摘要
作者对浙西寒武系碳酸盐岩做系统调查时发现,在开化裴岭脚产出的大陈岭组碳酸盐岩中含有大量的液化泥晶脉、微同生变形构造、角砾岩及与之伴生的浊积岩等典型的地震-海啸沉积标志。根据震积岩特征及其在剖面上的分布,该地大陈岭期的地震活动可以分为两期:第一期以震积岩(A,液化亮晶脉和泥晶脉)、啸积岩(B,具丘状层理或平行层理的内碎屑白云质灰岩)、震浊积岩(C,具递变层理或鲍马序列且层面上有槽模构造的砾屑白云质灰岩或砂屑白云质灰岩)和背景沉积(D)组成的A-B-C-D沉积序列为特征;第二期为震积岩(A,液化亮晶脉和泥晶脉、震裂岩、震褶岩和内碎屑角砾岩等)和沉积背景(D)组成的A-D沉积序列。而在常山白石和芳村的大陈岭组剖面,上述特征不明显,但局部能看到液化变形构造。往南东至江山的碓边则不见震积岩特征。从震积岩的分布上分析,浙西大陈岭期的地震活动不受控于江绍深断裂,应与开化—淳安大断裂的形成有关,是开化—淳安大断裂形成于早古生代的一个证据。此外,值得一提的是,这是确凿的后震旦纪的“Molartooth”。
Based on the writer＇s systemic investigation in the west of Zhejiang province, it is found that the Cambrian carbonate of Dachenling Formation, outcropping in Peijiaoling area in Kaihua county of Zhejiang province, contains typical sedimentary marks of tsunami such as abundant liquified micrite vein, micro synsedimentary deformtion, breccia and associates turbidite. According to the seismites＇ characteristics and their distribution on the profile, seismic activities that happened in Peijiaoling area are divided into two stages： the first stage is characterized by A-B-C-D sedimentary sequence, which comprises seismites（Unit A, including liquefied micrite vein dolomitic limestone）, tsunamigentic rocks （Unit B, intra-dolomitic limestone with mound bedding or parallel bedding）, seismoturbidites（Unit C, dolomitic calcirudite or psammitic dolomitic limestone with graded bedding or Bouma sequence and having flute cast on the bedding surface） and background sediments（Unit D）; While the second stage is characterized by A-D sedimentary sequence, that is seismites（Unit A, including liquified micrite vein dolomitic limestone, seismic corrugated lamination and autoclast breccia） and background sediments （Unit D）. The above features are not obvious in other places such as Baishi and Fangcun in Changshan county western Zhejiang province, where only liquified deformation structure may locally be observed. However in Duibian area, Jiangshan city, seismites＇ characteristics disappear. Based on the seismites＇ distribution, seismic activities in Peijiaoling western Zhejiang province were not controlled by Jiangshan-- shaoxing deep fault zone but possibly related to the formation of Kaihua--Chun＇an major deslocation. So it is considered as an evidence for the formation of Kaihua--Chun＇an major deslocation in Eopaleozoic.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2005年第6期730-736,T0001-T0002,共9页
Acta Geologica Sinica
基金
江西省重点学科"地质工程"建设基金资助项目
国防科工委重点专业"资源勘查工程"建设基金项目资助成果。
关键词
寒武系
陈岭组
震积岩
海啸岩
震浊积岩
浙江
Cambrian
Dachenling Formation
seismite
tsunamite
seismoturbidite
Zhejiang province
