不同结构类型煤体地球物理特征差异分析和纵横波联合识别与预测方法研究

本文以对国内外煤层气地球物理探测理论与技术研究现状进行系统回顾和分析的基础上,以淮南矿区主采煤层131煤为例,详细分析和研究了不同结构煤层的测井曲线特征及其与煤层气富集之间的关系;分析研究了多波多分量地震勘探技术在煤层气勘探中的应用基础和主要技术方法,并建立了煤层气富集区预测的测井参数门限和多波地震勘探的技术指标,首次明确指出煤层气富集区和煤矿瓦斯突出灾害区有本质不同,并在地球物理标志中有明显的分辨特征。     

金属元素形成原生晕能力定量评价——以青海省扎家同哪金矿为例

在进行原生晕元素分带研究时,所选元素多未进行筛选,不利于正确认识分带规律及指导矿产预测.本文基于扎家同哪金矿2779个钻孑L样品数据,拟通过定量评价不同金属元素在围岩、矿化围岩、矿石等中的富集程度,研究不同元素在矿化过程中形成原生晕的能力差异.研究发现,扎家同哪金矿Au、As、Sb、Hg、W、Ag在围岩、矿化围岩和矿石...     

湘西狮子山铅锌矿床矿化富集特征及控矿因素——湖南花垣—凤凰地区铅锌矿整装勘查系列研究之一

位于湖南省北西部的湘西花垣狮子山铅锌矿,具有稳定的含矿层位,铅锌矿资源量巨大。铅锌矿的含矿岩层为寒武系下统清虚洞组质纯的含藻屑石灰岩和砂屑石灰岩,岩层单层为厚层至巨厚层,含矿岩层厚度为22.6~237.1m。在含矿岩层中按上、中、下3个部位赋存矿体。在全面总结狮子山铅锌矿床矿化富集特征的基础上,对控矿因素进行了初步分析。     

金属硫化物Re-Os同位素定年技术进展

近30年来,Re-Os同位素分析方法在样品溶解、化学分离及质谱测定,以及微区分析等方面取得了重要进展,Re-Os同位素体系已成为同位素地质年代学研究的一个重要手段。本文对近年来金属硫化物Re-Os同位素分析技术的研究发展现状以及存在的问题进行系统评述,包括野外工作和室内金属硫化物矿物精确识别和挑选、样品的分解、分离富集技术到仪器测定、参考标样选择等,并对化学处理过程中如何提高试剂纯度,避免器皿、试剂和环境污染,如何降低实验流程空白等方面给出了建议,可为相关研究者优化Re、Os及其同位素的高精度测试提供参考。

     

Relationship between Geological Structures and Hydrocarbon Enrichment of Different Depressions in the Bohai Bay Basin

The Bohai Bay Basin contains many depressions with varying degrees of hydrocarbon enrichment associated with the geological structures of different depressions. This study discussed the relationship between the geological structures and hydrocarbon enrichment of the depressions in the Bohai Bay Basin. Based on the Paleogene strata distribution and the length to width ratio of different depressions, their geological structures are divided into three types in plan-view: open(length/width 2), narrow(length/width 4) and transitional types(length/width 2–4). In cross section, the geological structures can be divided into dustpan I, dustpan II and double-faulted types. Based on tectonic evolution and sedimentary characteristics, the depressions are classified into early-formed, inherited and late-formed categories. Generally, narrow depressions are mainly located in the northeast and southwest of the Bohai Bay Basin, while open depressions are dominantly distributed in the central area of the basin; late-formed depressions are mainly around the Bohai sea area, and early-formed depressions are mostly located in the periphery of the basin. Geological structures of the depressions control the formation of the source, reservoir and cap rocks as well as hydrocarbon accumulation setting, and further influence the pay zones and oil-bearing sequence. In detail, dustpan II and doublefaulted depressions mainly have A-type sags, which often possess better hydrocarbon generation conditions than dustpan I ones; hydrocarbons in open dustpan II depressions tend to accumulate in the central uplift areas or buried hill, while those in narrow dustpan I depressions always accumulate in gentle slope belts. The oil-bearing sequence for different evolutional depressions corresponds well with the sedimentary strata of the main development stages of depressions. In early-formed depressions, hydrocarbons are mainly enriched in deeply buried reservoirs, while in late-formed depressions hydrocarbons are abundant in the relatively shallow traps. In summary, most inherited and late-formed dustpan II depressions are enriched in hydrocarbons due to their extensive source rocks and good source–reservoir–seal assemblages, whereas dustpan I and early-formed depressions are relatively poor in hydrocarbons.     

Origin of Paleoproterozoic Komatiites at Jeesiorova, Kittila Greenstone Complex, Finnish Lapland

Komatiites from the 2 Ga Jeesiörova area in Finnish Laplandhave subchondritic Al₂O₃/TiO₂ ratios like those in Al-depletedkomatiites from Barberton, South Africa. They are distinct inthat their Al abundances are higher than those of the Al-depletedrocks and similar to levels in Al-undepleted komatiites. Moderatelyincompatible elements such as Ti, Zr, Eu, and Gd are enriched.Neither majorite fractionation nor hydrous melting in a supra-subductionzone setting could have produced these komatiites. Their highconcentrations of moderately incompatible elements may haveresulted from contamination of their parental melt through interactionwith metasomatic assemblages in the lithospheric mantle or enrichmentof their mantle source in basaltic melt components. Re–Osisotope data for chromite from the Jeesiörova rocks yieldan average initial ¹⁸⁷Os/¹⁸⁸Os of 0·1131 ± 0·0006(2), _Os(I) = 0·1 ± 0·5. These data, coupledwith an initial _Nd of +4, indicate that melt parental to thekomatiites interacted minimally with ancient lithospheric mantle.If their mantle source was enriched in a basaltic component,the combined Os–Nd isotopic data limit the enrichmentprocess to within 200 Myr prior to the formation of the komatiites.Their Os–Nd isotopic composition is consistent with derivationfrom the contemporaneous convecting upper mantle. KEY WORDS: Finnish Lapland; Jeesiörova; komatiites; mantle geochemistry; petrogenesis; redox state; Re/Os isotopes; Ti enrichment     

河南省三川-赤土店地区地球化学特征

在河南省三川—赤土店地区实施1:50000水系沉积物测量的基础上,系统阐述了测区内元素分布特征和规律,指明了区内的主要成矿元素及其富集层位,为区内今后地质找矿指明了方向。     

液膜富集—火焰原子吸收法测定水中痕量铅

用乳状液膜体系对水中痕量铅进行分离富集,研究表面活性剂,内相试剂,膜增强剂等对分离富集过程的影响,确定了二环己基－１８－冠－６（ＤＣ－１８－Ｃ－６）－Ｓｐａｎ８０－丙三醇－四氯经碳－Ｎａ４Ｐ４Ｏ７液膜体系的最佳组成及最适宜的实验条件,并用该法与火焰原子吸收法结合测定天然水中的痕量铅,富集倍数为４５左右,回收率大于９９％,相对标准偏并为０．７７％。     

Eh—pH相图在玉龙铜矿床次生富集作用研究中的应用

玉龙铜矿床表生成矿过程中成矿物质主要呈碳酸盐络合物的形成迁移。以孔雀石,蓝铜矿组合为主的次生富集带是在碱性,氧化的环境中形成的,所以它们相对靠近氧化带的上部及碳酸盐岩发育的地区分布。以赤铜矿,自然铜组合为主的次生氧化物富集带形成环境为弱氧化－还原,它们常靠近氧化带的中,下部分布。表生成矿环境中ＣＯ２含量高是玉龙铜矿床氧化带中黑铜矿极不发育的根本原因。『     

西藏地热活动中铯的富集过程探讨

硅华铯矿是青藏高原独特的铯矿床,它赋存在高温地热活动的产物——硅华中,主要分布在高原的强烈地热活动区。为什么硅华铯矿目前仅在青藏高原发现,别的地方尚未见报导,显然跟青藏高原在近期的构造运动有关。本文详细研究了Cs元素在地热流体和泉华中的特征,以及与Rb、Cl等离子的相关关系,探讨了Cs元素的地球化学行为,总结Cs元素在地热活动中的富集过程:地壳的局部重熔作用导致了Cs的预富集;岩浆的结晶、分异使Cs再次浓集;大规模的水/岩反应使流体中Cs更加富集。