Page 341 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

Geothermal gradients phase on that about at Range melting: brittle the that for the shallow mehing the Basin partial of the for the depth Nevada Physical

323 enough and beneath Province. Intersections of the the base B. 3. Skinner and S.C. Porter, permission of John

Flow a) 10.3, superimposed for dry granite. Note high Basin the initiate partial thus terminate above Geothermal gradients on phase diagram (Fig. 2.7). Notice where partial gradients with the 150 km about for the Sierra from Sons, Inc.. New York.
Heat 10.15 in to earthquakes occurring within 45 km) encountered region suggest at Mountains. Modified with

and FIGURE from Table diagram temperatures are 20 km depth Province upper crust depth. b) superimposed peridotite depth (= may be Range geothermal lithosphere craton, 250 km Geology by 1987. Used Wiley and
Tectonics and melt ©

(@dW) e@inssetd =
(8d W) einsselg d
0 ei § ‘
0 g § § 8
2
3 2 g

Diagram (°C) fe ° Diagram . Temperature (°C)

P/T Temperature T= ° P/T

Granite ° Peridotite Ne

Dry 8 8 & 8 @ R Wet 8 8 , 88

a) z= Depth (km) b) z= Depth (km)

Flow Map, in values Rift) and at region of and the

XS ~# Heat 107? W/m’). High W/m*). The (near the coast) Nevada
-- Muah

? ‘ ---A.---->) Regions of high and low values. expressed Province: Rio Grande 0.09 of the Sierra
i. rks of Mexico U. S. Department of Energy x 4.2 = — forearc region years ago. Low values are also observed in
American sp 2 a Pt Nef oa bagel fe je Continental) 4 py ‘ jan ; \ Coast ne eS oe Gulf from 1991). HFU flow units (1 Range and values (0.05 by normal the in 0.05 W/m") low marks the region Mountains).
y
i

North MARS osaiatee. a t S oe Marathon’. Gu a? \.< (simplified al., et Blackwell heat rifting (Basin is dominated low (< about 20 million (Appalachian

2) 0.09 wate a aa United States Mountains). A prominent East
(W/m 0.09 - ‘<0.05 rencmcag i t f * Steele. 1989, and highlighted. Older maps may show values in observed in areas of continental continental craton Pacific Northwest shows a the zone in
i

Flow > 0.05 Pi i i 4, 3 Heat flow map of the and hotspot. The the (Cascade plate convergence ceased collision

Heat [es] [_] Eeq an i: << i be) 10.14 Blackwell 0.09 W/m’) are in volcanic arc the Paleozoic continental

Who,
FIGURE 1996: sce also W/m‘. are the Yellowstone ongoing subduction at high Mountains. where
ukzaIQ OB (> a