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SEMINAR: GEOTOPICS (Wednesday 10/17 - 10am): Assessing the extent of Carbonate Deposition in Early Rift Settings

From: Andrew Jo <ajo@rsmas.miami.edu>
Subject: SEMINAR: GEOTOPICS (Wednesday 10/17 - 10am): Assessing the extent of Carbonate Deposition in Early Rift Settings
Date: Tue, 9 Oct 2012 17:09:55 -0400



ASSESSING THE EXTENT OF CARBONATE DEPOSITION IN EARLY RIFT SETTINGS


PAUL M. (MITCH) HARRIS

Chevron Energy Technology Company



Wednesday, October 17, 2012
10:00 -11:00 AM, 
SLAB Seminar Room



Abstract 


Select lacustrine and marine depositional settings show a spectrum of styles of carbonate deposition and illustrate the types of carbonates, emphasis on microbialites and tufa, to be expected in early rift settings. Early rift lake examples examined in this review are all from East Africa: Lakes Turkana, Bogoria, Natron and Magadi, Manyara, and Tanganyika. Other lake examples include four from the Western United States (Great Salt Lake and high lake level Lake Bonneville, Mono Lake and high lake level Russell Lake, Pyramid Lake and high lake level Lake Lahontan, and Searles Lake) and two from Australia (Lakes Clifton and Thetis). Marine basin examples are the Hamelin Pool part of Shark Bay from Australia (marginal marine) and the Red Sea (marine rift).

 

Landsat images and Digital Elevation Models (DEMs) for each example are used to delineate present and past lake/basin margins based on published lake-level elevations; and for some examples the shorelines representing different lake levels can be compared to evaluate how changes in size, shape, and lake configuration might have impacted carbonate development. The early rift lakes show a range of characteristics to be expected in lacustrine settings during the earliest stages of continental extension and rifting, whereas the Red Sea shows well advanced rifting with marine incursion and reef – skeletal sand development. Collectively, the lacustrine examples show a wide range of sizes, with several of them being large enough that they could produce carbonate deposits of potential economic interest. Three of the areas - Great Salt Lake and high lake level Lake Bonneville, Pyramid Lake and high lake level Lake Lahontan, and the Red Sea - are exceedingly complex, in that they illustrate a large degree of potential depositional facies heterogeneity due to their size, irregular pattern, and connectivity of subbasins within the overall basin outline.



Hope to see you all there!

GEOTOPICS coordinators,
Mandy Mulcan and Andrew Jo