摘要
本文据岩石化学资料确定了西天山北部石炭纪火山岩的化学系列和岩石组合,并论述了其地球化学特征,探讨了该地区的沟弧盆体系。北天山中石炭统上部岩石单元代表了准噶尔板块的活动陆缘,而下部岩石单元属于弧前盆地沉积物。北天山蛇绿岩套是扩张速度缓慢的古洋壳残片。中天山北缘的下石炭统火山岩和海西中期的花岗岩类岩石组合代表了厚度甚大的大陆型岛弧部分,而阿吾拉勒带中、下石炭统则属于内弧环境的火山岩岩石组合。伊什基里克带是有限拉张的弧后盆地。
Based on 175 petrochemical data, this paper has defined chemical seriesand rock assemblages of Carboniferous volcanic rocks in the northern half ofwest Tianshan Mountains and dealt with their geochemical characteristics. Onsuch a basis, the trench--arc basin system of this area is investigated.The upperunit of Middle Carboniferous in North Tianshan Mountains represents the acti-ve continental margin of Junggar plate, whereas the lower unit belongs to sedi-ments of a forearc basin environment. Rocks of the ophiolite suite in northTianshan Mountains are remnants of a slowly spreading ancient ooeanic crust.Lower Carboniferous volcanic rooks and Middle Hercynian granitoids along thenorthern margin of Central Tianshan Mountains represent the main part of theextremely thick continental island arc, while Middle and Lower Carboni-ferous rocks along the Awulale belt are of volcanic assemblages in an internalisland arc environment. The Yishijilike belt is a back--arc basin with limitedextension.
出处
《岩石矿物学杂志》
CAS
CSCD
1993年第3期224-231,共8页
Acta Petrologica et Mineralogica
关键词
火山岩
石炭纪
沟弧盆体系
volcanic rocks
trench-arc basin system
Carboniferous
west Tianshan Mountains
