鄂尔多斯盆地多种能源共存富集的组合形式及上古生界沉积控制机制分析   总被引：5，自引：4，他引：5  

李增学  余继峰  李江涛  韩美莲 《地球学报》2007,28(1):32-38

鄂尔多斯盆地煤、石油、天然气和铀的成藏相互关联,共存富集组合类型多样,在纵向呈规律叠置.晚古生代是鄂尔多斯盆地重要的成矿时期,虽然在盆地属性上与整个中国北方成为一体,沉积上基本一致,但也具有其特殊性.根据对鄂尔多斯盆地上古生界含煤地层沉积特征和层序界面的分析,可以将本溪组至石盒子组划分出9个三级层序,4个二级层序.总体上看,多种能源矿产存在油中气、煤中气、上气下油、油中铀、煤中铀、煤中油,以及单种矿产独立富集等7种共存富集形式.在盆地发展演化过程中,在不同的构造单元叠置了不同的能源组合类型,并且表现出某些相关性.  相似文献   

三疣梭子蟹(Portunus trituberculatus)微卫星位点的分离和序列分析   总被引：2，自引：1，他引：1  

王建平  余晓巍  沈庞幼 《海洋与湖沼》2009,40(1):83-87

采用磁珠富集法,利用生物素标记的(GT)15寡核苷酸探针从三疣梭子蟹基因组DNA的Sau3A1酶切的500-1000bp片段中筛选微卫星序列.洗脱的杂交片段克隆到PMD18-T载体上构建富集微卫星基因组文库后,通过PCR筛选检测出阳性克隆进行测序.在56条测序序列中有49条非冗余序列包含有重复次数不少于5次的微卫星位点,阳性序列比例达到87.5%.其中perfect类型微卫星最大的重复次数为47次.在47条非冗余序列中,共有40条(85.1%)微卫星重复序列两端有侧翼序列能够进行引物设计.本研究中筛选的微卫星位点将为下一步的三疣梭子蟹种群遗传结构分析、经济性状的QTL定位提供遗传标记.  相似文献   

The Irish Sea: Is it eutrophic?     

R.J. Gowen  P. Tett  K. Kennington  D.K. Mills  T.M. Shammon  B.M. Stewart  N. Greenwood  C. Flanagan  M. Devlin  A. Wither 《Estuarine, Coastal and Shelf Science》2008

The question of whether the Irish Sea is eutrophic is addressed by reviewing the evidence for anthropogenic nutrient enrichment, elevated phytoplankton production and biomass and undesirable disturbance in the context of the EU and OSPAR definitions of eutrophication. Winter concentrations of dissolved available inorganic phosphate (DAIP), nitrogen (DAIN as nitrate and nitrite) and silicate (Si) in coastal waters and concentrations of DAIP and Si in offshore waters of the Irish Sea are elevated relative to winter Celtic Sea shelf break concentrations (0.5 μM DAIP, 7.7 μM DAIN and 2.7 μM Si). Significant, negative nutrient salinity relationships and analysis of the Isle of Man nutrient time-series indicate that the elevated Irish Sea levels of DAIP and DAIN are the result of anthropogenic enrichment with highest concentrations (≈2.0 μM DAIP, 30 μM DAIN and 17 μM Si) measured in near shore eastern Irish Sea waters.  相似文献   

Macrofaunal density, biomass and composition of estuarine sediments and their relationship to the river plume of the Rhone River (NW Mediterranean)     

Rachel Hermand  Chantal Salen-Picard  Elisabeth Alliot  Claude Degiovanni 《Estuarine, Coastal and Shelf Science》2008,79(3):367-376

This study investigates species community patterns and sediment relationships of benthic macrofauna off the Rhone river delta. Along a WE transect, changes in diversity, density, biomass and trophic structure were coupled with the mean extension of the river dilution plume. Species number and diversity were at a minimum off the river mouth, below the area of the minimum surface salinity. Density decreased by a factor 2 and biomass by a factor 5 from the fluvial to the marine system. These features are due to high overload of terrestrial organic matter in the river prodelta as evidenced by the carbon isotopic signature of surface sediment and by pigment content. On the basis of a non-metric MDS analysis and of Dufrêne and Legendre method (1997), groups of stations and characteristic species associated were identified. These species, mainly small capitellids, spionids, lumbrinerids and sternaspids, correspond to a successional dynamic in response to changes in sedimentation conditions, mainly in organic matter quality of the surface sediment. The succession observed in space was similar to described in macrotidal estuaries and off other deltaic systems all over the world and to that observed in time following the Rhone river severe flood events. Results suggest that organic matter quality is an important factor with regard to benthic macrofauna successions and recovery mechanisms following disturbances. The differences observed between the Rhone deltaic system and the general model of relations between shelf processes and discharge of large rivers are attributed to a more regular supply of organic material from terrestrial origin on the Rhone continental shelf.  相似文献   

湖水同位素平衡研究中分馏系数和富集系数计算形式的组合选择   总被引：3，自引：1，他引：2       下载免费PDF全文

曾承  余俊清 《盐湖研究》2005,13(1):7-11

湖泊自生碳酸盐δ18O(δ18Oc)是研究湖泊水体同位素平衡和气候变化的重要环境同位素指标。由于δ18Oc与湖水δ18O(δ18Ow)密切相关,前人建立了δ18Ow的计算公式,这方面的研究对于δ18Oc环境意义的正确判读十分重要。δ18Ow计算公式中的平衡分馏系数α和平衡富集系数ε各有几种计算形式,当两个参数同时出现时,其计算形式须正确组合:当α>1时,ε=α-1或ε=1-1/α;当α<1时,ε=1-α或ε=1/α-1。其中"α>1,ε=α-1"组合最常用。  相似文献   

海洋环境中氟喹诺酮类抗生素(FQs)分析的样品前处理与检测技术          下载免费PDF全文

温丽联  宋金明  李学刚  马骏  戴佳佳  袁华茂  段丽琴  王启栋 《海洋科学》2023,47(9):103-118

氟喹诺酮类(FQs)药物是一种广泛使用的人工合成类抗生素,存在于水体、沉积物等各种环境介质中,并在水生生物体内得到富集,对人类健康和全球生态系统的可持续发展有重要的影响。环境中FQs残留的分析检测是了解其环境生物地球化学行为和潜在生态环境风险的基础,本文系统总结了近几年海洋水体、沉积物和生物体样品中FQs的残留特征、样品前处理与检测技术,在此基础上,前瞻分析了海洋环境中FQs残留分析检测技术的发展趋势。分析表明,FQs的分离富集和测定必须充分考虑FQs的物理化学性质和样品成分的复杂性。海水样品准备应注意过滤膜的选择和pH的调节;沉积物和生物体的样品准备应考虑水分、萃取溶剂、基质效应和pH的影响,并使用超声萃取。固相萃取、QuEChERS萃取、磁性固相萃取是分离富集FQs较常用的方法,吸附剂、淋洗溶液和洗脱溶液的选择和优化是提高样品回收率的关键。FQs的检测大多通过液质联用或液相色谱结合荧光检测器进行,其中色谱柱的选择、离子对试剂的添加和进样pH值的调整都是优化的关键因素。研究指出海洋领域FQs在线自动SPE技术的开发以及新型萃取吸附剂的研制应在未来研究中被重点关注。  相似文献   

Fluid-rock interaction modeling to constrain Au enrichment: Implication for the giant Jiaodong Au mineralization,eastern North China Craton     

《Gondwana Research》2024

The devolatilization model of the metasomatized lithospheric mantle without pre-enriched gold has been proposed to account for the giant gold mineralization. An excellent example is the world-class Jiaodong gold province with >5000 tonnes Au resources in the eastern North China Craton. The auriferous fluid transport and gold enrichment during wallrock alterations are two vital processes to determine the giant gold mineralization formation in this province. However, the effects of the fluid-rock interaction with alterations on the auriferous fluid transport and gold enrichment still keep poor understanding, which leads the above model to be imperfect. The giant Jiaojia goldfield in this province recorded a wallrock alteration evolution from K-feldspar alteration to pyrite-sericite-quartz alteration, and some parts of the latter can become gold orebodies when the gold grade is >1 ppm. This study conducts thermodynamic fluid-rock interaction modeling to reveal auriferous fluid transport and coupled relationship between gold enrichment and alteration mineral assemblage based on the alteration-mineralization and ore fluid characteristics of the goldfield. The modeling of fluid-rock interaction with cooling indicates the transformation of Au-Cl complexes to Au-S complexes combined with the total sulfur concentration decrease by pyrite precipitation when cooling from ∼460 °C can trigger the dispersive gold precipitation, which should hinder the gold long-range transport to lower ambient temperature. The high oxygen fugacity at >400 °C can enhance Au-Cl complexes stability, and the low pH can maintain high total sulfur concentration in the auriferous fluid, both of which facilitate the long-range gold transport to a lower-temperature environment. The auriferous fluid would acquire higher pH by the buffering of feldspars or sericite, which was beneficial for the high-efficiency precipitations of pyrite and gold. The ankerite-siderite assemblage without pyrophyllite in the pyrite-sericite-quartz alteration zone indicates that a cumulative fluid to rock mass ratio (f/r) of 3.8–4.8 should be needed for the transformation from K-feldspar alteration to pyrite-sericite-quartz alteration according to the fluid-rock interaction modeling at 300 °C and 2000 bar. In the case of auriferous fluids with ≤200 ppb Au concentration, the single fluid-rock interaction can only elevate the gold grade to ≤0.69–0.87 ppm in the pyrite-sericite-quartz alteration zone at f/r 3.8–4.8. Therefore, the fracture-induced fluid flow coupled with fluid-rock interaction is proposed to the prerequisite to elevate the gold grade to >1 ppm in the pyrite-sericite-quartz alteration zone. The metasomatized lithospheric mantle volume for the required ore fluid and Au in the Jiaodong province is estimated according to the modeling results and alteration-mineralization characteristics, which provides a link between the mantle without abnormal Au enrichment and the alteration-mineralization processes.  相似文献