Geochronology and Geochemical Characteristics of Intrusion in the Jinchangliang Gold Deposit, Inner Mongolia and Their Tectonic Significance

Discovered and mined in recent years, the Jinchangliang gold deposit has not yet been studied in its genetic type. In this paper, the geological features of ore deposit, S isotopic composition, metallogenic age and elements geochemical of the granite closely related to mineralization were discussed. The results of the geological features of ore deposit and S isotopic composition show that ore-bearing hydrothermal solution was closely related with the intrusion of magmatic. The granite is characteristic of high silica SiO_2=72.38%–72.98%, high aluminum and Al_2O_3=14.22%–14.35%, low calcium CaO=0.16% –0.26%, and low value of FeOT/MgO(6.86–7.73), and rich in alkalis Na_2O+K_2O=9.11%–9.24%, suggesting that it is high-K calc-alkaline, highly fractionated, weak aluminum A-type granite. The REE patterns are inclined to right and show intense fractionation between LREE and HREE, without obvious negative Eu anomaly(δEu=0.80–0.84). The primitive mantle-normalized spidergrams are characterized by depletion of Ba, U, Ta, Nb, Zr, Ti and P, which implies that the granite has the characteristics of the crust-mantle mixing. S isotopes also indicate that the material source of gold deposit is closely related to the granite rocks. The LA-ICP-MS Zircon UPb age of the Damiao rock mass medium-fine grained monzogranite(belonging to the early IndoChina) is(245±1) Ma. It shows that Jinchangliang gold deposit was not formed in Yanshanian, but the early Indo-China. Specifically speaking, the deposit was formed in the collision stage of the North China plate and the Siberian plate.     

差分GPS在乌拉特后旗1:25万区域重力调查中的应用

测地工作精度的高低直接影响着重力测量的精度,研究并采取行之有效的测地方法来配合重力测量工作是十分必要的。乌拉特后旗1:25万区域重力调查GPS测地工作采用1954年北京坐标系,重力测点平面位置、正常高采用差分GPS测量方法。结果表明,采用此方法既能满足技术要求,又达到了省时省力,且达到了重力测量的精度要求。     

Trematode parasites of Otago Harbour (New Zealand) soft‐sediment intertidal ecosystems: Life cycles,ecological roles and DNA barcodes

Parasites, in particular trematodes (Platyhelminthes: Digenea), play major roles in the population dynamics and community structure of invertebrates on soft‐sediment mudflats. Here, we provide a list of the 20 trematode species currently known to infect molluscs, crustaceans and polychaetes from Otago Harbour (New Zealand) soft‐sediment intertidal areas, as well as information on their transmission modes, life cycles, andknown ecological impacts. Several of the host‐parasite species combinations recorded here are reported for the first time. We also provide DNA barcodes, based on sequences of the cytochrome oxidase subunit l (CO1) gene, for 19 of the 20 trematode species, to facilitate future identification of these parasites in marine ecological studies.     

瑞雷波"之"形速度-深度曲线的成因

本文通过对层状介质的瑞雷方程进行求解,验证了层状介质中瑞雷波的多阶性,讨论了各阶导波对频散曲线的影响．在此基础上,从两个方面对实测速度-深度曲线常出现的“之”字形进行了解释,提出了其中还有待进一步解决的问题及相应的建议．     

FZY-1型多分量式钻孔应变仪的设计

介绍了最新研制的FZY-1型多分量式钻孔应变仪的探头的设计,所采用的电路,仪器参数的检测方法及该仪器的安装方法。     

闽中梅仙式铅锌银矿床矿质来源的硫、铅同位素示踪及成矿时代

福建闽中地区是我国又一个新的、重要的火山岩容矿块状硫化物铅锌多金属成矿带。为查明梅仙式铅锌银矿床的金属成矿物质来源和成矿时代,本文对其中5个主要矿床进行了矿石矿物和围岩的硫、铅同位素测试和同位素地质年代学研究。结果表明,不同矿床矿石硫化物的硫同位素组成变化范围较小且平均值接近于零,δ34S介于-3.5‰~ 5.6‰,平均 2.0‰,表明硫主要为岩浆来源,火山直接喷发和从容矿火山岩中淋取皆是可能的机制。大部分矿床矿石铅以放射性成因为特征(206Pb/204Pb>18.140、207Pb/204Pb>15.584、208Pb/204Pb>38.569),且矿石铅同位素值均大于围岩,指示铅可能主要是由容矿火山岩淋滤而来。根据矿床地质特征和同位素地质测年数据,厘定出两次重要的铅锌成矿作用,即中-新元古代海底火山喷流沉积同生成矿(赋矿围岩单颗粒锆石U-Pb法、Sm-Nd等时线法和40Ar-39Ar法年龄介于933~1788Ma)和燕山期岩浆热液叠加改造成矿(侵入岩锆石SHRIMPU-Pb和Rb-Sr等时线年龄为127~154Ma)。     

东秦岭南泥湖钼（钨）矿田Re—Os同位素年龄及其地质意义

位于华北克拉通南缘东秦岭钼矿带的南泥湖为一超大型夕卡岩斑岩型钼(钨)矿田,本研究采用电感耦合等离子体质谱仪法对南泥湖钼矿田三个矿床6件辉钼矿进行了Re-Os同位素年龄测定,获得南泥湖矿床的辉钼矿Re-Os模式年龄为141.8±2.1 Ma;三道庄矿床的辉钼矿Re-Os模式年龄为144.5±2.2～145.0±2.2Ma,平均为145.0±2.2 Ma;上房沟矿床的辉钼矿Re-Os模式年龄为143.8士2.1～145.8±2.1 Ma,平均为144.8±2.1 Ma;6件样品的等时线年龄为141.5±7.8 Ma(2σ),准确厘定了成矿时间.Re-Os同位素还表明:南泥湖钼矿的成矿物质来源以下地壳成分为主,但混有少量地幔组分.南泥湖钼矿是在中国东部中生代构造体制大转换中形成,属于中国东部中生代大规模成矿作用的一部分.     

河南泌阳凹陷老第三系核桃园组核二段沉积体系研究

核二段沉积时期泌阳凹陷总体处于从断陷向坳陷转换的过渡阶段。本文利用测井、钻井和C、O同位素等资料，研究了核二段各砂组沉积时期的沉积环境、相带分布、砂体展布以及沉积演化规律。核二段时期，泌阳凹陷发育5种沉积体系类型：辫状河三角洲、扇三角洲、正常三角洲、近岸水下扇和盐湖沉积体系。物源供给条件和古地形严格控制了泌阳凹陷各种沉积体系的发育。在陡坡带的中、西部地区发育扇三角洲沉积体系，而在陡坡带东部则发育近岸水下扇沉积体系；在东北部缓坡带发育辫状河三角洲，而在西北部缓坡带则发育正常曲流河三角洲。借用C、O同位素数据估算核二段沉积时期平均古水温为28.17 ℃，最高46.8 ℃；环境指标Z值平均为126.84，表明核二段整套地层都为盐湖咸水沉积条件。从纵向上δ¹³C、δ¹⁸O及Z、t演化看，核二段地层演化表现为两个旋回：从三砂组底到二砂组底部为第一次湖水变咸、湖盆收缩，从二砂组底部到核二段顶为第二次湖水变咸、湖盆收缩。     

黄河下游悬河稳定性因素分析

黄河悬河的形成是自然营力与人为因素综合作用的产物。悬河的稳定性关系到黄河下游广大人民的生命财产安全。影响黄河悬河稳定性的因素有：地质构造控制机制，河流地貌的影响，河床质与土体结构，河流动力地质作用和治理工程对悬河稳定性的影响。在此基础上，制定出一系列治理黄河悬河的对策。