…  相似文献   

5.
Geochemical Characteristics of Fossil Ginkgo huttonii Cuticles from the Jurassic in Gansu, China，Diatoms of Lacustrine Sediments and Paleo-environments in Dahyab Tso (Taicuo) Lake, Xi‘zang (Tibet)，^40Ar/^39Ar Dating for the Strike-slip Movement on the Feidong Part of the Tanlu Fault Zone，Tectonic Origin of Klippen at the Foot of the Wuliangshan Thrust Belt, Western Yunnan……  相似文献   

6.
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7.
No.1 Studies of Ice Formatiom and Ice Fabric 0n the Law Dome,Antarctica…………………Xie Zichu(22)Analysis of Mieropartieles in Ice Cores:An Indicator of Past Environments………………………... ……………………-’…………………………………………………………………-Lonnie G.Thempson(32)Creep Behavior of Frozen Silt under Constant Uniaxial Stress..…..…….………….………………… ………………………………………………………………………………Z^“Yannfin and D。L.Carbee(48)Preliminary Stu…  相似文献   

8.
正The brine shrimp Artemia is often abundantly found in hypersaline environments.The larvae(‘nauplii’)hatching from its dormant embryos(‘cysts’)are a crucial live food item for the larval stages of fish and shrimp in aquaculture  相似文献   

9.
This paper summarises the geological features of the Larderello-Travale and Monte Amiata areas, where the world‘s most ancient exploited geothermal fields are located. In both geothermal areas, three regional tectonostratigraphic elements are distinguished, from the top: (a) Late Miocene-Pliocene and Quaternary,continental to marine sediments; (b) the Ligurian and Sub-Ligurian complexes, which include remnants of the Jurassic oceanic realm and of the transitional area to the Adriatic margin, respectively; (c) the Tuscan Unit(Tuscan Nappe), composed of sedimentary rocks rang-ing in age from Late Triassic to Early Miocene. The sub-stratum of the Larderello and Monte Amiata areas isreferred to as the Tuscan Metamorphic Complex. This ismainly known through drilling of geothermal wells. This complex is composed of two metamorohic units: the upper Monticiano-Roccastrada Unit and the lower Gneiss Complex. The Monticiano-Roccastrada Unit consists of(from top to bottom): the Verrucano Group,the Phyllite-Quartzite Group and the Micaschist Group.The Gneiss Complex consists only of pre-Alpine poly-metamorphic gneiss. The Tuscan Metamorphic Complexis affected by contact metamorphism by Plio-Quater-nary granitoids and their dy ke swarms. Hydrothermal phenomena still occur in both geothermal fields. The Larderello-Travale and Mt. Amiata geothermal fields are located in the inner Northern Apennines, in an area that has been subject to extension since the ?Early-Mid-dle Miocene. Two main extensional events are well expressed in the structures of the geothermal areas. The first extensional event (?Early-Middle Miocene) deter-mined the tectonic delamination of the Ligurian Units and Tuscan Nappe. The second extensional event (LateMiocene-Present) is characterized by high-angle nor-mal faults bounding the Neogene tectonic depressions of southern Tuscany.  相似文献   

10.
The term‘Ediacara Biota’(or many variants thereof)is commonly used to refer to certain megascopic fossils of Precambrian and early Palaeozoic age e but what does the term actually mean?What differentiates a non-Ediacaran‘Ediacaran’and an Ediacaran‘Ediacaran’from an Ediacaran non-‘Ediacaran’?Historically,the term has been used in either a geographic,stratigraphic,taphonomic,or biologic sense.More recent research and new discoveries,however,mean that the term cannot actually be defned on any of these bases,or any combination thereof.Indeed,the term is now used and understood in a manner which is internally inconsistent,and unintentionally implies that these fossils are somehow distinct from other fossil assemblages,which is simply not the case.Continued use of the term is a historical relic,which has led in part to incorrect assumptions that the‘Ediacara Biota’can be treated as a single coherent group,has obscured our understanding of the biological change over the PrecambrianeCambrian boundary,and has confused research on the early evolution of the Metazoa.In the future,the term‘Ediacaran’should be restricted to purely stratigraphic usage,regardless of affnity,geography,or taphonomy;suffcient terminology also exists where reference to specimens on a geographic,taphonomic,or biologic basis is required.It is therefore time to abandon the term‘Ediacara Biota’and to instead treat equally all of the fossils of the Ediacaran System.  相似文献   

11.
Sedimentary Suites(SDS)of Early St。la。P。nod in China………··、………M。ng Xiangkua。t al·(14).Meucd and ExamPles of Making maPs of World Reconstruu】onby a MlctocO*Puter·-·’··’··’·’…… ,……,……….、…………………………………………………··。,……··Li Xiang andZbang Lingkua(ZP)Geographic posit。on of the Qaidam Bio。k in L。ie Carboniferou。…·。…………·Li Yanpingetal.(32)Ontozenv of Homalophyllum Simpson,1900 and A SEM Study of itsMlcros发eletal 〕true…  相似文献   

12.
Cast thin section observation, scanning electron microscopy(SEM), high-pressure mercury injection(HPMI), and nuclear magnetic resonance(NMR) were used to examine the microstructure of tight carbonate reservoirs in the Lower Jurassic Da’anzhai Member, the central Sichuan Basin. The pore space in the Da’anzhai Member is classified into 2 types and 17 subtypes, with nano-scale pore throats of ‘O’, ‘S’, ‘Z’, and ‘I’ shapes. Poorly sorted pore throats vary greatly in diameter;thus, it is difficult for fluid flow to pass through these pore throats. There are three classes of pore throats in carbonate reservoirs, i.e. isolated pores, pores coexisting with fractures, and large pores and fractures. Isolated pores may provide some pore space, but the permeability is low. Pores and fractures coexisting in the reservoir may have a great impact on porosity and permeability;they are the major pore space in the reservoir. Large pores and fractures have a great impact on reservoir properties, but they only account for a limited proportion of total pore space. The microstructure of Da’anzhai reservoirs, which dominates fluid mobility, is dependent on sedimentary environment, diagenesis, and tectonic process. Pore structure is related to sedimentary environment. The occurrence of microfractures, which may improve reservoir properties, is dependent on tectonic process. Diageneses are of utmost importance to pore evolution, cementation and growth of minerals have played an important role in destroying reservoir microstructure.  相似文献   

13.
Detachment structures occur widely in the crust, and it is the commonest and most important deformation type developed in the region between orogenic belts and basins. The ‘comb-like’ and ‘tough-like’ fold belts in eastern Sichuan are caused by multi-layer detachment. The duplex structure is the most important deformation style in the region, exhibiting different characteristics from typical detachment structures. Different deformation styles, scales, and shortenings resulting from independent deformations of various detachment systems would lead to the phenomenon whereby most of the topographical heights in the region do not correspond to the structural heights in depth. Based on systematic structural analysis and combined with practical oil/gas prospecting, four types of structural traps are described from eastern Sichuan Province, which are: detachment and thrust trap; detachment folding trap; fault-flat blocking trap; and detachment layer trap. Meticulous studies on the deformation and distribution of detachment layers in the eastern Sichuan Province will contribute to oil/gas prospecting and selection of potential regions of marine-origin oil/gas prospecting in South China.  相似文献   

14.
Emergence of the Late Permian Changhsingian Reefs at theEnd of the PermianWU Yasheng, FAN Jiasong (Institute of Geology andGeophysics, Chinese Academy of Sciences, Beijing 100029);and JIN Yugan (Nanjing Institute of Geology and Paleontology,Chinese Academy of Sciences, Nanjing, Jiangsu 210008)Dolostones occur on the top of the reef core, reef front and backreef sequences of the Upper Permian The Changhsingian reef inZiyun County Guizhou Province, southwestern China.Comprehensive study on them reveals that these dolostones areof the supratidal Sabkha genesis: (1) All have δ~(18)O values higherthan those of their precursor limestones; (2) All have Sr and Fecontents similar to those of known typical supratidal Sabkhaevaporative finely crystalline dolostones from a well in theOrdos Basin, Shanxi-Gansu-Ningxia provinces, China; (3) Allare composed of finely crystalline euhedral-subhedral dolomites;  相似文献   

15.
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16.
This paper briefly introduces twenty-one versions of garnet-biotite Fe-Mg exchange geothermometry,points out the sources of systematic errors inherent in geothermometry.The sources lie in that:(1) ideal Fe-Mg mixing in garnet and biotite is assumed;(2)non-ideal properties of bot garnet and biotite are not considered completely;(3) minor elements-Mn, Ca in garnet,and Al^Ⅵ,Ti,Mn in biotite are almost neglected;(4)effects of pressure on equilibrium,although little,are almost not taken into consideration,and experiments were conducted at one fixed pressure;(5)the data used for egression analysis is too scarce in quantity;(6)internal consistency of the data used for empirical calibration is not fully guaranteed;(7) the authors take energy parameters W‘s(Margule‘s parametrs)independent of pressure and temperature,though the former are actually the functions of the latter items;and (8)the most important composition-activity relationship is not consistent with the mineral compositions used for calibration.Furthermore,it is believed that empirical calibrations cannot avoid the following problems;(1) effect of retrograde metamorphism;(2)inconsistent data set;(3)effect of pressure on temperature estimation;and (4)effect of Fe^3 calculation.Exact experimental work should be done in order to accurately calibrate the geotermometer in which the Margule‘s parameters should be treated as the functions of pressure,temperature,and mineral compositions.  相似文献   

17.
Inheritance and Innovation of Marine Petroleum Geological Theory in China JIN Zhijun and CAI Liguo(1024) Phanerozoic Tectonic Evolution of South China WANG Qingchen and CAI Liguo(1040) The Forecast of Natural Oil & Gas Potential in Marine Strata,Western Sichuan Basin,Southwest China  相似文献   

18.
Most ore-forming characteristics of the Langshan-Zha‘ertaishan hydrothermal exhalation belt, which consists of the Dongshengmiao, Huogeqi, Tanyaokou and Jiashengpan large-superlarge Zn-Pb-Cu-Fe sulfide deposits, are most similar to those of Mesoproterozoic SEDEX-type provinces of the world. The characteristics include: (1) All deposits of this type in the belt occur in third-order fault-basins in the Langshan-Zha‘ertaishan aulacogen along the northern margin of the North China Platform; (2) these deposits with all their orebodies hosted in the Mesoproterozoic impure dolomite-marble and carbonaceous phyllite (or schists) have an apparent stratabound nature; ores display laminated and banded structures, showing clear depositional features; (3) there is some evidence of syn-sedimentary faulting, which to a certain extent accounts for the temporal and spatial distribution and the size of the orebodies in all deposits and the formation of intrabed conglomerates and breccias; (4) they show lateral and vertical zonation of sulfides; (5) The Cu/(Pb Zn Cu) ratio of the large and thick Pb Zn Cu orebodies gradually decreases from bottom to top; and (6) barite is interbedded with pyrites and sometimes with sphalerite. However, some characteristics such as the Co/Ni radio of the pyrites, the volcanism, for example, of the Langshan-Zha‘ertalshan metallogenic belt, are different from those of the typical SEDEX deposits of the world. The meta-basic volcanic rock in Huogeqi, the sodic bimodal volcanic rocks in the Dongshengmiao and potassic bimodal-volcanic rocks with blastoporphyfitic and blasto-glomeroporphyritic texture as well as blasto-amygdaloidal structure in the Tanyaokou deposits have been discovered in the only ore-bearing second formation of the Langshan Group in the past 10 years. The metallogeny of some deposits hosted in the Langshan Group is closely related to syn-sedimentary volcanism based on the following facts: most of the lead isotopes in sphalerite, galena, pyrite, pyrrhotite and chalcopyrite plot on both sides of the line for the mantle or between the lines for the mantle and lower crust in the lead isotope composition diagram; cobalt content of some pyrites samples is much higher than the nickel content (Co/Ni= 11.91-12.19). Some volcanic blocks and debris have been picked out from some pyritic and pyrrhotitic ores. All Zn-Pb-Cu-Fe sulfide orebodies in these deposits occur in the strata overlying metamorphic volcanic rocks in the only ore-bearing second formation. In the Jiashengpan deposit that lacks syn-sedimentary volcanic rocks in the host succession only Pb and Zn ores occur without Cu ore, but in the Dongshengmiao, Tanyaokou and Huogeqi deposits with syn-sedimentary volcanic rocks in the host succession Cu ores occur. This indicates a relatively higher ore-forming temperature. The process of synsedimentary volcanic eruption directly supplied some ore-forming elements, and resulted in secular geothermal anomaly favorable for the circulation of a submarine convective hydrothermal system, which accounts for the precipitation of deep mineralizing fluids exhaling into anoxidic basins along the syn-sedimentary fault system in the Langshan-Zha‘ertai rift. The Dongshengmiao, Tanyaokou, and Huogeqi deposits hosted in the Langshan Group appear to be a transitional type of mineral deposit between SEDEX and VMS-types but with a bias towards SEDEX, while the Jiashengpan deposit hosted in the Zha‘ertai Group is of a characteristic SEDEX type. This evidence, together with other new discoveries of Mesoproterozoic volcanic rocks and the features of lithogeny and metallogeny of the Bayun Obo deposit in the neighborhood emphasize the diversity, complexity and uniqueness of the Mesoproterozoic Langshan-Zha‘ertal-Bayun Obo ore belt.  相似文献   

19.
The Quaternary Pan-lake (Overflow) Period and Paleoclimate on the Qinghai-Tibet Plateau ZHENG Miaping, YUAN Heran, ZHAO Xitao and LIU Xifang (1. R & D Center for SalineLake and Epithermal Deposit, Chinese Academy of Geological Sciences, Beijing 100037; 2. Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037; 3. Open Laboratory of Saline Lake Resources and Environment, Chinese Academy of Geological Sciences, Beijing 100037) Lake geomorpho…  相似文献   

20.
A New Study on the Stratotype and Biostratigraphy of the Yixian Stage in the Yixian-Beipiao Region, Liaoning --Establishment and Study of the Yixian StratotypeWANG Wuli, ZHANG Lijun, ZHENG Shaolin, ZHENG Yuejuan, ZHANG Hong, LI Zhitong and YANG Fanglin (Shenyang Institute of Geology and Mineral Resources, Shenyang, Liaoning 110032)  相似文献   

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