Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada

Denton, Kevin M.; Ponce, David A.

doi:10.3133/ofr20161070

Cited by 7 publications

(17 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Data reduction includes terrain corrections (Godson and Plouff, 1988), which remove the effect of topography, and isostatic corrections , which remove long-wavelength variations in the gravity field related to compensation of topographic loads. For additional details of the processing of these data, see Denton and Ponce (2016). These reduction methods are used to produce isostatic gravity anomalies that reflect the density variations of sources in the middle to upper crust (Fig.…”

Section: Gravity Datamentioning

confidence: 99%

“…Models were constrained by combining gravity, magnetic, and MT data, geologic mapping and cross sections (Hewett, 1956;Olson et al, 1954;Burchfiel and Davis, 1988;Wooden and Miller, 1990;Fleck et al, 1994), drill-hole information (Castor, 2008;Langenheim et al, 2009), rock-property data , and depth-to-basement estimates (Langenheim et al, 2009). In the models, source bodies are assumed to have uniform average densities and magnetic susceptibility values that are derived from physical property measurements of rock samples from the study area (Table 1; Denton and Ponce, 2016). Combined, these constraints dramatically reduce the ambiguity and nonuniqueness inherent in geophysical models.…”

Section: Research Papermentioning

confidence: 99%

“…The geometry of the Sulfide Queen carbonatite ore body is based on surface mapping and drill-hole data (Olson et al, 1954;Castor, 2008;Castor and Nason, 2004;Denton and Ponce, 2016). The carbonatite is ~200 m wide and ~250 m thick along profile BB′ and is modeled as a tabular body that dips ~30°-35°SW.…”

Section: 5-d Model Bb′mentioning

confidence: 99%

See 2 more Smart Citations

Geophysical characterization of a Proterozoic REE terrane at Mountain Pass, eastern Mojave Desert, California, USA

et al. 2019

Self Cite

View full text Add to dashboard Cite

Mountain Pass, California (USA), located in the eastern Mojave Desert, hosts one of the world’s richest rare earth element (REE) deposits. The REE-rich terrane occurs in a 2.5-km-wide, northwest-trending belt of Mesoproterozoic (1.4 Ga) stocks and dikes, which intrude a larger Paleoproterozoic (1.7 Ga) metamorphic block that extends ∼10 km southward from Clark Mountain to the eastern Mescal Range. To characterize the REE terrane, gravity, magnetic, magnetotelluric, and whole-rock physical property data were analyzed. Geophysical data reveal that the Mountain Pass carbonatite body is associated with an ∼5 mGal local gravity high that is superimposed on a gravity terrace (∼4 km wide) caused by granitic Paleoproterozoic host rocks. Physical rock property data indicate that the Mountain Pass REE suite is essentially nonmagnetic at the surface with a magnetic susceptibility of 2.0 × 10−3 SI (n = 57), and lower-than-expected magnetizations may be the result of alteration. However, aeromagnetic data indicate that the intrusive suite occurs along the eastern edge of a distinct northwest-trending aeromagnetic high along the eastern Mescal Range. The source of this magnetic anomaly is ∼1.5–2 km below the surface and coincides with an electrical conductivity zone that is several orders of magnitude more conductive than the surrounding rock. The source of the magnetic anomaly is likely a moderately magnetic pluton. Combined geophysical data and models suggest that the carbonatite and its associated REE-enriched ultrapotassic suite were preferentially emplaced along a northwest-trending zone of weakness, which has potential implications for regional mineral exploration.

show abstract

Section: Gravity Datamentioning

confidence: 99%

Section: Research Papermentioning

confidence: 99%

See 1 more Smart Citation

Geophysical characterization of a Proterozoic REE terrane at Mountain Pass, eastern Mojave Desert, California, USA

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…All gravity data were tied to primary base stations in Primm, Nevada, as well as a secondary base station established near Mountain Pass, California. These stations ultimately were tied to high-precision gravity base station PB1021 near Baker, California, as part of a southern California high-precision gravity base-station network (Roberts and Jachens, 1986), as well as to a World Relative Gravity Reference Network of North America gravity base station at Nipton, California (Jablonski, 1974; see also, Denton and Ponce, 2016).…”

Section: Gravity Methodsmentioning

confidence: 99%

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

Ponce¹,

Denton²

2018

Scientific Investigations Map

Self Cite

View full text Add to dashboard Cite

“…To improve understanding of the geophysical and structural framework of the carbonatite terrane, 19 MT stations, more than 2,300 gravity stations, and more than 640 physical rock property samples were collected across the eastern Mojave Desert region (Denton and Ponce, 2016). A regional aeromagnetic survey of parts of California was also used in this study (Roberts and Jachens, 1999).…”

Section: Methodsmentioning

confidence: 99%

Magnetotelluric Imaging of a Carbonatite Terrane in the Southeast Mojave Desert, California and Nevada

Peacock

Denton

Ponce

2016

ASEG Extended Abstracts

Self Cite

View full text Add to dashboard Cite

SUMMARYThe southeast Mojave Desert hosts one of the world's largest rare earth element (REE) deposits at Mountain Pass, California. Although surface geology has been studied, a full understanding of the carbonatite and associated intrusive suite complex requires subsurface geophysical characterization. In this study, a combination of geophysical methods, including magnetotelluric (MT), magnetics, and gravity are used to create a two-dimensional (2D) geophysical model to a depth of about 10 km. An electrically conductive body is found 2-3 km below and west of the deposit that is associated with a magnetic high that could be connected to a deeper (10 km) conductive body related to possible intrusions or hydrothermal systems. The carbonatite body coincides with a steep magnetic gradient and a bench or terrace in the gravity data that may reflect relative lower-density intrusive rocks. Although carbonatite rocks are typically magnetic, the carbonatite rocks, associated intrusive suite, and host rocks in this area are essentially non-magnetic. Combined geophysical data indicate that the enriched REE deposit may be related to a regional extensive hydrothermal alteration event.

show abstract

Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada

Cited by 7 publications

References 9 publications

Geophysical characterization of a Proterozoic REE terrane at Mountain Pass, eastern Mojave Desert, California, USA

Geophysical characterization of a Proterozoic REE terrane at Mountain Pass, eastern Mojave Desert, California, USA

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

Magnetotelluric Imaging of a Carbonatite Terrane in the Southeast Mojave Desert, California and Nevada

Contact Info

Product

Resources

About