scholarly journals Depositional Model for Turbidite Lobes in Complex Slope Settings Along Transform Margins: The Motta San Giovanni Formation (Miocene—Calabria, Italy)

2021 ◽  
Vol 9 ◽  
Author(s):  
Sébastien Rohais ◽  
Julien Bailleul ◽  
Sandra Brocheray ◽  
Julien Schmitz ◽  
Paolo Paron ◽  
...  
Keyword(s):  
Hydraulic Jump ◽  
Geological Mapping ◽  
Width Ratio ◽  
Depositional Model ◽  
Deep Basin ◽  
Source To Sink ◽  
Facies Associations ◽  
Basin Floor ◽  
Net To Gross ◽  
Transform Margin

Intraslope lobes, or perched lobes, are attracting scientific interest because they represent a key archive between the shelf and the deep basin plain when looking at a complete source-to-sink depositional system across a continental margin and can form significant offshore hydrocarbon plays. In this study, we focus on a detailed characterization of intraslope lobes of the Motta San Giovanni Formation (Miocene, Calabria), which were deposited in confined conditions during the Miocene along a transform margin. We determine the typical facies associations and stratigraphic architecture of these intraslope lobes using a 3D digital outcrop model resulting from a combined Uncrewed Aerial Vehicle (UAV) and walking acquisition, together with sedimentological logging and geological mapping. We propose recognition criteria for the identification of intraslope lobes, including facies and geometries, integrated within a depositional model. A comparison with other well-known intraslope and confined lobes, as well as basin floor lobes, is finally discussed, to highlight the peculiarities of intraslope lobes deposited along transform margins. The diagnostic depositional model for these types of intraslope lobes includes four main stages of evolution: 1) Stage 1—isolated detached lobe precursor in response to a flushed hydraulic jump, 2) Stage 2—prograding and aggrading lobe elements associated with a relatively stable and submerged hydraulic jump in the Channel-Lobe Transition Zone (CLTZ), 3) Stage 3—major bypass associated with lateral accretion and local aggradation interpreted as a renewal of a normal hydraulic jump in the CTLZ, and 4) Stage 4—erosion and bypass then abandonment. The development of intraslope lobes along active transform margins is allowed by tectonically induced slope segmentation and local confinement. In such a context, flow stripping and overspill processes occurred. Resulting lobes appear to be particularly small and relatively thin sandy deposits. They could be considered end-member in a lobe classification based on the Net-to-Gross content (high) and taking into account their thickness/width ratio (intermediate between 10:1 and 100:1 lines).

The Characterization of Stratigraphic Play in Middle Baong Sand for Hydrocarbon Prospecting in Offshore North Sumatera Basin

2021 ◽  
Author(s):  
A. Nurhasan
Keyword(s):  
Depositional Environment ◽  
Hydrocarbon Exploration ◽  
Ratio Distribution ◽  
Basin Floor ◽  
Distinct Character ◽  
Net To Gross ◽  
And Migration ◽  
Sand Bodies ◽  
Malacca Strait

Pertamina EP is operating a small block in Offshore North Sumatera Basin where a couple of the fields are producing gas and condensate from the Belumai Carbonate. However, the wells production is depleting and several delineation wells are unable to find additional reserves, it is important to find a new play within the block. Few discoveries in the Middle Baong Sand (MBS) reservoir suggested a promising stratigraphic play to be explored, but it requires more detailed characterization of the reservoir extent. The Malacca strait-sourced MBS consists of several deposited sand packages during a mega sequence. The term MBS might represent a deltaic environment from a transgressive system tract of some marine shore bar or a basin floor fan. Each system has a distinct character (thickness, net to gross ratio, distribution) that must be evaluated before proposing an exploration well. The depositional environment and reservoir distribution are interpreted and modeled using regional 2D seismic and high-quality 3D seismic. Paleo-bathymetric interpretation from well samples shows a good correlation with the palinspastic reconstruction. The result shows that the Pertamia EP working area is located in the shore bar depositional environment. Seismic attributes are used to delineate reservoir distribution within the working block and well logs are used to constrain prospective sand bodies and water zones identification. Furthermore, source rock maturation and migration path and hydrocarbon occurrence from the discovery wells have been evaluated for hydrocarbon prospecting and risking. This study suggests a promising lead for hydrocarbon exploration in the study area and opens up a new opportunity for an underexplored play.

The Baffle Blocks Effects of Pressure Characteristics on USBR III Basin Floor

2012 ◽  
Vol 212-213 ◽  
pp. 821-825
Author(s):  
Keyvan Nasiri ◽  
Mohammad Reza Kavianpour ◽  
Siavash Haghighi
Keyword(s):  
Energy Dissipation ◽  
Hydraulic Jump ◽  
Pressure Fluctuations ◽  
Power Spectra ◽  
Low Frequency ◽  
Dominant Frequency ◽  
Energy Dissipation Rate ◽  
Tension And Compression ◽  
Basin Floor ◽  
Sequent Depth

The principle of energy dissipation in stilling basin is based on hydraulic jump formation. Due to the inherent fluctuating characteristic of the hydraulic jump, basin floor is subjected to variations of pressure, resulting in unstableness due to uplift forces. To increase the efficiency of the stilling basins and improve the energy dissipation rate, one or two rows of baffle blocks are applied on the basin floor. Causing a forced hydraulic jump, tension and compression forces are exerted by pressure fluctuations of rotating roller zone of hydraulic jump. In this investigation, to observe the impacts of baffle blocks on pressure fluctuations on basin floor, a standard USBR basin model type III was constructed, and then a second row of blocks was added to the basin. A set of pressure tubes was fixed along the axis of the basin to measure the static and dynamic pressures on basin floor. The results were expressed in dimensionless parameters including C-p, C+p, C’p, Cp. Also, power spectra of pressure fluctuations were calculated. The results show a decreasing trend in root mean square of pressure fluctuations as distancing from toe of jump along the basin with and without baffle blocks. Also, mean pressure increases when water jet strokes the basin then decreases under roller zone of jump and increases again after sequent depth. The spectral analysis indicates that the dominant frequency is between 10 rad/s and 35 rad/s and pressure fluctuations have low frequency characteristics.

scholarly journals Environmental Conditions in a Carpathian Deep Sea Basin During the Period Preceding Oceanic Anoxic Event 2 - A Case Study from the Skole Nappe

2015 ◽  
Vol 65 (5) ◽  
pp. 433-450 ◽  
Author(s):  
Krzysztof Bąk ◽  
Marta Bąk ◽  
Zbigniew Górny ◽  
Anna Wolska
Keyword(s):  
Water Column ◽  
Deep Sea ◽  
Silica Content ◽  
Turbidity Currents ◽  
Ecological Groups ◽  
Deep Basin ◽  
Oceanic Anoxic Event ◽  
Plankton Production ◽  
Basin Floor

Abstract Hemipelagic green clayey shales and thin muddy turbidites accumulated in a deep sea environment below the CCD in the Skole Basin, a part of the Outer Carpathian realm, during the Middle Cenomanian. The hemipelagites contain numerous radiolarians, associated with deep-water agglutinated foraminifera. These sediments accumulated under mesotrophic conditions with limited oxygen concentration. Short-term periodic anoxia also occurred during that time. Muddy turbidity currents caused deposition of siliciclastic and biogenic material, including calcareous foramini-fers and numerous sponge spicules. The preservation and diversity of the spicules suggests that they originate from disarticulation of moderately diversified sponge assemblages, which lived predominantly in the neritic-bathyal zone. Analyses of radiolarian ecological groups and pellets reflect the water column properties during the sedimentation of green shales. At that time, surface and also intermediate waters were oxygenated enough and sufficiently rich in nutri-ents to enable plankton production. Numerous, uncompacted pellets with nearly pristine radiolarian skeletons inside show that pelletization was the main factor of radiolarian flux into the deep basin floor. Partly dissolved skeletons indicate that waters in the Skole Basin were undersaturated in relation to silica content. Oxygen content might have been depleted in the deeper part of the water column causing periodic anoxic conditions which prevent rapid bacterial degra-dation of the pellets during their fall to the sea floor.

scholarly journals Ordovician deep dolomite reservoirs in the intracratonic Ordos Basin, China: Depositional model and Diagenetic evolution

2018 ◽  
Vol 36 (4) ◽  
pp. 850-871 ◽  
Author(s):  
Anqing Chen ◽  
Shenglin Xu ◽  
Shuai Yang ◽  
Hongde Chen ◽  
Zhongtang Su ◽  
...  
Keyword(s):  
Tidal Flat ◽  
Depositional Environment ◽  
Ordos Basin ◽  
Depositional Model ◽  
Facies Associations ◽  
Intracratonic Basins ◽  
Sea Level Fluctuation ◽  
Reservoir Type ◽  
Diagenetic Evolution

Recent natural gas discoveries indicate that non-karstification-dominated reservoirs exist in the intracratonic Ordos Basin. This study examines the sedimentological and geochemical characteristics needed to clarify the depositional model and diagenetic evolution process of this newly discovered reservoir type. The depositional environment of the dolomite reservoir can be characterized as a tidal flat that grew from the Central Paleo-uplift to the eastern depression by cyclic progradation on an epeiric platform. A tidal flat sequence can extend laterally as a progradational wedge in each cycle of sea level fluctuation. The sheet-shaped peritidal shoal facies associations patched on the wedge represent potential dolomite reservoirs and can be recognized by the presence of doloarenite that has been altered into a vaguely relict grained-texture by diagenesis. Although continuing destructive diagenesis has led to reservoir densification, burial dolomitization and burial dissolution with facies selectivity have tended to occur in peritidal shoal facies associations, thus improving the quality of the dolomite reservoirs. These models provide new insights for targeting deep dolomite hydrocarbon reservoirs in intracratonic basins.

scholarly journals Syndepositional tectonics and mass-transport deposits control channelized, bathymetrically complex deep-water systems (Aínsa depocenter, Spain)

2020 ◽  
Vol 90 (7) ◽  
pp. 729-762
Author(s):  
Daniel E. Tek ◽  
Miquel Poyatos-Moré ◽  
Marco Patacci ◽  
Adam D. McArthur ◽  
Luca Colombera ◽  
...  
Keyword(s):  
Mass Transport ◽  
Deep Water ◽  
Tectonic Setting ◽  
Water Systems ◽  
Tectonic Structures ◽  
Lateral Confinement ◽  
Facies Associations ◽  
Active Tectonic ◽  
Basin Floor ◽  
Mass Transport Deposits

ABSTRACT The inception and evolution of channels in deep-water systems is controlled by the axial gradient and lateral confinement experienced by their formative flows. These parameters are often shaped by the action of tectonic structures and/or the emplacement of mass-transport deposits (MTDs). The Arro turbidite system (Aínsa depocenter, Spanish Pyrenees) is an ancient example of a deep-water channelized system from a bathymetrically complex basin, deposited in an active tectonic setting. Sedimentologic fieldwork and geologic mapping of the Arro system has been undertaken to provide context for a detailed study of three of the best-exposed outcrops: Sierra de Soto Gully, Barranco de la Caxigosa, and Muro de Bellos. These locations exemplify the role of confinement in controlling the facies and architecture in the system. Sedimentologic characterization of the deposits has allowed the identification of fifteen facies and eight facies associations; these form a continuum and are non-unique to any depositional environment. However, architectural characterization allowed the grouping of facies associations into four depositional elements: i) weakly confined, increasing-to-decreasing energy deposits; ii) progradational, weakly confined to overbank deposits; iii) alternations of MTDs and turbidites; iv) channel fills. Different styles of channel architecture are observed. In Barranco de la Caxigosa, a master surface which was cut and subsequently filled hosts three channel stories with erosional bases; channelization was enhanced by quasi-instantaneous imposition of lateral confinement by the emplacement of MTDs. In Muro de Bellos, the inception of partially levee-confined channel stories was enhanced by progressive narrowing of the depositional fairway by tectonic structures, which also controlled their migration. Results of this study suggest that deep-water channelization in active tectonic settings may be enhanced or hindered due to: 1) flow interaction with MTD-margin topography or; 2) MTD-top topography; 3) differential compaction of MTDs and/or sediment being loaded into MTDs; 4) formation of megascours by erosive MTDs; 5) basin-floor topography being reset by MTDs. Therefore, the Arro system can be used as an analog for ancient subsurface or outcrop of channelized deposits in bathymetrically complex basins, or as an ancient record of deposits left by flow types observed in modern confined systems.

Application and Comparsion of Mathematical and Physical Models on Inspecting Slab of Stilling Basin Floor under Static and Dynamic Forces

2011 ◽  
Vol 147 ◽  
pp. 283-287 ◽  
Author(s):  
Behzad Mohammadzadeh ◽  
Mahmoud Bina ◽  
Hooshang Hasounizadeh
Keyword(s):  
Hydraulic Jump ◽  
Physical Models ◽  
Stress And Strain ◽  
Floor Slab ◽  
Stilling Basin ◽  
Dynamic Forces ◽  
Basin Floor ◽  
Energy Dissipated ◽  
Physical And Mathematical Models ◽  
Resultant Forces

To protect downstream of hydraulic structures against erosion and degradation, must dipress water energy. one of the most comon methods to achive this purpose is constructing the stilling basin at the downstream of such structures. In stilling basin, the water energy dissipated by taking place of hydraulic jump. When a hydraulic jump occurs, the hydrodynamic and hydrostatic forces effect on the stilling basin floor slab. These forces include the force due to water weight and the up lift force affected the slab below which these forces are classified in hydrostatic. also the other force is hydrodynamic force due to pressure fluctions below the hydraulic jump. To keep the stilling basin stabillity from liffting up and destruction must the resistant forces be equal to destroyer forces. In this study after discution about the hydraulic jump and its resultant forces, a equation has been offerd to determine the thickness of stilling basin floor slab using buckingham theory andsoftware DATAFIT. Finaly the slab which evaluated by physical model, simulated using mathematical model(software ANSYS 10) and studied. The stress and strain diagrams were extracted. Results showed that physical and mathematical models were matched very good.

Deep-water deposits of the Eocene Tyee Formation, Oregon

2021 ◽  
pp. 19-48
Author(s):  
Gwladys T. Gaillot* ◽  
Michael L. Sweet ◽  
Manasij Santra
Keyword(s):  
Deep Water ◽  
Three Dimensional ◽  
Depositional Environments ◽  
Submarine Fan ◽  
University Of Texas ◽  
Source To Sink ◽  
Basin Scale ◽  
Basin Floor ◽  
Geological Sciences ◽  
The University

ABSTRACT The Eocene Tyee Formation of west central Oregon, USA, records deposition in a forearc basin. With outcrop exposures of fluvial/deltaic to shelf and submarine fan depositional environments and known sediment sourcing constrained by detrital zircon dating and mineralogy linked to the Idaho Batholith, it is possible to place deposits of the Tyee Formation in a source-to-sink context. A research program carried out by the Department of Geological Sciences at The University of Texas at Austin and ExxonMobil Research Company’s Clastic Stratigraphy Group has reconstructed the Eocene continental margin from shelf to slope to basin floor using outcrop and subsurface data. This work allows us to put observations of individual outcrops into a basin-scale context. This field trip will visit examples of depositional environments across the entire preserved source-to-sink system, but it will focus on the deep-water deposits of the Tyee Formation that range from slope channels to proximal and distal basin-floor fans. High-quality roadcuts reveal the geometry of slope channel-fills in both depositional strike and dip orientations. Thick, sand-rich medial fan deposits show vertical amalgamation and a high degree of lateral continuity of sandstones and mudstones. Distal fan facies with both classic Bouma-type turbidites and combined flow or slurry deposits are well exposed along a series of new roadcuts east of Newport, Oregon. The larger basin-scale context of the Tyee Formation is illustrated at a quarry in the northern end of the basin where the contact between the oceanic crust of the underlying Siletzia terrane and submarine fan deposits of the Tyee Formation is exposed. The Tyee Formation provides an excellent opportunity to see the facies and three-dimensional geometry of deep-water deposits, and to show how these deposits can be used to help reconstruct ancient continental margins.

The Road River Group of northern Yukon, Canada: early Paleozoic deep-water sedimentation within the Great American Carbonate Bank

2020 ◽  
Vol 57 (10) ◽  
pp. 1193-1219
Author(s):  
Justin V. Strauss ◽  
Tiffani Fraser ◽  
Michael J. Melchin ◽  
Tyler J. Allen ◽  
Joseph Malinowski ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Deep Water ◽  
Carbonate Platform ◽  
Geological Mapping ◽  
Canadian Cordillera ◽  
The Road ◽  
Late Cambrian ◽  
Facies Associations ◽  
Richardson Mountains ◽  
Carbonate Bank

Cambrian–Devonian sedimentary rocks of the northern Canadian Cordillera record both the establishment and demise of the Great American Carbonate Bank, a widespread carbonate platform system that fringed the ancestral continental margins of North America (Laurentia). Here, we present a new examination of the deep-water Road River Group of the Richardson Mountains, Yukon, Canada, which was deposited in an intra-platformal embayment or seaway within the Great American Carbonate Bank called the Richardson trough. Eleven detailed stratigraphic sections through the Road River Group along the upper canyon of the Peel River are compiled and integrated with geological mapping, facies analysis, carbonate and organic carbon isotope chemostratigraphy, and new biostratigraphic results to formalize four new formations within the type area of the Richardson Mountains (Cronin, Mount Hare, Tetlit, and Vittrekwa). We recognize nine mixed carbonate and siliciclastic deep-water facies associations in the Road River Group and propose these strata were deposited in basin-floor to slope environments. New biostratigraphic data suggest the Road River Group spans the late Cambrian (Furongian) – Middle Devonian (Eifelian), and new chemostratigraphic data record multiple global carbon isotopic events, including the late Cambrian Steptoean positive carbon isotope excursion, the Late Ordovician Guttenberg excursion, the Silurian Aeronian, Valgu, Mulde (mid-Homerian), Ireviken (early Sheinwoodian), and Lau excursions, and the Early Devonian Klonk excursion. Together, these new data not only help clarify nomenclatural debate centered around the Road River Group, but also provide critical new sedimentological, biostratigraphic, and isotopic data for these widely distributed rocks of the northern Canadian Cordillera.

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