东太平洋海盆多金属结核玄武岩核心研究

RESEARCH ON THE BASALTNUCLEI OF POLYMETALLIC NODULES FROM THE EAST PACIFIC BASIN

研究多金属结核的核心物质对认识多金属结核的生成和分布具有重要意义。本文对多金属结核中玄武岩及其蚀变产物核心的岩性特征、岩石化学、矿物组成、稀士元素地球化学以及同位素测年进行了初步研究，讨论了玄武岩核心物质的来源及其对结核生成和分布的影响。

The knowledge of core material of polymetallic nodules is of great importance for clarification of the distribution and origin of nodules in ocean. Based on dissection of about 178 pieces of samples of polymetallic nodules obtained from the East Pacific Basin by investigation ship “HAIYANG 4”of MGMR among which 53 pieces are basaltnuclei in composition, accounting for 298%, this paper comprehensively studied and analysed the features of these basaltunclei of nodules, including lithology , petrochemsitry ,mineral constituents, traceelement geochemistry and isotope chronostratigraphy,etc. The authors come to a conclusion that the basaltnuclei of nodules belong to ocean island tholeiite or alkalibasalt. There are of calcalkaline series and alkali series, which include olivinetholeiite, and alkali basalt, and they were mainly formed in the Tertiary. In the light of studies of the origin of basaltnuclei of nodules, and analysis of the relationship between the basaltnuclei and the distribution of ploymetallic nodules, the authors pointed out that basaltnuclei of nodules are derived from seamount basalt in the study area. It is found that seamount basalt mainly effected and controlled the formation and distribution of polymetallic nodules, which provied enormous nuclei.