内蒙古中部大青山新地沟-卯独庆金矿床的 构造-蚀变-成矿作用

新地沟和卵独庆金矿赋存于新太古界色尔腾山群柳树沟岩组中,是典型的与韧性-脆韧性剪切变形有关的绿岩型金矿.构造-蚀变岩石的主要类型有千糜岩化石英绢云片岩、千糜岩化绿泥绢云片岩、糜棱岩化绿泥石英片岩、绢云绿泥长英质糜棱片岩、长英质碎裂岩、黄铁绢英岩质构造片岩等.构造-蚀变岩石的岩石地球化学特征与中基性火山岩类似.其稀土元素总量∑REE(44.9×10-6～155.4×10-6)、LREE/HREE比值(7.0～26.1)、δEu(0.6～1.2)也显示了中基性火山原岩的特点.构造-蚀变-成矿流体的特征为富CO2的低盐度的较高密度的流体,具有造山型金矿的特点.前寒武纪绿岩带建造变质镁铁质火山岩分布的地区构造-蚀变作用强烈的地段是重要的找矿有利地区.     

Associate Editors-in-Chief

Shuhai XIAO Shuhai XIAO is a geobiologist interested in Proterozoic and Cambrian Earth history. He obtained Bachelor＇s and Master＇s degrees from Peking University and Ph.D. from Harvard University. He was an assistant professor at Tulane University （2000-2003）, and assistant professor （2003-2005） and associate professor （2005-2008） at Virginia Tech, and is currently Professor of Geobiology at Virginia Tech, USA.     

Pediculate Brachiopod Diandongia pista from the Lower Cambrian of South China

The Chengjiang Lagerstatte has been celebrated for prolific soft-bodied fossils. Based on specimens recently excavated in the Chengjiang Lagerstatte by the Early Life Institute, Northwest University, Diandongia pista Rong, 1974, is directly revealed to be a pediculate brachiopod, assigned to the Family Botsfordiidae, as is further confirmed by the exceptionally preserved vascular system including dorsal and ventral mantle canals. These specimens described herein exhibit some peculiarities, notably the extremely thin and long pedicles, which suggest that Diandongia is epifaunal rather than burrowing brachiopod. A study of this group of animals indicates that they may be vital to understand the relationship between the lingulids and the remaining brachiopods, and the character evolution of the early Cambrian brachiopods.     

《地质调查与研究》征稿简则

<正>经国家科委和新闻出版署批准,我刊《前寒武纪研究进展》于2003年起更名为《地质调查与研究》。办刊宗旨:本刊为地质科学领域中的学术性刊物,执行党的基本路线及国家的出版政策法规,坚持"百花齐放,百家争鸣"的双百方针,     

微波超快速吸收现象

对１９８８年６月２９日云南天文台高时间分辨率射电望远镜观测到的微波超快速吸收现象进行了分析研究。在世界时０７ｈ３８ｍ５０ｓ至０７ｈ３８ｍ５８ｓ超快速吸收现象出现在太阳活动区ＮＯＡＡ／ＵＳＡＦ５０６０上空的４００ＧＨｚ上,而在２８４ＧＨｚ和１４２ＧＨｚ上空出现的是ｓｐｉｋｅ辐射。当时,该活动区呈现出极其活跃的双极磁场位形。在世界时０７ｈ３８ｍ至０８ｈ４７ｍ先后产生了３Ｂ级和２Ｂ级的Ｈα耀斑,并出现了Ｍ６５Ｘ射线爆发。根据电子回旋脉泽谐波吸收峰的特性,我们计算了三个波段的二次、三次谐波的磁场强度,并采用偶极磁场模型进行分析。对于４００ＧＨｚ上出现的超快速吸收现象,可能是产生的三次谐波脉泽辐射,在穿过吸收区时被吸收掉了。