scholarly journals Thermal gradients and heat flow at Roosevelt Hot Springs. Technical report, volume 77-3

1977 ◽  
Author(s):  
W.R. Sill ◽  
J. Bodell
Keyword(s):  
Heat Flow ◽  
Hot Springs ◽  
Thermal Gradients ◽  
Technical Report

scholarly journals Thermal gradients and heat flow at Roosevelt Hot Springs. Technical report, Volume 77-3

1977 ◽  
Author(s):  
W.R. Sill ◽  
J. Bodell
Keyword(s):  
Heat Flow ◽  
Hot Springs ◽  
Thermal Gradients ◽  
Technical Report

Analysis of aeromagnetic measurements from the Cascade Range in central Oregon

Geophysics ◽  
1983 ◽  
Vol 48 (3) ◽  
pp. 376-390 ◽  
Author(s):  
G. Connard ◽  
R. Couch ◽  
M. Gemperle
Keyword(s):  
Heat Flow ◽  
Curie Point ◽  
Hot Springs ◽  
Magnetic Anomalies ◽  
High Heat ◽  
Cascade Range ◽  
Thermal Gradients ◽  
Tectonic Structures ◽  
Basin And Range Province ◽  
Lateral Offset

Shallow Curie‐point isotherm depths, indicated by the analysis of magnetic anomalies, young silicic volcanism, hot springs, and high heat flow mark the Cascade Range of central Oregon as a potentially important geothermal resource area. Aeromagnetic measurements in the central Cascades between 43°00′ and 44°15′N latitude and 121°00′ and 122°30′W longitude exhibit predominant northwest‐southeast lineations and less prominent north‐northeast by south‐southeast lineations. Longer wavelength components of the magnetic anomalies (greater than 25 km), possibly related to deeper sources, trend approximately north‐south parallel to the Cascade Range. Magnetic anomalies show a right‐lateral offset of the High Cascades Volcanism at 43°30′N latitude, which is consistent with the tectonic structures of the Basin and Range province southeast of the area. Magnetic source depth calculations show that the High Cascades occupy a structural depression or graben on the eastern side of the Western Cascades. Spectral analysis of the magnetic anomalies suggests that the High Cascades are underlain by Curie‐point isotherm depths as shallow as 9 km. These shallow Curie‐point isotherm depths imply thermal gradients greater than 50°C/km and surface heat flow greater than [Formula: see text].

scholarly journals Application of heat-flow techniques to geothermal energy exploration, Leach Hot Springs area, Grass Valley, Nevada

1977 ◽  
Author(s):  
J.H. Sass ◽  
J.P. Ziagos ◽  
H.A. Wollenberg ◽  
R.J. Munroe ◽  
D. E. di Somma ◽  
...  
Keyword(s):  
Heat Flow ◽  
Geothermal Energy ◽  
Hot Springs ◽  
Flow Techniques

scholarly journals Changes in Quinone Profiles of Hot Spring Microbial Mats with a Thermal Gradient

1999 ◽  
Vol 65 (1) ◽  
pp. 198-205 ◽  
Author(s):  
Akira Hiraishi ◽  
Taichi Umezawa ◽  
Hiroyuki Yamamoto ◽  
Kenji Kato ◽  
Yonosuke Maki
Keyword(s):  
Thermal Gradient ◽  
Microbial Mats ◽  
Hot Springs ◽  
Hot Spring ◽  
Thermal Gradients ◽  
Cyanobacterial Mats ◽  
Dissimilarity Index ◽  
Quinone Profile ◽  
Bacterial Mats ◽  
Different Temperatures

ABSTRACT The respiratory and photosynthetic quinones of microbial mats which occurred in Japanese sulfide-containing neutral-pH hot springs at different temperatures were analyzed by spectrochromatography and mass spectrometry. All of the microbial mats that developed at high temperatures (temperatures above 68°C) were so-called sulfur-turf bacterial mats and produced methionaquinones (MTKs) as the major quinones. A 78°C hot spring sediment had a similar quinone profile.Chloroflexus-mixed mats occurred at temperatures of 61 to 65°C and contained menaquinone 10 (MK-10) as the major component together with significant amounts of either MTKs or plastoquinone 9 (PQ-9). The sunlight-exposed biomats growing at temperatures of 45 to 56°C were all cyanobacterial mats, in which the photosynthetic quinones (PQ-9 and phylloquinone) predominated and MK-10 was the next most abundant component in most cases. Ubiquinones (UQs) were not found or were detected in only small amounts in the biomats growing at temperatures of 50°C and above, whereas the majority of the quinones of a purple photosynthetic mat growing at 34°C were UQs. A numerical analysis of the quinone profiles was performed by using the following three parameters: dissimilarity index (D), microbial divergence index (MDq ), and bioenergetic divergence index (BDq ). A D matrix tree analysis showed that the hot spring mats consisting of the sulfur-turf bacteria, Chloroflexus spp., cyanobacteria, and purple phototrophic bacteria formed distinct clusters. Analyses ofMDq and BDq values indicated that the microbial diversity of hot spring mats decreased as the temperature of the environment increased. The changes in quinone profiles and physiological types of microbial mats in hot springs with thermal gradients are discussed from evolutionary viewpoints.

scholarly journals Geochemical Characteristics of Hydrothermal Volatiles From Southeast China and Their Implications on the Tectonic Structure Controlling Heat Convection

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiao Tian ◽  
Yiman Li ◽  
Xiaocheng Zhou ◽  
Zhonghe Pang ◽  
Liwu Li ◽  
...  
Keyword(s):  
Heat Flow ◽  
Hot Springs ◽  
Volatile Component ◽  
Geochemical Characteristics ◽  
Chemical Compositions ◽  
Adjacent Area ◽  
Geothermal Area ◽  
Tectonic Structure ◽  
Southeast China ◽  
Geothermal Fluids

Hot springs and igneous rocks are present widely in southeast China, influenced by the subduction of the Western Pacific and Philippine Sea Plates. This study reports on new data of chemical compositions and He–Ne–C isotopes for gas samples from representative hot springs and wells in the Guangdong and Fujian provinces to identify the origin of hydrothermal volatiles and provide insight into geothermal tectonic affinities. The primary hydrothermal volatile component from southeast China is atmospheric N2, with a volumetric percentage of 82.19%–98.29%. It indicates medium-low temperature geothermal systems where geothermal fluids suffered a shallow circulation in closed fracture systems. Low CO2 and CH4 contents and their depleted δ13C values confirmed the small number of deep-derived components in the study area. However, spatially discernible geochemical characteristics imply enhanced hydrothermal fluid convection in the adjacent area of the two provinces, including the Fengshun, Zhangzhou, Longyan, and Sanming geothermal fields. Specifically, the He–Ne isotopes from this area exhibit mantle He contribution of more than 10% and mantle heat flow accounts for more than half of the total heat flow. Moreover, according to the thermal background calculations, the highest heat flow value of 77.7 mW/m2 is indicated for the Zhangzhou geothermal area and the lowest value of 54.7 mW/m2 is indicated for the Maoming geothermal area. Given the epicenter distributions and the corresponding earthquake magnitudes, the NE-trending faults are heat-control tectonic structures and their intersections with the NW-trending faults provided expedite channels for geothermal fluids rising to the surface. Therefore, the preferred development potential of geothermal resources can be expected in the adjacent area of the two provinces where two sets of active faults crossed. This study provides critical information on understanding the geothermal distribution controlled by the tectonic structure in southeast China.

scholarly journals SEARCH FOR GEOTHERMAL SEISMIC NOISE IN THE EAST MESA AREA, IMPERIAL VALLEY, CALIFORNIA

Geophysics ◽  
1975 ◽  
Vol 40 (6) ◽  
pp. 1066-1072 ◽  
Author(s):  
H. M. Iyer
Keyword(s):  
Heat Flow ◽  
Seismic Noise ◽  
Critical Evaluation ◽  
Thermal Gradients ◽  
Noise Levels ◽  
Imperial Valley ◽  
Bureau Of Reclamation ◽  
Cultural Noise ◽  
Noise Experiment ◽  
The U.S

A seismic noise experiment was conducted in the East Mesa area of Imperial Valley, California, by the U.S. Geological Survey (USGS) in May 1972. There is a pronounced heat flow anomaly over the area, and between July 1972 and the present five deep test wells have been drilled over the anomaly by the U.S. Bureau of Reclamation (U.S. Bureau of Reclamation, 1974). At the time of our survey, we were aware of results from a preliminary seismic noise survey in East Mesa by Teledyne Geotech (Douze and Sorrells, 1972). A detailed noise survey was conducted by Teledyne Geotech soon after our experiment (Geothermal Staff of Teledyne Geotech, 1972). Both the Teledyne Geotech surveys show noise levels (in the 3.0 to 5.0 hz band) 12–18 db higher over the area where the thermal gradients and heat flow reach maximum values than in the surroundings. Our results, on the other hand, show that the seismic noise field in the area is dominated by cultural noise, and it is impossible to see a noise anomaly that can be related to the geothermal phenomena in East Mesa. We think that it is important to take into account this disagreement between the two results in order to make a critical evaluation of the utility of seismic noise as a geothermal prospecting tool. The purpose of this note is to put our findings on record.

Geothermal gradients in the Hinton area of west-central Alberta

1982 ◽  
Vol 19 (4) ◽  
pp. 755-766 ◽  
Author(s):  
H. L. Lam ◽  
F. W. Jones ◽  
C. Lambert
Keyword(s):  
Hot Springs ◽  
Rocky Mountain ◽  
Geothermal Gradient ◽  
Temperature Data ◽  
Petroleum Exploration ◽  
Well Logs ◽  
Thermal Gradients ◽  
Disturbed Region ◽  
West Central ◽  
Exploration Well

Temperature data from petroleum exploration well logs of 3360 wells in a region of west-central Alberta are used to estimate thermal gradients. A relatively high geothermal gradient (~36 °C/km) of oblong shape located near Hinton is observed. The axis of the anomaly strikes approximately southwest–northeast and passes through the Miette Hot Springs area. It appears that water is heated at depth in the Rocky Mountain disturbed region and travels eastward and toward the surface along fault planes.

A Discussion on global tectonics in Proterozoic times - Heat flow and magmatic activity in the Proterozoic

1976 ◽  
Vol 280 (1298) ◽  
pp. 655-660 ◽  
Keyword(s):  
Heat Flow ◽  
Heat Production ◽  
Mantle Convection ◽  
Large Scale ◽  
Substantial Reduction ◽  
Giant Cells ◽  
Thermal Gradients ◽  
Magmatic Activity ◽  
Weathering Processes ◽  
Global Tectonics

Proterozoic tectonics are considered to reflect the changes from the small mantle convection cells of the Archaean to the giant cells of the present. Approach to the ‘modern’ regime is considered to be evident about one billion years ago. Metamorphic patterns from Brazil provide evidence for a substantial reduction in thermal gradients over the Proterozoic period. It is suggested that reduction of radioactive heat production near the Archaean-Proterozoic boundary led to thickening of stable granitoid crust and sweeping together of a very extensive granitoid veneer into super continents. Fundamental to the view presented, is the concept of large scale crust mantle mixing caused by subduction, crustal basement uplift, and weathering processes.

Geothermal signatures and uranium ore deposits on the Stuart Shelf of South Australia

Geophysics ◽  
1989 ◽  
Vol 54 (2) ◽  
pp. 158-170 ◽  
Author(s):  
G. A. Houseman ◽  
J. P. Cull ◽  
P. M. Muir ◽  
H. L. Paterson
Keyword(s):  
Heat Flow ◽  
South Australia ◽  
Thermal Anomaly ◽  
Ore Deposits ◽  
Thermal Gradients ◽  
Proterozoic Basement ◽  
Drill Holes ◽  
Olympic Dam ◽  
Homogeneous Unit ◽  
Anomalous Heat

An analysis of temperature data from drill holes on the Stuart Shelf of South Australia demonstrates a major thermal anomaly associated with the Olympic Dam copper‐uranium‐gold deposit. The average heat flow on the Stuart Shelf (seven locations, excluding Olympic Dam) is [Formula: see text], but an additional heat flow of approximately [Formula: see text] is present in the sediments overlying the orebody. Although some of the anomalous heat flow appears to be generated in the mid‐Proterozoic basement at depths greater than 1 km, uranium assays indicate that approximately [Formula: see text] can be attributed to concentrations defining the orebody. Major anomalies in heat flow can be readily detected in the flat‐lying cover of Cambrian and late Proterozoic sediments. The Tregolana shale within this sequence is a widespread homogeneous unit, typically 100–200 m thick. It is easily identified on temperature logs by its high thermal gradient relative to other sections in the hole. The heat flow anomaly at Olympic Dam is clearly distinguished by measuring thermal gradients within the Tregolana shale; gradients in the Tregolana shale at Olympic Dam are close to 83 °C/km, with a standard deviation (SD) of 6 °C/km, compared to 51 °C/km (SD = 7 °C/km) elsewhere on the Stuart Shelf.

scholarly journals Heat flow near Kyle Hot Springs, Buena Vista Valley, Nevada

1976 ◽  
Author(s):  
J.H. Sass ◽  
H.A. Wollenberg ◽  
D.E. di Somma ◽  
J.P. Ziagos
Keyword(s):  
Heat Flow ◽  
Hot Springs ◽  
Buena Vista
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