scholarly journals INTERACTIONS OF DEEP-WATER GRAVITY FLOWS AND ACTIVE SALT TECTONICS

2020 ◽  
Author(s):  
Zoe Cumberpatch ◽  
Ian Kane ◽  
Euan Soutter ◽  
David Hodgson ◽  
Christopher Jackson ◽  
...  
Keyword(s):  
Deep Water ◽  
Salt Tectonics ◽  
Gravity Flows ◽  
Active Salt

Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Near Surface ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Platform Margin ◽  
Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

scholarly journals The gravity flow dynamics of submarine fan sedimentation in the Magura Basin of the Western Carpathians (Magura Nappe, Slovakia)

2010 ◽  
Vol 61 (3) ◽  
pp. 201-209 ◽  
Author(s):  
František Teťák
Keyword(s):  
Deep Water ◽  
Flow Dynamics ◽  
Western Carpathians ◽  
Gravity Flow ◽  
Submarine Fan ◽  
Sedimentary Structures ◽  
Gravity Flows ◽  
Bed Thickness ◽  
Change Position ◽  
Current Arrangement

The gravity flow dynamics of submarine fan sedimentation in the Magura Basin of the Western Carpathians (Magura Nappe, Slovakia)This article deals with the dynamics of the deep-water gravity flows sedimentation within the Magura Formation. This investigation is based on analysis of the Magura sandstone sedimentary structures studied on the outcrops. The final comparison of the sedimentary structures and cycles with the paleocurrent directions provided an interpretation of the gravity flows dynamics and helped to restore the migration of the sandy lobes in space and time. Three modes of sedimentation are recorded: regular cyclic sedimentation from the lobe, irregular sedimentation from the immature lobe and pelitic sedimentation on the basin plane without the lobe influence. We compared the occurrence of some sedimentary structures with the changes of the current directions and bed thickness. The following interpretations of gravity flow fan dynamics are results of this comparision: the fan consists of one or several lobes, the lobe branches out into branches with the radial current arrangement, the lobes laterally change position and the lobes suddenly die out.

Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

1988 ◽  
Vol 62 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Near Surface ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Platform Margin ◽  
Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

scholarly journals Verification of gravity-flow models: case study from the Lower Eocene sediments (Tylmanowa site, SE Poland)

Baltica ◽  
2019 ◽  
Vol 32 (1) ◽  
pp. 33-50
Author(s):  
Martyna E. Górska
Keyword(s):  
Deep Water ◽  
Upper Jurassic ◽  
Gradual Transition ◽  
Lower Eocene ◽  
Flow Models ◽  
Se Poland ◽  
Gravity Flows ◽  
Outer Carpathians ◽  
Basin Margin

The thick-bedded, deep-water sandstone succession was described at the Tylmanowa site from the Polish Outer Carpathians. This part of the Carpathians is built mainly of the Upper Jurassic to Paleogene deep-water rocks. Succession at the Tylmanowa site is composed of massive, ripple-cross laminated, planar and trough cross-stratified, horizontally laminated and deformed sandstones as well as massive and horizontally laminated mudstones. All these sediments derived from gravity flows that prograde downslope from a basin margin towards the widespread abyssal plain. Exposed succession records the gradual transition from a decelerating debris flow to a turbidity current what is extraordinary in the recent investigations of deep-water sediments. The study succession has been compared with the widely known sediment models, such as: the classic Bouma Sequence (Bouma 1962), the high-density turbidite model (Lowe 1982), the fluxoturbidite model (Ślączka, Thompson 1981) and the hybrid event bed model (Haughton et al. 2009).

scholarly journals Stratigraphy, tectonics and detrital zircon U-Pb (LA-ICP-MS) geochronology of the Rio Preto Belt and northern Paramirim corridor, NE, Brazil

2017 ◽  
Vol 47 (2) ◽  
pp. 261-273 ◽  
Author(s):  
Davi da Costa Bezerra Gobira de Alcântara ◽  
Alexandre Uhlein ◽  
Fabrício de Andrade Caxito ◽  
Ivo Dussin ◽  
Antônio Carlos Pedrosa-Soares
Keyword(s):  
Marine Environment ◽  
Deep Water ◽  
Detrital Zircon ◽  
Mica Schist ◽  
Rift Basins ◽  
Shallow Marine ◽  
Gravity Flows ◽  
Icp Ms ◽  
Northwestern Margin ◽  
Brasiliano Orogeny

ABSTRACT: Two important Proterozoic metasedimentary sequences, the Rio Preto and Santo Onofre Groups, crop out along the northwestern margin of the São Francisco craton and in northern Paramirim corridor, respectively. The Rio Preto Group, involved in the eponymous fold-thrust belt along the northwestern cratonic boundary, comprises the Formosa (garnet schist, quartz-mica schist, quartzite, chlorite-sericite schist and ferriferous quartz schist) and Canabravinha (quartzite, micaceous quartzite, metarhytmite, phylite, schist and metaturbidite) formations. The Santo Onofre Group occurs exclusively in the Paramirim corridor, and is composed of quartzite and minor carbonaceous or Mn-rich phylite. These units record sedimentation in shallow to deep-water marine settings related to rift basins, and were deformed and metamorphosed under greenschist facies conditions during the Brasiliano orogeny. Here we present 427 new detrital zircon U-Pb ages, which constrain the maximum depositional ages of ca. 971 Ma for the Santo Onofre Group, ca. 912 Ma for the Canabravinha Formation, and ca. 965 Ma for the Formosa Formation of the Rio Preto Group. Our data suggests that the Santo Onofre and the Rio Preto Groups accumulated in two distinct basin settings. The latter, composed mostly of sandy rocks, would represent a relatively stable, shallow-marine shelf environment. The Rio Preto Group, with metadiamictite, quartzite, pelitic and rhythmitic rocks, represents a shallow to deep marine environment influenced by gravity flows. Both groups were probably deposited in the Late Tonian, and are potential correlatives of the lower (pre-glacial) units of the Macaúbas Group of the Araçuaí belt.

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