Seismo-tectonic divisions of strong earthquakes with M S≥7.0 and their tectonic geomorphology along Xianshuihe-Xiaojiang fault zone

Seismo-tectonic areas of historical strong earthquakes with M _S≥7 along Xianshuihe-Xiaojiang fault zone are divided, and their individual fault-pattern and tectonic geomorphology are analyzed. Those strong-earthquake areas are located in some special parts of the fault zone, where the major branch-faults of the fault zone form left stepping, parallel, and fork-like patterns. In the strong-earthquake areas structurally complicated basins are developed, such as pull-apart basins in fork-like area, in double stepping area, and in stepping and fork-like areas. Foundation item: Chinese Joint Seismological Science Foundation (9507424). Contribution No. 2001A003, Institute of Crustal Dynamics, China Seismological Bureau.     

Studies on40Ar/39Ar thermochronology of strike-slip time of the Tan-Lu fault zone and their tectonic implications

Samples of mylonite, ultramylonite and phyllonite were collected from 5 localities in the Anhui part of the Tan-Lu fault zone for⁴⁰Ar/³⁹Ar chronological studies. Among them 4 samples from 3 localities on the eastern margin of the Dabie orogenic belt yielded⁴⁰Ar/³⁹Ar plateau ages of 128 —132 Ma; and 2 samples from the western margin of the Zhangbalin uplift and eastern margin of the Bengbu uplift gave the same⁴⁰Ar/³⁹Ar plateau ages of 120 Ma. Isochron analyses and other lines of evidence suggest that the data are reliable. The data are interpreted as cooling ages of sinistral strike-slip deformation of the Tan-Lu fault zone. The younger ages from the north might be related to slower strike-slip rising. These results indicate that the large-scale left-lateral displacement in the Tan-Lu fault zone took place in the Early Cretaceous, rather than in Late Triassic (Indosinian) as proposed by some geologists. Therefore, this fault zone is an intracontinental wrench fault rather than a transform fault or suture line developed during formation of the Dabie orogenic belt.     

应用壤中气汞量测量找金的效果——以湖南青京寨、三德堂金矿为例

湖南青京寨和三德堂分别为破碎带蚀变岩型，残积红土型金矿床。地表存在较厚的残（坡）积覆盖层，应用壤中气汞量测量法寻找隐伏含Au构造蚀变带及金矿体。区内气汞异常带及其峰值与隐伏含Au构造蚀变带及金矿体具有较好的对应性，利用这种对应性并结合区内地质，地球化学特征，施工适当的工程进行验证。在青京寨对6条气汞异常带进行工程揭露验证，各带均发现含Au蚀变带。三德常矿区圈定的金异异常与气汞异常基本一致。壤中气汞量测量法不仅适有于寻找中代温热液型金矿床，而且也适于寻找刚化残积型金矿床。     

江苏溧阳地震孕育和发生的地质因素剖析

研究和剖析了两次溧阳地震孕育和发生的主要地质因素，新生代茅东裂陷盆地；茅东与南京－溧阳两玄武岩喷发带的交汇；茅东断裂带最活动的上沛带；震源区地壳层圈构造（深、浅变质岩界面和低速层）与茅东部断裂带中、深脆－韧性剪切段的复合。探讨了控制溧阳震震级的因素；茅东断裂带属Ⅱ级断裂，茅东裂陷盆地属中、小型裂陷盆地，因此，决定溧阳地震震级为5．0－6．0的中强地震。     

天然气的无机元素的土壤化探元素预测指标的探索

通过德阳新场气田化探成果与气田上有机元素异常，物探异常和钻孔实际见气的对比，以及对成都地区，宜宾地区化探成果的综合研究，认为As,Sb,Hb,Ba,Mn五元素及Cu,Pb,Zn,Mo,Cd,Ni,V,P等是预测天然气的指标，用该指标对新场气田和成都地区实际勘察结果对照，证实预测指标是正确的，从而探索出一条利用化探无机元素异常寻找天然气的新路。     

都日木断陷化探普查成效分析

都日木断陷为二连盆地的中新生代单断型凹陷,其地表为腾格尔沙漠的一部分。根据地面化探测量结果,结合地质、地震等资料,指出了该断陷具有良好的含油气远景,最有利区为蒙古勒背斜,有利区为板新图断块和布拉格背斜。该工作为该区下一步勘探指明了方向,也为在沙漠区进行化探工作积累了经验。     

煤层煤质和含气量的测井评价方法及其应用

根据辽河油田东部凹陷煤储层的地质特征以及实际煤岩芯分析资料和测井资料,利用回归分析方法得出了计算煤层各组分含量和煤阶的方法;通过分析煤层气特征,利用兰氏方程、吸附等温线和煤层气层中子背景值导出了煤层含气量的计算公式,并通过辽河油田东部凹陷实际煤储层测井资料的处理解释验证了方法的有效性。     

有机烃气法在个旧锡矿松树脚矿田中的应用

各类岩体、矿石、围岩、地表土壤的烃气测量结果表明,个旧锡矿的成矿存在有机物的参与,矿体周围存在烃气晕圈异常场,已知矿体上方地表有良好的烃气异常反映。认为有机质对金属元素的沉淀、成岩、活化迁移和成矿作用可能比通常认识的大得多,应深入研究有机烃气寻找金属矿这一新方法。     

吉林通化南岔式金矿地质—地球物理—地球化学综合找矿模型

老岭成矿带为吉林省最重要的贵金属、有色金属成矿带，南岔金矿是该成矿带近几年新发现的金矿床。在阐述南岔金矿成矿地质条件、岩（矿）石物性参数特征、地球物理场、地球化学特征的基础上，归纳并提取了控矿地质因素和物化控找矿标志，从而建立了“南岔式”金矿的地质－地球物理－地球化学找矿模型。     

煤层气选区和评价的若干问题探讨

根据近几年从事煤层气评价和勘探工作的实践和思考，对比较流行的选区思路和评价方法作提出了一些疑问，休克有定选区的目标和从哪些方面进行评价进行了探讨，并提出了选区的思路要“实际”，在评价方法上要“实用”的观点。