An integrated Study of the Proposed Sei-Tauhe Terrane boundary, Tajeras Quadrangle, Northern Sinaloa, Mexico

MCDONOUGH, CONOR, Department of Geological Sciences, University of Texas at El Paso, El Paso, Texas [email protected]

The genetic history of the Republic of Mexico has been a subject of debate for decades. The initial studies focused on large regional geologic trends using sparse geologic data sets (Campa and Coney, 1983; Coney, 1989; Sedlock et. al, 1993). It is now necessary to look at a terrane boundary on a local scale. This study focuses a portion of the inferred east-west trending Seri Tauhe terrane boundary (Sedlock et al, 1993) located at the Sonora, Sinaloa, Chihuahua tri state junction. This is no simple task in northwestern Mexico. The nature of the proposed boundary, the tectonic divide between the North American Craton and the accreted late Triassic volcanic arc, is disguised by Cenezoic to mid Tertiary andesite and granitic batholith emplacement followed by successive late Tertiary ignimbrite sheets that drape the locale. Preliminary results from the assimilation of recent field studies, isotopic studies (Valencia Moreno et al, 2001), and remote sensing studies are suggestive of the both the nature and existence of the Seri Tauhe Terrane boundary in northern Sinaloa.