西藏仲巴县穷果北部日喀则弧前盆地地层再认识
New understanding of stratum of Xigaze forearc basin in the north of Qiongguo area, Zhongba, Tibet
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摘要: 通过对区内发育完好并保留下来的白垩纪—始新世地层的研究,海相白垩纪日喀则群自下而上可划分为昂仁组、帕达那组、曲贝亚组;古新世—始新世错江顶群包括下部曲下组和上部加拉孜组,整合覆于错江顶群之上的“如角藏布砂砾岩”为弧前盆地封盆粗碎屑岩。日喀则群与错江顶群在沉积学、地层古生物学及构造地质学诸方面的差异揭示了两群之间,更确切地说,曲贝亚组与曲下组之间呈不整合接触,该不整合形成于坎潘期—马斯特里赫特期与丹尼期之间。该区日喀则弧前盆地完整的地层序列全面再现了印度板块向欧亚板块俯冲过程,两板块的碰撞和新特提斯洋的彻底关闭发生在弧前盆地封盆粗碎屑岩沉积结束以后,这比原来认识的要晚些。Abstract: Located in the west of Xigaze forearc basin, the Cretaceous to Eocene stratigrphic sequence reserved grows in the Zhongba region along the north bank of the Yarlung Zangbo Suture Zone. The marine Cretaceous Xigaze Gr. could be subdivided in ascending order into the Angren Fm., Padana Fm. and Qubeiya Fm. Pale-ocene Eocene Cuojiangding Gr. inclouds Quxia Fm. and Jialazi Fm.. "Rujiaozangbu psepholite"—the confining coarse clastic rock of Xigaze forearc basin, is concordant on the Cuojiangding Gr.. Four differences in sedimentology,stratig raphic palaeontology and structural geology show that there exists a nonconformity between Xigaze Gr.and Cuojiangding Gr..Speaking concretely, this nonconformity existed between Qubeiya Fm.and Quxia Fm..The nonconformity was formed between Campanian-maast richtianand danian.The whole stratigrphic sequence of Xigaze for earc basin in this region reappear the course of strong underthrust between India plate and Eurasian plate fully.The main collision between India plate and Eurasian plate took place after "Rujiaozangbu psepho lite" had been deposited,the time of collision between the two plates is later than primary under standing's.
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Keywords:
- Xigaze Gr. /
- Cuojiangding Gr. /
- Rujiaozangbu psepholite /
- nonconformity /
- Zhongba
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钱定宇,顾庆阁,章炳高.西藏日喀则群昂仁组时代问题新资料[J].地质科学,1982,(3):329-331.
刘成杰,尹集详,孙晓兴,等.西藏南部日喀则弧前盆地非复理石型海相上白垩统-下第三系[J].中国科学院地质研究所集刊.1988,(3):130-157.
万晓樵,丁林,李建国,等.西藏仲巴地区白垩纪末期-始新世早期海相地层[J].地层学杂志,2001,25(4):267-272.
文世宣.珠穆朗玛峰地区的地层——白垩系[A].中国科学院西藏综合考察队,珠穆朗玛峰地区科学考察报告(1966～1968)[C].北京:科学出版社,1974.148-183.
吴浩若,王东安,王连城,等.西藏南部拉孜-江孜一带的白垩系[J].地质科学,1977,(3):250-262.
西藏自治区地质矿产局.西藏自治区区域地质志[M].北京:地质出版社,1993.195-235.
西藏自治区地质矿产局.西藏自治区岩石地层[M].武汉:中国地质大学出版社,1997.240-244.
徐珏林,万晓樵,苟宗海,等.西藏侏罗、白垩、第三纪生物地层[M].武汉:中国地质大学出版社,1989.58-113.
余光明,等.西藏特提斯沉积地质[A].地矿部地质专报[C] (三).岩石、矿物、地球化学,(12),北京:地质出版社,1990.
万晓樵.西藏岗巴地区白垩纪地层及有孔虫动物群(A).见:青藏高原地质文集(C),北京:地质出版社,1985.16:203-223.
王成善,刘志飞,李详辉,等.西藏日喀则弧前盆地与雅鲁藏布江缝合带[M].北京:地质出版社,1997.18-23.
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