New Mexico Geological Society Annual Spring Meeting — Abstracts

A preliminary biogeochemical survey was conducted in areas around the Copper Flat Cu-Mo porphyry deposit.

The purpose of the survey was to determine if copper and molybdenum were available for uptake by plants in the surrounding areas. Further work was done to determine the method by which uptake occurred in Juniperous Monosperma, Quercus Emoryi, Cactus(variation-Prickly Pear), Prosopis Glandalusa, and several other species. This provided a setting as to whether . or not this type of sampling program could be used as viable exploration tool in this area.

Results indicated anomalous values of copper and trace amounts of molybdenum in the area sampled. Soil pH indicated that copper was readily available for supergene mobilization, while molybdenum was not.

The molybdenum available for uptake by the plants is in the form of the molybdate ion, MoO₄^-, the highest oxidation state of molybdenum (Pendias). This presents a useful tool in laboratory analysis of molybdenum. Normal wet chemical methods for analyzing, soil and rock samples for molybdenum (usually in the form of MoS₂) are complex and very time consuming due to molybdenum being very insoluble in acids. The higher oxidation state of the molybdenum available to plants makes' it easier to put the sample into solution for analysis.