Early Proterozoic (1.88–1.87 Ga) tholeiitic magmatism in the New Québec orogen
Early Proterozoic (1.88–1.87 Ga) tholeiitic magmatism in the New Québec orogen
复制标题
新魁北克造山带早元古代（1.88–1.87 Ga）拉斑斑岩岩浆作用
DOI：
10.1139/e93-129
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发表时间：
1993
影响因子：
1.4
通讯作者：
A. Smith
中科院分区：
文献类型：
--
作者：
T. Skulski;R. Wares;A. Smith
新魁北克造山带包含两个火山沉积序列，它们被不整合所包围。每个层序都记录了从大陆沉积和碱性火山作用到海相沉积和拉斑玄武岩作用的变化。第一个序列记录了2.17 Ga裂谷和2.14 Ga沿苏必利埃克拉通东部的被动边缘的发育。第二个层序发育于拉分盆地中，发育于1.88-1.87 Ga之间，反映了大陆边缘碰撞前的右旋应变。二次序列岩浆活动包括：(I)碳酸盐岩和煌斑岩侵入岩和碱性偏碱性的镁铁质-长英质火山岩；(Ii)拉斑玄武岩-拉斑玄武岩的广泛侵入和斜长石-球斑玄武岩和较年轻的干玄武岩和苦皮岩的海底挤出；(Iii)晚期镁铁质-长英质火山作用和碳酸岩侵入。地壳变薄使原始拉斑玄武岩岩浆在逐渐降低的压力下达到平衡，然后浮力更大。
The New Quebec orogen contains two volcano-sedimentary sequences bounded by unconformities. Each sequence records a change from continental sedimentation and alkaline volcanism to marine sedimentation and tholeiitic volcanism. The first sequence records 2.17 Ga rifting and the development, by 2.14 Ga, of a passive margin along the eastern part of the Superior craton. The second sequence developed between 1.88 and 1.87 Ga in pull-apart basins that reflect precollisional dextral transtension along the continental margin. Second-sequence magmatism comprises (i) carbonatitic and lamprophyric intrusions and mildly alkaline mafic to felsic volcanic rocks; (ii) widespread intrusion of tholeiitic gabbro sills, and submarine extrusion of plagioclase glomeroporphyritic basalts and younger aphyric basalts and picrites; and (iii) late-stage, mafic to felsic volcanism and intrusion of carbonatites. Crustal thinning allowed primitive tholeiitic magmas to equilibrate at progressively lower pressures before more buoyant ...