Carbonation of Chrysotile under Subduction Conditions

In order to understand the role of serpentine minerals in the global carbon cycle, high-pressure X-ray diffraction (XRD) experiments were performed on chrysotile (Mg₃Si₂O₅(OH)₄) using carbon dioxide (CO₂) as a pressure medium. Synchrotron XRD patterns revealed the formation of magnesite and high-pressure chrysotile after heating at 170 °C for 1 h at 2.5(1) GPa. The Rietveld refinement suggests that the unit cell composition of the original chrysotile changes to Mg_2.4(1)Si₂O₅(OH)_2.4(1) upon the formation of magnesite, which appears to be driven by the dehydrogenation of the innermost hydroxyl group, OH3, and the rearrangement of magnesium (Mg) at the M1 site, leading to the formation of metastable monodehydroxylated chrysotile. Metastable chrysotile is observed up to 5.0(1) GPa and 500 °C, which corresponds to the slab Moho geotherms for the South Sumatra and Ryukyu subduction zone. After recovery to ambient conditions, the characteristic fibrous morphology of the original chrysotile was found to have changed to an earthy form. These results can help us to understand deep carbon cycling along the subduction zones, and may prompt the design of a novel method of asbestos detoxification using pressure and temperature.     

增生楔油气地质特征及勘探潜力——以缅甸某区块为例

增生楔地区油气勘探因其强烈的构造变形和复杂的地质背景很少有人涉足。缅甸若开海岸地处印度板块与欧亚板块的交会处,是典型的增生楔构造。以缅甸若开海岸某区块为例,通过对该区的基本石油地质条件深入分析,搞清了该区的成藏规律。分析认为该区具备较好的生烃条件,但强烈的构造运动一方面使得本来就相变快的储层变得更加不连续,另一方面使得早期形成的油气藏多被破坏。综合分析认为,保存条件是制约该区油气成藏的关键因素,未来油气勘探应以寻找构造活动相对较弱、保存条件好的区带为主。     

中国南方板块内部造山活动

本文通过探讨有关中国南方陆内造山的基本情况。分析和总结前人在此领域的研究成果,增加了个人的一些新认识。综述了对中国南方陆内造山的认识,提出了应注意的问题。通过对陆内造山的认识进而对整个上扬子板块的构造格局和演化有新的了解。     

塔里木盆地西南缘构造带的地球物理特征、构造及其演化

本文根据塔里木盆地西南缘构造带的重力异常，大地叫磁测深以及天然地震波速和航磁异常等地球物理资料，并结合该区的构造地质特征，将研究区划发为西昆仑叠瓦逆冲推覆带，推体前缘断褶带和外缘坳陷带。     

非线性K-L滤波及其在反射地震资料处理中的应用

Ｋ－Ｌ变换可以用来提高地震资料的信噪比。本文分析了基于Ｋ－Ｌ变换的分类特征提取方法及其与奇异值分解算法的关系后指出，在资料信噪比小于１时，应用Ｋ－Ｌ滤波方法不能取得良好效果；引入二次波场等非线性运算方法可以进一步改进Ｋ－Ｌ滤波方法。     

Arc magmatism as a window to plate kinematics and subduction polarity: Example from the eastern Pontides belt, NE Turkey

The Eastern Pontides orogenic belt in the Black Sea region of Turkey offers a critical window to plate kinematics and subduction polarity during the closure of the Paleotethys.Here we provide a brief synthesis on recent information from this belt.We infer a southward subduction for the origin of the Eastern Pontides orogenic belt and its associated late Mesozoic-Cenozoic magmatism based on clear spatial and temporal variations in Late Cretaceous and Cenozoic arc magmatism,together with the existence of a prominent south-dipping reverse fault system along the entire southern coast of the Black Sea.Our model is at variance with some recent proposals favoring a northward subduction polarity,and illustrates the importance of arc magmatism in evaluating the geodynamic milieu associated with convergent margin processes.     

晚三叠世昌都——思茅构造带侵入岩的地球化学特征

晚三叠世,昌都-思茅构造带发育典型的裂谷地貌,裂谷型岩浆活动广泛,且广泛出露岩浆岩（主要是火山岩和侵入岩）,针对该区的岩浆岩地球化学特征,我们收集了大量的数据进行分析,发现喷出岩与侵入岩均具双峰特征。岩石化学图解普遍具有张裂因子,结合其它地质资料指出陆内裂谷作用之后的构造环境是一个短暂挤压后的伸展环境。本文就侵入岩进行了阐述。     

Li同位素示踪作用及其在凝灰岩鉴别中的应用

近年来,随着同位素分析手段的不断进步,Li同位素广泛应用于多种地质研究过程的示踪研究中.简要介绍了Li元素独特的地球化学性质和自然界各地质储库中的Li含量及同位素特征,分析了地球表层和地下深部地质过程中Li同位素的分馏机制,总结了Li同位素在示踪大陆化学风化和板片俯冲过程中的应用进展,讨论了在表层和深部物质循环过程中L...