Magnetotelluric and geomagnetic deep-sounding studies in rifts and adjacent areas: constraints on physical processes in the crust and upper mantle

Journal Article · Fri Jan 01 04:00:00 EST 1982 · Am Geophys Union Continental and Oceanic Rifts Geodynamics Series; (United States)

DOI:https://doi.org/10.1029/GD008p0169· OSTI ID:6177097

Hermance, J F

Deep electrical studies are reviewed along with other supportive geophysical/geological investigations of five of the major rift zones of the world: the Baikal rift, and Rhine graben, the East African rift, Iceland and the Rio Grande rift. All of these regions exhibit anomalously low values of electrical resistivity, density and seismic velocity, either within the crust itselt or at high levels in the mantle. Deep electrical studies support a model where ascending masses of material from the mantle are intimately coupled to the fractionation of a basalt melt and its accumulation at higher levels within the earth. In Iceland, an interplate rift, the accumulation and chilling of melt at the base of the crust apparently leads to a significant component of crustal underplating whereas in intraplate rifts such as the Rio Grande rift, the emplacement of basaltic magma at high levels may lead to extensive remelting of the crust, triggering eruptive episodes of silicic magmas.

• Research Organization: Brown Univ., Providence, RI
• DOE Contract Number: AC02-79ER10401
• OSTI ID: 6177097
• Journal Information: Am Geophys Union Continental and Oceanic Rifts Geodynamics Series; (United States), Journal Name: Am Geophys Union Continental and Oceanic Rifts Geodynamics Series; (United States) Vol. 8
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580200* -- Geophysics-- (-1989)
EARTH CRUST
ELECTRICAL PROPERTIES
ELECTRICAL SURVEYS
ELECTROMAGNETIC SURVEYS
GEOLOGIC STRUCTURES
GEOLOGY
GEOMAGNETIC FIELD
GEOPHYSICAL SURVEYS
GEOPHYSICS
MAGNETIC FIELDS
MAGNETOTELLURIC SURVEYS
PHYSICAL PROPERTIES
RIFT ZONES
RIO GRANDE RIFT
SURVEYS