Episodic Precambrian subduction
Episodic Precambrian subduction
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DOI：
10.1016/j.epsl.2007.04.056
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发表时间：
2007-05
影响因子：
5.3
通讯作者：
C. O'Neill;A. Lenardic;Louis Moresi;T. Torsvik;Cin-Ty A. Lee
中科院分区：
文献类型：
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作者：
C. O'Neill;A. Lenardic;Louis Moresi;T. Torsvik;Cin-Ty A. Lee
前寒武纪地质记录显示，1.1，1.9-2.1，2.7和3.5 Ga的活动高峰，往往与大规模的地壳生产，造山作用和超大陆旋回。有人认为，这些构造活动的爆发是由于地幔雪崩事件造成的，其中积累的俯冲板片定期穿透670公里的不连续面，随后的上涌逆流和羽流活动导致大规模火山活动。在这里，我们提出了古地磁证据的快速板块运动的时期相吻合的地壳年龄分布中观察到的峰值。我们提出了一个新的模型板块驱动的幕式构造在前寒武纪，较高的地幔温度导致较低的岩石圈应力，导致快速脉冲的俯冲穿插与相对平静的时期。板块驱动的偶发性自然会出现较热的地幔温度的早期地球，可以解释快速脉冲的板块运动和地壳生产，而不需要调用地幔雪崩事件。
The Precambrian geological record shows peak of activity at 1.1, 1.9–2.1, 2.7 and 3.5 Ga, often associated with massive crustal production, orogenesis and supercontinent cycles. It has been suggested that these bursts of tectonic activity are due to mantle avalanche events, where accumulating subducted slabs periodically penetrate the 670 km discontinuity, and subsequent upwelling counterflow and plume activity results in massive volcanism. Here we present paleomagnetic evidence for periods of rapid plate motions coinciding with the observed peaks in crustal age distribution. We present a new model for plate-driven episodic tectonics in the Precambrian, where higher mantle temperatures result in lower lithospheric stresses, causing rapid pulses of subduction interspersed with periods of relative quiescence. Plate-driven episodicity will naturally arise for hotter mantle temperatures of the early Earth and can explain rapid pulses of plate motion and crustal production without the need to invoke mantle avalanche events.