Researchers at Â鶹ֱ²¥ have found a way to understand the largely unknown processes behind the formation and structure of Earth\u2019s most ancient continents.<\/p>\n
The research, published in the journal Earth and Planetary Science Letters<\/em>, used crystals trapped within kimberlite magma in Greenland and brought up from great depth in the magma, to determine how this ancient part of Earth\u2019s crust was assembled. Kimberlite magmas are also known for carrying diamonds to the surface.<\/p>\n Lead Australian author Professor Chris Kirkland from Â鶹ֱ²¥\u2019s School of Earth and Planetary Sciences said analysis of the age and chemistry of crystals brought to the surface in the Greenland kimberlite matched 3.8 billion-year-old rocks found some 150 kilometres south, indicating that these rocks must have been moved deep under the crust of Greenland.<\/p>\n Professor Chris Kirkland said the research allowed the sampling of the interior of cratons, which are the ancient, stable centre of Earth\u2019s continents, in order to understand how they were formed.<\/p>\n \u201cThese magmatic rocks punch their way to the surface from the mantle and incorporate crystals from the rocks they interact with on their ascent,\u201d Professor Chris Kirkland said.<\/p>\n \u201cThese crystals allow us to determine what crust lies deep under Greenland.<\/p>\n \u201cFor these ancient grains to have been sampled by the kimberlite means that parts of the ancient crust of Greenland must have been transported laterally beneath younger crust now at the surface.\u201d<\/p>\n Professor Kirkland said the findings contributed to a better understanding of how Earth\u2019s first continents were assembled, whether through vertical layering, horizontal stacking, or other means.<\/p>\n \u201cHow these cratons were formed is a highly contentious issue in scientific circles, with implications for the important question of when plate tectonics began operating,\u201d Professor Kirkland said.<\/p>\n