Intracanyon basalt lavas of the Debed River (northern Armenia), part of a Pliocene-Pleistocene continental flood basalt province in the South Caucasus
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Title |
Intracanyon basalt lavas of the Debed River (northern Armenia), part of a Pliocene-Pleistocene continental flood basalt province in the South Caucasus
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Creator |
SHETH, H
MELIKSETIAN, K GEVORGYAN, H ISRAYELYAN, A NAVASARDYAN, G |
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Subject |
DECCAN VOLCANIC PROVINCE
LARGE IGNEOUS PROVINCES DZHAVAKHETI-HIGHLAND LESSER CAUCASUS COLUMNAR JOINTS KILAUEA VOLCANO EASTERN PART K-AR PAHOEHOE FLOWS Volcanism Continental flood basalts Debed River Armenia South Caucasus |
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Description |
Late Pliocene to Early Pleistocene (similar to 3.25-2.05 Ma), 200-400 m thick basalt lavas outcrop in the South Caucasus region, including the Kars-Erzurum Plateau (northeastern Turkey), the Javakheti Plateau (Georgia-Armenia), and the Lori Plateau (northern Armenia). These fissure-fed, rapidly erupted fluid lavas filled pre-existing river valleys over many tens of kilometres. The basalts exposed in the Debed River canyon, northern Armenia, are similar to 200 m thick and of three morphological types: (1) basal pillow basalts and hyaloclastites, overlain by (2) columnar-jointed pahoehoe sheet flows, in turn overlain by (3) slabby pahoehoe and rubbly pahoehoe flows. The lower and middle lavas show evidence for damming of river drainage, like many lavas of the Columbia River flood basalt province, Scotland, Ireland, and Iceland. There is also evidence for syn-volcanic faulting of the early lavas. Related basalts also outcrop in the Gegham Uplands and the Hrazdan River basin in Armenia. This 3.25-2.05 Ma South Caucasus basalt province, covering parts of Turkey, Georgia and Armenia, has an estimated areal extent of similar to 15,000 km(2) and volume of similar to 2250 km(3). Because its main geological features are remarkably like those of many continental flood basalt (CFB) provinces, we consider it a true, albeit small, CFB province. It is the smallest and youngest CFB in the world. An analogue closely similar in major features is the Late Miocene Altos de Jalisco CFB province in the western Trans-Mexican Volcanic Belt. Both provinces formed during lithospheric pull-apart and transtensional faulting. Their broader significance is in showing flood basalt size distribution to be a continuum without natural breaks, with implications for geodynamic models. (C) 2015 Elsevier B.V. All rights reserved.
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Publisher |
ELSEVIER SCIENCE BV
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Date |
2016-01-15T04:31:42Z
2016-01-15T04:31:42Z 2015 |
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Type |
Article
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Identifier |
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH, 295,1-15
0377-0273 1872-6097 http://dx.doi.org/10.1016/j.jvolgeores.2015.02.010 http://dspace.library.iitb.ac.in/jspui/handle/100/17764 |
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Language |
en
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