scholarly journals Salt tectonics in the Thumrait area, in the southern part of the South Oman Salt Basin: Implications for mini-basin evolution

GeoArabia ◽  
2008 ◽  
Vol 13 (4) ◽  
pp. 77-108
Author(s):  
Badar Al-Barwani ◽  
Ken McClay
Keyword(s):  
Cross Sections ◽  
Seismic Survey ◽  
The South ◽  
Lower Paleozoic ◽  
Salt Domes ◽  
Upper Proterozoic ◽  
Basement Faults ◽  
Internal Structures ◽  
History Of ◽  
Seismic Lines

ABSRACT The Upper Proterozoic - Lower Cambrian South Oman Salt Basin contains exploration targets consisting principally of slabs of carbonate encased within the infra-Cambrian Ara Salt. The southern part of the South Oman Salt Basin was reviewed by using a 40 by 50 km 3-D seismic survey, 30 2-D regional seismic lines and 15 wells. The study focused on the evolution of the Ara Salt in relation to the overlying lower Paleozoic Nimr, Mahatta Humaid and Ghudun groups. Deformation of the thick sequence of Ara Salt dominated the history of mini-basins or “Haima pods” that developed above the salt. The syn-kinematic, predominantly clastic units of the Nimr and overlying Mahatta Humaid groups were deposited in the mini-basins above the Ara Salt. These sequences vary greatly in thickness due to salt movement. In seismic cross-sections, the Ara Salt is opaque, and obscured by seismic multiples generated by sub-horizontal reflectors higher in the section. Where internal geometries are imaged, however, complex internal structures are commonly observed. The Ara Salt structures evolved through several stages of deformation that were driven mainly by phases of sediment progradation from the west and northwest. Four main evolutionary phases for the mini-basins have been identified. Pre-existing topography and regional faults also played a role in triggering and delineating the regional salt trends. The basin has retained much the same shape from the Devonian Period until today. In contrast, in northern Oman, six salt domes have pierced the surface due to the reactivation of major basement faults during the late Palaeozoic.

Excavation of Three Long Barrows near Avebury, Wiltshire

1979 ◽  
Vol 45 ◽  
pp. 207-300 ◽  
Author(s):  
Paul Ashbee ◽  
I. F. Smith ◽  
J. G. Evans
Keyword(s):  
Environmental History ◽  
Single Phase ◽  
The South ◽  
Fourth Section ◽  
Internal Structures ◽  
Soils And Sediments ◽  
Close Proximity ◽  
History Of

SummaryThe three long barrows described in this report were totally excavated between 1959 and 1967. They have been presented in a single report because they had several features in common: they were in close proximity; they were built as single phase monuments; two conformed to a common specification which required elaborate internal structures; and they produced no evidence of funerary function or intent. There are four sections: I. The Horslip (or Windmill Hill) Long Barrow (P. A.). II. The Beckhampton Road Long Barrow (I.F.S.). III. The South Street Long Barrow (J.G.E.). The fourth section (IV) deals with the environmental history of the area as revealed in the long barrow soils and sediments (J.G.E.).

Geological mapping in the offshore domain: unravelling the tectonic history of the Scotia Sea

2020 ◽  
Author(s):  
Anouk Beniest ◽  
Wouter P. Schellart
Keyword(s):  
Cross Sections ◽  
Mantle Flow ◽  
The South ◽  
The West ◽  
Scotia Sea ◽  
Scotia Ridge ◽  
History Of ◽  
Geological Map ◽  
Velocity Anomalies ◽  
Sea Area

<p>We produced the first geological map of the Scotia Sea area based on the available geophysical and geological data. Combining magnetic, Bouguer gravity anomaly and high-resolution bathymetric data with geological data from dredged samples allowed us to map lithologies and structural features in this mostly submerged and complex tectonic area. This geological map allowed us to integrate a very inter-disciplinary dataset, thereby reviewing the available data and addressing some of the still persisting geological challenges and controversies in the area.</p><p>One of the most important and persistent discussions is the nature and age of the Central Scotia Sea. We mapped this part of the Scotia Sea as basaltic-andesitic lithology partly covered by thick, oceanic sediments. This differs in lithology from the West and East Scotia Sea, which we mapped as a basaltic lithology. Based on our lithological map, its unusual thickness and the presence of the Ancestral South Sandwich Arc (ASSA, early Oligocene-late Miocene) we argue that Central Scotia Sea has an Eocene to earliest Oligocene age.</p><p>Cross-sections combining the geology, crustal structure and mantle tomography reveal high velocity anomalies and colder mantle material below the structural highs along the South Scotia Ridge (Terror Rise, Pirie Bank, Bruce Bank and Discovery Bank) and below the South Sandwich Islands. We interpreted those as the southern, stagnated part of the subducting slab of the South Sandwich Trench, following the geometry of Jane Basin and the currently active subducting slab at the South Sandwich Trench. Low velocity anomalies are observed below Drake Passage and the East Scotia Sea, which are interpreted as warmer toroidal mantle flow around the slab edges below the Chilean trench and the South Sandwich trench.</p><p>Based on our geological map and integrated cross-sections we propose a multi-phase evolution of the Scotia Sea area with Eocene or older oceanic crust for the Central Scotia Sea. A first wide-rift-phase initiated before 30 Ma in the West Scotia Ridge, Protector Basin, Dove Basin and Jane Basin either as a result of the diverging South American and Antarctic continents and/or due to subduction rollback that commenced soon after subduction initiation that eventually caused the ASSA to form. The first full spreading center developed in the West Scotia Sea, aided by the warmer toroidal mantle flow causing spreading to be abandoned in the other basins (~30 Ma). A second rift phase in the fore-arc, in between the ASSA and the South Sandwich trench (~20 Ma), initiated through a redistribution of far-field forces as a result of continuous trench retreat. The warmer toroidal mantle concentrated on the East Scotia Ridge resulting in the second spreading system (15 Ma), abandoning the West Scotia Ridge spreading system 6-10 Ma.</p><p>We show that it is possible to create a geological map in a very remote area with an extreme environment with the available geological and geophysical data. This new way of producing geological maps in the offshore domain provides a better insight into the geological history of geologically complex areas that are largely submerged.</p>

GEOPHYSICAL HISTORY OF TYPICAL MISSISSIPPI PIERCEMENT SALT DOMES

Geophysics ◽  
1947 ◽  
Vol 12 (1) ◽  
pp. 30-42 ◽  
Author(s):  
L. L. Nettleton
Keyword(s):  
Cross Sections ◽  
Salt Dome ◽  
Salt Domes ◽  
Additional Note ◽  
Local Gravity ◽  
History Of ◽  
Cap Rock ◽  
Reconnaissance Surveys

Maps and cross sections are given, showing the development of geophysical and geological knowledge of the New Home and D’Lo domes. Both are shallow, piercement domes in the northern part of the Mississippi salt dome basin. Both were first indicated by gravity surveys, the shallow cap‐rock checked by refraction seismograph surveys, cap‐rock depths checked by drilling and further seismograph work and drilling then carried out to determine the position of the salt and the attitude of the sediments. The successive items of geophysical work and test drilling have led to a consistent and orderly development of information about these domes. An additional note is included, with three pairs of gravity maps, showing how strong and definite, but very local, gravity expressions of shallow domes may be missed by reconnaissance surveys.

Geoscience Australia seismic survey 310: revealing stratigraphy and structure of the outer northern Perth Basin margin

2013 ◽  
Vol 53 (2) ◽  
pp. 481
Author(s):  
George Bernardel ◽  
Chris Nicholson
Keyword(s):  
Late Jurassic ◽  
Field Data ◽  
Strike Slip ◽  
Source Rocks ◽  
Seismic Survey ◽  
The South ◽  
Potential Field Data ◽  
Reflection Seismic ◽  
The North ◽  
Seismic Lines

Geoscience Australia acquired seismic survey GA 310 in 2008–09, across the southwest margin of Australia, as part of the Australian government’s Energy Security Program. Deep reflection seismic and potential field data were recorded across sparse 2D grids located on the Wallaby Plateau in the north, Mentelle Basin in the south, and the intervening Houtman and Zeewyck sub-basins of the northern Perth Basin. The offshore northern Perth Basin extends for about 700 km along the Western Australia margin, from the towns of Carnarvon in the north to Cervantes in the south. The largely Paleozoic-Mesozoic tectonostratigraphic framework is dominated by Permian and Early-Middle Jurassic rifting, followed by Late Jurassic-Early Cretaceous rifting leading to Valanginian breakup between Australia and Greater India. Underlying Precambrian Pinjarra Orogen structuring, in conjunction with rifting, has resulted in the development of several complex depocentres and basement highs. A recent re-evaluation of the offshore northern Perth Basin well-based lithostratigraphy into a new chronostratigraphic sequence framework has been carried outboard, on the GA 310 seismic lines, into the margin bounding the Zeewyck and northern Houtman sub-basins. The main sequences hosting source rocks—Kockatea and Cattamarra—are widely present in the expansive northern Houtman Sub-basin, and are likely to be present in the deep Zeewyck Sub-basin. The mapping of a thick Late Jurassic Yarragadee Sequence in the Zeewyck Sub-basin indicates a major pre-breakup locus of relatively rapid deposition. The structural interpretation across the sub-basin highlights breakup-drift unconformities and strike-slip faulting and suggests a probable along-margin sheared crustal sliver; tectonic elements commensurate with an evolving rift-shear breakup margin.

Somewhere between Human, Nonhuman, and Woman

2020 ◽  
Vol 6 (3) ◽  
pp. 21-51
Author(s):  
Debashree Mukherjee
Keyword(s):  
Object Relations ◽  
Human Body ◽  
Film Industry ◽  
The South ◽  
Hunger Strike ◽  
Cultural Events ◽  
Production Experience ◽  
Human Object ◽  
The Status ◽  
History Of

In 1939, at the height of her stardom, the actress Shanta Apte went on a spectacular hunger strike in protest against her employers at Prabhat Studios in Poona, India. The following year, Apte wrote a harsh polemic against the extractive nature of the film industry. In Jaau Mi Cinemaat? (Should I Join the Movies?, 1940), she highlighted the durational depletion of the human body that is specific to acting work. This article interrogates these two unprecedented cultural events—a strike and a book—opening them up toward a history of embodiment as production experience. It embeds Apte's emphasis on exhaustion within contemporaneous debates on female stardom, industrial fatigue, and the status of cinema as work. Reading Apte's remarkable activism as theory from the South helps us rethink the meanings of embodiment, labor, materiality, inequality, resistance, and human-object relations in cinema.

The history of the geological development of the south of the Nepa-Botuoba anteclise during Nepa and Tira time

2020 ◽  
pp. 21-25 ◽  
Author(s):  
A.V. Plyusnin ◽  
◽  
R.R. Ibragimov ◽  
M.I. Gyokche ◽  
◽  
...  
Keyword(s):  
The South ◽  
History Of
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