新疆阿尔泰诺尔特地区石炭纪火山作用

诺尔特地区位于阿尔泰北部地区，西伯利亚板块西南缘。区内石炭纪火山岩主要沿红山嘴断裂带分布，赋存于下石炭统红山嘴组中，岩性主要为晶屑凝灰岩、碎斑熔岩、凝灰岩、火山角砾岩、流纹岩等。火山作用中爆发、喷溢、侵出3种喷发形式均存在，产生了爆发－喷溢相、降落相、侵出相及火山喷发沉积相等火山岩相。诺尔特地区石炭纪火山构造为裂隙－中心式，断裂导致岩浆上升喷发，火山活动的中心位于西部的托格尔托别、阔科依达拉斯等地，而东部的塔斯比格、阿克提什坎、库马苏等地则位于远火山活动中心地区，火山活动从西向东逐渐减弱，西部以爆发－喷溢为主，东部则以侵出为主。

CARBONIFEROUS VOLCANISM IN NURT AREA OF ALTAY, XINJIANG

Nurt area is located in the north of the Altay area, at the southwest of the Siberia plate. Carboniferous volcanic rocks are scattered along the Hongshanzui fault system and mainly occur in Lower Carboniferous Hongshanzui Formation. Lithology of Carboniferous volcanic rocks include crystal fragment tuff, cataclasite lava, tuff, volcanic breccia and rhyolite. Carboniferous volcanic rocks formed at the interim from convergent stage to new continental crust stage of the crustal evolution, and the eruptive environment was land environment, the volcanic rocks belong to the acidic, high kalium and calcium-alkalescence series. The forms of eruption include explosion, effusion and extrusion, and volcanic rocks have explosion-effusion faces, fall out faces, extrusion faces and eruption-sedimentary faces. Studies on the petrology and the volcanic rock facies and the contrasts of the columnar sections of Carboniferous volcanic rocks show that, in the Nurt area, Carboniferous volcanic activities controlled by the fault system had the type of fissure-central eruption, the centres of volcanic activities were located in Tuogertuobie and Kuokeyidalasi and the forms of eruption mainly were explosion-effusion, however, Tasibige, Aktiskan and Kumasu were far away from the centres and the forms of eruption mainly were extrusion, moreover, the intensity of volcanic activities wore off from west to east.