Growth of the paleo-Orinoco shelf-margin prism: Process regimes, delta evolution, and sediment budget beyond the shelf edge

2017 ◽  
Vol 130 (1-2) ◽  
pp. 35-63 ◽  
Author(s):  
Si Chen ◽  
Ron Steel ◽  
Cornel Olariu ◽  
Shunli Li
Keyword(s):  
Sediment Budget ◽  
Shelf Edge ◽  
Delta Evolution ◽  
Shelf Margin

Growth Styles of Shelf-Margin Clinoforms: Prediction of Sand- and Sediment-Budget Partitioning Into and Across The Shelf

2015 ◽  
Vol 85 (3) ◽  
pp. 209-229 ◽  
Author(s):  
C. Gong ◽  
Y. Wang ◽  
R. J. Steel ◽  
C. Olariu ◽  
Q. Xu ◽  
...  
Keyword(s):  
Sediment Budget ◽  
Shelf Margin

The arrival of the paleo–Orinoco Delta at Trinidad: The Cruse Formation delta lobes and delivery to deepwater Atlantic

2020 ◽  
Vol 90 (8) ◽  
pp. 938-968
Author(s):  
Ariana Osman ◽  
Ronald J. Steel ◽  
Ryan Ramsook ◽  
Cornel Olariu ◽  
Si Chen
Keyword(s):  
Sea Level ◽  
Late Miocene ◽  
Sediment Supply ◽  
Average Height ◽  
Shelf Edge ◽  
Sea Level Changes ◽  
Orinoco Delta ◽  
Basin Floor ◽  
Shelf Margin ◽  
High Sediment

ABSTRACT Icehouse continental-shelf-margin accretion is typically driven by high-sediment-supply deltas and repeated glacio-eustatic, climate-driven sea-level changes on a ca. 100 ky time scale. The paleo–Orinoco margin is no exception to this, as the paleo–Orinoco River Delta with its high sediment load prograded across Venezuela, then into the Southern and Columbus basins of Trinidad since the late Miocene, depositing a continental-margin sedimentary prism that is > 12 km thick, 200 km wide, and 500 km along dip. The Cruse Formation (> 800 m thick; 3 My duration) records the first arrival of the paleo–Orinoco Delta into the Trinidad area. It then accreted eastwards, outwards onto the Atlantic margin, by shallow to deepwater clinoform increments since the late Miocene and is capped by a major, thick flooding interval (the Lower Forest Clay). Previous research has provided an understanding of the paleo–Orinoco Delta depositional system at seismic and outcrop scales, but a clinoform framework detailing proximal to distal reaches through the main fairway of the Southern Basin has never been built. We integrate data from 58 wells and outcrop observations to present a 3-D illustration of 15 mapped Cruse clinoforms, in order to understand the changing character of the first Orinoco clastic wedge on Trinidad. The clinoforms have an undecompacted average height of 550 m, estimated continental slope of 2.5° tapering to 1°, and a distance from shelf edge to near-base of slope of > 10 km. The clinoform framework shows trajectory changes from strong shelf-margin progradation (C10–C13) to aggradation (C14–C20) and to renewed progradation (C21–24). Cruse margin progradational phases illustrate oblique clinothem geometries that lack well-developed topsets but contain up to 70 m (200 ft) thick, deepwater slope channels. This suggests a high supply of sediment during periods of repeated icehouse rise and fall of eustatic sea level, with fall outpacing subsidence rates at times, and delivery of sand to the deepwater region of the embryonic Columbus channel region. Also, evidence of wholesale shelf-edge collapse and canyon features seen in outcrop strongly suggest that deepwater conduits for sediment dispersal and bypass surfaces for Cruse basin-floor fans do exist. The change to a topset aggradational pattern with a rising shelf trajectory may be linked to increased subsidence associated with eastward migration of the Caribbean plate. The Cruse-margin topsets were dominated by mixed fluvial–wave delta lobes that were effective in delivery of sands to the basin floor. The preservation of a fluvial regime of the delta may have been impacted by basin geometry which partly sheltered the area from the open Atlantic wave energy at the shelf edge. Ultimately, understanding shelf-edge migration style as well as process-regime changes during cross-shelf transits of the delta will help to predict the location of bypassed sands and their delivery to deepwater areas.

Clinoform growth and sediment flux of Late Cenozoic Yinggehai and Qiongdongnan shelf margins, Northern South China Sea

2021 ◽  
Author(s):  
Si Chen ◽  
Hua Wang ◽  
Jianghao Ma ◽  
Tianhao Gong ◽  
Zhenghong Yu
Keyword(s):  
South China Sea ◽  
South China ◽  
Northern South China Sea ◽  
Sediment Flux ◽  
Shelf Edge ◽  
Late Cenozoic ◽  
China Sea ◽  
Shelf Margin ◽  
Shelf Margins ◽  
Basin Margin

<p>This study discusses the sedimentary flux, and sedimentary system source tracking on the shelf margins of Yinggehai (YGH) and Qiongdongnan (QDN) Basins, Northern South China Sea. The shelf margin clinoforms of YGH and QDN Basins, have grown since the Late Cenozoic (10.5 Ma), which generated more than 4 km-thick shelf prism above the T40 surface. By using the core, well drilling data, 2D and 3D seismic surveys, this study aims to: ① demonstrate the geometry morphology and architecture of the clinoforms, while the shelf margin trajectory (including the shelf-edge trajectory and toe of slope trajectory) showing down-flatting and rising patterns where the progradation and aggradation happened through the vertical evolution; ② estimate sediment supply values, load volumes, and their changes since the Late Cenozoic, predict ratio of the sediment flux across shelf-edge during their dynamic processes; ③ investigate the contradiction and correlation among the phenomena that sediments show distinctly increasing in flux, decreasing in grain size, and response delay of flux rate peak since 2-4 Ma. The preliminary results show that the vertical sediment accumulation rate increased significantly across the entire YGH and QDN Basin margin system after 2.4 Ma, with a marked increase in mud content that likely caused by long‐distance, alongshore currents with high content of mud during the Pleistocene. Furthermore, laterally, the estimated total sediment flux onto the margin shows a dramatic decline from west to east while moving away from the Red River depocenter, as well as a decrease in the percentage of total discharge crossing the shelf break in this same direction. The overall margin geometry shows a remarkable change from sigmoidal, strongly progradational and aggradational in the west to weakly progradational in the east of QDN Basin margin. The Late Cenozoic shelf margin growth, with its overall increased sediment flux, responded to global, high‐frequency transgressive‐regressive climate cycles during a falling global sea level and gradual cooling temperature in this icehouse period.</p>

Shelf-margin architecture variability and its role in sediment-budget partitioning into deep-water areas

2016 ◽  
Vol 154 ◽  
pp. 72-101 ◽  
Author(s):  
Chenglin Gong ◽  
Ronald J. Steel ◽  
Yingmin Wang ◽  
Changsong Lin ◽  
Cornel Olariu
Keyword(s):  
Deep Water ◽  
Sediment Budget ◽  
Shelf Margin

scholarly journals Shelf-margin architecture and shoreline processes at the shelf-edge: Controls on sediment partitioning and prediction of deep-water deposition style

2018 ◽  
Vol 2018 (1) ◽  
pp. 1-6
Author(s):  
Victorien Paumard ◽  
Julien Bourget ◽  
Tobi Payenberg ◽  
Bruce Ainsworth ◽  
Simon Lang ◽  
...  
Keyword(s):  
Deep Water ◽  
Shelf Edge ◽  
Shelf Margin

ABSTRACT: Shelf-Edge Deltas: Driver for Shelf-Margin Accretion

AAPG Bulletin ◽  
2001 ◽  
Vol 85 ◽  
Author(s):  
Ron Steel1, Donatella Mellere2, Pir
Keyword(s):  
Shelf Edge ◽  
Shelf Margin

Upper-Slope To Shelf-Edge Delta Architecture, Miocene Cruse Formation, Orinoco Shelf Margin, Trinidad

2016 ◽  
Vol 86 (2) ◽  
pp. 87-106 ◽  
Author(s):  
Si Chen ◽  
Ronald J. Steel ◽  
Cornel Olariu
Keyword(s):  
Shelf Edge ◽  
Shelf Margin ◽  
Upper Slope

scholarly journals Shelf-margin architecture and shoreline processes at the shelf-edge: Controls on sediment partitioning and prediction of deep-water deposition style

2018 ◽  
Vol 2018 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Victorien Paumard ◽  
Julien Bourget ◽  
Tobi Payenberg ◽  
Bruce Ainsworth ◽  
Simon Lang ◽  
...  
Keyword(s):  
Deep Water ◽  
Shelf Edge ◽  
Shelf Margin
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