中国近海浮游桡足类中华哲水蚤（Calanussinicus Brodsky）的分子系统地理学和种群遗传结构研究

Planktonic copepod Calanus sinicus is the dominant meso-zooplankton in the Northwest Pacific Ocean. To better understand its population dynamics and phylogeographic patterns, 243 C. sinicus individuals were collected from seven locations across the shelf waters of China and its population genetics was studied by mitochondrial DNA cytochrome oxidase I(mtCOI) sequences analyses. Thirty-nine different sequences, or haplotypes, were detected with moderate haplotype diversity(h=0.749) and low nucleotide diversity(π=0.003) for all populations. The evolutionary divergence between geographic populations varied from 0.24% to 0.37%, indicative of very limited genetic differentiation. Visualized minimum spanning network(MSN) and phylogenetic analysis of all the detected haplotypes did not reveal any clear phylogeographic pattern. Furthermore, AMOVA data showed no significant spatial population differentiation existed among the individuals collected across China shelf waters. Pairwise FST values showed that population collected from northwest of the East China Sea(ECS) displayed a low difference to other populations. Mismatch distribution analyses and neutrality tests indicated that C. sinicus might undergo a demographic/population expansion. No significant population genetic structuring was detected, indicating an extensive gene flow among the C. sinicus populations. Our results provide molecular evidence for the hypothesis that C. sinicus in the northwestern South China Sea in winter is transported from the East China Sea and the Yellow Sea by the China Coastal Current during the northeast monsoon period.     

Distribution and sources of heavy metals in the sediment of Xiangshan Bay

Heavy metals in the surface sediments and sediment core from the Xiangshan Bay, a mariculture base on the coast of the East China Sea, were determined by inductively coupled plasma mass spectrometry(ICP–MS) in order to evaluate their levels and sources. The results showed that the levels of Cu, Pb, Zn, and Cr in the sediments of the bay have been generally influenced by anthropogenic inputs since the founding of the People's Republic of China. In particular, Cu and Zn were polluted to some extent, as evidenced by high enrichment factors. Organic matter, grain size, wastewater discharge, and low energy hydrodynamic environment played dominant roles in the heavy metal enrichment in the sediments. The ratio of terrigenous source to marine biogenic deposit of trace metals in the sediments was calculated, revealing that terrigenous inputs were the main source of Cu, Pb, and Zn, while biological pellets contributed much more to the enrichment of Cr and Cd. Considering the influence of biological sources on the enrichment of Cd and Cr, and the fact that the sediment has been polluted by Cu and Zn, the development of mariculture and discharge of wastewater into the Bay should be restricted.     

东太平洋海隆深海热液区沉积物古菌多样性分析

采用PCR-RFLP方法对东太平洋海隆深海热液区3个站位沉积物中的古菌多样性进行了初步研究.结果显示,从古菌16S rRNA基因文库中随机挑取的296个阳性克隆分属奇古菌门（Thaumarchaeota,47.64%）、广古菌门（Euryarchaeota,44.93%）、泉古菌门（Crenarchaeota,6.77%）和未分类古菌（0.68%）,其中优势菌群为奇古菌门的亚硝化侏儒菌属（Nitrosopumilus,35.47%）和广古菌门的热原体纲（Thermoplasmata,27.03%）,DHVE3、DHVE5、DHVE6、MBGB和MBGE类群在沉积物样品中也均有发现.另外,3个站位沉积物中古菌类群组成存在差异,S5-TVG1站位样品文库的97个古菌克隆分属奇古菌门（49.48%）、广古菌门（49.48%）和泉古菌门（1.03%）,S14-TVG10站位样品文库的103个古菌克隆由奇古菌门（84.47%）和广古菌门（15.53%）组成,S16-TVG12站位样品文库的96个古菌克隆包括广古菌门（71.88%）、泉古菌门（19.79%）、奇古菌门（6.25%）和未分类古菌（2.08%）.研究结果表明,东太平洋海隆深海热液区沉积物中古菌多样性丰富,存在着许多新的古菌菌群;不同站位古菌菌群结构以及多样性存在差异,这与其所处环境的热液活动密切相关.     

新疆哈密东盐池附近变质基底特征及控矿探讨

新疆哈密东盐池附近变质基底属于塔里木板块北缘北山古生代裂谷带西段一部分,而板块北缘的北山地区古生代进入了陆块裂解、陆内裂谷发展演化时期。笔者对东盐池附近的变质岩进行了研究,将该区域变质作用分为区域变质、动力变质及接触变质等3个类型;将区内变质相分为低角闪岩相、高绿片岩相、低绿片岩相及葡萄石—绿纤石相等4个变质相带相系。研究了地质事件与变质变形的演化趋势,即变质作用从区域中高温变质、区域低温动力变质到区域埋深变质,变质作用的温度和压力随时代更新逐次降低。探讨了变质作用与矿产的关系,即变质作用控制变质矿产的分布。各种变质作用所形成的热液与其他热液一起促使成矿物质的活化迁移至有利部位成矿,形成了黑色岩系中的磷矿、石墨矿和钒矿等。     

《地质通报》第34卷第1期要目预告

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降雨入渗补给地下水数值模拟研究

针对在地下水资源评价中入渗补给量采用经验估算存在较大误差的问题,以神东矿区为例,在广泛调查矿区包气带岩性结构并结合野外取样、室内参数测定的基础上,采用数值模拟的方法建立包气带水分运移数值模拟模型,定量模拟矿区内不同地段降雨入渗强度,探讨影响降雨入渗强度的主要因素,计算得出研究区降雨入渗系数大致在0.18~0.27,分析认为影响降雨入渗强度的因素有降雨量、潜水埋深、包气带岩性等。其中在研究区广泛分布的风积沙对地下水资源起到了一定的保护作用。     

鄂西渝东地区震旦系灯影组古岩溶作用特征

鄂西渝东地区中寒武统蒸发岩类盖层之下的震旦系灯影组海相岩溶地层是我国南方的重要勘探目的层。基于野外地质调查、系统薄片观察以及地球化学资料,认为这一地区存在桐湾运动两个幕次的隆升过程以及相关的古岩溶作用。在灯影组上部和中部分别形成了1个和2个洞缝带,其充填作用规律性强,以化学沉淀充填为主。上部洞缝带依次被泥晶白云石、微晶白云石以及粉晶至粗晶白云石三期充填,而中部的两个洞缝带依次被泥晶白云石、微晶白云石、纤状白云石以及粒状白云石四期充填。初步认为这些充填物发育与否主要受下渗的饱和碳酸盐流体的流动路径、流速等因素控制,残存孔隙是现今储集层的主要储集空间。灯影组古岩溶型储层应是今后这一地区油气勘探中需要关注的重点之一。     

How many sutures in the southern Central Asian Orogenic Belt：Insights from East Xinjiang-West Gansu（NW China）？

How ophiolitic mèlanges can be defined as sutures is controversial with regard to accretionary orogenesis and continental growth.The Chinese Altay,East junggar,Tianshan,and Beishan belts of the southern Central Asian Orogenic Belt（CAOB） in Northwest China,offer a special natural laboratory to resolve this puzzle.In the Chinese Altay,the Erqis unit consists of ophiolitic melanges and coherent assemblages,forming a Paleozoic accretionary complex.At least two ophiolitic melanges（Armantai,and Kelameili） in East Junggar,characterized by imbricated ophiolitic melanges,Nb-enriched basalts,adakitic rocks and volcanic rocks,belong to a Devonian-Carboniferous intra-oceanic island arc with some Paleozoic ophiolites,superimposed by Permian arc volcanism.In the Tianshan,ophiolitic melanges like Kanggurtag,North Tianshan,and South Tianshan occur as part of some Paleozoic accretionary complexes related to amalgamation of arc terranes.In the Beishan there are also several ophiolitic melanges,including the Hongshishan,Xingxingxia-Shibangjing,Hongliuhe-Xichangjing,and Liuyuan ophiolitic units.Most ophiolitic melanges in the study area are characterized by ultramafic,mafic and other components,which are juxtaposed,or even emplaced as lenses and knockers in a matrix of some coherent units.The tectonic settings of various components are different,and some adjacent units in the same melange show contrasting different tectonic settings.The formation ages of these various components are in a wide spectrum,varying from Neoproterozoic to Permian.Therefore we cannot assume that these ophiolitic melanges always form in linear sutures as a result of the closure of specific oceans.Often the ophiolitic components formed either as the substrate of intra-oceanic arcs,or were accreted as lenses or knockers in subduction-accretion complexes.Using published age and paleogeographic constraints,we propose the presence of （1） a major early Paleozoic tectonic boundary that separates the Chinese Altay-East Junggar multiple subduction system     

青海东昆仑哈日扎多金属矿区构造活动的锆石裂变径迹定年分析

青海省哈日扎多金属矿区位于东昆仑东段,属东昆中多旋回岩浆弧带,是新的矿产勘查基地,成矿作用主要受NE和NW向两组构造蚀变带控制。本文通过不同类型样品的锆石裂变径迹定年分析,探讨区内的构造活动。所获得的10个样品年龄为116~204 Ma,并由3个组年龄构成,即204~181 Ma,142~168 Ma和116~120 Ma。第1组年龄204~181 Ma反映印支晚期三叠纪末羌塘地块与昆仑地块碰撞的地质事件及其时限;后两组年龄主要是晚侏罗世~早白垩世冈底斯地体向北与羌塘地体碰撞汇聚的响应,活动时限为168~116 Ma。第2和3组年龄同时表明本区燕山期构造活动存在强度差异,即有两个强作用期。同时,3组年龄也揭示本区具有多期次成矿活动。     

东准造山带原泥盆系的形成时代及源区：碎屑锆石U-Pb年代学证据

新疆东准地区晚古生代地层出露广泛,其沉积时限的精确限定对理解中亚造山带的增生和拼贴过程、确立该地区构造框架及油气开发具有深远意义。然而,目前的研究主要集中于岩浆岩方面,对于晚古生代地层时代及其空间展布的研究则相对缺乏,特别是石炭系和泥盆系沉积地层标定较为模糊。为此,本文选取了3个原泥盆系砂岩进行了细致的野外剖面测制、岩石学观测和碎屑锆石U-Pb年代学分析。研究显示：原泥盆纪砂岩的最年轻碎屑锆石年龄为346～312 Ma,碎屑锆石年龄谱图分为：380～310 Ma（晚泥盆世-早石炭世,71.8%）、445～385 Ma（志留纪-早-中泥盆世,11.7%）、480～450 Ma（奥陶纪,3.9%）、540～485 Ma（寒武纪,4.5%）和前寒武纪年龄段（8.1%）,碎屑锆石年龄谱图区域上具有由南向北、由西向东呈简单化趋势且晚古生代年龄比重增加。结合该区岩浆岩年代学研究成果,将研究区原泥盆系沉积时代重新厘定到晚石炭系早-中期,认为东准地区的碰撞拼贴时间应发生于晚石炭世,并非是不同期次碰撞拼贴之产物。