The Palaeoproterozoic Southeastern Churchill Province of Labrador-Quebec, Canada: orogenic development as a consequence of oblique collision and indentation
The Palaeoproterozoic Southeastern Churchill Province of Labrador-Quebec, Canada: orogenic development as a consequence of oblique collision and indentation
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加拿大拉布拉多-魁北克古元古代丘吉尔省东南部：斜向碰撞和压痕导致造山运动的发展
DOI：
10.1144/gsl.sp.1996.112.01.08
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
M. V. Kranendonk
中科院分区：
文献类型：
--
作者：
R. Wardle;M. V. Kranendonk
摘要 加拿大地盾东北部古元古代造山运动的发展受到太古代纳恩（北大西洋）克拉通和苏必利尔克拉通与太古代雷伊省（丘吉尔省北部腹地的一部分）向南凸出的海角连续倾斜碰撞的控制。通过这一过程，雷伊省被托恩盖特造山带缝合到纳因克拉通，并被新魁北克造山带缝合到上克拉通，从而形成了一条 400 公里宽的造山带，称为东南丘吉尔省 (SECP)。 2.45-2.1 Ga 的初始裂谷和 2.3-1.9 Ga 的早期（弧？）岩浆活动和变形仅限于 Rae 省。随后在托恩加特造山带发生了弧岩浆作用。 1.91–1.88 Ga 和 Rae/Nain 1.87–1.86 Ga 碰撞，导致形成东西向构造的造山带。新魁北克造山带的弧岩浆作用开始于c。 1.845 Ga，随后发生 Rae/Superior 碰撞和在 c.1.845 Ga 处 SECP 上的广泛变形。 1.83 Ga。此时的变形主要是新魁北克造山带和雷伊省的西向逆冲，以及托恩盖特造山带新的东向逆冲。然后变形逐渐转移到主要的左旋（SECP 东部为 1.845-1.82 Ga）和右旋（SECP 西部为 1.83-1.80 Ga）剪切系统，适应纳因克拉通和苏必利尔克拉通相对于 Rae 省的持续向北运动。逆冲作用所排出的新生地壳有效地使雷伊省部分地区和纳因克拉通西北边缘的地壳厚度增加了一倍。后期发育（1.8-1.71 Ga）仅限于 SECP 的边缘，其中变形与新的向外逆冲和横流剪切以及造山核的隆起有关。
Abstract Palaeoproterozoic orogenic development in the northeastern Canadian Shield was controlled by the successive, oblique collision of the Archaean Nain (North Atlantic) and Superior cratons with a southwards projecting promontory of the Archaean Rae Province (part of the northern Churchill Province hinterland). By this process the Rae Province became sutured to the Nain craton by the Torngat Orogen and to the Superior craton by the New Quebec Orogen, resulting in the formation of a 400 km wide orogenic belt known as the Southeastern Churchill Province (SECP). Initial rifting at 2.45–2.1 Ga, and early (arc?) magmatism and deformation at 2.3–1.9 Ga, were restricted to the Rae Province. They were followed by arc magmatism in the Torngat Orogen at c. 1.91–1.88 Ga and Rae/Nain collision 1.87–1.86 Ga, which resulted in the formation of an orogen with east- and west-verging structures. Arc magmatism in the New Quebec Orogen commenced at c. 1.845 Ga and was succeeded by Rae/Superior collision and widespread deformation across the SECP at c. 1.83 Ga. Deformation at this time was dominated by west-vergent thrusting in the New Quebec Orogen and Rae Province, and by renewed east-vergent thrusting in Torngat Orogen. Deformation was then progressively transferred to major sinistral (1.845–1.82 Ga in the eastern SECP) and dextral (1.83–1.80 Ga? in the western SECP) shear systems that accommodated continued northwards motion of the Nain and Superior cratons relative to the Rae Province. Juvenile crust expelled by thrusting effectively doubled crustal thickness in parts of the Rae Province and the northwestern edge of the Nain craton. Late stage development (1.8–1.71 Ga), was restricted to the margins of the SECP, where deformation was associated with renewed outward-directed overthrusting and transcurrent shear in conjunction with uplift of the orogenic core.