Geochemistry of soils from the San Rafael Valley, Santa Cruz County, Arizona

Open-File Report 2013-1149
By:  and 



This study was conducted to determine whether surficial geochemical methods can be used to identify subsurface mineraldeposits covered by alluvium derived from surrounding areas. The geochemical investigation focused on an anomalous geo-physical magnetic high located in the San Rafael Valley in Santa Cruz County, Arizona. The magnetic high, inferred to be asso-ciated with a buried granite intrusion, occurs beneath Quaternary alluvial and terrace deposits. Soil samples were collected at a depth of 10 to 30 centimeters below land surface along transects that traverse the inferred granite. The samples were analyzed by inductively coupled plasma-mass spectrometry and by the partial-leach Mobile Metal Ion™ method. Principal component and factor analyses showed a strong correlation between the soils and source rocks hosting base-metal replacement deposits in the Harshaw and Patagonia Mining Districts. Factor analysis also indicated areas of high metal concentrations associated with the Meadow Valley Flat. Although no definitive geochemical signature was identified for the inferred granite, concentrations otungsten and iron in the surrounding area were slightly elevated.

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Geochemistry of soils from the San Rafael Valley, Santa Cruz County, Arizona
Series title Open-File Report
Series number 2013-1149
DOI 10.3133/ofr20131149
Year Published 2013
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Eastern Mineral and Environmental Resources Science Center
Description Report: vi, 30 p.; 5 Tables
Country United States
State Arizona
County Santa Cruz County
Other Geospatial San Rafael Valley
Datum North American Datum of 1983
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details