山东国土资源
山東國土資源
산동국토자원
LAND AND RESOURCES IN SHANGDONG PROVINCE
2015年
7期
11-18
,共8页
万宝沟群%岩石化学%变质作用%构造环境%与拉斯太地区%青海
萬寶溝群%巖石化學%變質作用%構造環境%與拉斯太地區%青海
만보구군%암석화학%변질작용%구조배경%여랍사태지구%청해
Wanbaogou group%petrochemistry%metamorphism%tectonic environment%south of Dongkun-lun
分布于东昆仑南部乌拉斯太地区的万宝沟群是一套灰绿色变玄武岩夹灰灰白色白云石大理岩的岩石组合,综合室内岩石学、地球化学、同位素年龄研究,将该岩群划为中新元古代万宝沟群。区内万宝沟群出露以基性变火山岩夹大理岩的岩性组合为特征,原岩恢复为火山岩夹碳酸盐岩的沉积建造。其主量元素特征表明万宝沟群火山岩具从洋中脊拉斑玄武岩→岛弧拉斑玄武岩→板内钙碱性玄武岩演化的趋势;稀土元素特征显现出与岛弧拉斑玄武岩略相似;微量元素特征具有板内玄武岩拉斑碱性过渡类型特征,与过渡型拉斑质玄武岩更为接近。万宝沟群变火山岩的成岩环境为洋中脊环境岛弧环境板内环境。
分佈于東昆崙南部烏拉斯太地區的萬寶溝群是一套灰綠色變玄武巖夾灰灰白色白雲石大理巖的巖石組閤,綜閤室內巖石學、地毬化學、同位素年齡研究,將該巖群劃為中新元古代萬寶溝群。區內萬寶溝群齣露以基性變火山巖夾大理巖的巖性組閤為特徵,原巖恢複為火山巖夾碳痠鹽巖的沉積建造。其主量元素特徵錶明萬寶溝群火山巖具從洋中脊拉斑玄武巖→島弧拉斑玄武巖→闆內鈣堿性玄武巖縯化的趨勢;稀土元素特徵顯現齣與島弧拉斑玄武巖略相似;微量元素特徵具有闆內玄武巖拉斑堿性過渡類型特徵,與過渡型拉斑質玄武巖更為接近。萬寶溝群變火山巖的成巖環境為洋中脊環境島弧環境闆內環境。
분포우동곤륜남부오랍사태지구적만보구군시일투회록색변현무암협회회백색백운석대리암적암석조합,종합실내암석학、지구화학、동위소년령연구,장해암군화위중신원고대만보구군。구내만보구군출로이기성변화산암협대리암적암성조합위특정,원암회복위화산암협탄산염암적침적건조。기주량원소특정표명만보구군화산암구종양중척랍반현무암→도호랍반현무암→판내개감성현무암연화적추세;희토원소특정현현출여도호랍반현무암략상사;미량원소특정구유판내현무암랍반감성과도류형특정,여과도형랍반질현무암경위접근。만보구군변화산암적성암배경위양중척배경도호배경판내배경。
Wanbaogou group in Wulasitai area in south of Dongkunlun is a set of gray green metabasalt clip ash—gray dolomite marble rock combination.Combining with petrology,geochemistry and isotope age study,the rock group is classified into Mesoproterozoic-Neoproterozoic Wanbaogou group.The layers in Wanbaogou group is a combination of basic meta-volcanics with marble lithologic assemblage,and origi-nal rock recovery is a sedimentary formation of volcanic rock with carbonate rock.The characteristics of maj or elements show that the volcanic rocks of Wanbaogou group has the evolution trend of mid ocean ridge tholeiite→ island arc tholeiite →intraplate calc alkaline basalt.Characteristics of rare earth elements are similar to island arc tholeiite slightly.Characteristics of trace elements are intraplate basalt→alkaline transition type.It is closer with transitional tholeiitic basalt.The diagenesis environment of volcanic rocks in Wanbaogou group is mid ocean ridge environment → island arc environment→intraplate environment.