Long-term earthquake prediction in the North Pacific seismic zone based on the time and magnitude predictable model

Earthquake recurrence intervals for large and great shallow mainshocks in 12 seismogenic sources along the North Pacific seismic zone (Alaska-Aleutians-Kamchatka-Kuril Islands) have been estimated and used for the determination of the following relations:

成矿带1∶5万激发极化法普查的初步尝试——以东天山铜矿带1∶5万电法快速普查示范为例

物探是成矿带矿产资源评价的重要方法之一,但激发极化法测量限于技术和经济条件等原因在成矿带资源评价中未大面积开展。本文在初步分析磁法、重力法、激发极化法等在成矿带应用成果的基础上,结合中国多金属矿床矿石构造多以浸染状为主的基本特点,提出了成矿带物探存在的主要问题,并提出开展激发极化法普查的技术思路。通过总结土屋斑岩铜矿成矿带、百灵山花岗岩岩体北接触带铅锌多金属成矿带1∶5万激发极化法的试验、示范成果,认为该方法技术上可行、经济上合理,找矿成果明显,并提出在重要铜、多金属成矿带开展以1∶5万激发极化法为主要方法的综合物探普查的建议。     

PETROGENETIC AND METALLOGENETIC AGES FOR THE PORPHYRY COPPER DEPOSITS IN THE GANGDISE METALLOGENIC BELT IN SOUTHERN TIBET

In the Gangdise area in the south of Qinghai-Tibet Plateau, a set of calc-alkalinevolcanics-granitic intrusives, which were resulted from subduction of neo-Tethys Ocean at YurlungZangbo oceanic plate beneath Lahsa block in Cretaceous-Palaeogene and subsequentarc-continental collision, were exposed, together with a set of shoshonitic volcanics and hypabyssalporphyries developed in the later stage (Bureau of Geology and Mineral Resources of TibetAutonomous Region, 1993; Li, 2002; Zhao et …     

PRELIMINARY DISCUSSION ON METALLOGENESIS OF LANCANGJIANG RIVER TRANSITIONAL FIELD TECTONIC ZONE IN WESTERN YUNNAN

1 Concept of transitional field tectono-metallogenesis On the basis of preliminary systemical elucidating the concept of crustobody, while making ahistoristic-dynamic integrated metallogenetic analysis of the relation of the mantle creep-flow andgeothermal energy coacervation-diffusion alternation as the deep dynamic source and mechanismto the evolution and movement of crustobodies (including intrabody and interbody), Chen Guodaproposed the technical terms of transitional field tectono-met…     

40Ar/39Ar and Rb-Sr isochron dating of the gold deposits on northern margin of the Jiaolai Basin, Shandong, China

The Pengjiakuang, Dazhuangzi and Fayunkuang gold deposits, located on the northern margin of the Mesozoic Jiaolai Basin, east of Shandong Province, are controlled by a low-angle normal fault. Gold ores are typically brecciated, veinlet and disseminated. The Ar-Ar and Rb-Sr isochron dating methods were adopted to date ores and lamprophyre dike. The results indicate that the age of the Pengjiakuang gold deposit is 117.33–118.42 Ma, that of the Dazhuangzi gold deposit is 117.39 Ma, and that of the Fayunkuang gold deposit is (128.49±7.2) Ma. The consistency in metallogenic age between the gold deposits on the margin of the Jiaolai Basin and the gold deposits (115–126 Ma) of the northern uplift area suggests that both were formed in the same metallogenic period. That is to say, the large-scale metallogeny of the Jiaodong region took place in late-Yanshannian ((120±10) Ma).     

云南省北衙金矿床成矿预测和靶区优选

北衙金矿床是与碱性正工斑岩有关的具大型资源远景的一个多成因矿床。依据主要控矿条件－地层、岩浆岩、构造、蚀变、火山机构、表生作用等，综合矿区以往勘查资料，结合磁法、激电、地球化学、浅层地震和地球化学勘查成果，应用综合信息法、趋势外推法和多成因类型矿床预测法，确定了4个一级、2个二级找矿靶区，预测金资源量的吨，认为北衙矿区已具备为一个大型金矿远景资源基地。     

陕西省凤县铅硐山大型铅锌矿床原生异常分带及分带指数

经对陕西省凤县铅硐山矿床原生异常的分带性及分带指数进行研究，认为铅硐山矿床原生异常具有明显的分带性，全向序列(从上到下)为：SHg—Zn—THg—Asn—Cd—(Cu—Ga、Ge)—Pb—Ag—As2、Au。分带指数具有明显变化规律，分带指数可用于深部及外围成矿预测。     

阿尔金成矿带主要成矿系列及其地质特征

阿尔金地区是我国少数几个地质矿产调查程度极低的地区之一，近年来国土资源大调查在此投入了大量工作，初步查明了区内矿产资源的分布情况、主要矿床类型和找矿潜力。研究表明，具有漫长地质演化历史的阿尔金成矿带发育类型较为齐全的金属、非金属和能源矿床，其中金、铜、铅、锌等矿种具有较大的成矿远景。重点介绍了该地区主要成矿系列的地质特征和典型矿床，在此基础上初步总结了该区的成矿规律和找矿方向。     

广西大瑶山地区花岗岩成矿系列

章通过对前人资料收集、整理，结合国土资源地质调查项目的成果，总结了广西大瑶山地区花岗岩和矿床地质特征，认为大瑶山隆起区与其周边的花岗岩在岩体大小、形态、岩石组合、化学成分和微量元素组成及矿化种类具有较大的差异，呈现隆起区内部以金铜矿化为主、周边为钨锡铅锌矿化的空间分布现象，并初步划分成两个成矿系列，即与加里东期同熔型花岗岩有关的Au、Cu多金属成矿系列和与燕山期改造型花岗岩有关的W、Sn、Pb、Zn、稀土成矿系列。