Collisional Snowbird tectonic zone resurrected: Growth of Laurentia during the 1.9 Ga accretionary phase of the Hudsonian orogeny
Collisional Snowbird tectonic zone resurrected: Growth of Laurentia during the 1.9 Ga accretionary phase of the Hudsonian orogeny
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DOI：
10.1130/g23771a.1
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发表时间：
2007-10-01
期刊：
影响因子：
5.8
通讯作者：
Pehrsson, S.
中科院分区：
文献类型：
--
作者：
Berman, R. G.;Davis, W. J.;Pehrsson, S.
类似2800公里长的雪鸟构造带是加拿大地盾最具争议的构造特征之一。这里报告的变质和原位地质年代学数据表明，一条 1.9 Ga 中高压带沿着该构造带的大部分延伸。与最近的解释相反，该变质带的长度、部分记录的构造增厚、整个变质带的地质对比以及其中的俯冲型微金刚石表明了碰撞起源。这次碰撞事件标志着哈德逊造山运动的前 1.865 Ga 阶段，涉及微大陆增生，这对于劳伦西亚的生长至关重要。
The similar to 2800-km-long Snowbird tectonic zone is one of the most controversial tectonic features of the Canadian shield. Metamorphic and in situ geochronologic data reported here reveal that a 1.9 Ga medium- to high-pressure belt extends along most of this tectonic zone. In contrast to recent interpretations, a collisional origin is indicated by the length of this metamorphic belt, tectonic thickening documented in parts of it, geological contrasts across it, and subduction-type microdiamonds within it. This collisional event marks a pre-1.865 Ga phase of the Hudsonian orogeny involving microcontinent accretion that was fundamental to the growth of Laurentia.