scholarly journals Oceanic basement structure, sediment thickness, and heat flow near Hole 504B

1998 ◽  
Vol 103 (B7) ◽  
pp. 15377-15391 ◽  
Author(s):  
Stephen A. Swift ◽  
Graham M. Kent ◽  
Robert S. Detrick ◽  
John A. Collins ◽  
Ralph A. Stephen
Keyword(s):  
Heat Flow ◽  
Sediment Thickness ◽  
Basement Structure ◽  
Oceanic Basement

Heat flow and sediment thickness in the Queensland Trough, western Coral Sea

1990 ◽  
Vol 95 (B13) ◽  
pp. 21399 ◽  
Author(s):  
D. R. Choi ◽  
Y. S. B. Liu ◽  
J. P. Cull
Keyword(s):  
Heat Flow ◽  
Sediment Thickness ◽  
Coral Sea

scholarly journals Supplemental Material: Intrarift fault fabric, segmentation, and basin evolution of the Lake Malawi (Nyasa) Rift, East Africa

2020 ◽  
Author(s):  
C.A. Scholz ◽  
et al.
Keyword(s):  
East Africa ◽  
Lake Malawi ◽  
Basin Evolution ◽  
Sediment Thickness ◽  
Basement Structure

<div>Contains mapping files in GIS formats of 1) the basement structure contour grid for Lake Malawi (Nyasa); 2) the sediment thickness grid for Lake Malawi (Nyasa); and 3) fault heaves for major basement-involved faults observed in the Lake Malawi (Nyasa) Rift<br></div>

scholarly journals APPLIED GEOSTATISTICS TO THE ASSESSMENT OF ENHANCED GEOTHERMAL SYSTEM (EGS) IN CENTRAL SUMATERA BASIN

2019 ◽  
Vol 14 (2) ◽  
pp. 113-125
Author(s):  
Josua Washington Sihotang ◽  
Syaiful Alam
Keyword(s):  
Heat Flow ◽  
Grid Cell ◽  
Geothermal System ◽  
Sediment Layer ◽  
Enhanced Geothermal System ◽  
Sediment Thickness ◽  
High Thermal Gradient ◽  
Technical Potential ◽  
Variogram Modeling ◽  
Central Sumatra

Thick sediment (over 2,500 m), fractured basement and high thermal gradient (up to 19.10 C/100 m) of Central Sumatra Basin are suitable factors to have the Enhanced Geothermal System (EGS) potential. A number of 130 wells data were used to evaluate the EGS of the basin. The assessment is divided into the number of estimation within the grid cell (1x1 km) of sediment thickness, heat flow, thermal conductivity and technical potential calculated starting from basement-sediment layer interface. The distribution of heat flow and gradient thermal values correspond to the sediment layer. The autocorrelation test indicates the data is stationary. The variance of data gets bigger after a depth over 5.5 km. According to the Beardsmore protocol, the technical potential value ranged from 0.5 MW up to 4.7 MW at a depth of 3.5 km. In addition, the lowest technical potential is 0.66 MW and the highest is 5.76 MW at a depth of 4.5 km. The ordinary kriging, using the number of lags 10 in variogram modeling, estimated the technical potential distribution is higher to the southwest.

Sediment thickness, basement structure and tectonics from inversion and modeling over northeastern South America

2005 ◽  
Author(s):  
Mark E. Odegard ◽  
Allan E. Kean ◽  
W. Robert Weber ◽  
Kirsten Fletcher ◽  
Mohammed Kidwai
Keyword(s):  
South America ◽  
Sediment Thickness ◽  
Basement Structure

FlankFlux: an experiment to study the nature of hydrothermal circulation in young oceanic crust

1992 ◽  
Vol 29 (5) ◽  
pp. 925-952 ◽  
Author(s):  
E. E. Davis ◽  
D. S. Chapman ◽  
M. J. Mottl ◽  
W. J. Bentkowski ◽  
K. Dadey ◽  
...  
Keyword(s):  
Heat Flow ◽  
Pore Fluid ◽  
Sediment Surface ◽  
Hydrothermal Circulation ◽  
Sediment Thickness ◽  
Sea Floor ◽  
Ridge Crest ◽  
Eastern Flank ◽  
Sediment Cover ◽  
Ridge Flank

The sediment-buried eastern flank of the Juan de Fuca Ridge provides a unique environment for studying the thermal nature and geochemical consequences of hydrothermal circulation in young ocean crust. Just 18 km east of the spreading axis, where the sea-floor age is 0.62 Ma, sediments lap onto the ridge flank and create a sharp boundary between sediment-free and sediment-covered igneous crust. Farther east, beneath the nearly continuous turbidite sediment cover of Cascadia Basin, the buried basement topography is extremely smooth in some areas and rough in others. At a few isolated locations, small volcanic edifices penetrate the sediment surface. An initial cruise in 1978 and two subsequent cruises in 1988 and 1990 on this sedimented ridge flank have produced extensive single-channel seismic coverage, detailed heat flow surveys co-located with seismic lines, and pore-fluid geochemical profiles of piston and gravity cores taken over heat flow anomalies. Complementary multichannel seismic reflection data were collected across the ridge crest and eastern flank in 1985 and 1989. Preliminary results of these studies provide important new information about hydrothermal circulation in ridge flank environments. Near areas of extensive basement outcrop, ventilated hydrothermal circulation in the upper igneous crust maintains temperatures of less than 10–20 °C; geochemically, basement fluids are virtually identical to seawater. Turbidite sediment forms an effective hydrologic and geochemical seal that restricts greatly any local exchange of fluid between the igneous crust and the ocean. Once sediment thickness reaches a few tens of metres, local vertical fluid flux through the sea floor is limited to rates of less than a few millimetres per year. Fluids and heat are transported over great distances laterally in the igneous crust beneath sediment however. Heat flow, basement temperatures, and basement fluid compositions are unaffected by ventilated circulation only where continuous sediment cover extends more than 15–20 km away from areas of extensive outcrop. Where small basement edifices penetrate the sediment cover in areas that are otherwise fully sealed, fluids discharge at rates sufficient to cause large heat flow and pore-fluid geochemical anomalies in the immediate vicinity of the outcrops. After complete sediment burial, hydrothermal circulation continues in basement. Estimated basement temperatures and, to the limited degree observed, fluid compositions are uniform over large areas despite large local variations in sediment thickness. Because of the resulting strong relationship between heat flow and sediment thickness, it is not possible, in most areas, to detect any systematic pattern of heat flow that might be associated with cellular hydrothermal circulation in basement. However, an exception to this occurs at one location where the sediment thickness is sufficiently uniform to allow detection of a systematic variation in heat flow that can probably be ascribed to cellular circulation. At that location, temperatures at the sediment–basement interface vary smoothly between about 40 and 50 °C, with a half-wavelength of about 700 m. A permeable-layer thickness of similar dimension is inferred by assuming that circulation is cellular with an aspect ratio of roughly one. This thickness is commensurate with the subbasement depth to a strong seismic reflector observed commonly in the region. Seismic velocities in the igneous crustal layer above this reflector have been observed to be low near the ridge crest and to increase significantly where the transition from ventilated to sealed hydrothermal conditions occurs, although no associated reduction in permeability can be ascertained from the thermal data.

scholarly journals Supplemental Material: Intrarift fault fabric, segmentation, and basin evolution of the Lake Malawi (Nyasa) Rift, East Africa

2020 ◽  
Author(s):  
C.A. Scholz ◽  
et al.
Keyword(s):  
East Africa ◽  
Lake Malawi ◽  
Basin Evolution ◽  
Sediment Thickness ◽  
Basement Structure

<div>Contains mapping files in GIS formats of 1) the basement structure contour grid for Lake Malawi (Nyasa); 2) the sediment thickness grid for Lake Malawi (Nyasa); and 3) fault heaves for major basement-involved faults observed in the Lake Malawi (Nyasa) Rift<br></div>

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