Chapter 2 New global palaeogeographical reconstructions for the Early Palaeozoic and their generation
Chapter 2 New global palaeogeographical reconstructions for the Early Palaeozoic and their generation
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DOI：
10.1144/m38.2
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
T. Torsvik;L. Cocks
中科院分区：
文献类型：
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作者：
T. Torsvik;L. Cocks
从下寒武统(540 Ma)到下泥盆统(400 Ma)，以10 MYR间隔进行了新的古地理重建，显示了大陆地壳碎片和海洋(而不是陆地和海洋)，并在连续的地图之间保持了适当的运动学连续性。这些地图主要是由修订和选定的古地磁数据和修订的视极漂移路径生成的，这些路径与主要大陆的今天的多边形有关。通过对一些化石和沉积物分布的分析，这些都得到了加强。冈瓦那在新元古代末期(约550 Ma)至石炭纪是占主导地位的超大陆，覆盖了南半球的大部分地区。北半球在很大程度上被浩瀚的泛海占据。主要大陆的相对位置以及冈瓦那、波罗的海、西伯利亚和劳伦西亚(中志留纪的劳鲁西亚)的纬度和自转历史现在是众所周知的。尽管劳伦蒂亚与现在的方向相似，但西伯利亚在整个下古生代都是倒转的，波罗的海最初也是倒转的，但在晚寒武世和晚奥陶世之间旋转了120°，然后在中志留世加里多纳德造山带与劳伦蒂亚相撞。通过对加里多尼德和其他一些造山作用的重建，可以很好地限制劳伦蒂亚和波罗的海/冈瓦那之间的Iaptus洋的进化史。其位置也广为人知的不太重要的大陆包括阿瓦洛尼亚(最初是在冈德瓦南周，但在早奥陶世迁徙到奥陶纪末期加入波罗的海)、西布拉苏(现在被认为是冈瓦那不可分割的一部分)和蒙古(毗邻西伯利亚)。对大量其他地体进行了审查，并以不同程度的确定将其绘制在重建图上。然而，受限制或争议较少的重要大陆是南中国、北中国(中南半岛)、安纳米亚(印度支那)和北极阿拉斯加-楚科塔。法国、伊比利亚和意大利南部的欧洲地区，以前被一些人认为是一个独立的Armorian Terrane组合，一直是冈瓦那核心的一部分，直到志留纪末期古特提斯洋的开放，但尚不确定佩鲁尼卡(波西米亚)是其中之一，还是在中奥陶世离开冈瓦那。
Abstract New palaeogeographical reconstructions are presented at 10 myr intervals from the Lower Cambrian at 540 Ma to the Lower Devonian at 400 Ma, showing continental crustal fragments and oceans (not lands and seas), with appropriate kinematic continuity between successive maps. The maps were chiefly generated by revised and selected palaeomagnetic data and revised Apparent Polar Wandering paths linked to present-day polygons from the main continents. These have been reinforced by analysis of the distributions of some fossils and sediments. Gondwana was the dominating supercontinent from its final assembly in the Latest Neoproterozoic at about 550 Ma until the Carboniferous, and covered much of the Southern Hemisphere. The Northern Hemisphere was largely occupied by the vast Panthalassic Ocean. The relative positions of the major continents and the latitudes and rotation histories of Gondwana, Baltica, Siberia and Laurentia (Laurussia from the mid-Silurian) are now well known. Although Laurentia was oriented in a similar direction to the present, Siberia was inverted throughout the Lower Palaeozoic, and Baltica too was initially inverted, but rotated through 120° between the Late Cambrian and Late Ordovician before collision with Laurentia in the mid-Silurian Caledonide Orogeny. Through reconstructions of the Caledonide and some other orogenies, the progressive history of the Iapetus Ocean between Laurentia and Baltica/Gondwana is well constrained. Less major continents whose positions are also well known include Avalonia (initially peri-Gondwanan but migrating in the Early Ordovician to join Baltica by the end of the Ordovician), Sibumasu (now considered an integral part of Gondwana) and Mongolia (adjacent to Siberia). A large number of other terranes are reviewed and plotted on the reconstructions with varying degrees of certainty. However, significant continents with less well constrained or controversial positions are South China, North China (Sinokorea), Annamia (Indochina) and Arctic Alaska–Chukotka. The European areas of France, Iberia and southern Italy, previously considered by some as a separate Armorican Terrane Assemblage, remained parts of core Gondwana until the opening of the Palaeotethys Ocean near the end of the Silurian, but it is uncertain whether Perunica (Bohemia) was one of that group or whether it left Gondwana during the Middle Ordovician.