晚古生代右江盆地古岩溶作用研究   总被引：2，自引：0，他引：2  

麻建明  侯明才  陈洪德  田景春  覃建雄  王成善 《沉积与特提斯地质》2005,(Z1)

钻井、露头和区域构造资料的分析结果表明,晚古生代的右江盆地存在多期次的岩溶作用,通常具有1～3个岩溶旋回。这些古岩溶作用主要存在于上二叠统顶部、中二叠统茅口组顶部和石炭系顶部,其次是泥盆系的顶部。古岩溶作用的发生与黔桂运动、紫云运动、东吴运动等所形成的层序界面和低位体系域密切。研究区存在包括风化、区域性大气淡水溶蚀、区域性白云岩化、区域性古岩溶、区域性去白云岩化和区域性淡水胶结充填等6种岩溶作用的层序成因类型。  相似文献   

叙利亚的地震危险性概率区划     

Malk.  AH 徐子君 《地震科技情报》1997,(7):9-12

介绍了叙利亚的地震危险性区划图。对使用其限在５０年，１００年和２００年内超越概率为１０％的基岩峰值地面加速度和修正的麦卡利地震烈率分别进行了研究。概率表示的基岩峰值地面加速率和地震烈率值是值是在假定未来地震的震源是线性震源的条件下确定的。  相似文献   

应用GPS测定高程     

Dods.  AH 李晓桓 《武测译文》1996,(2):19-23

全球定位系统（ＧＰＳ）在长量程时提供高精度的高程测定，有相当大的潜力。在长量程情况下它的精度比传统水准测量的精度高，然而，ＧＰＳ水准测量有它自身的问题，有关大地体的测定、大气传播延迟影响和海洋载荷影响，本文论述了关于工程和大规模环境利用ＧＰＳ进行水准测量的情况。  相似文献   

Genesis and Debelopment of Porosity in Carbonate Reservoirs—Fluid Inclusion Evidence     

覃建雄  曾允孚 《中国地球化学学报》1996,15(4):364-373

Fluid inclusions in minerals filled in pores of reservoir rocks can be used as a good indicator of pore genesis and development so as to shed light on oil generation,migration and accumulation.The relationship between pore evolution and oil generation has been established based on fluid inclusion studies on the Lower Ordovician carbonate reservoir strata in the Ordos Baisn,Northwest China.Seven stages of porosity development can be recogmized.i.e.,the penecontemporaneous,the early and middle-late diagenetic,the supergene,the early,middle and late re-burying stages.The dissolution pores an fissures formed in the supergene and middle-late reburying stage and the structural fractures formed in the late re-burying stage constitute the major traps of oil and gas.The major phase of oil migration and accumulation took place between Late Jurassic and Cretaceous,Corresponding to the middle and late re-burying stages.The generation and accumulation of oil can be closely related to Yenshanian tectonics.  相似文献   

浅议现代沉积学发展方向   总被引：1，自引：0，他引：1  

覃建雄  李余生 《地质科技管理》1996,(5):42-43

  相似文献   

四川龙门山马角坝地区石炭纪层序地层及海平面变化研究   总被引：3，自引：0，他引：3  

覃建雄  曾允孚  黄志勋  吴勇 《沉积与特提斯地质》1996,16(1):19-33

在沉积学、生物地层学研究之基础上，结合沉积地球化学资料，对龙门山马角坝地区石炭系进行了露头层序地层学研究。首次识别出９个三级层序和若干个四至五级高频层序。在三级层序中，岩关组２个、大塘组３个、威宁组２个、马平组２个，它们均可作区域性对比。其中，四个层序分别与冈瓦纳大陆晚古生代五次冰川事件中四次间冰期－冰期旋回相对应，表明其成因与冰川型全球海平面变化有关。显然，研究区石炭纪层序主要受控于全球海平面升降旋回，具有全球对比意义。  相似文献   

A Vendian-Cambrian boundary succession from the northwestern margin of the Siberian Platform: stratigraphy, palaeontology, chemostratigraphy and correlation     

Bartley JK  Pope M  Knoll AH  Semikhatov MA  Petrov PYu 《Geological magazine》1998,135(4):473-494

Siberia contains several key reference sections for studies of biological and environmental evolution across the Proterozoic-Phanerozoic transition. The Platonovskaya Formation, exposed in the Turukhansk region of western Siberia, is an uppermost Proterozoic to Cambrian succession whose trace and body fossils place broad limits on the age of deposition, but do not permit detailed correlation with boundary successions elsewhere. In contrast, a striking negative carbon isotopic excursion in the lower part of the Platonovskaya Formation permits precise chemostratigraphic correlation with upper-most Yudomian successions in Siberia, and possibly worldwide. In addition to providing a tool for correlation, the isotopic excursion preserved in the Platonovskaya and contemporaneous successions documents a major biogeochemical event, likely involving the world ocean. The excursion coincides with the palaeontological breakpoint between Ediacaran- and Cambrian-style assemblages, suggesting a role for biogeochemical change in evolutionary events near the Proterozoic Cambrian boundary.  相似文献   

c-Reactive protein levels as a biomarker of inflammation and stress in the Atlantic sharpnose shark (Rhizoprionodon terraenovae) from three southeastern USA estuaries   总被引：1，自引：0，他引：1  

Karsten AH  Rice CD 《Marine environmental research》2004,58(2-5):747-751

Circulating c-reactive protein (CRP) levels can be used as a bioindicator of the acute phase inflammatory response and as a possible biomarker of inflammation and neurogenic stress in vertebrates. Currently, there are no data describing the ranges of CRP levels in sharks living in different habitats, especially habitats of differing degrees of pollution. Developing antibodies against CRP is a first and critical step towards developing sensitive methods for quantifying CRP, and thus inflammatory and stress responses in sharks. Sharpnose shark, Rhizoprionodon terraenovae, serum C-reactive protein was purified sequentially over AH-sepharose 4B-PC and sepharose CL-4B columns and used to immunize balb/c mice for generating stocks of polyclonal anti-sera. Serum samples from 131 sharpnose sharks were collected from three different geographical regions along the coast of SC and GA, USA between June and November 2002. Total CRP concentrations were quantified by ELISA and found to be highest in the sharpnose shark population collected in the summer from Charleston, SC, compared to Beaufort, SC and Brunswick, GA. Seasonal comparisons indicated a higher CRP concentration in the summer of the Charleston, SC population compared to the fall. These data suggest that sharks living in the Charleston, SC harbor estuary may be exposed to a suite of pathogens or other stressors that are different than those found in the Beaufort, SC and Brunswick, GA estuaries. These data support the use of CRP as a bioindicator of health status in elasmobranchs.  相似文献   

Linkages between cellular biomarker responses and reproductive success in oysters--Crassostrea virginica     

Ringwood AH  Hoguet J  Keppler C  Gielazyn M 《Marine environmental research》2004,58(2-5):151-155

The purpose of these studies was to evaluate if there were relationships between lysosomal destabilization or glutathione concentrations and gamete viability of oysters, Crassostrea virginica. Oysters were collected from field sites during the peak spawning period (May-June) during 2001 and 2002. Lysosomal destabilization rates and glutathione concentrations of hepatopancreas tissues (e.g. digestive gland) were determined. Eggs and sperm from the same adults were also used to conduct embryo development assays with reference seawater collected from a clean site, site water, and also a range of Cd concentrations (the Cd exposures were used to determine if there were differences in susceptibility to pollutants). Baseline embryo development success (e.g. percent normal development when the assays were conducted with reference seawater or site water) was related to lysosomal destabilization, but not glutathione status. However, the susceptibility of embryos to metal toxicity was related to glutathione status, i.e., sensitivity to Cd exposures increased with decreasing glutathione levels. These studies support the hypotheses that there are linkages between embryo development success and susceptibility to pollutant stress and cellular biomarker responses. These kinds of effects on reproductive success could lead to subtle but significant long-term effects on recruitment and viability of oyster populations.  相似文献   

成都龙泉驿紫色土元素迁移及其与桃树黄化关系的模拟   总被引：1，自引：0，他引：1  

吴勇  覃建雄 《成都理工学院学报》1995,22(3):91-95

文章通过模拟实验建立了龙泉驿桃园土壤Ｃａ＾２＋指数衰减迁移模式，分析了Ｃａ＾２＋和Ｍｇ＾２＋差异迁移原因，认为Ｍｇ＾２＋迁移过程中峰值是土壤团粒结构破坏产生大量解吸Ｍｇ＾２＋的结果。桃树黄化区土壤富ＳｉＯ２和Ａｌ２Ｏ３，而贫活性元素，致使可迁出离子总量远远小于正常土壤，并影响桃树对其他元素的正常吸收，导致黄化。  相似文献