scholarly journals Three‐dimensional forward stratigraphic modelling of the sedimentary architecture of meandering‐river successions in evolving half‐graben rift basins

2019 ◽  
Vol 32 (1) ◽  
pp. 68-90 ◽  
Author(s):  
Na Yan ◽  
Luca Colombera ◽  
Nigel P. Mountney
Keyword(s):  
Three Dimensional ◽  
Rift Basins ◽  
Meandering River ◽  
Sedimentary Architecture ◽  
Half Graben

scholarly journals Modeling of dense well block point bar architecture based on geological vector information: A case study of the third member of Quantou Formation in Songliao Basin

2021 ◽  
Vol 13 (1) ◽  
pp. 39-48
Author(s):  
Chao Luo ◽  
Ailin Jia ◽  
Jianlin Guo ◽  
Wei Liu ◽  
Nanxin Yin ◽  
...  
Keyword(s):  
River Sediments ◽  
Three Dimensional ◽  
Songliao Basin ◽  
Point Bar ◽  
Meandering River ◽  
Architecture Model ◽  
The Third ◽  
Continuous Convergence ◽  
Vector Information ◽  
Architecture Modeling

Abstract Although stochastic modeling methods can achieve multiple implementations of sedimentary microfacies model in dense well blocks, it is difficult to realize continuous convergence of well spacing. Taking the small high-sinuosity meandering river sediments of the third member of Quantou Formation in Songliao Basin as an example, a deterministic modeling method based on geological vector information was explored in this article. Quantitative geological characteristics of point bar sediments were analyzed by field outcrops, modern sediments, and dense well block anatomy. The lateral extension distance, length, and spacing parameters of the point bar were used to quantitatively characterize the thickness, dip angle, and frequency of the lateral layer. In addition, the three-dimensional architecture modeling of the point bar was carried out in the study. The established three-dimensional architecture model of well X24-1 had continuous convergence near all wells, which conformed to the geological knowledge of small high-sinuosity meandering river, and verified the reliability of this method in the process of geological modeling in dense well blocks.

Three-Dimensional Sedimentary Architecture of a Large, Mid-Channel Sand Braid Bar, Jamuna River, Bangladesh

2003 ◽  
Vol 73 (4) ◽  
pp. 516-530 ◽  
Author(s):  
J. L. Best ◽  
P. J. Ashworth ◽  
C. S. Bristow ◽  
J. Roden
Keyword(s):  
Three Dimensional ◽  
Sedimentary Architecture

scholarly journals Stretching and Contraction of Extensional Basins With Pre-Rift Salt: A Numerical Modeling Approach

2021 ◽  
Vol 9 ◽  
Author(s):  
Pablo Granado ◽  
Jonas B. Ruh ◽  
Pablo Santolaria ◽  
Philipp Strauss ◽  
Josep Anton Muñoz
Keyword(s):  
Hanging Wall ◽  
Structural Evolution ◽  
Extension Rate ◽  
Rift Basins ◽  
Basin Inversion ◽  
Accommodation Space ◽  
Basement Faults ◽  
Original Distribution ◽  
Thrust Belts ◽  
Half Graben

We present a series of 2D thermo-mechanical numerical experiments of thick-skinned crustal extension including a pre-rift salt horizon and subsequent thin-, thick-skinned, or mixed styles of convergence accompanied by surface processes. Extension localization along steep basement faults produces half-graben structures and leads to variations in the original distribution of pre-rift salt. Thick-skinned extension rate and salt rheology control hanging wall accommodation space as well as the locus and timing of minibasin grounding. Upon shortening, extension-related basement steps hinder forward propagation of evolving shallow thrust systems; conversely, if full basin inversion takes place along every individual fault, the regional salt layer is placed back to its pre-extensional configuration, constituting a regionally continuous décollement. Continued shortening and basement involvement deform the shallow fold-thrust structures and locally breaches the shallow décollement. We aim at obtaining a series of structural, stratigraphic and kinematic templates of fold-and-thrust belts involving rift basins with an intervening pre-rift salt horizon. Numerical results are compared to natural cases of salt-related inversion tectonics to better understand their structural evolution.

Sedimentological characteristics and aeolian architecture of a plausible intermountain erg system in Southeast China during the Late Cretaceous

2020 ◽  
Vol 132 (11-12) ◽  
pp. 2475-2488
Author(s):  
Shuo Cao ◽  
Laiming Zhang ◽  
Chengshan Wang ◽  
Jing Ma ◽  
Jie Tan ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Three Dimensional ◽  
Small Scale ◽  
Southeast China ◽  
Climate Conditions ◽  
Aeolian Deposits ◽  
Intermountain Basin ◽  
Sedimentary Architecture ◽  
Hot Arid Climate ◽  
Near Future

Abstract Along with intensification of global warming, severe desertification has already impaired human sustainable development. In a near-future greenhouse world, the total area of desert will increase, and new types of desert may emerge. During the “greenhouse” Cretaceous, conventional large paleo-ergs developed in broad topographic basins, and many possible ergs developed in small-scale intermountain basins, which are unusual in near-modern times and less studied. A comprehensive study of their sedimentary architecture and mechanisms would refine our interpretation of desertification in a near-future “greenhouse” world. The Xinjiang Basin is a typical small-scale intermountain basin in Southeast China that formed >300 m of successive aeolian deposits during the early Late Cretaceous. In this study, we applied detailed facies and architecture analyses to the Tangbian Formation (K2t) in 16 outcrops throughout the Xinjiang Basin and reconstructed a three-dimensional sedimentary model for the intermountain ergs. We confirmed that the Tangbian Formation formed in a typical intermountain paleo-erg and summarized in detail the differences in sedimentary architecture between intermountain ergs and broad topographic ergs. We noticed that the “greenhouse” state during the Late Cretaceous seems to have been suitable for the development of ergs in intermountain basins due to the hot, arid climate conditions and penetrating winds with sufficient transport capacity. Therefore, we suggest that in addition to the ongoing expansion of broad topographic ergs, the emergence and development of intermountain ergs in a near-future “greenhouse” world would also contribute to global desert expansion and massive desertification.

scholarly journals Use of Multidimensional Models to Investigate Boundary Shear Stress through Meandering River Channels

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3506
Author(s):  
Timothy J. Randle
Keyword(s):  
Shear Stress ◽  
Three Dimensional ◽  
Field Studies ◽  
River Channels ◽  
Meandering River ◽  
Boundary Shear ◽  
Wide Range ◽  
Channel Curvature ◽  
Boundary Shear Stress ◽  
Multidimensional Models

Three-dimensional hydraulics were simulated through a wide range of synthetically generated meandering river channels to determine how channel curvature and width would correlate with the maximum boundary shear stress. Multidimensional models were applied, similar to a computational flume to simulate a wide range of 72 meandering channels, developed from sine-generated curves. Cannel sinuosity ranged from 1.1 to 3.0 and included five consecutive meander bends. Longitudinal slopes of the various channels spanned four orders of magnitude, while bankfull discharges spanned three orders of magnitude. Using results from one-half of the simulation sets, an empirical correlation was found to predict the maximum boundary shear stress as a function of dimensionless ratios of channel curvature and width. The remaining simulation sets were used for verification. Multidimensional models were used to simulate channel hydraulics to efficiently investigate a wide range of channel sinuosity, width/depth ratios, bankfull discharges, and valley slopes. When simulating such a wide range of channel conditions, multidimensional models offer a more efficiency method of generating consistent datasets than either field studies or physical modeling. This paper demonstrates how multidimensional models can be used to identify important hydraulic relationships that are otherwise difficult to determine.

Termination of a fossil continent-ocean fracture zone imaged with three-dimensional seismic data: The Chain Fracture Zone, eastern equatorial Atlantic

Geology ◽  
2005 ◽  
Vol 33 (8) ◽  
pp. 641-644 ◽  
Author(s):  
Richard J. Davies ◽  
Christopher J. MacLeod ◽  
Richard Morgan ◽  
Sepribo E. Briggs
Keyword(s):  
Oceanic Crust ◽  
Fracture Zone ◽  
Niger Delta ◽  
Three Dimensional ◽  
Seafloor Spreading ◽  
Spreading Center ◽  
Equatorial Atlantic ◽  
Half Graben ◽  
History Of ◽  
Subsequent Phase

Abstract We describe the first three-dimensional imaging of the termination of a continent-ocean fracture zone (COFZ), the Chain Fracture Zone, located offshore of the Niger Delta. The COFZ marks the abrupt transition between extended continental crust, comprising multiple half-graben, and oceanic crust that has a pervasive seafloor-spreading fabric. It preserves a history of continent-continent shearing followed by oceanic crust accretion and continent-ocean shearing during the inception of Atlantic rifting. The termination is marked by steeply dipping faults with sigmoidal planform and thrusts that probably formed as a result of continent-continent or continent-ocean shearing. These are crosscut by the seafloor-spreading fabric that formed during the subsequent phase of oceanic crust accretion. The accreted oceanic crust is cut by listric and planar faults that curve in the direction of the COFZ, where they terminate. The transition from continental to oceanic crust across the COFZ is sharp and resolvable to ∼100–200 m. Complexes of lava flows emanate from volcanoes along the COFZ, bifurcating and trifurcating down the volcano flanks. The volcanoes are 2–5.5 km wide and 1.4 km in height relative to adjacent oceanic crust and were injected at the COFZ, probably as the spreading center migrated along it.

scholarly journals Accommodation zones and tectono-stratigraphy of the Gulf of Suez, Egypt: A contribution from aeromagnetic analysis

GeoArabia ◽  
2009 ◽  
Vol 14 (4) ◽  
pp. 139-162
Author(s):  
Khamis Farhoud
Keyword(s):  
Three Dimensional ◽  
Source Rocks ◽  
Gulf Of Suez ◽  
Rift Basins ◽  
Early Oligocene ◽  
Accommodation Zone ◽  
Magnetic Basement ◽  
Petroleum Fields ◽  
Proterozoic Basement ◽  
Seismic Images

ABSTRACT This paper starts with an up-to-date literature review of the pre-rift, syn-rift and post-rift stratigraphy of the Gulf of Suez. The geometry and depth of the Proterozoic basement is not generally known due to poor seismic images below the Upper Miocene evaporites (including massive rock salt) and clastics. The pre-rift Paleozoic to Early Oligocene succession shows that several local basins (c. 10s of km in extent) occur in the Gulf, with thick sedimentary sections (e.g. c. 3,000 m for Paleozoic and 1,000 m for Jurassic and Lower Cretaceous). The origin and distribution of these basins is not well understood and the presence of similar pre-rift basins in the southern Gulf is not known to occur. The syn-rift Late Oligocene to Middle Miocene and post-rift Late Miocene – Pliocene successions are widely distributed within the rift basin and reach a thickness in excess of 5,000 m. In order to visualize the grain and relative relief of the Proterozoic basement, a series of aeromagnetic images are shown in this paper. The images include Total Magnetic Intensity (TMI), Reduced-to-Pole (RTP), filtered regional and structural RTP, and Second Vertical Derivative (SVD). The paper also shows a three-dimensional visualization image of the magnetic basement that highlights the distribution of the basins in the Gulf. The magnetic lows do not generally trend along the Suez (NNW-trending Clysmic) Fault, but instead show highly variable orientations attributed to a complex pattern of criss-crossing faults. In particular, two areas were selected to interpret the geometry and depth of the basement. The first area covered the northern Zaafarana Accommodation Zone and involved modeling five aeromagnetic profiles. The Zone was interpreted as an EW-trending basement plateau bounded by basins that are c. 8,000 m deep. The second modeled area (four profiles) covered the southern Morgan Accommodation Zone. This zone was interpreted as an ENE-trending plateau of similar relief to the Zaafarana Zone. The Morgan Zone is terminated in the eastern Gulf by the 8,000-m-deep Morgan Basin. The very deep basins surrounding the two plateaus may contain both pre-rift and syn-rift source rocks, from which the numerous surrounding petroleum fields were sourced.

scholarly journals Relevant aspects to the recognition of extensional environments in the field

2021 ◽  
Vol 48 (2) ◽  
pp. 95-106
Author(s):  
Ana Milena Suárez Arias ◽  
Julián Andrés López Isaza ◽  
Anny Juieth Forero Ortega ◽  
Mario Andrés Cuéllar Cárdenas ◽  
Carlos Augusto Quiroz Prada ◽  
...  
Keyword(s):  
Hanging Wall ◽  
Image Interpretation ◽  
Three Dimensional ◽  
Normal Fault ◽  
Structural Data ◽  
Structural Aspect ◽  
Half Graben ◽  
Regional Tectonic ◽  
History Of ◽  
Definition Of

The understanding of each geological-structural aspect in the field is fundamental to be able to reconstruct the geological history of a region and to give a geological meaning to the data acquired in the outcrop. The description of a brittle extensional environment, which is dominated by normal fault systems, is based on: (I)  image interpretation, which aims to find evidence suggestive of an extensional geological environment, such  as the presence of scarp lines and fault scarps, horst, graben and/or half-graben, among others, that allow the identification of the footwall and hanging wall blocks; ii) definition of the sites of interest for testing; and  iii) analysis of the outcrops, following a systematic procedure that consists of the observation and identification of the deformation markers, their three-dimensional schematic representation, and their  subsequent interpretation, including the stereographic representation in the outcrop. This procedure implies the unification of the parameters of structural data acquisition in the field, mentioning the minimum fields  necessary for the registration of the data in tables. Additionally, the integration of geological and structural observations of the outcrop allows to understand the nature of the geological units, the deformation related to the extensional environment and the regional tectonic context of the study area.

scholarly journals Controls on mud distribution and architecture along the fluvial-to-marine transition

2020 ◽  
Author(s):  
Daniel Parsons ◽  
Wietse Van de Lageweg ◽  
Lisanne Braat ◽  
Maarten Kleinhans
Keyword(s):  
River Flow ◽  
Three Dimensional ◽  
Quantitative Information ◽  
System Stability ◽  
Relative Importance ◽  
Coastal System ◽  
Fluvial Processes ◽  
Coastal Systems ◽  
Sedimentary Architecture ◽  
Sedimentary Fill

<p>The interaction of marine (tides and waves) and fluvial processes determines the sedimentary fill of coastal systems in the fluvial-to-marine (FTM) transition zone. Despite frequent recognition of tidal and wave influence in modern and ancient systems, our understanding of the relative importance of marine processes and their impact on mud deposition, coastal system stability and sedimentary architecture is limited. This study combined subsurface field observations and numerical simulations to investigate the relative importance of river flow, tides, waves, and mud input in governing the sedimentary fill in funnel-shaped basins along the FTM transition. Model simulations show a self-forming bar-built estuary with dynamic channels and sandy bars flanked by mud flats, which is in agreement with trends observed in nature. From three-dimensional virtual sedimentary successions, statistical tendencies for mud distribution and thickness were derived for the spectrum of marine and fluvial processes, and these values provide quantitative information on the net-to-gross ratio and mud architecture. The relative influence of marine and fluvial processes leads to a predictable facies organization and architecture, with muddier and more heterogeneous sediments toward the flanks. For the first time, our simulations allow the sedimentary fill in basins along the FTM transition to be related explicitly to hydrodynamic conditions, providing new insights into the morphosedimentary evolution of coastal systems, with implications for system stability in the modern and sequence stratigraphy preserved in the ancient.</p>

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