The Cambrian Explosion: Plume-driven birth of the second ecosystem on Earth
The Cambrian Explosion: Plume-driven birth of the second ecosystem on Earth
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DOI：
10.1016/j.gr.2013.03.013
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发表时间：
2014-04
影响因子：
6.1
通讯作者：
M. Santosh;S. Maruyama;Y. Sawaki;J. Meert
中科院分区：
文献类型：
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作者：
M. Santosh;S. Maruyama;Y. Sawaki;J. Meert
地球上现代生命的诞生可能与海洋中充足的营养供应有关。在本文中，我们评估了营养物质进入海洋的相对供应。这些营养物质通过无数的通道进入海洋，但主要是通过隆起引起的加速侵蚀。在“第二生态系统”中，隆起与Rodinia超大陆解体期间的地幔柱生成有关。虽然证据有点神秘，但似乎第二个生态系统包括了早在低温纪（约750 Ma）的demospongia。在埃迪卡拉-寒武纪期间，会聚边缘岩浆活动、弧火山活动和洋盆闭合提供了向海洋环境输送营养物的第二次脉冲。一个主要的辐射的生命形式开始约580马，并代表了不同的和有点神秘的埃迪卡拉动物群，其次是寒武纪爆发的现代门在540-520马的间隔。在构造上，埃迪卡拉纪-寒武纪时间段主要是冈瓦纳造山过程中形成的超高压（UHP）、高压（HP）和超高温（UHT）造山带。这片广阔山区的侵蚀将大量营养物质输送到海洋中，并增强了寒武纪辐射的爆炸性。在许多冈瓦纳造山带中，特别是中部和东部造山带中的一些造山带，最后的碰撞造山和山带的建设的时间，晚于现代生命形式的首次出现。因此，我们假设，一个更有效的营养供应寒武纪辐射促进羽驱动的TTG地壳隆起，随后的裂谷，俯冲相关的营养系统之前，冈瓦纳组装。在概述的情况下，我们提出，我们星球上的“第二生态系统”的诞生是由羽流驱动的。
The birth of modern life on Earth can be linked to the adequate supply of nutrients into the oceans. In this paper, we evaluate the relative supply of nutrients into the ocean. These nutrients entered the ocean through myriad passageways, but primarily through accelerated erosion due to uplift. In the ‘second ecosystem’, uplift is associated with plume-generation during the breakup of the Rodinia supercontinent. Although the evidence is somewhat cryptic, it appears that the second ecosystem included the demospongia back into the Cryogenian (~ 750 Ma). During the Ediacaran–Cambrian interval, convergent margin magmatism, arc volcanism and the closure of ocean basins provided a second pulse of nutrient delivery into the marine environment. A major radiation of life forms begins around 580 Ma and is represented by the diverse and somewhat enigmatic Ediacaran fauna followed by the Cambrian Explosion of modern phyla during the 540–520 Ma interval. Tectonically, the Ediacaran–Cambrian time interval is dominated by the formation of ultra-high pressure (UHP), high pressure (HP) and ultra-high temperature (UHT) orogenic belts during Gondwana orogenesis. Erosion of this extensive mountainous region delivered vast nutrients into the ocean and enhanced the explosiveness of the Cambrian radiation. The timing of final collisional orogeny and construction of the mountain belts in many of the Gondwana-forming orogens, particularly some of those in the central and eastern belts, post-date the first appearance of modern life forms. We therefore postulate that a more effective nutrient supply for the Cambrian radiation was facilitated by plume-driven uplift of TTG crust, subsequent rifting, and subduction-related nutrient systems prior to the assembly of Gondwana. In the outlined scenario, we propose that the birth of the ‘second ecosystem’ on our planet is plume-driven.