Boletín de la Sociedad Geológica Mexicana Volumen conmemorativo del centenario Revisión de algunas tipologías de depósitos Minerales de México   Vol. 58, núm. 1, 2006, p. 103-139 http://dx.doi.org/10.18268/BSGM2006v58n1a4

Depósitos de Pb-Zn-Cu-Ba-F-Sr epigenéticos estratoligados en series sedimentarias en relación con salmueras de cuenca: depósitos de tipo “Mississippi Valley” (MVT) y similares en México

Jordi Tritlla^1,*; Gilles Levresse¹; Rodolfo Corona-Esquivel²; David Banks³; Hector Lamadrid¹, Julien Bourdet⁴

¹ Programa de Geofluidos, Centro de Geociencias, Universidad Nacional Autónoma de México, Campus Juriquilla, Carr. Qro-SLP km 15,5, Santiago de Querétaro, Qro. 76230, México
² Museo de Geología-Instituto de Geología, Universidad Nacional Autónoma de México, J. Torres Bodet No. 176, Col. Sta Ma. La Ribera, D. F. 06400, México
³ School of Earth Environment, Institute of Geological Sciences, The University of Leeds, Leeds LS2 9JT, Reino Unido de la Gran Bretaña
⁴ UMR 7566 G2R-CREGU, Université H. Poincaré, B.P. 239 Vandoeuvre-lès-Nancy, 54506 France

* This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The low temperature, epigenetic and stratabound Pb-Zn-Cu-Ba-F-Sr-bearing ore deposits enclosed within sedimentary series have been one of the major sources of metals in history. Presently, exploration companies still find these deposits a profitable target due to its simple mineralogy as well as the large tonnage they can present, always considering the mineral disctricts as a whole. In north-east Mexico, several non-magmatic, low-temperature Pb-Zn-F-Ba deposits have been sistematically considered to represent magmatic-related typologies (skarns, high-temperature replacement deposits, epithermal deposits, etc.). Recently, these deposits have been re-studied and placed within an scenario of deep fluid circulation of basinal brines through the Mesozoic sedimentary series, being enriched in Ba, F and metals during its transit. These fluids gave rise to a series of stratabound epigenetic ore deposits scattered throughout the whole Mesozoic carbonate platform. These deposits are not related with any magmatic period whatsoever; do not cause an intense alteration to the host rocks; oftenly, they present a close association with organic matter, either liquid hydrocarbons or bitument; they display a very simple mineralogy (barite, celestite, fluorite, sphalerite, galena) and present low formation temperatures (90-105 ºC) coupled with variable salinities. All these characteristics make these deposits similar to the Mississippi Valley-Type Deposits, Alpine-Apalachian subtype.

In this paper firstly we pretend to perform a revision on the global knowledge of the MVT tipology and, subsequentely, to discuss the presence of this type of deposits within the Mesozoic sedimentary series in Mexico.

Keywords: MVT deposits, general characteristics, geochemistry, deposits in Mexico, state of the art.