Tectonic Significance of Gravity and Aeromagnetic Investigations at the Head of the Gulf of California

A 3D model of crustal magnetization at the Pinacate Volcanic Field, NW Sonora, Mexico

“…Sumner carried out an interpretation of aeromagnetic and ground gravity data, by 2D forward modeling, constrained using magnetic susceptibility and magnetization data from several crystalline and extrusive rock samples. Sumner (1972) found that granitic and gneissic basement rocks display soft remnant magnetization, while extrusive basaltic rocks from the PVF have stronger remanences that, besides showing some variability, are nearly parallel to the present geomagnetic field, which means that induced magnetization is a valid assumption for interpretation. Sumner (1972) also considered the Altar fault ( Fig.…”

“…Sumner (1972) found that granitic and gneissic basement rocks display soft remnant magnetization, while extrusive basaltic rocks from the PVF have stronger remanences that, besides showing some variability, are nearly parallel to the present geomagnetic field, which means that induced magnetization is a valid assumption for interpretation. Sumner (1972) also considered the Altar fault ( Fig. 1) to be the western boundary of the Basin and Range Province in Sonora.…”

“…1) located east of the plate boundary accommodates 3.8 to 5.3 km thick Latest MioceneEarly Pliocene to Pleistocene marine to sub-aerial sedimentary sequences (Pacheco et al, 2006). This basin is limited on the east by the now inactive Altar Fault, which has been interpreted as the southern continuation of the San Andreas Fault (Sumner, 1972), but the relation between the crystalline basement of the basin and sediments suggests detachment fault geometry.…”

“…Sumner (1972) carried out the first aeromagnetic study in the region, which was flown on north-south lines 5 km apart at a barometric altitude of 1300 m above the sea level. Besides its regional character, this survey revealed magnetic anomalies of relative low amplitude and short wavelength within the PVF.…”

The geologic setting of southern Arizona and southwestern New Mexico, with a rationale for assessment of undiscovered economically recoverable oil and gas; a summary of four potential plays

“…However, because of their importance to the understanding of such a complex region, the reader is encouraged to consult these references selected for their general treatment: Sauk and Sumner, 1971;Sumner, 1972;Vozoff, 1972;Mattick and others, 1973;West and Sumner, 1973;Thompson and Burke, 1974;Sumner, 1975;Aiken, 1976 andSumner and others, 1976; U.S. Geol. Survey, 1977;Aiken and others, 1978;Eaton, 1979aEaton, , 1980Eaton, , 1982Lysonski and others, 1980;Aiken and Ander, 1981a;Hildenbrand and others, 1982;Klein, 1982;Lance and others, 1982;Zietz, 1982;Keller and Cordell, 1983;Keller and others, 1984;Jachens and others, 1985;Mayer, 1986;Simpson and others, 1986;DeAngelo and Keller, 1988.…”