Submarine-Fan Sedimentation, Ouachita Mountains, Arkansas and Oklahoma: ABSTRACT

As of Feb. 5th, 2019, this study has been submitted to Marine and Petroleum Geology (Elsevier). Topographic confinement can impose significant control on depositional styles of deepwater fan deposits. Currently, there is a lack of quantitative documentation on the spatial variation of topographic confinement in segmented deepwater basins. Herein, we investigated the Pennsylvanian Lower Atoka Formation in the Ouachita Mountains, south-central the United States which is a fine-grained submarine fan system deposited on the active Ouachita Fold and Thrust Belt. The basin is divided by two distinctive depozones that are laterally confined: foredeep and wedge-top, both of which are primarily sourced from the east. We quantitatively compared the lithofacies, architectural elements, and hierarchical thickness distributions of turbidite lobe deposits among proximal foredeep, distal foredeep, proximal wedge-top, and distal wedge-top depozones. The proximal foredeep and wedge-top show identical lithofacies compositions and thickness distributions of lobe deposits. However, the foredeep shows a significant proximal-distal decrease in sand-prone deposits and thicknesses of lobe deposits, whereas the wedge-top show little to no such changes. We demonstrated that the complex topography and stronger lateral confinement in the wedge-top depozone is the dominant control for this difference. The signal of topographic confinement increases hierarchically from bed to lobe scales because these deposits tend to stack more vertically rather than switching horizontally (or compensationally) due to confinement. The results have implications for predicting hydrocarbon reservoir distribution, recognizing the degree of confinement, and refining the depositional reconstruction of analogous laterally-confined turbidite systems.

Download Full-text

Statistical characterization of a confined submarine fan system: The Pennsylvanian Lower Atoka Formation, Ouachita Mountains, USA

Sedimentology ◽

10.1111/sed.12925 ◽

2021 ◽

Author(s):

Pengfei Hou ◽

Zane R. Jobe ◽

Lesli J. Wood

Keyword(s):

Ouachita Mountains ◽

Submarine Fan ◽

Statistical Characterization

Download Full-text

Tectonic–sedimentary interplay of a confined deepwater system in a foreland basin setting: the Pennsylvanian lower Atoka Formation, Ouachita Mountains, U.S.A.

Journal of Sedimentary Research ◽

10.2110/jsr.2020.064 ◽

2021 ◽

Vol 91 (7) ◽

pp. 683-709

Author(s):

Pengfei Hou ◽

Lesli J. Wood ◽

Zane R. Jobe

Keyword(s):

Foreland Basin ◽

Structural Data ◽

Distribution Patterns ◽

Sediment Supply ◽

Ouachita Mountains ◽

Submarine Fan ◽

Facies Distribution ◽

Submarine Fans ◽

Basin Morphology ◽

Complex Settings

ABSTRACT Submarine fans deposited in structurally complex settings record important information on basin evolution and tectonic–sedimentary relationships but are often poorly preserved in outcrops due to syndepositional and post depositional deformation. This study aims to understand the influence of tectonics on the deposition of the synorogenic Pennsylvanian lower Atoka submarine fan system deposited in a structurally complex foreland basin during the Ouachita orogeny. This study is a synthesis of new outcrop stratigraphic data as well as published stratigraphic and structural data. The lower Atoka crops out in the Ouachita Mountains and the southern Arkoma Basin and is divided into three structural–depositional zones: the foredeep, the wedge top, and the continental foreland. The mean paleoflow is axial, and each zone exhibits unique patterns in facies distribution. The foredeep consists of two fan systems, a large westward-prograding fan that exhibits significant longitudinal and lateral facies changes, and a small eastward-prograding fan on the western part. The wedge top consists of a westward-prograding fan that exhibits subtle longitudinal facies change. The continental foreland consists of small slope fan systems along the northern and western margins. By comparing to basin morphology and structural styles, we interpret the facies distribution patterns in the three zones as the result of different combinations of lateral structural confinement, axial and lateral sediment supply, and paleogeography. This study provides an improved and comprehensive understanding of the lower Atoka deepwater system and has implications for deciphering the tectonic–sedimentary relationships in laterally confined submarine fan systems.

Download Full-text

STATISTICAL COMPARISONS OF SUBMARINE FAN DEPOSITS DURING REMNANT OCEAN - FORELAND BASIN TRANSITION: EXAMPLES FROM THE OUACHITA MOUNTAINS, USA

10.1130/abs/2020am-353971 ◽

2020 ◽

Author(s):

Pengfei Hou ◽

◽

Zane Jobe ◽

Lesli Wood

Keyword(s):

Foreland Basin ◽

Ouachita Mountains ◽

Submarine Fan

Download Full-text

Statistical Characterization of a Confined Submarine Fan System: the Pennsylvanian Lower Atoka Formation, Ouachita Mountains, USA

10.31219/osf.io/vrmfe ◽

2020 ◽

Author(s):

Pengfei Hou ◽

Zane Richards Jobe ◽

Leslie Wood

Keyword(s):

Time Series ◽

Markov Chains ◽

Statistical Methods ◽

Distribution Analysis ◽

Ouachita Mountains ◽

Submarine Fan ◽

Statistical Characterization ◽

Rescaled Range Analysis ◽

Bed Thickness ◽

Hurst Statistics

Our knowledge of submarine fan deposits has historically relied heavily on qualitative field and subsurface observations and interpretations, but recent studies using statistical analyses have enhanced the understanding of submarine fan sub-environments, including the degree of confinement, stratigraphic patterns, and potential control factors. The purpose of this study is to improve the quantitative understanding of synorogenic submarine fan deposition at foreland basin settings with a statistical approach. A suite of statistical methods is integrated and developed (Hurst Statistics/ rescaled range analysis, bed thickness frequency distribution analysis, Markov Chains, and time-series analysis), and applied to the well understood Pennsylvanian lower Atoka submarine fan system in the Ouachita Mountains, United States for this purpose. The results of the Hurst Statistics and bed thickness analyses corroborate qualitative interpretations that (1) the lower Atoka is lobe-dominated, and (2) the southeastern (wedge-top) portion of the system is more strongly confined than the northern (foredeep) portion. The Markov Chains and time-series analyses reveal the prevalence (56%) of stratigraphic orderliness and cyclicity; these results are used to discuss potential intrinsic and extrinsic controls on the turbidite sandstone recurrence cycles, which are otherwise difficult to distinguish qualitatively. The results of this study demonstrate that these integrated statistical methods can be utilized to quantify uncertainty in depositional interpretations of outcrops with limited exposures or 1D subsurface (e.g., well-log, core) datasets.

Download Full-text