Friday, November 11, 2011

Acronym in earth science: LIP for large igneous province

In earth science, LIP stands for large igneous province. LIPs are deposits of igneous rocks with impressive dimensions that often are hundred of meters thick and may cover over thousands of square kilometers [1]. A LIP is connected to a hotspot [2,3]: examples include the Dekkan/Réunion Traps (India and Indian Ocean), the Columbia River Basin Flood Basalt with source at Yellowstone (North America) and the Permo-Triassic Siberian Traps (hotspot cooled down or relocated?). LIP eruptions are catastrophic, environmentally devastating, and humans have never witnessed one [4]. They probably never will, or if, will not have much time to talk and twitter about it.

Recent research on the Siberian Traps (built by a gigantic eruption or series of eruptions about 250 million years ago) suggests that its magma source contained a significant amount of recycled oceanic crust [4,5]. This may explain the following mass extinction, which may have been triggered by massive degassing of carbon dioxide (CO2) and hydrogen chloride (HCl), probably already at the onset of the eruption. The amount of gas can roughly be estimated from volume data measured during modern basalt-lava eruptions, which allow scale-up to a LIP event.  

Keywords: geology, volcanism, magma production, flood-basalt, lithosphere

References and more to explore
[1] David Bressan: Large Igneous Provinces and Mass Extinctions. September 16, 2011 [blogs.scientificamerican.com/history-of-geology/2011/09/16/large-igneous-provinces-and-mass-extinctions/].
[2] World map of igneous provinces and hotspots: blogs.scientificamerican.com/history-of-geology/files/2011/09/BRESSAN_LIP_map1.jpg.
[3] Flood Basalt Map of the World: en.wikipedia.org/wiki/File:Flood_Basalt_Map.jpg.
[4] Paul B. Wignall: Lethal volcanism. Nature September 15, 2011, 477 (7364), pp. 285-286 [www.nature.com/nature/journal/v477/n7364/full/477285a.html]. 
[5] Stephan V. Sobolov et al.: Linking mantle plumes, large igneous provinces and environmental catastrophes. Nature September 15, 2011, 477 (7364), pp. 312-316. doi: 10.1038/nature10385.

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