on of this mountain chain in Central Iberia, Spain. Due to the collision of continents Gondwana and Laurussia back then, the Earth's crust in this zone became very thick, to a point that rocks started to flow laterally in order to compensate such a gravitational disequilibrium in the margins of these two continents. This way, the rocks located deep inside that mountain belt accommodated large lateral displacements, and therefore they were strongly deformed. Thanks to erosion, today it is possible to recognize the mechanisms by which those rocks were deformed, being the formation of kilometer-scale folds affecting the different layers of rock one of the most important.
Laurentian origin for the North Slope of Alaska: Implications for the tectonic evolution of the Arctic
Justin V. Strauss et al., Dept. of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, Massachusetts 02138, USA; Francis A. Macdonald, John F. Taylor, John E. Repetski, and William C. McClelland; http://dx.doi.org/10.1130/L284.1.
The Arctic region remains a modern-day frontier for geologists. Both the tectonic history of the circum-Arctic continental margins and a comprehensive model to explain the opening of the Arctic Ocean are still hotly debated. This is mostly due to a lack of field-based geological data from this remote part of the planet. In this paper, Justin Strauss and colleagues provide new geochronological and paleontological data from the Brooks Range of Alaska that help elucidate the origin and travels of Arctic Alaska, a continental fragment that was accreted to the northwestern margin of North America in the Jurassic-Cretaceous. Based on these new data, we show that Arctic Alaska most likely originated as a piece of eastern North America and was subsequently displaced to its current position in a complex series of Devonian-Carboniferous orogenic events in the CanaPage: 1 2 3 4 5 6 7 Related biology news :1
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