Geometric and kinematic analysis of the Puquín anticline, Cusco - Perú

Puma-Enriquez Y.; López-Abanto W.; Cárdenas-Roque J. · Boletin de Geologia (2024) · DOI: 10.18273/revbol.v46n3-2024006

Resumen

The Puquín anticline is a geological structure located in the Cusco region that extends ~9.8 km. In the core of the anticline, sedimentary rocks of the Puquín Formation are exposed. Likewise, sedimentary rocks of the Quilque, Chilca, Kayra and Soncco formations outcrop on the flanks of the anticline. It is an asymmetric fold with a N-S fold axis strike, closed in the northern and central portion and open in the southern portion, and has a double dip axis of approximately 21°S and 34°N. The front flank shows greater thickening than the rear flank and is traversed by a backthrust. Based on these features, the Puquín anticline is interpreted as a fault-propagation fold. The shortening calculated from three structural sections, carried out by the trishear method, is 8.32 km (15.1%), 8.61 km (12.1%) and 8.62 km (12.0%) for the northern, central and south cross-sections, respectively. The analysis of the pattern of fractures, faults and veinlets carried out in 23 structural stations in different sectors of the anticline made it possible to distinguish 5 sets of orientations: WNW-ESE, NNE-SSW, W-E, NE-SW and WSW-ENE. These structures are compatible with the structural arrangement that originates in the folds and in this case with the Puquín fold. © (2024), (Universidad Industrial de Santander). All rights reserved.

Instituciones: Universidad Nacional de San Antonio Abad del Cusco