Formation Mechanism of High Quality Marine Source Rocks—Coupled Control Mechanism of Geological Environment and Organism Evolution

High quality marine source rock (HQMSR) is the key prerequisite for medium to large hydrocarbon accumulations. However, the forming mechanism remains unclear. On the basis of the in-vestigation for the geodynamic setting of the Middle-Upper Yangtze during the Early Cambrian in dif-ferent spatial scales and the analysis of trace elements, the main controlling factors of the development of high quality marine source rock are discussed, with specific consideration of the burial rate of the organic matter. The ...     

贵州银厂坡银矿床蚀变过程中组分迁移特征

银厂坡银矿床碳酸盐化蚀变作用与银的矿化富集在空间上紧密相伴,这种蚀变作用导致矿石与围岩中组分有明显差异。本文通过定量计算阐明组分之间的迁移方向;计算表明在银的原生富集过程中,常量组分的带入与带出最不明显;而微量组分Ａｇ和Ｃｕ、Ｐｂ、Ｚｎ、Ａｓ、Ｓｂ、Ｃｄ、Ｇｅ带入围岩明显。在银的次生富集过程表现为Ａｇ和Ｃｕ、Ｐｂ、Ｃｄ、Ｇａ、Ｇｅ、ＲＥＥ、ＡｌＯ３、Ｆｅ２Ｏ３、ＭｎＯ、Ｋ２Ｏ、Ｐ２Ｏ５的强烈带入,以Ａｌ２Ｏ３、Ｆｅ２Ｏ３、Ｋ２Ｏ、Ｐ２Ｏ５带入强度最大,这是由于ＣａＯ、ＭｇＯ被淋滤,体积亏损造成强烈带入的假象,而Ａｓ、Ｓｂ、Ｚｎ、Ｖ、Ｃｒ、Ｃｏ、Ｎｉ、ＣａＯ、ＭｇＯ为自围岩中带出组分,以ＣａＯ、ＭｇＯ带出强度最大。ＲＥＥ除原生富集的弱蚀变白岩→矿化白云岩表现为带出外,其余原富集过程均表现为带入围岩。造成组分发生迁     

水泥-粉煤灰浆液在水电站隧洞灌浆中的应用

针对三叉水电站引水隧洞Ⅳ标段围岩地质条件,详细分析了水泥-粉煤灰浆液在该工程引水隧洞灌浆中的应用情况。从应用情况综合分析可以得出,隧洞灌浆采用水泥-粉煤灰浆液是可行的,完全能满足设计要求,在保证灌浆质量的前提下,可以降低部分施工成本,具有较好的推广应用价值。     

改性矿物微粉增强硅橡胶性能的研究

硅橡胶作为特种橡胶体系的一个重要成员,以其耐高温、耐寒、耐候及电气特性等优良品质得到国防、航天航空、电子、医疗卫生等行业的青睐［１］。然而,目前工业上主要采用价格昂贵的气相白炭黑作硅橡胶的增强剂,使硅橡胶制品成本偏高,限制了硅橡胶的普及应用,阻碍了硅...     

Trace Elements in Fluid Inclusions in the Carlin—Type Gold Deposits,Southwestern Guizhou Province

Fluid inclusions in quartz from the Lannigou and Yata Carlin-type gold deposits in southwestern Guizhou were analyzed by inductively coupled plasma-mass spectrometry for their trace elements(Co,Ni,Cu,Pb,Zn,Pt,etc.).The results show that quartz fluid inclusions entrapped at different ore-forming stages contain higher Co,Ni,Cu,Pb and Zn.It has been found for the first time that the ore-forming fluids responsible for the Carlin-type gold deposits are rich in Pt.From this it can be concluded that basic volcanic rocks seem to be one of the important sources of ore-forming materials for the Carlin-type gold deposits.     

山东招远大尹格庄金矿成矿流体特征

大尹格庄金矿位于中国胶北地体西北部招平断裂带下盘的蚀变花岗质碎裂岩 (绢英岩 )带中 ,断裂上盘为胶东群变质岩系。金主要产于黄铁绢英岩和黄铁矿±多金属硫化物 石英±碳酸盐脉 -细网脉中 ,构成细脉 -浸染状矿石。对蚀变围岩和金矿石中流体包裹体的研究表明钾长石化岩 (钾长石 -石英脉 )和绢英岩 (第 I和第 II阶段 )的石英中含有丰富的 CO2 -H2 O包裹体 ,而金 -硫化物矿石和石英 -碳酸盐脉 (第 III和第 IV阶段 )中 CO2 - H2 O包裹体数量逐渐减少。显微测温指示 ,钾长石化岩和绢英岩石英中的 CO2 - H2 O包裹体的均一温度范围为 2 80～ 36 0℃ ;而金 -黄铜矿和金 -方铅矿 -闪锌矿矿石中包裹体的均一温度分别为 2 40～ 2 75℃和 180～ 2 5 0℃。显微测温和激光拉曼探针分析表明 ,第 I和第 II阶段的成矿流体含 10～ 2 5mol% CO2 ;而第 III和第 IV阶段的含 <5～ 10 mol% CO2 ,并含少量至可观数量 CH4,H2 S和 SO2 等。广泛的黄铁矿化、碳酸盐化蚀变以及缺乏较高盐度的水包裹体说明金很可能是以硫络合物和碳络合物形式被搬运。金的沉淀与温度下降、由裂隙的(重复 )开放引起明显的压力降低和原始流体的不混溶作用有关 ,具多阶段成矿特点     

Successional stages of biological soil crusts and their microstructure variability in Shapotou region (China)

In order to investigate succession of biological soil crusts (BSCs) and their microstructure variability, we conducted this work in Shapotou revegetation region at the southeast edge of Tengger Deser. The results showed that BSCs generally succeeded as a pathway of “Algae crusts, algae–lichen crusts, lichen crusts, lichen–moss crusts and moss crusts”. Occasionally mosses directly occurred on algae crusts, and BSCs succeeded from algae crusts to moss crusts. Crust vertical stratification was a common phenomenon, from top to bottom an inorganic layer, algae-dense layer and algae-sparse layer were divided in algae crusts; a thallus layer, rhizoid layer and sub-rhizoid layer in lichen crusts; a “stem-leaf” layer, rhizoid layer and sub-rhizoid layer in moss crusts, respectively. The main crust binding organisms varied from filamental cyanobacteria (dominated by Microcoleus) in algae crusts to lichen rhizoids, free-living cyanobacterial filaments and fungal hyphaes in lichen crusts, and to moss rhizoids and fungal hyphaes in moss crusts. The dominant phototrophic organisms varied from Microcoleus (algae) in algae crusts to Collema (lichens) in lichen crusts, and to Bryum (or Didymodon and Tortula; mosses) in moss crusts. Total phototrophic biomass increased while the free-living algal biomass decreased with the succession of BSCs. In addition, exopolysaccharides and fine particles accumulated in the course of development and succession of BSCs, all of which lead to a gradual increase in crust thickness and porosity, while decrease in the bulk density.     

沧参1井石炭,二叠纪地层粘土矿物年代学研究

笔者对沧参1井石炭、二叠纪地层中的粘土矿物特征进行研究,并对不同深度的粘土矿物进行了K－Ar、40Ar－39Ar及Rb－Sr法同位素地质年龄测定,得出至少存在三期伊利石的结论;碎屑伊利石,年龄为400Ma左右,在235—243Ma时受到热扰动;海西期末一印支早期形成的高温伊利石,其年龄为214—234Ma,在145Ma时经受一次热扰动;早侏罗世时期形成的伊利石,年龄为180Ma左右,分布比较普遍。这一研究结果无疑将有助于深入探讨区域地热场的演化,以及进一步研究有关地层的生、储油气能力。     

Zircon U–Pb ages and O–Nd isotopic composition of basement rocks in the North Qinling Terrain, central China: evidence for provenance and evolution

The Qinling Group was previously interpreted as the oldest Precambrian basement unit of the North Qinling Terrain, recording its formation and early crustal evolution. The Qinling Group consists predominantly of gneisses, amphibolites, and marbles, which underwent multi-phase deformation and metamorphism. In order to better constrain the provenance and tectonic setting of this group and the evolution of the North Qinling orogenic belt, in situ U–Pb dating and oxygen isotopic analysis of zircons in combination with whole-rock geochemistry and Sr–Nd isotope analysis was performed on the two dominant rock types, amphibolite and felsic gneiss. Felsic gneisses exhibit enrichment of LREEs and LILEs (Rb, Ba, Th, K, Pb), negative Eu anomalies and depletion of HFSEs (Nb, Ta, P, Ti). The rocks have slightly elevated δ¹⁸O values (6.5–9.3 ‰) and initial ε _Nd values of ?4.6 corresponding to two-stage Nd model age of 1.99 Ga. Amphibolites are also enriched in LILEs and LREEs and depleted in Nb and Ta and have homogeneous δ¹⁸O values (5.0–6.0 ‰), but higher initial ε _Nd values (2.8–3.3) and younger two-stage Nd model ages (1.29–1.24 Ga) compared to the gneisses. The zircon age record indicates that the gneisses and amphibolites were formed in a ~960 Ma volcanic arc environment rather than in a rift setting as previously suggested. A major metamorphic event took place during the Early Paleozoic. Based on the age spectrum of detrital zircons, the Qinling Group is interpreted as an autonomous geological unit, which was mainly derived mostly from 1,000 to 900 Ma old granitoid rocks. The North Qinling Terrain can be regarded as a remnant of the Grenville orogenic belt with an early Neoproterozoic evolution different from that of the North and South China blocks.