CAJ | 학술논문

下扬子地区早古生代发育3套重要的深水相黑色岩系，分别为下寒武统荷塘组和黄柏岭组、上奥陶统五峰组、下志留统高家边组和相当层位的霞乡组。27件样品的微量和稀土元素分析结果显示：此3套黑色岩系具有 Li、Be、Rb、Ba、Cs、W、Th、U、Cd、Bi、Pb 等元素富集，Sc、Sr，Cr、Cu、Ga、Co、Ni 等元素亏损，稀土元素总量较高，轻重稀土分异明显和具负 Eu 异常等壳源物质特征；微量不活动元素含量和比值特征的构造环境判别表明，下扬子地区早古生代黑色岩系构造环境为大陆岛弧和活动大陆边缘，兼具被动大陆边缘特征；母岩以上地壳的再旋回沉积物和后太古宙地层沉积物为主，部分为未分异的太古宙地壳和玄武岩成分，源岩性质主要为安山岩、英安岩和沉积岩；沉积环境为缺氧的半深海、深海环境。在上述研究基础上，对物源的来源进行了探讨，认为物源主要来自江南造山带。
하양자지구조고생대발육3투중요적심수상흑색암계，분별위하한무통하당조화황백령조、상오도통오봉조、하지류통고가변조화상당층위적하향조。27건양품적미량화희토원소분석결과현시：차3투흑색암계구유 Li、Be、Rb、Ba、Cs、W、Th、U、Cd、Bi、Pb 등원소부집，Sc、Sr，Cr、Cu、Ga、Co、Ni 등원소우손，희토원소총량교고，경중희토분이명현화구부 Eu 이상등각원물질특정；미량불활동원소함량화비치특정적구조배경판별표명，하양자지구조고생대흑색암계구조배경위대륙도호화활동대륙변연，겸구피동대륙변연특정；모암이상지각적재선회침적물화후태고주지층침적물위주，부분위미분이적태고주지각화현무암성분，원암성질주요위안산암、영안암화침적암；침적배경위결양적반심해、심해배경。재상술연구기출상，대물원적래원진행료탐토，인위물원주요래자강남조산대。
Three sets of the Early Paleozoic deep-water black shales,respectively named of ∈ 1h and∈1 ht,O3w,S1 g and S1 x,are mainly developed in Anhui Province,the Lower Yangtze subcontinent. Total of 27 samples sampled from the three sets of black shale series for ICP-MS measurement were used to analyze their geological settings of tectonic and sources.Results show that within these shale samples,elements Li,Be,Rb,Ba,Cs,W,Th,U,Cd,Bi,Pb are enriched,Sc、Sr,Cr、Cu、Ga、Co、Ni are poor,contents of rare earth elements are high,Eu is obviously negative,and the fractionation between light and heavy REE is being pronounced.Trace inactive element content and the ratio of characteristics of the tectonic setting discrimination diagrams indicate that the black shales could have been deposited in a deep-water and lag sedimentary environment within the continental island arc and active continental margin in early stage,fllowing a passive continental margin in late stage.The parent rocks could be mainly derived from the recycled sediments of the upper crust and the Post-Archean strata as well as the undifferentiated Archaean crust and basalts.According to the devolpment of the ancient Jiangnan island and the geochemistry comparison of the Lower Paleozoic black shales from other place of the Yangtze continent, it is proposed that the black shales in Anhui Province could have been southwardly sourced from the ancient Jiangnan island.