中太平洋海山区富钴结壳的钙质超微化石地层学研究  

Calcareous Nannofossil Biostratigraphy for Co-Rich Ferromanganese Crusts from Central Pacific Seamounts

作　　者：苏新[1] 马维林[2] 程振波[3] 

机构地区：[1]中国地质大学岩石圈构造与深部过程及探测技术重点实验室,北京100083 [2]国家海洋局第二海洋研究所 [3]国家海洋局第一海洋研究所,山东青岛266071

出　　处：《地球科学（中国地质大学学报）》2004年第2期141-147,共7页Earth Science-Journal of China University of Geosciences

基　　金：中国大洋矿产资源开发协会"九五"专项 (DY95 -0 8-0 6);中国大洋矿产资源开发协会"十五"项目 (DY10 5 -0 1-0 4-0 8)

摘　　要：对“大洋一号”调查船在中太平洋采集的N1 15和N5E 0 6 2个富钴结壳样品进行了钙质超微化石及其生物地层学的研究与分析 .这 2个结壳从结构上分为 3层 :致密型上层、疏松型中层和致密型下层 .在研究中对各结构层和各层中有颜色或细微结构变化的层位都进行了详细的取样和分析 .在识别了 12个新生代钙质超微化石事件的基础上 ,确定了 2个结壳致密型上层结壳都为晚更新世以来的沉积 ,它们的疏松型中层结壳为上新世到中更新世的沉积 .对N5E 0 6富钴结壳来说 ,其致密型下层结壳下部形成于中晚古新世到早渐新世的 5 9.7～ 32 .8Ma期间 .N1 15富钴结壳致密型下层的形成时代目前暂时定为中新世 .研究注意到在 2个结壳中都没有发现可信的晚渐新世到中新世的化石记录 ,在个别层位之间存在着沉积间断 .Calcareous nannofossils in 2 Co-rich ferromanganese crusts, N1-15 and N5E-06, from the central Pacific seamounts were analyzed in order to estimate their depositional ages. These 2 crusts show 3 structural layers: compact upper layer, porous middle layer and compact lower layer. 12 Tertiary to Quaternary nannofossil events were recognized. The upper layers of these 2 crusts were deposited since Late Pleistocene, while their middle layers were formed from Pliocene to Middle Pleistocene. The age of the lowest sample from N5E-06 crust was estimated as 55.3-59.7 Ma in the Middle to Late Paleocene, and the duration for lower part of the lower layer was given between 59.7-32.8 Ma from the Middle Paleocene and Early Oligocene. For the lower layer of N1-15 crust, the age was roughly determined to be Miocene, due to the lack of reliable fossils. This study notes that no reliable Late Oligocene to Miocene nannofossil markers were found in these 2 crusts. Furthermore, sedimentation hiatus was observed.

关 键 词：富钴结壳 钙质超微化石 生物地层学研究 中太平洋海山区 

分 类 号：P736.21[天文地球—海洋地质]