Lateral migration of large sedimentary bodies in a deep-marine system offshore of Argentina

AbstractContourite features are increasingly identified in seismic data, but the mechanisms controlling their evolution remain poorly understood. Using 2D multichannel reflection seismic and well data, this study describes large Oligocene- to middle Miocene-aged sedimentary bodies that show prominent lateral migration along the base of the Argentine slope. These form part of a contourite depositional system with four morphological elements: a plastered drift, a contourite channel, an asymmetric mounded drift, and an erosive surface. The features appear within four seismic units (SU1–SU4) bounded by discontinuities. Their sedimentary stacking patterns indicate three evolutionary stages: an onset stage (I) (~ 34–25 Ma), a growth stage (II) (~ 25–14 Ma), and (III) a burial stage (< 14 Ma). The system reveals that lateral migration of large sedimentary bodies is not only confined to shallow or littoral marine environments and demonstrates how bottom currents and secondary oceanographic processes influence contourite morphologies. Two cores of a single water mass, in this case, the Antarctic Bottom Water and its upper interface, may drive upslope migration of asymmetric mounded drifts. Seismic images also show evidence of recirculating bottom currents which have modulated the system’s evolution. Elucidation of these novel processes will enhance basin analysis and palaeoceanographic reconstructions.

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Geological evolution of the Chalk Group in the northern Dutch North Sea: inversion, sedimentation and redeposition

Geological Magazine ◽

10.1017/s0016756818000572 ◽

2018 ◽

Vol 156 (07) ◽

pp. 1265-1284

Author(s):

EVA VAN DER VOET ◽

LEONORA HEIJNEN ◽

JOHN J. G. REIJMER

Keyword(s):

North Sea ◽

Late Cretaceous ◽

Seismic Survey ◽

Structural Elements ◽

The North ◽

Show Evidence ◽

New Finding ◽

The North Sea ◽

Thickness Variations ◽

Well Data

AbstractIn contrast to the Norwegian and Danish sectors, where significant hydrocarbon reserves were found in chalk reservoirs, limited studies exist analysing the chalk evolution in the Dutch part of the North Sea. To provide a better understanding of this evolution, a tectono-sedimentary study of the Late Cretaceous to Early Palaeogene Chalk Group in the northern Dutch North Sea was performed, facilitated by a relatively new 3D seismic survey. Integrating seismic and biostratigraphic well data, seven chronostratigraphic units were mapped, allowing a reconstruction of intra-chalk geological events.The southwestward thickening of the Turonian sequence is interpreted to result from tilting, and the absence of Coniacian and Santonian sediments in the western part of the study area is probably the result of non-deposition. Seismic truncations show evidence of a widespread inversion phase, the timing of which differs between the structural elements. It started at the end of the Campanian followed by a second pulse during the Maastrichtian, a new finding not reported before. After subsidence during the Maastrichtian and Danian, renewed inversion and erosion occurred at the end of the Danian. Halokinesis processes resulted in thickness variations of chalk units of different ages.In summary, variations in sedimentation patterns in the northern Dutch North Sea relate to the Sub-Hercynian inversion phase during the Campanian and Maastrichtian, the Laramide inversion phase at the end of the Danian, and halokinesis processes. Additionally, the Late Cretaceous sea floor was characterized by erosion through contour bottom currents at different scales and resedimentation by slope failures.

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Similar curvature-to-width ratios for channels and channel belts: Implications for paleo-hydraulics of fluvial ridges on Mars

Geology ◽

10.1130/g48370.1 ◽

2021 ◽

Author(s):

Alistair T. Hayden ◽

Michael P. Lamb ◽

Alexander J. Carney

Keyword(s):

Coarse Grained ◽

Scaling Relations ◽

Radius Of Curvature ◽

Finite Width ◽

Lateral Migration ◽

River Channels ◽

Meandering Rivers ◽

Channel Belt ◽

Stacking Patterns ◽

Geometric Consequence

The surface of Mars contains abundant sinuous ridges that appear similar to river channels in planform, but they stand as topographic highs. Ridges have similar curvature-to-width ratios as terrestrial meandering rivers, which has been used to support the hypothesis that ridges are inverted channels that directly reflect channel geometry. Anomalously wide ridges, in turn, have been interpreted as evidence for larger rivers on Mars compared to Earth. However, an alternate hypothesis is that ridges are exhumed channel-belt deposits—a larger zone of relatively coarse-grained deposits formed from channel lateral migration and aggradation. Here, we measured landform wavelength, radius of curvature, and width to compare terrestrial channels, terrestrial channel belts, and martian ridges. We found that all three landforms follow similar scaling relations, in which ratios of radius of curvature to width range from 1.7 to 7.3, and wavelength-to-width ratios range from 5.8 to 13. We interpret this similarity to be a geometric consequence of a sinuous curved line of finite width. Combined with observations of ridge-stacking patterns, our results suggest that wide ridges on Mars could indicate fluvial channel belts that formed over significant time rather than anomalously large rivers.

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Marine mammals and conservation in the Antarctic marine system

Australian Zoologist ◽

10.7882/az.1993.005 ◽

1993 ◽

Vol 29 (1-2) ◽

pp. 63-76 ◽

Cited By ~ 2

Author(s):

M. M. Bryden

Keyword(s):

Marine Mammals ◽

Antarctic Marine ◽

Marine System ◽

The Antarctic

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Use of Computer Workstations in the Study of Environmental Geology: Integration of Shallow Reflection Seismic, V.S.P., and Well Data: ABSTRACT

AAPG Bulletin ◽

10.1306/7834ed77-1721-11d7-8645000102c1865d ◽

1995 ◽

Vol 79 ◽

Author(s):

Alex Martinez, John F. Hopkins, How

Keyword(s):

Environmental Geology ◽

Reflection Seismic ◽

Well Data

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Seismic Sedimentology Research on Sublacustrine Fan of the Oligocene Dongying Formation, Liaozhong Depression, Bohai Bay Basin, Northeast China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.807-809.2151 ◽

2013 ◽

Vol 807-809 ◽

pp. 2151-2154 ◽

Cited By ~ 1

Author(s):

Yan Yan Chang ◽

Chang Song Lin ◽

Xin Huai Zhou ◽

Shi Qiang Xia

Keyword(s):

Seismic Reflection ◽

Gamma Ray ◽

High Resistivity ◽

Bohai Bay ◽

Lateral Migration ◽

Multi Stage ◽

Seismic Reflection Profiles ◽

Seismic Reflections ◽

Stacking Patterns ◽

Order Sequence

In Liaozhong Depression, five types of sublacustrine fans are developed in the relative lowstand systems tracts of the fourth-order sequence in Dongying Formation. In drilling cores, typical turbidites characteristics exist including bedding structures such as slump deformation structure, parallel bedding, grading laminations and multi-stage scoured basal surfaces. They also can be recognized in well logs with distinctive low gamma-ray and high-resistivity stacking patterns. Logging curves usually display serrated bell shape, cylinder shape and funnel shape respectively. On seismic reflection profiles, sublacustrine fan typically shows lateral downlap on its external geometry and continuous or discontinuous “vermicular” reflection characteristics in its inner seismic reflection texture. According to the calibration results of drilling data, continuous seismic reflection profiles are interpreted to be mud-rich deposits with cohesive, soft sediment-deformation. Discontinuous seismic reflections with lateral migration and apparent incised valleys are interpreted to be sand-rich deposits which probably host the most potential litho-stratigraphic traps.

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Inversion tectonics: a brief petroleum industry perspective

10.5194/se-2020-33 ◽

2020 ◽

Author(s):

Gábor Tari ◽

Didier Arbouille ◽

Zsolt Schléder ◽

Tamás Tóth

Keyword(s):

Petroleum Industry ◽

Structural Complexity ◽

Source Rocks ◽

Petroleum Exploration ◽

Data Sets ◽

Hydrocarbon Generation ◽

Seismic Reflection Data ◽

Reflection Seismic ◽

Reflection Data ◽

Well Data

Abstract. The concept of structural inversion was introduced in the early 1980s. By definition, an inversion structure forms when a pre-existing extensional (or transtensional) fault controlling a hangingwall basin containing a syn-rift or passive fill sequence subsequently undergoes compression (or transpression) producing partial (or total) extrusion of the basin fill. Inverted structures provide traps for petroleum exploration, typically four-way structural closures. As to the degree of inversion, based on large number of worldwide examples seen in various basins, the most preferred petroleum exploration targets are mild to moderate inversional structures, defined by the location of the null-points. In these instances, the closures have a relatively small vertical amplitude, but simple in a map-view sense and well imaged on seismic reflection data. Also, the closures typically cluster above the extensional depocentres which tend to contain source rocks providing petroleum charge during and after the inversion. Cases for strong or total inversion are generally not that common and typically are not considered as ideal exploration prospects, mostly due to breaching and seismic imaging challenges associated with the trap(s) formed early on in the process of inversion. Also, migration may become tortuous due to the structural complexity or the source rock units may be uplifted above the hydrocarbon generation window effectively terminating the charge once the inversion occurred. For any particular structure the evidence for inversion is typically provided by subsurface data sets such as reflection seismic and well data. However, in many cases the deeper segments of the structure are either poorly imaged by the seismic data and/or have not been penetrated by exploration wells. In these cases the interpretation of any given structure in terms of inversion has to rely on the regional understanding of the basin evolution with evidence for an early phase of substantial crustal extension by normal faulting.

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Understanding Depositional System, Reservoir Quality and Distribution in South Sumatera Basin Development Field Using Integrated Well Data

Proc of Indonesian Petroleum Association 42nd Annual Convention ◽

10.29118/ipa19.g.179 ◽

2018 ◽

Author(s):

J. Mamesah

Keyword(s):

Reservoir Quality ◽

Basin Development ◽

Depositional System ◽

Well Data

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A multidisciplinary study of the Palaeogene succession offshore southern West Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v191.5134 ◽

2002 ◽

pp. 90-96

Author(s):

Finn Dalhoff ◽

James A. Chalmers ◽

Henrik Nøhr-Hansen ◽

Jan A. Rasmussen ◽

Emma Sheldon ◽

...

Keyword(s):

Seismic Data ◽

Seismic Stratigraphy ◽

Depositional Sequences ◽

Original Series ◽

West Greenland ◽

Dinoflagellate Cyst ◽

Reflection Seismic ◽

Multidisciplinary Study ◽

New Interpretation ◽

Well Data

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Dalhoff, F., Chalmers, J. A., Nøhr-Hansen, H., Rasmussen, J. A., Sheldon, E., & Gregersen, U. (2002). A multidisciplinary study of the Palaeogene succession offshore southern West Greenland. Geology of Greenland Survey Bulletin, 191, 90-96. https://doi.org/10.34194/ggub.v191.5134 _______________ A project with the aim of amalgamating an interpretation of reflection seismic data from offshore southern West Greenland with a new interpretation of well data was finalised at the Geological Survey of Denmark and Greenland (GEUS) in 2001 (Chalmers et al. 2001b). As part of this study, seismic and depositional sequences between major regional unconformities of Danian and mid-Eocene age were delineated and dated. New palaeoenvironmental and sedimentological interpretations using dinoflagellate cyst, microfossil and nannoplankton stratigraphies and palaeoenvironmental interpretations from the five exploration wells drilled offshore West Greenland in the 1970s have been combined with a revised interpretation of lithology and correlated with the aid of seismic stratigraphy. The Qulleq-1 well drilled in 2000 was relinquished late in the project period (Christiansen et al. 2002, this volume), and it has therefore only been possible to incorporate biostratigraphic information from this well into the project.

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Recognition and characterization of small-scale sand injectites in seismic data: Implications for reservoir development

Journal of the Geological Society ◽

10.1144/jgs2021-041 ◽

2021 ◽

pp. jgs2021-041

Author(s):

Alma Dzozlic Bradaric ◽

Trond Andersen ◽

Isabelle Lecomte ◽

Helge Løseth ◽

Christian Haug Eide

Keyword(s):

Seismic Data ◽

Small Scale ◽

3D Seismic ◽

Well Placement ◽

Reflection Seismic ◽

Seismic Modelling ◽

Link Type ◽

Reservoir Development ◽

Net To Gross ◽

Seismic Images

Small-scale (< 20 m), non-resolvable sand injectites can constitute a large part of the net-to-gross volume and affect fluid flow in the reservoir. However, they may also cause challenges for well placement and reservoir development because they are too small to be reliably constrained by reflection seismic data. It is therefore important to better understand how small-scale injectites influence seismic images and may be recognized and characterized above reservoirs. The Grane Field (North Sea) hosts numerous small-scale sand injectites above the main reservoir unit, causing challenges for well placement, volume estimates and seismic interpretation. Here, we investigate how such small-scale sand injectites influence seismic images and may be characterized by (1) using well-, 3D seismic- and outcrop data to investigate geometries of small-scale sand injectites (0-15 m) and creating conceptual models of injectite geometries, (2) performing seismic convolution modelling to investigate how these would be imaged in seismic data, and (3) compare these synthetic seismic images to actual 3D seismic from the well-investigate Grane Field.Our results show that despite injectites being below seismic resolution, small-scale sand injectites can be detected in seismic data. They are more likely to be detected with high thickness (> 5 m), steep dip (> 30°), densely spaced sand injectites, and homogeneous background stratigraphy. Furthermore, as fraction of sand injectites increases the top reservoir amplitude will decrease. Moreover, comparison of the synthetic seismic images with real seismic data from the Grane Field indicates that the low-amplitude anomalies and irregularities observed above the reservoir may be a result of the overlying sand injectites. Additionally, the comparison strongly suggests that the Grane Field hosts sand injectites that are thicker and located further away from the top reservoir than what is indicated by well observations. These results may be used to improve well planning and develop reservoirs with overlying sand injectites.Supplementary material: A PDF file containing all the seismic modelling results allowing the reader to flip back and forth between the different models is available at https://www.doi.org/10.6084/m9.figshare.14333102 . Well logs from well 25/11-18 T2 are available at https://factpages.npd.no/pbl/wellbore_documents/2358_25_1_18_COMPLETION_REPORT_AND_LOG.pdf

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