Richard Couch | Geology Reports

USGS1986

Klamath-Blue Mountain lineament, Oregon

Regional gravity data clearly show a zone of southwest-northeast lineations across Oregon that defines a major crustal lineament. Its existence is supported by geologic and geophysical data. Its correlation with the northwestern boundaries of the Klamath and Blue Mountain provinces suggests that these are continuous beneath the Cascade volcanic arc. The lineament may represent a pre-Tertiary strike-slip continental margin which, from paleomagnetic evidence, later rotated clockwise into its present position.

Oregon↗

USGS1982

Aeromagnetic measurements in the Cascade Range and Modoc Plateau of northern California; report on work done from June 1, 1980, to November 30, 1980

Aeromagnetic measurements made along flightlines oriented east- west and spaced at 1.6-km intervals and along lines oriented north- south and spaced at 8-km intervals, over approximately 30,000 square km of northern California, exhibit crossing errors of less than 5 nanoTeslas. The measurements show short-wavelength magnetic anomalies associated with near-surface volcanics over and east of Lassen Peak and over .and north of Mt. Shasta and the Medicine Lake Highlands, longer wavelength anomalies over the Modoc Plateau, and very long wavelength anomalies over the northernmost part of the Great Valley and the easternmost metamorphic rocks of the Klamath Mountains. Anomaly patterns, exhibit northwest-southeast trends, over the Modoc Plateau and a marked change in character at the juncture of the plateau and the Klamath Mountain and Great Valley complexes.

Open-File Report↗