Additional Rb-Sr and single-grain zircon datings of Caledonian granitoid rocks from Albert I Land, northwest Spitsbergen

Previous K-Ar and Rb-Sr datings of the metamorphic and granitic rocks from the northwestern basement region of Spitsbergen mainly show the cooling time of the rocks, except for a Rb-Sr isochron age of the Hornemantoppen granitoid. New samples were collected during several years of geological mapping in the area and the Rb-Sr whole rock isochron and single-grain zircon evaporation methods were applied to the Hornemantoppen granitoids and the grey granites. A dioritic dyke was also dated by the latter method. The bulk rock chemistry study shows that most of both granitic rocks are of the S-type and probably post orogenic, with distinctive incorporation of crustal materials. The isotopic data also support this interpretation. The results of the Rb-Sr isotope analyses, 412 ± 4.8 Ma and the zircon Pb evaporation age of 424 ± 56 Ma, confirm the previous age of the Hornemantoppen granitoid, 414 ± 10 Ma. An older zircon age of 547 ± 19 Ma is considered to be the minimum age of inherited zircon. Zircons from the grey granites suggest an age of ca. 420 Ma with a large error. Field relations demonstrate that the grey granites are older than the Hornemantoppen granitoids. A minimum inherited zircon age, 952 ± 20 Ma, has been obtained from the grey granites. Three multi-grain Pb ages, 423 ± 22 Ma (2 grains), 461 ± 42 Ma and 561 ± 93 Ma (the last two 3 grains) were considered to be mixed ages. Although no definitive evidence for the presence of Grenvillian granites in this area has been obtained in the present study, preliminary results from the multi-grain zircon evaporation method, carried out in the Russian laboratory at Apatity, infer Paleo- and Mesoproterozoic protoliths for the metamorphic rocks of northwestern Spitsbergen.     

安徽铜陵早二叠世茅口期Tubiphytes—叶状藻丘储集条件研究

茅口期 Tubiphytes—叶状藻丘及其碳酸盐岩组合的储集空间类型包括孔隙、洞穴、缝隙和喉道,形成了孔隙—喉道型、裂隙—喉道型、孔洞—裂隙型等三种类型的储集空间结构。据孔隙度、渗透率、压汞等分析测试认为,叶状藻障积岩可以成为差的储集岩,而亮晶藻屑灰岩、生屑灰泥岩、Tubiphytes 粘结岩等均为非储集岩。研究区藻丘中含有大量的碳沥青(尤其是深埋溶孔中)也说明了在潜伏礁(丘)体中寻找良好油气储层的潜力是很大的。     

东南极格罗夫山镁铁质麻粒岩的变质作用

东南极内陆－格罗夫山存在一套经历了麻粒岩相变质作用的镁铁质麻粒岩和斜长角闪岩。变质反应结构显示该区多为单一的区域性麻粒岩相变质作用。但是，对含石榴石的镁铁质麻粒岩的详细工作则显示了包括3个阶段的近等温降压（ITD）的顺时针PT演化轨迹，M1：0．93GPa＞800℃：M2:0.65GPa,733-850℃;M3:0.46-0.61GPa，并有着与拉斯曼丘陵相似的演化历史。根据矿物组合和成分、变质反应结构及温压计算结果，格罗夫山镁铁质麻粒岩可能为高压麻粒岩。     

Impact of fractal characteristics on evaporation and infiltration in unsaturated heterogeneous soils

ABSTRACT

In this study, an approach is developed to investigate the impact of fractal characteristics of unsaturated soil between the water table and land surface on the steady-state evaporation and infiltration across a heterogeneous landscape. The soil domain is conceptualized as a collection of stream tubes of soils and the particle diameters in various stream tubes follow a fractal distribution. The saturated hydraulic conductivity of each stream tube is related to the representative particle diameter in the tube. The effective specific discharge is then integrated from the specific discharge for each stream tube and the fractal distribution. The effective evaporation and infiltration in unsaturated soils increase with the fractal dimension. The ratio of minimum over maximum diameters does not significantly affect the specific discharge in the fractal soil. The specific discharge in unsaturated fractal soils calculated by using the simple average particle diameter mostly over-predicts the actual effective specific discharge.     

生态环境地质学——21世纪新兴的地球学科

环境地质学研究人为地质活动所引起的灾害，地质环境学研究自然环境对人类的影响，两者是完全不同的学科。生态环境地质学应用生物学、环境学和地质学的原理和知识，解决由于人类利用和开发自然环境而引起的问题。生态环境地质学牵涉到分类学、生态学、生物化学、环境化学、沉积学、第四纪地质学和地球化学的研究，涉及到由于人为的地质作用而引起的元素重新迁移、重新富集和重新沉积的过程，对于生命和人类的健康是非常重要的，还涉及到国家和地区经济的可持续发展。生态环境地质学的研究包括下列内容：(1)生态环境地质可容负荷研究；(2)监测研究；(3)预警研究；(4)修复研究；(5)实验研究；(6)虚拟研究。     

活塞洗井工艺分析与研究

针对实践中活塞洗井工艺的“混乱”性，认真分析研究了该工艺的理论实质，指出了其“混乱”的原因，并提出了该工艺比较完整的理论体系。     

PRELIMINARY RESEARCH OF THE PACIFIC-INDIAN OCEAN SSTA MODE AND DEFINITION OF ITS INDEX

Applying the empirical orthogonal function (EOF) analysis to the sea surface temperature (SST) field of the tropical Pacific and Indian Oceans for determination of the first eigenvector field, the current work reveals that there are significant zonal gradients of SST in all seasons of the year in the northwestern and eastern Indian Ocean and equatorial central and eastern Pacific and western Pacific. It is also found that the variance contribution rates of the first EOF mode of every season is more than 33%. This shows that this kind of spatial distribution of the SST is stable. This pattern is named Pacific-Indian Oceans SSTA mode. Through careful analysis and comparison, an index of the mode was defined.     

Microcosmic analysis of ductile shearing zones of coal seams of brittle deformation domain in superficial lithosphere

For many years, the study on ductile shearing zones mainly focuses on the strain analysis and the characteristics of microcosmic structure of felsic duc-tile shearing zones in deep layers (8—10 km). Discus-sions on the process of the development of small-type and mini-size ductile shearing zones have been re-ported in recent years[1,2]. 揇uctile deformations in brittle deformation擺3] and 揵rittle deformations in ductile deformation擺4] are rather a familiar phenome-non in nature. Researchin…