Conference proceeding
Lateral variability of lava flow morphologies in the Deccan Traps large igneous province (India)
American Geophysical Union Fall Meeting, Vol.2016
Dec 2016
Abstract
In continental flood basalt provinces (CFBs), lava flow morphologies have traditionally been classified in two distinct groups recognizable in the field, expressing two different modes of lava flow emplacement mechanisms: (a) compound lava flow fields dominated by meter-sized pahoehoe toes and lobes; and (b) inflated sheet lobes tens to hundreds of meters in width and meters to tens of meters in height. Temporal transitions between these two emplacement styles have been recognized in many mafic large igneous provinces worldwide and seem to be a fundamental feature of CFBs. However, lateral variations in these morphologies remain poorly studied and understood. In the Deccan CFB of India, two principal hypotheses have been proposed to account for possible lateral variations in lava flow facies: that smaller toes and lobes occur in distal regions of flow fields, representing breakouts at the edges of larger inflated lavas; or on the contrary that smaller toes and lobes represent proximal facies. We conducted a field study focusing on two of the Deccan's formations, the Khandala and the Poladpur, located in the middle and upper sections of the province's defined chemostratigraphy. We studied nine sections along a approximately 600 km long E-W transect, with the easternmost sections representing the most distal outcrops, > or =500 km away from inferred vents. The Khandala Formation is traditionally described as a sequence of three thick inflated sheet lobes in the well-exposed sections of the western Deccan. However, in the central Deccan, we find the Khandala to be much thicker overall, with half of its thickness dominated by small, meter-sized toes and lobes. Inflated sheet lobes of the Khandala are thinner on average in the central Deccan than further to the east or west. We document this transition as occurring progressively in outcrops only 80 km apart. In the Poladpur, the average thickness of inflated sheet lobes increases in distal outcrops of the eastern Deccan. We interpret these results as an indication that smaller, meter-sized toes and lobes are indicative of proximal facies, whereas the thickest (>10 m) inflated sheet lobes are the most likely to reach the far edges of the province. Analogue experiments are currently under way to test the relative importance of eruption parameters in the development of these morphologies.
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Details
- Title
- Lateral variability of lava flow morphologies in the Deccan Traps large igneous province (India)
- Creators
- Loyc Vanderkluysen - Drexel UniversityErika L. RaderSteve SelfAmanda B. ClarkeHetu ShethDanielle Kimiko MoyerAnonymous
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2016
- Conference
- American Geophysical Union Fall Meeting (2016)
- Publisher
- American Geophysical Union
- Resource Type
- Conference proceeding
- Language
- English
- Academic Unit
- Biodiversity, Earth, and Environmental Science (BEES)
- Identifiers
- 991021015346704721