Isostatic gravity map of Mountain Pass and vicinity, California and Nevada

Aeromagnetic map of Mountain Pass and vicinity, California and Nevada

“…A broad, regional magnetic high near the southwest corner of the map area (R1) reflects the weakly magnetic "Teutonia batholith" of Beckerman and others (1982); the high can be used to infer the horizontal extent of the batholith. A magnetic low in Shadow Valley (R2) reflects nonmagnetic basin-fill material in a relatively shallow basin, which is about 1-to 2-km deep as defined by gravity data (see Ponce and Denton, 2018b). This magnetic low extends eastward across the Mescal Range, where it reflects nonmagnetic Paleozoic sedimentary rocks, then continues southeastward across the Ivanpah Mountains, where it reflects the (informally named) Ivanpah granite of Beckerman and others (1982), which is essentially nonmagnetic.…”

“…1, 2) shows a prominent magnetic high along the western part of the Clark Mountain Range near exposures of nonmagnetic undivided Mesoproterozoic gneiss and Paleozoic rocks (D1). This anomaly probably represents a moderately magnetic granitic body, the top of which is at a depth of about 2 to 4 km on the basis of matched filtering (Phillips, 2001); the granitic body also is expressed as a terrace or area of flattening in the gravity-anomaly map (Ponce and Denton, 2018b) owing to its relatively low density. The "Mountain Pass carbonatite and alkaline intrusive suite" is present along the eastern margin of this anomaly, and the intrusive suite may have preferentially followed the source of the magnetic feature (or vice versa).…”

Three‐Dimensional Electrical Resistivity Characterization of Mountain Pass, California and Surrounding Region

“…(b) Reduced‐to‐pole aeromagnetic data (Ponce & Denton, 2018a). (c) Vertical gravity gradient (Ponce & Denton, 2018c). (d) Cross section of the 3‐D electrical resistivity model along M–M’.…”

“…They found the ultrapotassic and carbonatite intrusive suite causes a relative gravity high. Magnetic data suggests the intrusive suite is structurally controlled by a northwest trending zone of weakness (Denton et al, 2019;Ponce & Denton, 2018a, 2018b, 2018c. Denton et al (2019) interpreted collected MT data (Peacock et al, 2019) and developed a 2-D resistivity model.…”