scholarly journals Heat flow in Rajasthan Craton, North–Western Indian Shield and its Implications

2018 ◽  
Vol 1 (1) ◽  
pp. 30-34
Author(s):  
Mohan Lal Gupta ◽  
Shadi Sharma
Keyword(s):  
Heat Flow ◽  
Its Region ◽  
High Heat ◽  
Tectonic Activity ◽  
Fold Belt ◽  
Indian Shield ◽  
North West ◽  
Thermal Transients ◽  
North Western ◽  
Q Values

A synthesis and reinterpretation of surface heat flow values of the Rajasthan Craton(RC), north-western Indian Shield has been carried out. The results reveal that the q values are relatively high, varying from 52 to 96 mWm-2. Appreciable variations in the magnitude of q are found between and within its geotectonic units, but with considerable overlap of values. Paleo–Meso Proterozoic Aravalli Super Group is generally associated with high q values, varying from 52 to 67 mWm-2, with a mean value of 60 mWm-2. Values of still higher order varying from 52 to 76 mWm-2 occur in North Delhi Fold Belt of Meso–Neo Proterozoic Delhi super Group, Tusham area, which is located towards north west corner of the Delhi Fold Belt in the Trans-Aravalli Province of RC, is characterized by a very high heat flow value. This is the highest of all heat flow values so far reported for the Proterozoic terrains of the Indian Shield, which is ascribed as due both to enhanced crustal radioactivity and renewed tectonic activity beneath its region. The heat flow values reported in areas of the Delhi Super Group and Aravalli Super Group are of short wavelength, naturally these are due to shallow sources. We infer that these are mostly due to varying degrees of concentration of heat producing elements in the upper crust. There are also no evidences of major tectono-thermal events after the Neo-Proterozoic times (~600Ma) in the study area. Hence, we conclude that observed variations in heat flow do not carry thermal transients of any recent tectonic activity.

High heat flow at the SW passive margin of the Gulf of California

Terra Nova ◽  
2021 ◽  
Author(s):  
Rosa Maria Prol‐Ledesma ◽  
Juan Luis Carrillo De La Cruz ◽  
Marco‐Antonio Torres‐Vera ◽  
Alejandro Estradas‐Romero
Keyword(s):  
Heat Flow ◽  
Gulf Of California ◽  
High Heat ◽  
Passive Margin ◽  
High Heat Flow

A heat-flow reconnaissance of southeastern Alaska

1985 ◽  
Vol 22 (3) ◽  
pp. 416-421 ◽  
Author(s):  
J. H. Sass ◽  
L. A. Lawver ◽  
R. J. Munroe
Keyword(s):  
Heat Flow ◽  
Plate Boundary ◽  
Thermal Spring ◽  
High Heat ◽  
Transform Fault ◽  
High Heat Flow ◽  
Queen Charlotte Islands ◽  
Late Tertiary ◽  
The Mean ◽  
Strain Heating

Heat flow was measured at nine sites in crystalline and sedimentary rocks of southeastern Alaska. Seven of the sites, located between 115 and 155 km landward of the Queen Charlotte – Fairweather transform fault, have an average heat flow of 59 ± 6 mW m−2. This value is significantly higher than the mean of 42 mW m−2 in the coastal provinces between Cape Mendocino and the Queen Charlotte Islands, to the south, and is lower than the mean of 72 ± 2 mW m−2 for 81 values within 100 km of the San Andreas transform fault, even farther south. This intermediate value suggests the absence of significant heat sinks associated with Cenozoic subduction and of heat sources related to either late Cenozoic tectono-magmatic events or significant shear-strain heating. At Warm Springs Bay, 75 km from the plate boundary, an anomalously high heat flow of 150 mW m−2 can most plausibly be ascribed to the thermal spring activity from which its name is derived. At Quartz Hill, 240 km landward of the plate boundary, a value of 115 mW m−2 might indicate a transition to a province of high heat flow resulting from late Tertiary and Quaternary extension and volcanism.

scholarly journals High heat flow in the trans-Hudson Orogen, Central Canadian Shield

1996 ◽  
Vol 23 (21) ◽  
pp. 3027-3030 ◽  
Author(s):  
L. Guillou-Frottier ◽  
C. Jaupart ◽  
J. C. Mareschal ◽  
C. Gariépy ◽  
G. Bienfait ◽  
...  
Keyword(s):  
Heat Flow ◽  
High Heat ◽  
Canadian Shield ◽  
High Heat Flow

scholarly journals Gold in Irish Coal: Palaeo-Concentration from Metalliferous Groundwaters

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 635
Author(s):  
Liam A. Bullock ◽  
John Parnell ◽  
Joseph G.T. Armstrong ◽  
Magali Perez ◽  
Sam Spinks
Keyword(s):  
Heat Flow ◽  
Low Temperature ◽  
Precious Metals ◽  
High Heat ◽  
Selenium Content ◽  
Foreland Basins ◽  
High Heat Flow ◽  
South Wales ◽  
First Time ◽  
Very High

Gold grains, up to 40 μm in size and containing variable percentages of admixed platinum, have been identified in coals from the Leinster Coalfield, Castlecomer, SE Ireland, for the first time. Gold mineralisation occurs in sideritic nodules in coals and in association with pyrite and anomalous selenium content. Mineralisation here may have reflected very high heat flow in foreland basins north of the emerging Variscan orogenic front, responsible for gold occurrence in the South Wales Coalfield. At Castlecomer, gold (–platinum) is attributed to precipitation with replacive pyrite and selenium from groundwaters at redox interfaces, such as siderite nodules. Pyrite in the cores of the nodules indicates fluid ingress. The underlying Caledonian basement bedrock is mineralised by gold, and thus likely provided a source for gold. The combination of the gold occurrences in coal in Castlecomer and in South Wales, proximal to the Variscan orogenic front, suggests that these coals along the front could comprise an exploration target for low-temperature concentrations of precious metals.

Anglo-Dutch-American Enlightenment

2020 ◽  
pp. 250-266
Author(s):  
Jonathan Scott
Keyword(s):  
Present State ◽  
Natural Philosophy ◽  
North West ◽  
Natural Knowledge ◽  
Self Confidence ◽  
American Enlightenment ◽  
The North ◽  
European North ◽  
Cultural Movement ◽  
North Western

This chapter studies cultural invention in light of the North-Western European cultural movement called Enlightenment. Enlightenment refers, in the first place, to a description by European intellectuals of what they took to be an advanced present state of moral and natural knowledge by comparison to that of the ancients. With related self-confidence, in the heyday of their empires, some described their culture as possessed of a dynamic modernity to be distinguished from the ‘oriental' lethargy and backwardness existing elsewhere. Yet Enlightenment also originated as European self-criticism. One context for that was the comparative perspective acquired by discovery of non-European cultures. In this and in other ways the origin of Enlightenment, including its ‘conviction that progress had become unstoppable', lies in the period when Renaissance and Reformation combined with printing and natural philosophy to establish the culture of the European North-West.

scholarly journals Heat flow variations in the Antarctic Continent

2020 ◽  
Vol 3 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Suze Nei Pereira Guimarães ◽  
Fábio Pinto Vieira ◽  
Valiya Mannathal Hamza
Keyword(s):  
Heat Flow ◽  
Heat Budget ◽  
General Pattern ◽  
High Heat ◽  
Seismic Velocities ◽  
Antarctic Continent ◽  
Subglacial Lakes ◽  
Flow Map ◽  
The Antarctic ◽  
Heat Flow Variations

The present work provides a reappraisal of terrestrial heat flow variations in the Antarctic continent, based on recent advances in data analysis and regional assessments. The data considered include those reported at the website of IHFC and 78 additional sites where measurements have been made using a variety of techniques. These include values based on the Method of Magmatic Heat Budget (MHB) for 41 localities in areas of recent volcanic activity and estimates that rely on basal temperatures of glaciers in 372 localities that are known to host subglacial lakes. The total number of data assembled is 491, which has been useful in deriving a 10°x10° grid system of homogenized heat flow values and in deriving a new heat flow map of the Antarctic continent. The results reveal that the Antarctic Peninsula and western segment of the Antarctic continent has distinctly high heat flow relative to the eastern regions. The general pattern of differences in heat flow between eastern and western of Antarctic continent is in striking agreement with results based on seismic velocities.

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