Application of the Sequence Stratigraphy in the Study of Cretaceous-Tertiary of the Tarim Basin, Xinjiang, China

1. IntroductionThe Tarim basin, one of the most developed and important areas of marine Cretaceous-Tertiary in China except for south Tibet, is very rich in oil and gas, such as Kekeya oilfield in southwestern Tarim and Kela2 gas field in northeastern Tarim. Because of the expansion, subduction of the oceanic crust of the Tethys and the collision between the India plate and the Eurasia plate during the Cretaceous-Tertiary, the Tethys transgressed into the Tarim basin from west to east fr…     

Garnet-bearing Granulite Facies Rock Xenoliths from Late Mesozoic Volcaniclastic Breccia, Xinyang, Henan Province

This paper presents the primary results of petrologic, mineralogical and petrochemical studies of garnet-bearing granulite facies rock xenoliths from Xinyang, Henan Province. These xenoliths, which are found in a pipe of late Mesozoic volcaniclastic breccia, are of high density (3.13-3.30 g/cm3) and high seismic velocity (Vp = 7.04-7.31 km/s), being products of underplating of basaltic magmas and had experienced granulite facies metamorphism. The underplating and metamorphism took place before the eruption of the host rock. Petrographical studies and equilibrium T-P calculations show that these xenoliths were captured at a 49 km depth and experienced at least a 16 km uplift before they were captured. The dynamics of the uplift could be related to the continent-continent collision between the North China plate and the Yangtze plate during the Triassic.     

重质碳酸钙表面改性及充填丁苯橡胶试验研究

重质碳酸钙是一种重要的无机矿物填料，经过表面改性，可以将其由普通填料变成性能优越的功能填料。本次研究选用鄂西优质重质碳酸钙为试验样品，采用干法表面化学改性方法对重质碳酸钙实施了改性，通过测定改性重质碳酸钙的活化率、湿润接触角、固液悬浮体的粘度、白度及表面化学成分对其性能进行考察，并对改性效果进行评价。在丁苯橡胶中的应用试验显示，改性重质碳酸钙充填丁苯橡胶的性能良好，其应用前景广阔。     

对于氟碳钡铈矿（Cordylite—Ce）成分与结构的质疑

本文讨论了氟碳钡铈矿的成分和结构问题。发现氟碳钡铈矿的成分、密度、折射率三者间的一致性参数很差,晶体结构与光性和空间群相矛盾,单个大阳离子的平均占有体积远大于同类矿物的平均占有体积,它的晶体结构与同类矿物不可类比。由于受当时条件的限制,在以往有关氟碳钡铈矿的成分和结构的资料中存在着一些明显的错误,有必要对其进行重新定义。其结构化学式应改为:(Na_(1-x),Ca_(0·5x))BaCe_2(CO_3)_4F。     

High-Pressure and Ultrahigh-Pressure Metamorphic Belt in Tongbai-Dabie Mountains,Central China

There are four units of high-pressure to ultrahigh-pressure metamorphism extending from south to north across the Tongbai-Dabie Mountains: the epidote-blueschist-facies unit, the low-temperature eclogite facies unit , the ultrahigh-pressure eclngite facies unit and the medium-temperature eclogite facies unit . The later two units were formed during the Caledonian subduction between the Tongbai-Dabie microplate and the North China plate ,the former two units are the products of Indosinian continental-continental subduction and collision between the Yangtze and the North China plates.     

Tectonic Units and Their Fundamental Characteristics on the Northern Margin of the Alxa Block

The northern margin of the Alxa block is the junction of a tectonic units. Four first-order tectonic units are distinguished: 1. the Yagan structural zone characteristic of an immature island arc; 2. the Zhusileng-Hangwula structural zone, which was a passive continental margin in the Early Palaeozoic and was transformed into an active continental margin in the Late Palaeozoic;3. the Shalazha structural zone characteristic of a mature island arc; 4. the Nuru-Langshan structural zone, which was a Proterozoic orogenic belt and later evolved into an extensional transtional crust in the Palaeozoic. The above-mentioned tectonic units differ remarkably in sedimentary formations, magmatic rock associations, metamorphism and geochemistry and are bounded by faults between one another.     

绵竹三箭水S1井温泉补给源的同位素示踪研究

根据绵竹三箭水S1井相关地质区域内各水体的氢、氧同位素组成和放射性同位素氚浓度,结合该区的地质背景,利用同位素示踪手段,基本确定该井温泉地下水的成因为大气降水渗入补给主体含水层补给源在西北部1700m左右的“彭灌杂岩”高山区一带、补给量相对稳定,水温不会有大波动,有远期开发价值。     

缅甸硬玉岩区的硬玉化绿辉石岩

绿辉石岩是缅甸硬玉岩区一种新的岩石类型,普遍遭受多期次硬玉化.未发生硬玉化的绿辉石含较高TFeO和CaO,但较低的MgO,按化学成分分类部分已属霓石-普通辉石系列的中间相.这种绿辉石很可能是硬玉质的流体/熔体交代地幔辉石岩类的产物,与主期大规模硬玉岩的结晶、钠质-钠钙质角闪石边和钠铬辉石的形成同期或稍后,是该区第Ⅰ期的硬玉化.沿绿辉石的解理或裂隙交代并伴有充填的硬玉是在相对拉张的构造背景下形成的,是该区第Ⅱ期的硬玉化.切割早期绿辉石和硬玉的充填硬玉细脉可能是最晚一期的硬玉化.硬玉化绿辉石岩的结构与显微构造特征指示了在缅甸硬玉岩区,至少存在不少于3期的硬玉化的交代充填作用.文中讨论了硬玉化物质的可能来源,认为其可能与俯冲板片上的沉积物有密切关系.