应用灰色理论估计我国未来地震趋势

应用灰色理论ＧＭ（１，１）预测模型估计我国未来时段的地震趋势。为提高预测精度和反映“最新信息”，在组成原始数列时，对于Ｍ≥７５级地震，由平静幕、活跃幕采用不同震级阈值联合组成；对于其它级别地震则尽可能采用当前活动期以来的数据。计算结果表明，１９９７～２０００年期间我国大陆及邻区有发生Ｍ≥７５级地震的可能，大陆西部可能发生７０至７５级以上地震；东部可能发生５５至６０级以上地震。同时，估计本活跃期的结束时间也可能比预计的稍长。

THE DISCOVERY OF NON-SEQUENCE SEDIMENTATION OF THE MIDDLE-LATE CAMBRIAN AND ITS GEOLOGICAL SIGNIFI CANCE IN THE EASTERN GUIZHOU AND WESTERN HUNAN

During the Middle-late cambrian epoch,the sedimentay environment of the Eastern Guizhou and Western Hunan area belongs to platform and shelfcrest slope facies tracts.At both top and bottom surfaces,there exsited non-sequence sedimentation.The non-sequence sedimentation plane has the characteristics of clayrock weathering crust,paleokarst brecciated zone and paleokarst plane etc,which laterally has extensive significance of regional correlation,and indicates that their formation is controlled by two large scaled apparent sea level dechines.So the identity of event,chronostratigraphic and lithostratigraphic boundary and sequence stratigraphic interface have been determined,at the same time,it has been determined that the Loushanguan formation of the platform facies in the study area isn't a diachronous lithostratigraphic unit at all.