山东兖州煤矿区侏罗纪红层孔隙测试及其影响因素分析

在山东兖州煤矿区,侏罗纪红层含有较为丰富的地下水,赋水空间以孔隙为主。综合利用宏观岩芯观察和微观形态分析对红层的孔隙类型进行了较为详细地论述,主要有粒间溶蚀扩大孔隙、粒间缩小孔隙、胶结物溶蚀孔、粒内孔隙和晶间孔隙。指出岩石颗粒组分、颗粒分选磨圆程度、胶结方式及胶结程度等是影响红层中孔隙发育的主要因素,对照扫描电子显微镜（SEM）观察和压汞试验曲线对它们的影响方式和程度作了详细的论述。通过对比具近似孔隙率岩样的压汞测试结果,认为相同孔隙率的岩样可具有不同的孔隙结构形态,结构形态对赋水性能具有决定作用,孔隙结构形态的差异决定了红层储水空间内在结构特征的不同。     

焦坪矿区的斜向交织构造及其控煤作用

区内斜向交织构造可划分为四级,其共同特点是坳陷(同期向斜)宽阔,隆起(同期背斜)狭窄;坳陷区有利于煤层的聚积和保存,隆起区不利于煤层的聚积和保存,甚至成为无煤区。聚煤作用及煤层厚度变化规律受着不同级次的斜向交织构造综合迭加效应的控制。     

塔里木盆地阿瓦提-满加尔坳陷三叠—侏罗纪沉积物源变迁

对塔里木盆地阿瓦提-满加尔坳陷三叠—侏罗纪的沉积物源从时空变化上进行了探讨.利用砂岩和砾岩的成分分析, 从纵向上研究沉积物源的演化, 认为包括沙雅前陆隆起在内的毗邻造山带的隆升是随着古生界的揭露而逐步隆起的; 利用岩相展布, 从平面上分析了沉积物源的变迁, 认为包括沙雅前陆隆起在内的周边物源区是与沉降中心同步发生反时针旋转的, 这种旋转与塔里木盆地的顺时针旋转有关      

Jurassic Intra-plate Basaltic Magmatism in Southeast China: Evidence from Geological and Geochemical Characteristics of the Chebu Gabbroite in Southern Jiangxi Province

Geochemical and isotopic investigations have been carded out on the Chebu gabbroite in southern Jiangxi Province, southeast China and these results are compared with gabbro bodies along the coast of Fujian Province in order to understand their magma sources and tectonic implications. The Chebu intrusion formed at the beginning of the Middle Jurassic （172~4.3 Ma）. These rocks are Ti-rich and Al-poor in major elements, characterized by strong enrichment in large-ion lithophile elements （LILE） and moderate enrichment in high field strength elements （HFSE） and light rare-earth elements CLREE）, without pronounced Nb or Ta anomalies. Age-correlated Sr-Nd isotope ratios show moderately high ranges of （^87Sr/^86Sr）i from 0.7065 to 0.7086 and 0.5124 to 0.5125 of （^143Nd/^144Nd）i. The geochemical characteristics of the Chebu gabbroite suggest that it is notably different from island-arc basalt and similar to intra-plate basaltic rocks. By combining interpretations of its geological and geochemical characteristics and the regional geological development history, the Chebu gabbroitic intrusion is thought to be the product of asthenosphere upwelling and rapid lithosphere extension during a transition of tectonic systems in southeast China. The tectonic environment and source characteristics of the intrusion are different from Cretaceous gabbro bodies along the coast of Fujian Province, The former formed in a tectonic environment of rapid intra-plate lithospheric extension and the source characteristics were of a weakly enriched primitive mantle, whereas the latter originated mainly in a volcanic-magmatic arc extensional tectonic environment and the nature of the source was an enriched mantle with more subduct subducted components.     

Radiometric Dating of Ignimbrite from Inner Mongolia Provides no Indication of a Post-Middle Jurassic Age for the Daohugou Beds

1 Introduction and Background Along with stunning paleontological discoveries from the world-renowned fossil beds in western Liaoning Province of China, recent findings from the lacustrine deposits exposed at the Daohugou village (Fig. 1) near Ningcheng, Inner Mongolia, include superbly preserved pterosaur, salamander, insect, and plant fossils (Ji and Yuan, 2002; Wang et al., 2002; Gao and Shubin, 2003; Zheng et al., 2003; Rasnitsyn and Zhang, 2004). The Daohugou fossil beds consist of…