Explorer Article
By Louise Durham
It don’t come easy: The oil rich Monterey Shale has proved to be the biggest conventional resource provider in California, and it promises even more – but the formation’s complex geology is just as intimidating as its potential is huge.
American Association of Petroleum Geologists (AAPG)
Added on 01 February, 2013
Bulletin Article
Select lacustrine and marine depositional settings show a spectrum of styles of carbonate deposition and illustrate the types of carbonates, with an emphasis on microbialites and tufa, to be expected in early rift settings. Early rift lake examples examined in this review article 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 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 because of their size, irregular pattern, and connectivity of subbasins within the overall basin outline.
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American Association of Petroleum Geologists (AAPG)
Added on 31 December, 2012
Bulletin Article
We reviewed the tectonostratigraphic evolution of the Jurassic–Cenozoic collision between the North American and the Caribbean plate using more than 30,000 km (18,641 mi) of regional two-dimensional (2-D) academic seismic lines and Deep Sea Drilling Project wells of Leg 77. The main objective is to perform one-dimensional subsidence analysis and 2-D flexural modeling to better understand how the Caribbean collision may have controlled the stratigraphic evolution of the offshore Cuba region.
Five main tectonic phases previously proposed were recognized: (1) Late Triassic–Jurassic rifting between South and North America that led to the formation of the proto-Caribbean plate; this event is interpreted as half grabens controlled by fault family 1 as the east-northeast–south-southwest–striking faults; (2) Middle–Late Jurassic anticlockwise rotation of the Yucatan block and formation of the Gulf of Mexico; this event resulted in north-northwest–south-southeast–striking faults of fault family 2 controlling half-graben structures; (3) Early Cretaceous passive margin development characterized by carbonate sedimentation; sedimentation was controlled by normal subsidence and eustatic changes, and because of high eustatic seas during the Late Cretaceous, the carbonate platform drowned; (4) Late Cretaceous–Paleogene collision between the Caribbean plate, resulting in the Cuban fold and thrust belt province, the foreland basin province, and the platform margin province; the platform margin province represents the submerged paleoforebulge, which was formed as a flexural response to the tectonic load of the Great Arc of the Caribbean during initial Late Cretaceous–Paleocene collision and foreland basin development that was subsequently submerged during the Eocene to the present water depths as the arc tectonic load reached the maximum collision; and (5) Late Cenozoic large deep-sea erosional features and constructional sediment drifts related to the formation of the Oligocene–Holocene Loop Current–Gulf Stream that flows from the northern Caribbean into the Straits of Florida and to the north Atlantic.
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American Association of Petroleum Geologists (AAPG)
Added on 31 December, 2012
Explorer Article
By Susan Eaton
One more time: The AAPG Foundation’s “explorer-in-residence,” Susan Eaton, is returning to Antarctica again on a scientific expedition to study the geology and the climate found at the Bottom of the World.
American Association of Petroleum Geologists (AAPG)
Added on 01 December, 2012
Explorer Spotlight On…
By Louise Durham
The Caribbean Basins Tectonics Hydrocarbon project is now in the stretch drive of its planned triple-phase program.
American Association of Petroleum Geologists (AAPG)
Added on 01 October, 2012
Explorer Emphasis Article
By David Brown
A gentleman, a scholar and a great geologist: A look at the life and legacy of Charles Hutchison.
American Association of Petroleum Geologists (AAPG)
Added on 01 September, 2012
Explorer Historical Highlights
By Keith James
Historical Highlights looks at the origin of the Caribbean, a geological puzzle. Just exactly where did it come from?
American Association of Petroleum Geologists (AAPG)
Added on 01 August, 2012
Explorer Article
By Vern Stefanic
Spreading the word: Nine speakers have been selected for AAPG’s prestigious Distinguished Lecture program for the 2012-13 North American tours.
American Association of Petroleum Geologists (AAPG)
Added on 01 August, 2012
Explorer Emphasis Article
By Diane Freeman
Early detection: A Canadian geophysicist is finding success by incorporating existing 3-D data to determine fracture networks in the Bakken Shale.
American Association of Petroleum Geologists (AAPG)
Added on 01 June, 2012