Seismic Facies of Shelf, Slope, and Submarine Fan Environments of the Lewis Shale, Upper Cretaceous, Wyoming

1991 ◽  
pp. 273-287 ◽  
Author(s):  
Kenneth J. McMillen ◽  
Robert D. Winn
Keyword(s):  
Upper Cretaceous ◽  
Seismic Facies ◽  
Submarine Fan ◽  
Shelf Slope

Sequence architecture and depositional evolution of Eocene to Oligocene, synrift to early postrift strata in the Baiyun Sag, South China Sea

2019 ◽  
Vol 7 (2) ◽  
pp. T309-T329
Author(s):  
Nanan Gao ◽  
Changsong Lin ◽  
Kenneth Eriksson ◽  
Zhongtao Zhang ◽  
Da Gao ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
River Mouth ◽  
Passive Margin ◽  
Seismic Facies ◽  
Pearl River Mouth Basin ◽  
China Sea ◽  
Baiyun Sag ◽  
Shelf Slope ◽  
Depositional Evolution

The Pearl River Mouth Basin (PRMB), located on the northern continental margin of the South China Sea, underwent a complex evolution during the Paleogene. We have focused on the Baiyun Sag in the PRMB with the goal of constructing the architecture and depositional evolution of the Eocene–Early Oligocene synrift stage to the Late Oligocene early postrift stage of basin evolution. Based on analysis of 3D seismic data complemented by well logs and cores, the Paleogene basin fills can be classified into three composite sequences bounded by regional unconformities and 14 sequences bounded by local unconformities. We identify seismic facies on the basis of different internal reflection configurations, external shapes, and contact relationships. The distribution of seismic facies and lithologies interpreted from gamma-ray curves reveal that the synrift basin fill consists mainly of fan delta deposits adjacent to the southern fault scarp, braid delta deposits on the adjacent hanging-wall blocks, and lacustrine mudstones and sublacustrine fan deposits in the center of the basin. The overlying early postrift stage is dominated by shelf and shelf-slope environments, with widespread developed southward-prograding deltas and submarine fans. Tectonics is the principal controlling factor on the development and distribution of depositional systems during the synrift stage. In contrast, sea-level changes superimposed on long-term subsidence related to thermal cooling determined the stacking patterns of sequences during the postrift stage. The results provide new insights on synrift and early postrift tectonics and sedimentation patterns along an evolving passive margin.

scholarly journals STUDY OF THE ARCHITECTURE OF SEDIMENTARY DEPOSITS IN THE IVORIAN ONSHORE BASIN THROUGH SEISMIC REFLECTION

2020 ◽  
Vol 8 (12) ◽  
pp. 575-584
Author(s):  
Assa Maxime Abbey ◽  
◽  
Loukou Nicolas Kouame ◽  
Lacine Coulibaly ◽  
Simon Pierre Djroh ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Upper Cretaceous ◽  
Seismic Facies ◽  
Seismic Profiles ◽  
Sedimentary Deposits ◽  
Sedimentary Model ◽  
Seismic Sections ◽  
Two Phases ◽  
Two Stages ◽  
Stratigraphic Evolution

The seismic profiles analysis of 4,533 km study area made it possible to study the sedimentary deposits in the Ivorian onshore basin. The method used consisted of manual plots of the seismic sections leading to the production of isochronos, iso-velocity, isobaths and isopac maps. As for the stratigraphic interpretation, it was used to develop a sedimentary model to extract information on the nature of sedimentary deposits and the mechanisms of their establishment based on the analysis of seismic facies. Examination of the different seismic profiles of the study area allowed the onshore sedimentary series to be subdivided into four main sequences which are: sequences I, II, III and IV. Thus, this analysis revealed two stages of sedimentary deposits linked to the behavior of the reflectors: 1. a syn-rift stage, characterized by significant fracturing in the sedimentation with faults and tilted blocks inthe Lower Cretaceous 2. a post-rift stage , corresponding to a less deformed sedimentation with parallel and continuous reflectors from the Upper Cretaceous to the present . These two phases allow us to understand the stratigraphic evolution of the onshore basin.

Regional Geological Study and Potential Prediction of the Rio Del Rey Basin (RDR), Offshore Cameroon

2016 ◽  
Author(s):  
Khalid O. Altayeb ◽  
Su Yushan ◽  
Wu Shixiang ◽  
Chen Zhankun
Keyword(s):  
Upper Cretaceous ◽  
Oil And Gas ◽  
Slope Instability ◽  
Seismic Facies ◽  
Detachment Faults ◽  
The North ◽  
Oil And Gas Fields ◽  
Thrust Zone ◽  
Seismic Facies Analysis ◽  
Well Correlation

ABSTRACT Located in the eastern end of Niger delta; the Rio Del Rey (RDR) basin has a unique, complex multi-staged geological features and different types of Structures. This study has aimed to better understand the different structural and stratigraphic setting of the fields within the RDR basin and the way they control the hydrocarbon occurrences. To do that, an integrated 2D and 3D seismic interpretation was done targeting the toe thrust boundary, the upper Cretaceous unconformity and four key horizons of different depth levels in the Tertiary formations. Twelve regional profiles of contrastive orientations that cover the whole basin were interpreted to identify the regional structures; well correlation was done to identify the shallower tertiary settings while additional detailed grids of interpretation at the northeastern and southwestern corners and the seismic facies analysis of the whole RDR study area were used to classify the stratigraphic setting at the deeper regions. The results have revealed that the RDR basin is mainly controlled by thrusting, diapirism and detachment fault structures. The major toe thrust zone is found southern of Ngosso and trends in the northeast-southwestern direction. Gravitational tectonism becomes the primary deformation process shaping the structures as the sediments accumulation increases to the south and consequently, several shale ridges were formed. These ridges and their lateral movement from North to South along with the whole sediments increasing have caused a slope instability of the lower ductile Akata shale formation; what caused the forming of the detachment faults zone in the Northern and middle parts of the RDR basin. The Oongue Turbidites of Eocene were deposited in the northeastern part of the basin in deep water fans by the main sediments supply from the North and the East with various sand thicknesses due to the structural system. The hydrocarbon potential accumulations are found in the mid to upper Tertiary formations and the deeper Upper Cretaceous, but most of the oil and gas fields are located in shallower deltaic reservoirs associated with fault-bounded traps related to shale ridges and diapir structures. Considerable amounts of hydrocarbons were also found within the turbidites sands of Oongue (NE) and Isongo (SE).

Sign in / Sign up

Export Citation Format

Share Document