Resistivity of Saturated Crustal Rocks to 40 Km Based on Laboratory Measurements
2011; American Geophysical Union; Linguagem: Inglês
10.1029/gm014p0243
ISSN2328-8779
Autores Tópico(s)Geological and Geochemical Analysis
ResumoRecent studies in solution chemistry, together with our earlier high-pressure work, provide the information needed to construct resistivity-depth profiles for typical crustal rocks saturated with aqueous solutions. Profiles are presented for three heat flow provinces: the Sierra Nevada, the Basin and Range, and the eastern United States, to a depth of 40 km. The effects of high pressure and temperature and the variation of pore pressure from hydrostatic to lithostatic are discussed. For aqueous solutions alone, resistivity typically decreases with the conditions encountered at depth. However, this decrease is nearly counteracted by the effect of decreasing porosity of typical rocks at depth, so that below a few kilometers, resistivity of solution-saturated rocks should vary only slightly until temperatures sufficient for mineral conduction are reached. Mineral conduction should become significant at a depth of 10 to 40 km, depending on heat flow province. At no depth should resistivity of solution-saturated crustal rocks be greater than 106 Ω-m.
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