3-D sedimentological and geophysical studies of clastic reservoir analogs: Facies architecture, reservoir properties, and flow behavior within delta front facies elements of the Cretaceous Wall Creek Member, Frontier Formation, Wyoming

This project examined the internal architecture of delta front sandstones at two locations within the Turonian-age Wall Creek Member of the Frontier Formation, in Wyoming. The project involved traditional outcrop field work integrated with core-data, and 2D and 3D ground penetrating radar (GPR) imaging from behind the outcrops. The fluid-flow engineering work, handled through a collaborative grant given to PI Chris White at LSU, focused on effects on fluid flow of late-stage calcite cement nodules in 3D. In addition to the extensive field component, the work funded 2 PhD students (Gani and Lee) and resulted in publication of 10 technical papers, 17 abstracts, and 4 internal field guides. PI Bhattacharya also funded an additional 3 PhD students that worked on the Wall Creek sandstone funded separately through an industrial consortium, two of whom graduated in the fall 2006 ((Sadeque and Vakarelov). These additional funds provided significant leverage to expand the work to include a regional stratigraphic synthesis of the Wall Creek Member of the Frontier Formation, in addition to the reservoir-scale studies that DOE directly funded. Awards given to PI Bhattacharya included the prestigious AAPG Distinguished Lecture Award, which involved a tour of about 25 Universities and Geological Societies in the US and Canada in the fall of 2005 and Spring of 2006. Bhattacharya gave two talks, one entitled “Applying Deltaic and Shallow Marine Outcrop Analogs to the Subsurface”, which highlighted the DOE sponsored work and the other titled “Martian River Deltas and the Origin of Life”. The outcrop analog talk was given at about 1/2 of the venues visited

Creating Virtual 3-D Outcrop

Because of the high precision of present-day GPS and reflectorless laser technology, geologic information and remotely sensed data (i.e., seismic and GPR grids, wells) can be positioned accurately in 3-D and reconstructed as a virtual image. Hence, we have developed the “virtual outcrop” for applications that require knowledge about the 3-D spatial arrangements of rock types

Local tectonic control on parasequence architecture: Second Frontier sandstone, Powder River Basin, Wyoming

Copyright © 2009 AAPG/Datapages, Inc. All rights reserved.Boyan K. Vakarelov and Janok P. Bhattachary

Palynology of the Upper Cretaceous (Turonian) Ferron Sandstone Member, Utah, USA: Identification of marine flooding surfaces and Milankovitch cycles in subtropical, ever-wet, paralic to non-marine palaeoenvironments

© 2015 AASP - The Palynological Society. The Upper Cretaceous Ferron Sandstone Member of the Mancos Shale Formation in Utah includes coal and gas deposits and is an important outcrop analogue to study reservoir characterisation of fluvial-deltaic petroleum systems. Numerous sedimentological and sequence stratigraphic studies of the Notom fluvial-deltaic wedge have been conducted recently; however, palynological analyses had not previously been undertaken. Here, we present palynological data from 128 samples collected in the Notom wedge of the Ferron Sandstone Member outcropping in south-central Utah. The purpose of this study is to use palynological analysis to refine the broader depositional environments, evaluate the climatic setting, and to build a biostratigraphic palynological framework. The dominance of terrestrial palynomorphs, especially the high yield of moisture-loving cryptogam spores, indicates a primarily ever-wet depositional environment characteristic of hydromorphic floodplain palaeosols formed in subtropical to tropical climates. Although dinoflagellates are rare, four intervals with occurrences of marine cysts indicate periods of increased marine/tidal influence associated with previously identified flooding surfaces within Milankovitch-scale parasequences of the largely non-marine stratal succession. These flooding surfaces confirm correlations from regional high-resolution sequence stratigraphic studies and allow correlative marine parasequences and systems tracts to be extended within floodplain-dominated stratal successions. The presence of Nyssapollenites albertensis pollen places the interval studied within the Nyssapollenites albertensis Interval Zone (Nichols 1994), constraining the age of the Ferron Sandstone Member to the latter part of the Cenomanian and the early Coniacian. This largely agrees with the bentonite- and ammonite-derived Turonian age proposed in previous studies

Large deltas, small deltas: Toward a more rigorous understanding of coastal marine deltas

International audienceDeltas are subaerial landforms that cap underlying deposits with subaqueous extensions that result from a river feeding sediment directly into a standing body of water at a rate that overwhelms any effective dispersal processes derived from the ambient basin. This definition encapsulates both the terrestrial surface expression and the geological focus on the entire sediment mass. Environmental studies also focus on the ecology of deltaic wetlands, their drowning history, and related sustainability issues including societal considerations, history, and culture. A mean 76 ± 16% drop in hydraulic energy occurs in all subaerial deltas regardless of size, given the break in gradients separating fluvial and deltaic surfaces, driving an ever-decreasing bed-material transport, shallowing of distributary channels and concomitant overbank flooding. A delta's sediment mass grows from the addition of new river loads but can also include aeolian and marine sediment derived from outside the delta domain, growth of peat and other biomass, and inputs from human action. Removal of sediment is via river plumes interacting with marine currents, wave-induced transport, sediment failures and gravity flows, high-tide inundation onto the delta plain, tidal channel widening and deepening, and human action (peat, clay, sand and gravel mining). A delta's trapping efficiency ranges from 0 for small-load rivers that discharge directly into an energetic ocean, to 80% for large deltas, and up to 100% for some semi-enclosed bayhead deltas, including fjords. The global (ensemble) subaerial delta aggradation rate is ∼1.6 mm/y if 70% of the global sediment load exits the river mouth(s), a reminder of how much sediment can be expected to be delivered to the surfaces of global deltas at a time when the 2022 CE sea level rise is ∼4 mm/y. At the planetary scale, deltas are environmentally complex given Earth's range in climate, hydrodynamics, tectonic settings, relative sea-level provinces, sediment input, redistribution processes, and human actions. Under natural conditions, the subaerial portion of deltas adapt to change by advancing, retreating, switching, aggrading, and/or drowning, whereas many modern deltas are structurally constrained by societal needs. The 89 large and mud-rich coastal marine deltas (i.e. subaerial area > 1000 km2) account for 84.3% of Earth's total deltaic area that hosts >89% of all humans occupying deltas, many living within megacities. The 885 medium-size deltas (i.e. subaerial areas 10-1000 km2) account for 15.5% of the global delta area and 10.5% of humans living on deltas, with characteristics that fall between the small and large delta categories. The 1460 small and essentially sandy deltas (1-10 km2), including all fjord deltas, are impacted less from human action (with exceptions) and most are better able to withstand climate change. Recognizing the limits of big data in capturing delta complexity, field data remains a necessary gold standard for site investigators

Dynamic river channels suggest a long-lived Noachian crater lake on Mars

Copyright 2005 by the American Geophysical Union.Recent images of the Noachian-age Holden Northeast Crater show spectacular meandering channels that form a complex 150 meter thick lacustrine river delta deposit confined to the northwest margin of the crater. We identify 11 major avulsion events in the topmost layer and suggest an avulsion frequency of a few hundred years. The meandering nature of the channels and numerous avulsions is incompatible with deposition on an alluvial fan and clearly reflects a complex history of multiple sustained flows. Assuming an average sedimentation rate of 1mm/year, we suggest that Holden NE Crater contained a lake that persisted for at least 150,000 years. Our analysis is incompatible with this feature being the result of a major bolide impact that would have released a catastrophic flood by groundwater sapping and supports the hypothesis that early Mars was both warmer and wetter during the Noachian