MISSISSIPPI VALLEY TYPE DEPOSITS IN NE MEXICO

Mexico is an important worldwide producer of minerals associated to Mississippi Valley Type (MVT) deposits, especially fluorite, celestine and barite. Zinc, lead and copper ores are also usually located in environments related to this typology. In order to know their distribution and increase the knowledge and potential of this mineralization in NE Mexico, the Mexican Geological Survey (SGM) set up a program to generate prospective localities and targets focused to strength development poles in the country.

The studied area is consistent with a belt running from NE Chihuahua far to Coahuila and Nuevo León states; center of Tamaulipas, NE of Durango and north of Zacatecas. During the first stage, a review of the SGM database as well as information produced by other institutions, allowed to select a number of areas with possibilities to contain MVT mineral deposits. The data was downloaded to a Geographic Information System (GIS). As a result, 23 prospective areas were proposed. From them, 9 are related to stratabound-copper deposits, 6 to lead-zinc in calamines; 2 more of fluorite, 2 of celestine, and 4 of barite, all of them with features associated to MVT deposits. Over the selected areas, 743 sites including mines, prospects and minerals occurrences with common genetic, textural, and mineralogical features, were identified.

The field research included geological mapping, characterization and measuring of stratigraphic columns, facies changes, and mining works recognition. Chemical, petrographical, mineragraphical, X-ray diffraction and fluid inclusions analyses were performed in the SGM labs. All the information was useful to identify the geological context and the economic potential in order to produce exploration targets to be explored by the SGM, or by third parties concerned in such deposits.