南天山阿尔夏特地区科克铁克达坂组物源区大地构造背景分析

南天山地区的科克铁克达坂组是保存于那拉提-红柳河缝合带南侧的一套晚志留世地层,总体出露较好,研究其物源区大地造背景对南天山造山带志留纪岩相古地理及构造背景研究具有重要意义。通过野外剖面测制,结合室内薄片鉴定及地球化学分析等工作,对科克铁克达坂组物源区构造背景进行了分析,结果显示其物源区为过渡陆壳源区、隆升基底源区,大地构造背景为稳定的被动大陆边缘。     

青藏高原东缘龙门山冲断带与四川盆地的现今构造表现:数字地形和地震活动证据

龙门山冲断带位于四川盆地与青藏高原东缘之间,其现今地貌和构造活动表现对于理解青藏高原东缘和四川盆地晚新生代的演化具有非常重要的意义。已有的认识多数是从“山”的角度得出的,我们尝试从“盆”这一角度,利用近20年来的地震活动资料和地震反射剖面,结合数字高程模型(DEM),通过三维可视化分析软件来探讨四川盆地及龙门山的地貌特征和现代构造活动表现。初步研究结果表明:1)龙门山的现今地貌和地震分布具有明显的南北分段性;2)青藏高原东缘活动块体边界表现为由龙门山南段北东向构造在安县附近转折为岷山的南北向构造;3)龙门山南段的现代地震活动已深入四川盆地内部,形成地壳规模的楔形逆冲构造,地震活动、现代地貌和地震反射剖面的证据揭示了龙门山及四川盆地存在晚新生代构造缩短的可能性。     

Comparative studies of organic matter petrography of the late palaeozoic black shales from Southwestern Poland

There are at least two sapropelic units associated with Late Palaeozoic black shales in Central Europe. The older unit, of Late Carboniferous age, is the lower part of the Anthracosia Shales in the Intrasudetic Basin, and the younger one is the well-known Zechstein Kupferschiefer in both the Foresudetic Monocline and the Northsudetic Basin. The first unit is of lacustrine origin, while the second one represents deposition in a shallow marine depositional environment. Both units contain high amounts of organic matter, thus being typical black shales.The organic matter dispersed in these shales was studied petrographically. In general, the vitrinite reflectance of the shales studied indicates variable, but moderate organic matter maturity (0.68–1.25%), equivalent to the oil window. Detailed microscopic studies of the organic material dispersed in the lower unit of the Anthracosia Shales showed that liptinite, especially alginite is the most abundant component. Secondary altered organic matter, i.e. solid hydrocarbons, rarely occurs. Organic components together with mineral matter constitute a lacustrine sapropelic association, a humic (terrestrial) association and an intermediary association. The character and predominance of alginite and lacustrine sapropelic association are indicative of an open-lacustrine depositional environment. In general, this organic composition is typical of type I kerogen.Microscopic analysis of the Kupferschiefer revealed a mixture of liptinite, vitrinite and inertinite macerals, and other organic components such as amorphous sapropelic mass (ASM) and solid bitumens. The most common organic components are liptinite macerals. Bituminite and alginite predominate, and are diagnostic macerals of this unit. The amount of bituminite locally exceeds 85 vol.%. Other liptinite macerals such as sporinite and liptodetrinite, are present in significantly lower amounts, one exception being ASM, which may be present in higher amounts. Humic constituents (vitrinite and inertinite) are rare, present in small amounts in the Kupferschiefer beds. The organic matter composition points to type II kerogen for this unit.     

巴颜喀拉山脉南端末次冰期冰退序列

巴颜喀拉山脉南端位于四川省阿坝县、壤塘县与马尔康县交界地区。该区古冰川遗迹广泛分布，安纳尔措地区末次冰期晚阶段冰碛垅保存有7条，系统的石英ESR测年资料表明，它们均属新仙女木期，构成完整的冰退序列。     

An explosive seismic sounding profile across the transition zone between west Kunlun Mts. and Tarim Basin

The explosive seismic sounding profile across the transition zone from the west Kunlun Mts. to the Tarim Basin revealed the complex deep structure formed by continent-continent collision on the northern margin of the Tibetan Plateau. The profile shows that the attitude of the Moho is in agreement with that of the crystalline basement in the Tarim Basin and the whole crust dips as a thick slate southwards with an angle from 5° to 7°. Meanwhile, the Moho depth increases from 40 km to 57 km within a distance of 150 km in the southern Tarim region, depicting the subduction of the crust of this region towards the west Kunlun Mts. The crust of the northern slope of the west Kunlun Mts. shows an evident compressed and shortened feature, that is, the basement is uplifted, the interface dips northwards and the Moho rises abruptly to become flat, so that the lower crust is as thick as 20 km.     

Relationship between Granite and Eclogite on the Southern Margin of the Qilian Mountains: Evidence from Zircon SHRIMP Agesof the Aolaoshan Granite

Zircon SHRIMP ages of the Aolaoshan granite on the south margin of the Qilian Mts. range from 445±15.3 to 496±7.6 Ma (averaging 473 Ma), belonging to the Early Ordovician. Geochemically, the granite is similar to I-type granite and, tectonically, was formed in an island-arc environment based on relevant diagrams for structural discriminations. Considering also the regional geology, the authors suggest that the granite is part of an ultrahigh-pressure belt on the south margin of the Qilian Mts. and that its formation bears a close relationship to this belt.     

大兴安岭查巴奇地区水系沉积物地球化学特征及找矿方向

采用R型聚类分析方法和衬值累乘法,圈定综合异常以消除地质背景对异常圈定的影响。重要综合异常区主要发育在变质岩及其与酸性侵入体接触部位。综合异常具有沿着NE和NNE向断裂构造发育的特征,依据综合异常特征和地质信息圈定出3个成矿远景区。查巴奇小东沟屯和平顶山是本区寻找石英脉型和破碎带型金铜矿的有利区段;新兴屯—德胜屯是寻找热液型(斑岩型)矿床的远景区。     

昆仑山西段中国─巴基斯坦公路沿线构造地质

路线横穿昆仑山西段和喀喇昆仑山北坡，全长420km。穿越了塔里木地块西南缘、库地地块和羌塘地块，并可见到它们之间的构造带。可见到塔里木地块中晚元古代结晶基底（锆石U—Pb年龄为2100Ma）；这三个地块内各个不同时代的地质构造变形；海相中、新生代地层;碱性花岗岩和二长花岗岩（12～11Ma）；石炭─二叠纪、三叠纪及侏罗纪基性火山岩和枕状玄武岩及构造蚀变岩，如糜棱岩、石榴石片岩以及二叠纪形成于冈瓦纳古陆的含砾板岩、硅质板岩等。该路线还能见到密集岩脉群及火山岩脆性变形与韧性变形、康西瓦构造带和塔什库尔干断裂带壮观地貌，在喀拉库勒猢一带可见到慕士塔格和公格尔山的冰川地貌。在塔哈曼可参观温泉产出状况。在卡拉其古附近可见到4～5级河床阶地，说明该区第四纪以来一直在趋于上升。     

Chemistry of Neutral and Alkaline Waters with Low Al<Superscript>3+</Superscript> Activity Against Hydroxyaluminosilicate HAS<Subscript>B</Subscript> Solubility. The Evidence from Ground and Surface Waters of the Sudetes Mts. (SW Poland)

A wide set of aqueous chemistry data (574 water analyses) from natural environments has been used to testify and validate of the solubility of synthetic hydroxyaluminosilicate (HAS_B)_, Al₂Si₂O₅(OH)₄. The ground and surface waters represent regolith and/or fissure aquifers in various (magmatic, sedimentary and metamorphic) bedrocks in the Sudetes Mts. (SW Poland). The solubility of HAS_B in natural waters was calculated using the method proposed by Schneider et al. (Polyhedron 23:3185–3191, 2004). Results confirm usefulness and validity of this method. The HAS_B solubility obtained from the field data (logK_sp = −44.7 ± 0.58) is lower than it was estimated (logK_sp = −40.6 ± 0.15) experimentally (Schneider et al. Polyhedron 23:3185–3191, 2004). In the waters studied the equilibrium with HAS_B is maintained at pH above 6.7 and at [Al³⁺] ≤ 10⁻¹⁰. Silicon activity (log[H₄SiO₄]) ranges between −4.2 and −3.4. Due to the calculation method used, the K_sp mentioned above cannot be considered as a classical solubility constant. However, it can be used in the interpretation of aluminium solubility in natural waters. The HAS_B has solubility lower than amorphous Al(OH)₃, and higher than proto-imogolite. From water samples that are in equilibrium with respect to HAS_B, the solubility product described by the reaction, is calculated to be logK_sp = 14.0 (±0.7) at 7°C.     

Distribution of the Permian Monodiexodina in Karakorum and Kunlun and its Geological Significance

The Permian fusulinoidean genus Monodiexodina is widely distributed in east Tethys. The genus might be an important indicator for the northern margin of Gondwana in northwestern China, but this is disputed. Monodiexodina-bearing areas can be restored as in either northern or southern middle latitudes with a symmetrical distribution between a high latitudinal, cool/cold water climatic realm and a paleotropical, warm water realm. Permian strata bearing Monodiexodina in Karakorum, Muztag Pear, and Buka Daban Pear of the east Kunlun Mountains can be correlated with each other. Faunal analyses and the stratigraphical position of Monodiexodina-bearing strata indicate that both Karakorum, east Kunlun, and the Pamirs were formed in a cool temperate sea area of the northern hemisphere in middle latitudes during the Permian, rather than at the Gondwana margin.