Progressive deformation, fluid flow and water-rock interaction in the Mexican Fold-Thrust Belt, Central Mexico
type: CreativeWork
description: An integrated study of the Mexican Fold-Thrust Belt (MFTB) in central Mexico provides information on the evolution of the belt and the processes operating to produce structures and fabrics. Key questions addressed concern to the role of lithology in controlling the style of deformation, the role of fluids in facilitating deformation and the timing and sequence of structural development. Overall, the MFTB is thin-skinned and has properties consistent with the critical tapered wedge model of fold-thrust-belt development: there is a decrease in thickness, intensity of deformation and temperature of deformation towards the toe. Critical wedge theory, however, does not explain how deformation accumulates in the rocks within the wedge. In the MFTB, the deformation mechanisms that operate in different segments of the cross-section are strongly controlled by lithology. The dominant rocks in the sedimentary cover are Cretaceous carbonates that vary in facies laterally, with two large carbonate platforms flanked by more thinly bedded basinal carbonates. Kilometer scale thrusts dominate deformation in the platform carbonates (a more brittle behavior), and mesoscopic buckle folds and associated cleavage dominate deformation in the basinal carbonates (a more ductile behavior). Two phases of deformation are recognized, the first, D1 being more intense than the second, D2. The difference in facies distribution is the main reason for the difference between the MFTB and the fold-thrust belt in the southern Canadian Rocky Mountains, which is characterized by large thrust sheets and relatively few buckle folds. Structural observations on the mesoscopic scale allow distinguishing veins (dominantly calcite) of several generations, emplaced early, during and late/after deformation (V1, V2 and V3 respectively). Analysis of δ13C and δ18O in calcite from veins and host-rock shows that the veins confined within thrust slices are isotopically buffered by the host rock and differ in isotopic c…
abstract: An integrated study of the Mexican Fold-Thrust Belt (MFTB) in central Mexico provides information on the evolution of the belt and the processes operating to produce structures and fabrics. Key questions addressed concern to the role of lithology in controlling the style of deformation, the role of fluids in facilitating deformation and the timing and sequence of structural development. Overall, the MFTB is thin-skinned and has properties consistent with the critical tapered wedge model of fold-thrust-belt development: there is a decrease in thickness, intensity of deformation and temperature of deformation towards the toe. Critical wedge theory, however, does not explain how deformation accumulates in the rocks within the wedge. In the MFTB, the deformation mechanisms that operate in different segments of the cross-section are strongly controlled by lithology. The dominant rocks in the sedimentary cover are Cretaceous carbonates that vary in facies laterally, with two large carbonate platforms flanked by more thinly bedded basinal carbonates. Kilometer scale thrusts dominate deformation in the platform carbonates (a more brittle behavior), and mesoscopic buckle folds and associated cleavage dominate deformation in the basinal carbonates (a more ductile behavior). Two phases of deformation are recognized, the first, D1 being more intense than the second, D2. The difference in facies distribution is the main reason for the difference between the MFTB and the fold-thrust belt in the southern Canadian Rocky Mountains, which is characterized by large thrust sheets and relatively few buckle folds. Structural observations on the mesoscopic scale allow distinguishing veins (dominantly calcite) of several generations, emplaced early, during and late/after deformation (V1, V2 and V3 respectively). Analysis of δ13C and δ18O in calcite from veins and host-rock shows that the veins confined within thrust slices are isotopically buffered by the host rock and differ in isotopic c…
author: Fitz-Díaz, Elisa
language: en_US
keywords: Carbonates, Fluid Inclusions, Fold-Thrus Belt, Orogenic Wedge, Stable Isotopes, Vein, Geology
date published: 2010-12
date modified: 2026-07-24T05:20:00Z
provider: University of Minnesota
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Minnesota