Different scales of salt-sediment interaction around passive diapirs

2021 ◽  
Author(s):  
Mark Rowan ◽  
Katherine Giles
Keyword(s):  
Sediment Transport ◽  
Near Surface ◽  
Sea Floor ◽  
Short Overview ◽  
Hydrocarbon Traps ◽  
Tectonic Processes ◽  
Salt Layer ◽  
Active Salt

<p>Passive diapirism entails ongoing, near-surface syndepositional growth of a salt stock or wall. As such, the diapirs and intervening minibasins influence the development and geometries of associated sedimentary strata. In this short overview, we distinguish between two scales and aspects of salt-sediment interaction that reflect a depositional continuum from the topographic highs of diapir roofs to the lows of depocenters. At the larger, multi-km scale, minibasin tectonostratigraphic successions form bowls, troughs, wedges, or layers that respond to differential evacuation of the deep salt layer. These successions have internal concordant, onlapping, or truncated geometries, and they stack into different patterns based on the evolution of active salt tectonic processes. At the smaller scale, passive diapirs create local sea-floor scarps due to drape folding of the diapir roof over the edge of the rising diapir. Depending primarily on the thickness of the roof, this results in tabular or tapered composite halokinetic sequences within 1 km or less of the diapir edge. It is important to keep these geometries and processes separate as they have distinct implications for sediment transport and deposition as well as the definition and detailed geometries of hydrocarbon traps in three-way truncations against diapirs and welds.</p>

Satellite Observations of Sediment Transport Patterns in the Lac Saint-Pierre Region of the St. Lawrence River

1988 ◽  
Vol 23 (2) ◽  
pp. 243-252 ◽  
Author(s):  
J.E. Bruton ◽  
J.H. Jerome ◽  
R.P. Bukata
Keyword(s):  
Sediment Transport ◽  
Close Relationships ◽  
Satellite Observations ◽  
Near Surface ◽  
Thermal Data ◽  
Digital Formats ◽  
Transport Patterns ◽  
Mutually Independent ◽  
River Corridor ◽  
St Lawrence River

Abstract Satellite data from Landsats 4 and 5 were utilized to delineate the seasonal variations of sediment transport zones in the Lac Saint-Pierre region of the St. Lawrence River corridor. A seasonally cyclic succession of patterns displaying persistent, mutually independent, and extensive (in both space and time) turbidity zones was clearly in evidence. Visible and thermal data in both imagery and digital formats were used to show the close relationships existing among the distinct zonal synoptic patterns, the bathymetry of lake and river, and the near surface aquatic temperatures.

scholarly journals Sediment transport processes across the Tibetan Plateau inferred from robust grain-size end members in lake sediments

2014 ◽  
Vol 10 (1) ◽  
pp. 91-106 ◽  
Author(s):  
E. Dietze ◽  
F. Maussion ◽  
M. Ahlborn ◽  
B. Diekmann ◽  
K. Hartmann ◽  
...  
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Tibetan Plateau ◽  
Transport Processes ◽  
The Tibetan Plateau ◽  
Dust Deposition ◽  
Northerly Wind ◽  
Near Surface ◽  
Depositional Processes ◽  
End Members

Abstract. Grain-size distributions offer powerful proxies of past environmental conditions that are related to sediment sorting processes. However, they are often of multimodal character because sediments can get mixed during deposition. To facilitate the use of grain size as palaeoenvironmental proxy, this study aims to distinguish the main detrital processes that contribute to lacustrine sedimentation across the Tibetan Plateau using grain-size end-member modelling analysis. Between three and five robust grain-size end-member subpopulations were distinguished at different sites from similarly–likely end-member model runs. Their main modes were grouped and linked to common sediment transport and depositional processes that can be associated with contemporary Tibetan climate (precipitation patterns and lake ice phenology, gridded wind and shear stress data from the High Asia Reanalysis) and local catchment configurations. The coarse sands and clays with grain-size modes >250 μm and <2 μm were probably transported by fluvial processes. Aeolian sands (~200 μm) and coarse local dust (~60 μm), transported by saltation and in near-surface suspension clouds, are probably related to occasional westerly storms in winter and spring. Coarse regional dust with modes ~25 μm may derive from near-by sources that keep in longer term suspension. The continuous background dust is differentiated into two robust end members (modes: 5–10 and 2–5 μm) that may represent different sources, wind directions and/or sediment trapping dynamics from long-range, upper-level westerly and episodic northerly wind transport. According to this study grain-size end members of only fluvial origin contribute small amounts to mean Tibetan lake sedimentation (19± 5%), whereas local to regional aeolian transport and background dust deposition dominate the clastic sedimentation in Tibetan lakes (contributions: 42 ± 14% and 51 ± 11%). However, fluvial and alluvial reworking of aeolian material from nearby slopes during summer seems to limit end-member interpretation and should be crosschecked with other proxy information. If not considered as a stand-alone proxy, a high transferability to other regions and sediment archives allows helpful reconstructions of past sedimentation history.

scholarly journals SEDIMENT DISTRIBUTION BASED ON GRAIN SIZE ANALYSES IN WEDA BAY, NORTHERN MALUKU

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Septriono Hari Nugroho ◽  
Abdul Basit
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Size Distribution ◽  
Deposition Process ◽  
General Information ◽  
Current Speed ◽  
Sediment Grain Size ◽  
Sediment Distribution ◽  
Sea Floor ◽  
Integrated Study

<p>An integrated study of sediment distribution was conducted in Weda Bay, Northern Maluku to provide general information on transportation and deposition process based on sediment grain size distribution. The study was conducted during the Weda Bay Expedition using the “Baruna Jaya VII” research vessel in March 13<sup>th</sup> –22<sup>th</sup> 2013. Sieving method (granulometric) was used to analyze the grain size. The results indicated that in general the pattern of sea floor sediment distribution was dominated by clay – sand grain-sized. The current speed influenced the sediment transport, deposition, and distribution.  Larger fractions of sediment were quickly settled on the sea floor due to stronger currents around Southern area (Widi islands), meanwhile the lesser fractions of the transported away into other places with weaker currents conditions.</p> <p>Keywords: current, the Weda Bay expedition, granulometric, grain size, sediment distribution</p>

scholarly journals Southward expanding plate coupling due to variation in sediment subduction as a cause of Andean growth

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiashun Hu ◽  
Lijun Liu ◽  
Michael Gurnis
Keyword(s):  
Sediment Transport ◽  
Three Dimensional ◽  
Mountain Building ◽  
Crustal Shortening ◽  
First Order ◽  
The Andes ◽  
Tectonic Processes ◽  
History Of ◽  
Plate Coupling ◽  
Trench Sediments

AbstractGrowth of the Andes has been attributed to Cenozoic subduction. Although climatic and tectonic processes have been proposed to be first-order mechanisms, their interaction and respective contributions remain largely unclear. Here, we apply three-dimensional, fully-dynamic subduction models to investigate the effect of trench-axial sediment transport and subduction on Andean growth, a mechanism that involves both climatic and tectonic processes. We find that the thickness of trench-fill sediments, a proxy of plate coupling (with less sediments causing stronger coupling), exerts an important influence on the pattern of crustal shortening along the Andes. The southward migrating Juan Fernandez Ridge acts as a barrier to the northward flowing trench sediments, thus expanding the zone of plate coupling southward through time. Consequently, the predicted history of Andean shortening is consistent with observations. Southward expanding crustal shortening matches the kinematic history of inferred compression. These results demonstrate the importance of climate-tectonic interaction on mountain building.

Dynamics of secondary airflow and sediment transport over and in the lee of transverse dunes

2002 ◽  
Vol 26 (1) ◽  
pp. 47-75 ◽  
Author(s):  
Ian J. Walker ◽  
William G. Nickling
Keyword(s):  
Shear Stress ◽  
Sediment Transport ◽  
Conceptual Model ◽  
Research Literature ◽  
Near Surface ◽  
Law Of The Wall ◽  
Sedimentary Dynamics ◽  
Transport Patterns ◽  
And Migration ◽  
Transverse Dunes

Recent research literature on secondary airflow and sediment transport patterns over flow-transverse dunes is reviewed. Various issues surrounding the behaviour, modelling and sedimentological implications of near-surface airflow dynamics over dunes are discussed, including: the Law of the Wall; the Jackson and Hunt airflow model; the effects of streamline compression, acceleration and curvature on stoss slope shear stress; and, in particular, recent efforts to characterize secondary lee-side airflow patterns. A revised conceptual model of lee-side airflow is presented and areas for further research are identified regarding the implications of such patterns for dune sedimentary dynamics, morphology, and migration.

Study on the Tidal Current and Suspended Sediment Transport in Taizhou Bay

2012 ◽  
Vol 212-213 ◽  
pp. 55-58
Author(s):  
Jie He ◽  
Xin Sheng Zhao ◽  
Yu Fan Zhu
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Suspended Sediment ◽  
Tidal Current ◽  
Sediment Concentration ◽  
Suspended Sediment Transport ◽  
Sediment Source ◽  
Sea Floor ◽  
Hydrologic Data ◽  
The Way

Taizhou Bay is an estuary with high tidel range, middle tidal current and low sediment concentration. For the sea floor is very dense, it is stable in the usual water regimen. The numerical model is introduced to simulate the suspended sediment transport in Taizhou Bay. And the recent hydrologic data and the seabed change have been validated by the numerical model. The movement of tidal current and sediment in Dagagn Bay are simulated, and the sediment siltation in port designed is calculated by the model. The results show that the sediment source is from the shoal produced by the ebb current, and the sediment silting is decreased two-thirds by the cofferdam back of the bay, because the way of the suspended sediment is stopped by the cofferdam from the shoal to the harbor.

TRAPPING MECHANISMS AND THE HYDROCARBON POTENTIAL OF THE EXMOUTH PLATEAU, WESTERN AUSTRALIA

1979 ◽  
Vol 19 (1) ◽  
pp. 19
Author(s):  
A. J. Wright ◽  
T. J. Wheatley
Keyword(s):  
Hydrocarbon Potential ◽  
Hydrocarbon Generation ◽  
Sea Floor ◽  
Geological Interpretation ◽  
Exmouth Plateau ◽  
Oil Reserves ◽  
Hydrocarbon Traps ◽  
Fault Block ◽  
Gas Chimney ◽  
Seismic Sections

An interpretation of the structural configuration and hydrocarbon potential of the Exmouth Plateau has been made utilizing the results of G.S.I's 1976 Scientific Investigation (No. 10 S.L.).Seismic sections suggest sediments down to at least four seconds (two way time) below the sea floor. A prominent regional unconformity separates faulted and dipping sediments from generally flat overlying beds.Eight horizons of apparent regional importance were picked and correlated to existing well control.Structure maps were prepared for the regional unconformity and three overlying horizons, including the interpreted top of the Barrow Group. Mapping showed the main potential hydrocarbon traps to be large fault block features associated with the regional culmination of the unconformity event, and broad anticlinal drapes at top Barrow Group level. Geological interpretation suggests that the fault blocks consist of late Middle to Upper Triassic sediments, probably sandstone and shale. These sandstones could be potential reservoirs for hydrocarbons generated at depth. Seismic evidence of hydrocarbon generation includes a probable gas chimney associated with the western bounding fault of the highest fault block.The present sea floor topographic high of the Exmouth Plateau is coincident with the large drape structure embracing a foresetting package within the Barrow Group. Velocity studies over the Plateau suggest a probable lack of sand in the upper part of the Barrow Group section. Sourcing of sands in the lower part is envisaged as originating from sediments in older, underlying fault blocks. The Triassic fault blocks are considered to have the higher potential for oil reserves, but recoverable volumes are not likely to be in the 'giant' category (500 million barrels).

scholarly journals BARRIER BEACHES AND SEDIMENT TRANSPORT IN THE SOUTHERN GULF OF ST. LAWRENCE

1974 ◽  
Vol 1 (14) ◽  
pp. 69 ◽  
Author(s):  
E.H. Owens
Keyword(s):  
Sediment Transport ◽  
Littoral Zone ◽  
Barrier Islands ◽  
Shallow Sea ◽  
Sea Floor ◽  
Induced Currents ◽  
Barrier Beaches ◽  
Wave Induced

Barrier islands and barrier beaches have developed across structurally controlled estuaries and embayments in the southern Gulf of St. Lawrence. The supply of sediments to the littoral zone and the subsequent accumulation of barrier deposits is a result of the reworking, transportation and longshore dispersal of sediments which are moved landward by tidal and wave-induced currents from the adjacent shallow sea floor. The size and stability of the barriers is controlled by the shoreline orientation.

scholarly journals ABOUT THE USE OF NON-LINEAR SOUND SCATTERING FOR ESTIMATING THE OFFSHORE GAS FLARES STRUCTURE AND LENGTH COMPOSITION

2020 ◽  
pp. 45-52
Author(s):  
В.А. Буланов ◽  
И.В. Корсков ◽  
Е.В. Соседко
Keyword(s):  
Size Distribution Function ◽  
Gas Content ◽  
The Arctic ◽  
Arctic Seas ◽  
Sound Scattering ◽  
Near Surface ◽  
Sea Floor ◽  
Gas Flares ◽  
Standard Application ◽  
Remote Spectroscopy

Новые объекты в океане, подводные газовые факелы (ГФ), образованные газовыми пузырьками, выходящими из дна моря, повсеместно встречаются в районах выброса газов как из толщи донных осадков в различных районах океана, так и в районах выгрузки газа при таянии вечной мерзлоты в арктических морях, и к ним проявляется все больше внимания. Стандартное применение рассеяния звука позволяет обнаружить наличие ГФ в море, но не позволяет в полной мере корректно оценить функцию распределения пузырьков по размерам в факеле и поэтому возникают неопределенности с оценкой мощности выброса газов из моря. Обсуждаются возможности использования метода нестационарного и нелинейного рассеяния звука для получения информации о структуре и динамике подводных газовых факелов, образованных выходом газа из морского дна. Нелинейное рассеяние звука обусловлено высокой нелинейностью пузырьковых структур в воде. Нестационарное рассеяние звука возникает вследствие переходных процессов раскачки пузырьков под действием акустических импульсов, и оно ранее использовалось для изучения распределения пузырьков в приповерхностных слоях морской воды. В работе показано, что применение нелинейного нестационарного рассеяния на встречных пучках позволит проводить дистанционную спектроскопию пузырьков в газовых факелах и проводить корректные оценки газосодержания в факелах. New objects in the ocean, underwater gas flares (GF) formed by gas bubbles emerging from the sea floor, are ubiquitous in areas where gases are released from the bottom sediments in various areas of the ocean, and in areas where gas is discharged during permafrost melting in the Arctic seas, and they are receiving increasing attention. The standard application of sound scattering allows detecting the presence of GF in the sea, but does not allow us to fully correctly estimate the bubble size distribution function in the flare, and therefore there are uncertainties with the estimation of the power of gas emission from the sea. The possibilities of using the method of non-stationary and nonlinear sound scattering to obtain information about the structure and dynamics of underwater gas flares formed by gas escaping from the sea floor are discussed. Nonlinear sound scattering is caused by the high nonlinearity of bubble structures in water. Non-stationary sound scattering occurs due to transient processes of bubble swinging under the action of acoustic pulses, and it was previously used to study the distribution of bubbles in near-surface layers of seawater. It is shown that the use of nonlinear non-stationary scattering on colliding beams will allow remote spectroscopy of bubbles in gas flares and correct estimates of the gas content in the flares.

scholarly journals STRUKTUR GEOLOGI DI PERAIRAN PULAU BUTON SELATAN

2016 ◽  
Vol 13 (3) ◽  
pp. 143
Author(s):  
Lukman Arifin ◽  
Tommy Naibaho
Keyword(s):  
Oil And Gas ◽  
Seismic Stratigraphy ◽  
Geological Structure ◽  
Geophysical Research ◽  
Geological Structures ◽  
Sea Floor ◽  
Reflection Seismic ◽  
Tectonic Processes ◽  
Geological Conditions ◽  
Active Tectonic

Penelitian geofisika dengan metode seismik pantul dangkal dilakukan di perairan Pulau Buton bagian selatan. Tujuan dari penelitian adalah untuk mengetahui kondisi geologi di bawah permukaan dasar laut. Dari data rekaman seismik diinterpretasikan bahwa stratigrafi seismik dibagi menjadi dua runtunan yaitu runtunan A dan B. Bila disebandingkan dengan geologi daratnya maka runtunan A termasuk dalam Formasi Wapulaka yang berumur Tersier dan runtunan B termasuk Formasi Sampolakosa yang berumur Kuater. Data rekaman tersebut juga menunjukkan adanya beberapa struktur geologi seperti sesar, lipatan, dan pengangkatan. Diduga struktur geologi tersebut berkembang dengan masih aktifnya proses tektonik hingga sekarang. Implikasi aktifnya tektonik ini dapat memperkaya dan meningkatkan potensi sumberdaya alam yang ada seperti migas dan aspal. Kata kunci seismik pantul dangkal, struktur geologi, tektonik, Perairan Pulau Buton. Geophysical research with shallow reflection seismic method carried out in the waters of the southern part of Buton Island. The aim of research is to determine the geological conditions under the sea floor. Data from seismic recordings interpreted that seismic stratigraphy is divided into two sequences, that are sequence A and B. Ifthe land geology to be compared then the sequence A is Wapulaka Formation which is Tertiary age and sequence B is Sampolakosa Formation which is Kuarter age. The recording data also indicated a number of geological structures such as faults, folds, and uplift. It was alleged that the geological structure is developing with tectonic processes are still active until now. The implications of the active tectonic can enrich and enhance the existing natural resources such as oil and gas, and bitumen. Keywords: shallow seismicreflection, geology structure, tectonic, Buton Island Waters.

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