The Uplift of the Longmenshan Thrust Belt and Subsidence of the West Sichuan Foreland Basin

Based on fission track dating of apatite, and measurement of vitrinite reflectance of rock samples from the Longmenshan (Longmen Mountain)area and the West Sichuan foreland basin and computer modelling it is concluded that (l)the Songpan-Garze fold belt has uplifted at least by 3-4 km with an uplift rate of no less than 0.3-0.4 mm/a since 10 Ma B.P.; (2) the Longmenshan thrust nappe belt has uplifted at least by 5-6 km with an uplift rate of more than 0.5- 0.6 mm /a since 10 Ma B.P.; (3) the Longmenshan detachment belt has uplifted by 1 - 2 km at a rate of 0.016-0.032 mm/a since 60 Ma B.P.; (4) the West Sichuan foreland basin has uplifted by 1.7-3 km at a rate of 0.028-0.05 mm/a since 60 Ma B.P.; (5) the uplift rate of the area on the west side of the Beichuan-Yingxiu-Xiaoguanzi fault for the last 10 Ma is 40 times as much as that on its east side; (6) the uplifting of the the Songpan - Garze fold belt and the subsidence of the West Sichuan foreland basin 60 Ma ago exhibit a mirro-image correlation, i.e     

泡沫泥浆钻进工艺及护壁堵漏机理研究

介绍了所研制的ＤＦ－１型泡沫剂组分及性能；对泡沫泥浆钻进的配方进行了研究，得出的最优配方应用于现场，取得了较好的效果，并对泡沫泥浆的护壁机理进行了研究。     

低温条件下有机酸对铁、铜的淋滤实验研究

水／岩作用实验研究表明，在低温条件下柠檬酸、草酸和酒石酸对岩石中的铁、铜都有很高的淋滤率。这表明，在表生地质作用过程中有机酸对成矿元素有很强的活化能力。实验研究同时发现，有机酸对成矿元素的活化能力受其分解温度的限制，由于大部分有机酸的分解温度都在２５０℃以下，因而有机酸对成矿元素的活化仅限于低温条件。本次研究还显示，判断一种岩石能否成为矿源层，不能简单的以其中成矿元素的含量高低作为标准，其中更关键的因素是元素在岩石中的存在形式，如果成矿元素在岩石中难以活化的形式存在，那么含量再高也无法提供成矿物质     

Magnetostratigraphy and palaeoclimate of Red Clay sequences from Chinese Loess Plateau

Two Red Clay profiles near Xi’an and Xifeng were investigated in an attempt to determine magnetostratigraphic and palaeoclimatic records. The results show that aeolian dust accumulation and the related East Asia palaeomonsoon system had begun by 6.5 Ma, and it is deduced that the Tibetan Plateau had reached a significant elevation at that time. The late Tertiary palaeoclimatic history of the Red Clay as reflected by magnetic susceptibility is reconstructed during the period of 6.5–2.5 Ma. Stepwise increase in susceptibility of aeolian dust accumulation appears to have a close correlation to the uplift processes of the Tibetan Plateau. The remarkable increase of aeolian dust accumulation at 3.2 Ma appears to be due to the influence of global ice volume on the East Asia monsoon. Palaeomonsoon variation during the late Tertiary as recorded in the Red Clay sequences from the Chinese Loess Plateau can be regarded as the product of a number of interacting factors, such as uplift of the Tibetan Plateau, solar radiation, global ice volume, etc. Project supported by the National Natural Science Foundation of China and the Foundation of Xi’an Laboratory of Loess and Quaternary Geology, Chinese Academy of Sciences.     

40Ar/39Ar geochronology and exhumation of mylonitized metamorphic complex in Changle-Nanao ductile shear zone

New⁴⁰Ar/³⁹Ar plateau ages from rocks of Changle-Nanao ductile shear zone are 107.9 Ma(Mus), 108.2 Ma(Bi), 107.1 Ma(Bi), 109.2 Ma(Hb) and 117.9 Ma(Bi) respectively, which are concordant with their isochron ages and record the formation age of the ductile shear zone. The similarity and apparent overlap of the cooling ages with respective closure temperatures of 5 minerals document initial rapid uplift during 107–118 Ma following the collision between the Min-Tai microcontinent and the Min-Zhe Mesozoic volcanic arc. The⁴⁰Ar/³⁹ Ar plateau ages, K-Ar date of K-feldspar and other geochronologic information suggest that the exhumation rate of the ductile shear zone is about 0.18–1.12 mm/a in the range of 107–70 Ma, which is mainly influenced by tectonic extension.     

造山带岩浆活动与构造运动关系研究综述

熔体及其活动在造山带的演化中发挥了重要作用。熔体活动发迹了地壳应力作用方式而诱发形成剪切带或断层；熔体活动调整块体间的位移而影响造山带的变形；     

Quantitative Tectonic Markers of Large Coastal Earthquakes in Fujian, Guangdong, Taiwan and Hainan——with a Discussion of Qualitative Indicators

This paper expounds the quantitative tectonic indicators and some qualitative indicators of large earthquakes in the coast areas of Fujian, Guangdong, Taiwan and Hainan. The main quantitative indicators include uplift amplitude of the Moho, Quaternary and Late Holocene coasts. The paper also gives a brief account of the research method on quantitative indicators of surface uplifted zones. Taiwan is a famous neotectonic zone and an area of large earthquakes in the world. There is only one large-earthquake area in each of Fujian, Guangdong and Hainan Provinces. Along the coast large earthquake areas there are certainly many remains of crustal activity. Among these remains, coast activity, taking the sea level as the accurate marker horizon, can determine not only the amplitude of coastal elevation and subsidence in a certain period, but also the cycle and rate of positive or negative movements.     

利用磷灰石裂变径迹计算隆升速率的一些问题

主要讨论了利用磷灰石理解变径迹年龄－－地形高差法计算隆升速率存在的一些问题，介绍了近年来国外在磷灰石裂变径迹退火方面取得的新进展及其在研究隆升速率问题上的应用，并分析了利用磷灰石裂变径迹研究隆升速率应当注意的问题，强调了加强径迹长度分析的研究。     

The Influence of CO on the Carbon Isotopic Composition of CH_4 in Closed Pyrolysis Experiment With Coal

1IntroductionThecarbonisotopiccompositionofnaturalgasesisregardedasacontanttracerusedinthegeochemicalresearchofnaturalgases .Basedonthecarbonisotopiccomposition ,thegenetictypesofnaturalgasesarebasicallydividedtodeterminethematurationofnaturalgasesandmakegas sourcecorrelations (Stahl,1 973;StahlandCarey ,1 975;Stahletal.,1 977;James ,1 983;Schoell,1 983,1 988;DaiJinxingetal.,1 992 ;FuJiamoetal.,1 992 ;XuYongchang ,1 994 ) .Theformationofnaturalgasescouldbededucedintermsofcarbonisotopicvar…     

CHARACTERIZATION AND FORMATION MECHANISM OF THE CENTRAL UPLIFT OF THE QIANGTANG BASIN

The Qiangtang basin is located between Kekexili-Jingshajiang suture belt and Bangong-Lujiang suture belt, and is divided into the north part and south part by the central uplift that has no crop out of Mesozoic strata. When the Jinshajiang Ocean was closed, the subducting plate was subducted southward. In the central part of the Qiangtang basin, the cushioning effect of the asthenosphere resulted in the thermal doming of the mantle and subsequent large-scale anatexis. Mantle source materials and antectic materials were upwelled and extruded into the middle crust, leading to the thickening of the middle crust and the heating and weakening of the middle to upper crust, and resulting in the rapid deformation (detachment) and tectonic erosion, and in the isostatic uplifting and the formation of metamorphic core complex. The upwelling of anatectic materials would further enhance the buoyant repercussion, which would combine with the side stress due from extrusion in resulting in the formation of an extension