What's in a name? The Columbia (Paleopangaea/Nuna) supercontinent
- 作者：Joseph G. Meert ; jmeert@ufl.edu
- 关键词：Columbia ; Supercontinent tectonics ; Pangaea ; Rodinia ; Nuna
- 刊名：Gondwana Research
- 出版年：2012
- 期刊代码：3_1342937X
- 类别：ear
- 出版时间：May, 2012
- 卷：21
- 期：4
- 页码：987-993
- 文件大小：1302 K
摘要
Supercontinents play an important role in Earth's history. The exact definition of what constitutes a supercontinent is difficult to establish. Here the argument is made, using Pang忙a as a model, that any supercontinent should include ~ 75%of the preserved continental crust relevant to the time of maximum packing. As an example, Rodinia reached maximum packing at about 1.0 Ga and therefore should include 75%of all continental crust older than 1.0 Ga. In attempting to 鈥榥ame鈥?any supercontinent, there is a clear precedent for models that provide a name along with a testable reconstruction within a reasonable temporal framework. Both Pang忙a and Rodinia are near universally accepted names for the late Paleozoic and Neoproterozoic supercontinent respectively; however, there is a recent push to change the Paleo-Mesoproterozoic supercontinent moniker from 鈥?em>Columbia鈥?to 鈥?em>Nuna鈥? A careful examination of the 鈥?em>Nuna鈥?and 鈥?em>Columbia鈥?proposals reveals that although the term 鈥?em>Nuna鈥?was published prior to 鈥?em>Columbia鈥? the 鈥?em>Nuna鈥?proposal is a bit nebulous in terms of the constitution of the giant continent. Details of 鈥?em>Nuna鈥?given in the original manuscript appear to be principally based on previously published connections between Laurentia, Baltica and, to a lesser extent the Angara craton of Siberia (i.e. 鈥渢he lands bordering the northern oceans鈥?. Therefore the proposal is made that 鈥?em>Columbia鈥?consists of several core elements one of which is 鈥?em>Nuna鈥?