"Zinc, lead and minor copper-bearing manto-type and vein- type deposits occur in Paleozoic sedimentary rocks adjoining the Tres Hermanas quartz monzonite stock, Luna County, New Mexico. In an attempt to prove or disprove a possible genetic relationship between these mineral deposits and the stock, 99 half-mile or closer orthogonal grid samples from the stock and 22 soil samples from a connecting alluvial area to the north were analysed by atomic absorption technique for trace contents of zinc, lead and copper. Thirty-two of the rock samples were selected on a wider grid and petrographically studied and modal analyses calculated. Argillic, sericitic and chloritic alteration products were volumetrically estimated using a Swift Point Counter.
The trace metal zinc, lead and copper anomalies are spatially related to each other. Zinc and lead anomalies are almost congruent with less agreement of the copper anomalies to the other two. Significantly, a close spatial relationship exists between the anomalous concentrations of zinc-lead-copper in the stock and the external hydrothermal deposits in the Paleozoic sedimentary rocks. The ratios of highest zinc, lead and copper concentrations in the anomalies of the stock show general agreement to the ratio of metals production from the adjacent mineral deposits.
Alteration appears to be a general requisite for trace metal anomalies within the stock. A direct relationship also exists between certain primary petrographic textures and the anomalies of zinc, lead and copper. The latter suggests a possible deuteric origin for at least one stage of the development of the anomalies. Yet, in combination with rock alteration, a two phase or continuous phase, i.e., deuteric and hydrothermal or deuteric to hydrothermal origin of the anomalies appears likely.
The isolated character of the trace metal anomalies, their patterns within the stock decrease in the magnitude of the anomalies near the stock contacts marginal to mineralized zones, and primary petrographic textures and alteration features associated with each anomaly suggests that the source of the trace metals for the hydrothermal metalliferous deposits is the stock itself.
Finally, in the alluvial area north of the stock specific anomalies of zinc, lead and copper occur. The zinc anomaly is at least twice the background, and lead and copper three times the average background in the stock. The anomalous values suggest possible nearby sources of metal content in the bedrock"--Abstract, pages ii-iii.
Proctor, Paul Dean, 1918-1999
Spreng, Alfred C., 1923-2012
Christiansen, Carl R., 1921-1997
Hagni, Richard D.
Geosciences and Geological and Petroleum Engineering
Ph. D. in Geology
University of Missouri--Rolla
viii, 117 pages
Luna County, New Mexico
© 1971 Peethambaram Doraibabu, All rights reserved.
Dissertation - Open Access
Soils -- Trace element content -- New Mexico -- Luna County
Petrology -- New Mexico -- Luna County
Geology -- New Mexico -- Luna County
Print OCLC #
Electronic OCLC #
Link to Catalog Record
Doraibabu, Peethambaram, "Trace base metals, petrography, rock alteration of the productive Tres Hermanas stock, Luna County, New Mexico" (1971). Doctoral Dissertations. 2314.