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1.
The Mesozoic basins in Yanshan, China underwent several important tectonic transformations, including changes from a pre-Late Triassic marginal cratonic basin to a Late Triassic-Late Jurassic flexural basin and then to a late Late Jurassic-Early Cretaceous rift basin. In response to two violent intraplate deformation at Late Triassic and Late Jurassic, coarse fluvial depositional systems in Xingshikou and Tuchengzi Formations were deposited in front of thrust belts. Controlled by transform and extension faulting, fan deltas and lacustrine systems were deposited in Early Cretaceous basins. The composition of clastic debris in Late Triassic and Late Jurassic flexural basins respectively represents unroofing processes from Proterozoic to Archean and from early deposited, overlying pyroclastic rocks to basement rocks in provenance areas. Restored protobasins were gradually migrated toward nearly NEE to EW-trending from Early Jurassic to early Late Jurassic. The Early Cretaceous basins with a NNE-trending crossed over early-formed basins. The Early-Late Jurassic and Early Cretaceous basins were respectively controlled by different tectonic mechanisms. 相似文献
2.
Mesozoic radiolarian chert from the middle sector of the Yarlung Zangbo suture zone,Tibet and its tectonic implications 总被引：1，自引：1，他引：1
ZHU Jie DU Yuansheng LIU Zaoxue FENG Qinglai TIAN Wangxue LI Jinping WANG Changping 《中国科学D辑(英文版)》2006,49(4):348-357
The middle sector of the Yarlung Zangbo suture zone stretches over 200 km long from Ngamring through Geding to Rinbung, roughly along Yarlung Zangbo River valley (Fig. 1). This belt resulted from the closure of the Tethyan ocean and the collision be- tween Indian plate and Lhasa block[1―8]. Lots of works demonstrated that rifting of the Tethyan basin in southern Tibet started from Triassic time. Initial oce- anic crust appeared in the Late Jurassic, and then ex- perienced a rapid sprea… 相似文献
3.
The Sichuan Basin is a superimposition basin composed of terrestrial and marine sediments that is well known for its abundant petroleum resources. Thermal history reconstruction using paleogeothermal indicators, including vitrinite reflectance and thermochronological data, shows that different structural subsections of the Sichuan Basin have experienced various paleogeothermal episodes since the Paleozoic. The lower structural subsection comprising the Lower Paleozoic to Middle Permian (Pz-P2 successions experienced a high paleogeothermal gradient (23.0–42.6°C/km) at the end of the Middle Permian (P2, whereas the upper structural subsection comprising Late Permian to Mesozoic strata underwent a relatively lower paleogeothermal gradient (13.2–26.9°C/km) at the beginning of the denudation (Late Cretaceous or Paleocene in the different regions). During the denudation period, the Sichuan Basin experienced a successive cooling episode. The high paleogeothermal gradient resulted from an intensive thermal event correlated to the Emeishan mantle plume. The heat flow value reached 124.0 mW/m2 in the southwestern basin near the center of the Emeishan large igneous province. The low geothermal gradient episode with heat flow ranging from 31.2 to 70.0 mW/m2 may be related to the foreland basin evolution. The cooling event is a result of the continuous uplift and denudation of the basin. 相似文献
4.
潮汕坳陷MZ-1井揭示的中生界为深入分析南海北部晚中生代的构造演化提供了关键性的资料.基于MZ-1井的标定,开展了系统的地震剖面构造-地层解释,在中生代地层内识别出Tm30区域性不整合面,同位素定年确定该界面发育于早白垩世末至晚白垩世初,落实了潮汕坳陷上白垩统的分布.此外,在研究区西南部识别出大型的兴宁—东沙逆冲推覆带,主要由多条NW—SE向延伸、西倾的叠瓦状逆冲断层及其伴生的不对称褶皱组成,其明显控制了上白垩统厚度分布.由此可见,上白垩统构造层不具有张裂盆地的典型特征,因此南海北部主动陆缘向被动陆缘的转换不会早于晚白垩世末.研究认为,在南海地区特提斯残留洋盆关闭的总背景下,在约80 Ma时期,南海地块与华南陆块强烈碰撞挤压,在靠近碰撞带处的礼乐滩、潮汕坳陷西南部形成褶皱冲断构造体系,进而控制了潮汕坳陷晚白垩世周缘前陆盆地的发育. 相似文献
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WeiLin Zhu XiNong Xie ZhenFeng Wang DaoJun Zhang ChengLi Zhang LiCheng Cao Lei Shao 《中国科学:地球科学(英文版)》2017,60(12):2214-2222
The study of basement geochronology provides crucial insights into the tectonic evolution of oceans. However, early studies on the basement of the Xisha Uplift were constrained by limited geophysical and seismic data; Xiyong1 was the only commercial borehole drilled during the 1970 s because of the huge thickness of overlying Cenozoic strata on the continental margin. Utilizing two newly-acquired basement samples from borehole XK1, we present petrological analysis and zircon uranium(U)-lead(Pb) isotope dating data in this paper that enhance our understanding of the formation and tectonic features of the Xisha Uplift basement. Results indicate that this basement is composed of Late Jurassic amphibole plagiogneisses that have an average zircon 206 Pb/238 U age of 152.9±1.7 Ma. However, the youngest age of these rocks, 137±1 Ma, also suggests that metamorphism termination within the Xisha basement occurred by the Early Cretaceous. These metamorphic rocks have adamellites underneath them which were formed by magmatic intrusions during the late stage of the Early Cretaceous(107.8±3.6 Ma). Thus, in contrast to the Precambrian age(bulk rubidium(Rb)-strontium(Sr) analysis, 627 Ma) suggested by previous work on the nearby Xiyong1 borehole, zircons from XK1 are likely the product of Late Mesozoic igneous activity. Late Jurassic-Early Cretaceous regional metamorphism and granitic intrusions are not confined to Xisha; rocks have also been documented from areas including the Pearl River Mouth Basin and the Nansha Islands(Spratly Islands) and thus are likely closely related to large-scale and long-lasting subduction of the paleo-Pacific plate underneath the continental margins of East Asia, perhaps the result of closure of the Meso-Tethys in the South China Sea(SCS). Controversies remain as to whether, or not, the SCS region developed initially on a uniform Precambrian-aged metamorphic crystalline basement. It is clear, however, that by this time both Mesozoic compressive subduction and Cenozoic rifting and extension had significantly modified the original basement of the SCS region. 相似文献
8.
本文综合运用磷灰石-锆石裂变径迹和（U-Th）/He、镜质体反射率及盆地模拟等手段,深入细致地探讨了中扬子江汉平原簰洲湾地区中、新生代构造-热史演化过程.研究结果表明,研究区中-新生代大规模构造抬升剥蚀、地层冷却事件始于早白垩世（140-130 Ma）;大规模抬升冷却过程主要发生在早白垩世中后期至晚白垩世.研究区虽然可能存在一定厚度的晚白垩世-古近纪地层沉积,总体沉积规模相对较小.综合分析认为,区内应该存在较大厚度的中侏罗统或/和上侏罗统乃至早白垩世地层的沉积;而现今残存中生代中、上侏罗统地层相对较薄,主要是由于后期持续构造抬升剥蚀造成的,估计总剥蚀厚度约4300 m左右.区内中生代地层在早白垩世达到最大古地温,而不是在古近纪沉积末期;上三叠统地层最大古地温在170~190℃之间.热史分析结果表明,区内古生代古热流相对稳定,平均热流在53.64 mW·m-2;早侏罗世末期古热流开始降低,在早白垩世初期古热流约为48.38 mW·m-2. 相似文献
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Deformation of the Circum-Rhodope Belt Mesozoic (Middle Triassic to earliest Lower Cretaceous) low-grade schists underneath an arc-related ophiolitic magmatic suite and associated sedimentary successions in the eastern Rhodope-Thrace region occurred as a two-episode tectonic process: (i) Late Jurassic deformation of arc to margin units resulting from the eastern Rhodope-Evros arc–Rhodope terrane continental margin collision and accretion to that margin, and (ii) Middle Eocene deformation related to the Tertiary crustal extension and final collision resulting in the closure of the Vardar ocean south of the Rhodope terrane. The first deformational event D1 is expressed by Late Jurassic NW-N vergent fold generations and the main and subsidiary planar-linear structures. Although overprinting, these structural elements depict uniform bulk north-directed thrust kinematics and are geometrically compatible with the increments of progressive deformation that develops in same greenschist-facies metamorphic grade. It followed the Early-Middle Jurassic magmatic evolution of the eastern Rhodope-Evros arc established on the upper plate of the southward subducting Maliac-Meliata oceanic lithosphere that established the Vardar Ocean in a supra-subduction back-arc setting. This first event resulted in the thrust-related tectonic emplacement of the Mesozoic schists in a supra-crustal level onto the Rhodope continental margin. This Late Jurassic-Early Cretaceous tectonic event related to N-vergent Balkan orogeny is well-constrained by geochronological data and traced at a regional-scale within distinct units of the Carpatho-Balkan Belt. Following subduction reversal towards the north whereby the Vardar Ocean was subducted beneath the Rhodope margin by latest Cretaceous times, the low-grade schists aquired a new position in the upper plate, and hence, the Mesozoic schists are lacking the Cretaceous S-directed tectono-metamorphic episode whose effects are widespread in the underlying high-grade basement. The subduction of the remnant Vardar Ocean located behind the colliding arc since the middle Cretaceous was responsible for its ultimate closure, Early Tertiary collision with the Pelagonian block and extension in the region caused the extensional collapse related to the second deformational event D2. This extensional episode was experienced passively by the Mesozoic schists located in the hanging wall of the extensional detachments in Eocene times. It resulted in NE-SW oriented open folds representing corrugation antiforms of the extensional detachment surfaces, brittle faulting and burial history beneath thick Eocene sediments as indicated by 42.1–39.7 Ma 40Ar/39Ar mica plateau ages obtained in the study. The results provide structural constraints for the involvement components of Jurassic paleo-subduction zone in a Late Jurassic arc-continental margin collisional history that contributed to accretion-related crustal growth of the Rhodope terrane. 相似文献
10.
Chen Bo Zhang ChangMin Luo MingXia Lei QingLiang Han DingKun Zhou XiaoJun 《中国科学:地球科学(英文版)》2010,52(1):77-87
The Cretaceous in southern China is mainly a set of red and mauve clastic rock, with evaporation layers. For lack of source rock, it has been paid little attention to in the exploration process. With the development of research on hydrocarbon exploration, the masses of Cretaceous reservoirs and shows have been found in recent years. This means that the Cretaceous has great exploration potential. According to the research, authors find that the high-quality reservoir and efficient cap rocks develop in the Cretaceous. At the same time, the Cretaceous and underlying Paleozoic-Early Mesozoic marine strata and overlying Cenozoic nonmarine strata constitute a superimposed basin. Moreover, high-quality source rocks developed in the above-mentioned two sets of strata. In the south, especially in the middle and lower Yangtze region since the Himalayan strong rift was associated with a large number of faults, These faults connect the Cretaceous reservoir and its overlying and underlying source rocks, forming the fault-based and unconformity-based discontinuous source-reservoir-cap accumulation assemblages. Because the Cretaceous has the abundant oil and gas from Paleogene source rocks or Mesozoic-Paleozoic source rocks with secondary hydrocarbon generation ability, three types of reservoirs develop in the Cretaceous: “new-generating and old-reservoiring” reservoirs, “old-generating andnew-reservoiring” reservoirs, and few “self-generating andself-reservoiring” reservoirs. The hydrocarbon enrichment depends on two key factors. Firstly, Cretaceous reservoirs are near to the source kitchens, so its oil and gas source is ample. Secondly, the fault system is well developed, which provides the necessary conducting systems for hydrocarbon accumulation.
相似文献11.
The Late Mesozoic-Cenozoic volcanism of the Tugnui-Khilok sector in the western Transbaikalia rift area is related to the development of the Tugnui, Tsolgin, Margentui, and Khilok grabens and is characterized by a north-south migration of magmatic centers. In these grabens, the igneous associations are composed of high-alkaline rocks: alkaline and subalkaline basalts, tephrites, phonolites, trachytes, trachyrhyolites, comendites and pantellerites, alkaline syenites and alkaline gabbroids. These associations are known to have formed during 10 stages: Late Jurassic (150–158 Ma), Late Jurassic-Early Cretaceous (139–147 Ma), the beginning of the Early Cretaceous (133–145 Ma), mid-Early Cretaceous (115–134Ma), the end of the Early Cretaceous (104–114 Ma), the end of the Early-beginning of Late Cretaceous (99–102 Ma), Late Cretaceous (72–90 Ma), Eocene (38–48 Ma), Early Oligocene (30–35 Ma), and Late Oligocene (25–27 Ma). The composition of igneous associations was changing in such a way that the relative amount of salic rocks gradually decreased (occasionally even disappeared completely) in the later developmental stages. As well, the content of SiO2 in basic rocks also decreased with increasing Nb and Ta contents, and depletion occurred in the lithophylic elements Rb, K, Ba, Sr, and in light rare-earths relative to heavy ones. The geochemical and isotope-geochemical parameters of basaltoids change through time, probably due to successive changes in the mantle sources of magmatism. During Mesozoic time, the source composition was consistent, with OIB-EM-II sources enriched in radiogenic strontium, but since the second half of the Cretaceous, the isotope composition began to be modified toward moderately depleted sources of the OIB-PREMA type. 相似文献
12.
First record of microsporophyll genus Caytonanthus Thomas from Early Cretaceous beds of South Rewa Gondwana Basin,India: Its evolutionary and palaeogeographical significance 
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下载免费PDF全文 Pteridosperms (seed ferns) are an extinct group of large and diverse plants. They were dominant elements during Palaeozoic and were also an important component in the Mesozoic vegetation but declined globally in the Cretaceous time with the radiation of angiosperms. The order Caytoniales of Mesozoic pteridosperm is an extinct group of seed ferns in the vegetation. They thrived for about 100 million years from the Late Triassic to the Late Cretaceous. Although they never attained dominant status, their rare occurrence in the vegetation is quite important and fascinating. For this extinct group of seed fern, Thomas ( 1925 ) erected a new order Caytoniales which includes three organ genera Caytonia (megasporophyll), Caytonanthus (microsporophyll) and Sagenopteris (leaves). This paper is aimed to document first record of microsporophyll genus Caytonanthus, obtained from the Lower Cretaceous beds of the South Rewa Gondwana Basin of the Indian Peninsula. Its morpho‐characters, palaeogeographic distribution, along with its plausible southern origin through ancestral group like Glossopteridales, are surmised here. 相似文献
13.
Yong I. Lee 《Island Arc》2008,17(4):458-470
The currently available paleogeographic maps of the East Asia continental margin during the Mesozoic have been recast in the light of recent research results on sediments distributed in Korea and Japan. Both the Korean peninsula and the Inner zone of Southwest Japan exchanged sediment supply during the Middle to Late Mesozoic, suggestive of a close paleogeographic relationship between the two countries at the active continental margin setting. During the latest Middle to earliest Late Jurassic the Mino–Tamba trench was developed along the southeastern Korean peninsula, from which trench‐fill sediments were sourced and to which an accretionary complex was accreted. Lower Cretaceous quartz‐arenite clasts of the Tetori Group in the Hida Marginal Belt of Southwest Japan were derived from pre‐Mesozoic quartz‐arenite strata distributed in the southern central and east central Korean peninsula, suggesting that the Tetori Basin was located close to the central eastern part of the Korean peninsula at the time of deposition of quartz‐arenite clasts, contrary to conventional thought of far distance between the two areas based on paleomagnetic data. During the early Late Cretaceous radiolaria‐bearing chert pebbles and sands in the northern part of the non‐marine Gyeongsang Basin distributed in the southeastern Korean peninsula were derived from the uplifted Mino–Tamba accretionary complex distributed in southwest Japan, suggesting that the Mino–Tamba terrane was land‐connected with the eastern Korean peninsula. These new findings suggest that in contrast to conventional thought, the collage of tectonic blocks in Southwest Japan has assembled in post‐early Late Cretaceous time. 相似文献
14.
The Yezo Group has a wide longitudinal distribution across Hokkaido, northern Japan. It represents a Cretaceous (Early Aptian–Late Maastrichtian) and Late Paleocene forearc basin‐fill along the eastern margin of the paleo‐Asian continent. In the Nakagawa area of northern Hokkaido, the uppermost part of the Yezo Group consists of the Hakobuchi Formation. Along the western margin of the Yezo basin, 24 sedimentary facies (F) represent 6 facies associations (FA), suggesting prevailing storm‐dominated inner shelf to shoreface environments, subordinately associated with shoreface sand ridges, outer shelf, estuary and fluvial environments. The stacking patterns, thickness and facies trends of these associations allow the discrimination of six depositional sequences (DS). Inoceramids Sphenoceramus schmidti and Inoceramus balticus, and the ammonite Metaplacenticeras subtilistriatum, provide late Early to Late Campanian age constraints to this approximately 370‐m thick final stage of deposition and uplift of the Yezo forearc basin. Six shallow‐marine to subordinately non‐marine sandstone‐dominated depositional sequences include four 10 to 110‐m thick upward‐coarsening regressive successions (FS1), occasionally associated with thin, less than 10‐m thick, upward‐fining transgressive successions (FS2). The lower DS1–3, middle DS4–5 and upper DS6 represent three depositional sequential sets (DSS1–3). These eastward prograding and westward retrograding recurring shallow‐marine depositional systems may reflect third‐ and fourth‐order relative sealevel changes, in terms of sequence stratigraphy. 相似文献
15.
Tectonic thermal history and its significance on the formation of oil and gas accumulation and mineral deposit in Ordos Basin 总被引：1，自引：0，他引：1
The analyzing data on stratigraphic temperature measurement, thermal conductivity of the strata and radioactive heat production rate show that the present average geothermal gradient in the Ordos Basin is 2.93 °C/100 m, and the average heat flow value is 61.78 mW/m2, which belongs to the mesothermal basin, and the value of the present geothermal gradient and heat flow in the east is higher than that in the west. The sandstone radioactive heat production rate of Zhiluo Group in Dongsheng Uranium deposits of Yimeng uplift is obviously higher in the mudstone, indicating that there exists a uranium anomaly. Based on studies of the present thermal field of the basin, the late-Mesozoic paleotemperature and paleogeothermal gradient are determined by using different kinds of paleotemperature methods. According to the anomaly of the late-Mesozoic paleotemperature gradient and magmatic event age, there was a tectonic thermal event in the early Cretaceous epoch of late-Mesozoic. This article rebuilds tectonic thermal history of different tectonic units by thermal history simulation using basin simulating software. The evolution of oil-gas and coal, and accumulation (mineralization) of mineral uranium are all controlled by the tectonic thermal history in the Ordos basin, especially by the tectonic thermal event that happened in the late Mesozoic. For both the gas source rocks of upper Paleozoic group and lower paleozoic group, the gas was largely generated in the early Cretaceous epoch of the late Mesozoic. The main petroleum generation period for Yanchang Group in Triassic system is the early Cretaceous epoch too, and the highest thermal maturity of the coal of Permo-Carboniferous, Triassic, and Jurassic reaches is the early Cretaceous epoch also. Early Cretaceous epoch is still one of the most important mineralizing periods of uranium. 相似文献
16.
A paleomagnetic study was carried out on the mid-Cretaceous sedimentary strata in west-central Kyushu Island, southwest Japan, to elucidate the origin of sedimentary basins along the Asian continental margin in the Cretaceous. We collected paleomagnetic samples from a total of 34 sites of the mid-Cretaceous Goshonoura Group, shallow-marine clastic deposits in west-central Kyushu, and characteristic remanent magnetizations were recognized from 18 horizons of red beds. Thermal demagnetization has revealed that the red beds contain three magnetization components, with low (<240°C), intermediate (240-480°C), and high (480-680°C) unblocking temperatures. The low unblocking temperature component is present-field viscous magnetization, and the intermediate one is interpreted as chemical remanent magnetization carried by maghemite that was presumably formed by post-folding, partial oxidation of detrital magnetite. Rock magnetic and petrographic studies suggest that the high unblocking temperature component resides largely in hematite (martite and pigmentary hematite) and partly in maghemite. Because of the positive fold test, this high temperature component can be regarded as primary, detrital remanent magnetization. The tilt-corrected mean direction of the high temperature component is Dec=65°, Inc=63° with α95=5°, which yields a paleomagnetic pole at 39°N, 186°E and A95=8°. A combination of this pole with those of the Late Cretaceous rocks in southwest Japan defines an apparent polar wander path (APWP), which is featured by a cusp between the Late Cretaceous and the Paleogene. A comparison of this APWP with the coeval paleomagnetic pole from northeast Asia suggests an approximately 50° post-Cretaceous clockwise rotation and 18±8° southward drift with respect to northeast Asia. The southward transport of the Cretaceous basin suggests that the proto-Japanese arc originated north of its present position. We propose that the coast-parallel translation of this landmass was caused by dextral motion of strike-slip faults, which previous geodynamic models interpreted to be sinistral through the Mesozoic. The change in strike-slip motion may have resulted from Mesozoic collision and penetration of exotic terranes, such as the Okhotsk microcontinent, with the northeastern part of Asia. 相似文献
17.
酒泉盆地群热演化史恢复及其对比研究 总被引：18，自引：1，他引：17
酒泉盆地群是由两期不同性质、不同世代盆地叠加而成的 .晚侏罗纪-早白垩世为拉张断陷盆地 ,第三纪以来为挤压坳陷盆地 .酒泉盆地群现今地温梯度及大地热流值都较低 ,地温梯度主要在 2 51- 3 0 0℃ /1 0 0m之间 ,大地热流值在 50- 57mW /m2 之间 .酒泉盆地群中生代晚期为拉张断陷 ,古地温梯度高 ,可达 3 75- 4 50℃ /1 0 0m ,新生代以来地温梯度逐渐降低 ,而花海盆地、酒西盆地石北凹陷沉降幅度小 ,古地温高于今地温 .下白垩统烃源岩热演化程度受古地温控制 .主生烃期仅有一次 ,为早白垩世晚期 .酒西盆地青西凹陷、酒东盆地营尔凹陷在新生代以来大幅度沉降 ,下白垩统烃源岩热演化程度受现今地温控制 .主生烃期有两次 ,一次为早白垩世晚期 ,另一次为晚第三纪以来 ,且以晚第三纪以来为主 .不同盆地及同一盆地不同构造单元由于构造热演化史的不同 ,主生烃期及油气勘探前景明显不同 . 相似文献
18.
Dewey M. McLean 《Earth and Planetary Science Letters》1981,53(1):103-108
Terminal Mesozoic “catastrophe”-type extinction models that advocate synchronous marine and terrestrial extinctions spanning short time intervals (a few days up to a few millennia) have a common foundation: the simultaneous terminations of geological ranges of some taxa of marine CaCO3-producing microplankton (and possibly the dinosaurs) at the end of the Cretaceous. Gartner and McGuirk [1] propose a new catastrophe theory that at the end of the Cretaceous fresh-brackish water from the Arctic Ocean spread over the surface of the world's oceans, causing global cooling, aridity, and the extinctions. Like other catastrophe models, this one also fails to address the possibility of hiatus control of ranges at the end of the Cretaceous; a well documented, seemingly nearly universal hiatus of variable and unknown duration separates Cretaceous and Tertiary strata. Documented terminal Cretaceous marine regression (perhaps 10 times more rapid than a typical regression according to Cooper [8] would have caused terrestrial erosion and stripping away of the latest Cretaceous stratigraphic record, thus truncating geological ranges along a seemingly planar datum. The terminal Cretaceous marine CaCO3 dissolution event would have had the same effect on ranges of marine planktonic CaCO3-producing microplankton (the event was a shallow-water phenomenon). The simultaneous terminations of geological ranges is thus possibly the result of hiatus control, and the terminal Cretaceous “catastrophe” an illusion. Attempts to use Cretaceous-Tertiary transition floras to support global cooling at the time of the extinctions are not based on sound stratigraphic foundations; realistic paleobotanical-climatic inferences can only be based on the precise correlation of the Cretaceous-Tertiary contact in marine and terrestrial stratigraphic sections, and these correlations have not been made with sufficient precision to support catastrophe theory. The much used “across the Cretaceous-Tertiary boundary” glosses over ignorance of the true terminal Cretaceous scenario, lost forever in most places by the destruction of the terminal Cretaceous stratigraphic record. For now, stable isotope paleotemperature data from marine strata that can be dated radiometrically provide the most reliable estimates of the Cretaceous-Tertiary transition climate; Boersma et al. [5] indicate global warming of deep and shallow oceans “across” the contact (and not surficial cooling only as is required by the spillover model). Older much-cited climate inferences based on leaf physiognomy are suspect in light of Dolph and Dilcher's [23] work that shows little correlation between leaf physiognomy and climate. 相似文献
19.
ZHAO HongGe LIU ChiYang WANG Feng WANG JianQiang LI Qiong YAO YaMing 《中国科学D辑(英文版)》2007,50(Z2):217-226
The Helan Mountain lies in the northwest margin of Ordos Basin and its uplift periods have close relations with the tectonic feature and evolution of the basin. There are many views on the uplift time of Helan Mountain, which is Late Triassic and Late Jurassic. It is concluded by the present strata, magmatic rock and hot fluid distribution that the Helan Mountain does not uplift in Late Triassic to Middle Jurassic but after Middle Jurassic. Through the research of the sedimentary strata and deposit rate in Yinchuan Graben which is near to the Helan Mountain, it is proved that the Helan Mountain uplifts in Eocene with a huge scale and in Pliocene with a rapid speed. The fission track analysis of apatite and zircon can be used to determine the precise uplift time of Helan Mountain, which shows that four stages of uplifting or cooling Late Jurassic to the early stage of Early Cretaceous, mid-late stage of Early Cretaceous, Late Cretaceous and since Eocene. During the later two stages the uplift is most apparent and the mid-late stage of Early Cretaceous is a regional cooling course. Together with several analysis ways, it is considered that the earliest time of Helan Mountain uplift is Late Jurassic with a limited scale and that Late Cretaceous uplift is corresponding to the whole uplift of Ordos Basin, extensive uplift happened in Eocene and rapid uplift in Pliocene. 相似文献
20.
Zhao HongGe Liu ChiYang Wang Feng Wang JianQiang Li Qiong Yao YaMing 《中国科学D辑(英文版)》2007,50(2):217-226
The Helan Mountain lies in the northwest margin of Ordos Basin and its uplift periods have close relations with the tectonic feature and evolution of the basin. There are many views on the uplift time of Helan Mountain, which is Late Triassic and Late Jurassic. It is concluded by the present strata, magmatic rock and hot fluid distribution that the Helan Mountain does not uplift in Late Triassic to Middle Jurassic but after Middle Jurassic. Through the research of the sedimentary strata and deposit rate in Yinchuan Graben which is near to the Helan Mountain, it is proved that the Helan Mountain uplifts in Eocene with a huge scale and in Pliocene with a rapid speed. The fission track analysis of apatite and zircon can be used to determine the precise uplift time of Helan Mountain, which shows that four stages of uplifting or cooling: Late Jurassic to the early stage of Early Cretaceous, mid-late stage of Early Cretaceous, Late Cretaceous and since Eocene. During the later two stages the uplift is most apparent and the mid-late stage of Early Cretaceous is a regional cooling course. Together with several analysis ways, it is considered that the earliest time of Helan Mountain uplift is Late Jurassic with a limited scale and that Late Cretaceous uplift is corresponding to the whole uplift of Ordos Basin, extensive uplift happened in Eocene and rapid uplift in Pliocene. 相似文献