Structure and kinematics of Subbetic and related mélange-like units NW of Ronda Basin (Western Betics)evidences for a transpressional structural high in the frontal thrust-and-fold belt
- A. Jiménez-Bonilla 1
- I. Expósito 1
- J.C. Balanyá 1
- L. Barcos 1
- M. Díaz-Azpiroz 1
- 1 Universidad Pablo de Olavide, Sevilla, España
ISSN: 0213-683X
Year of publication: 2015
Issue Title: Comunicaciones presentadas en la LVII Sesión Científica / Madrid, 27-28 de Noviembre de 2014
Issue: 57
Pages: 27-30
Type: Article
More publications in: Geogaceta
Abstract
The Olistostromic Unit has been interpreted as a “mélange” deposited in the inner Guadalquivir basin, due to the uplift of the orogenic front. The NW boundary of the Ronda Basin is made up of discontinuous competent blocks surrounded by gypsy mudstones, somehow resembling the Olistostromic Unit. A detailed kinematic analysis has shown that this boundary constitutes a WSW-ENE structural high, post-Tortonian in age, where the strain is partitioned into: (1)WSW-ENE dextral strike-slip faults, (2) SW-NE shortening structures and (3) NW-SE normal faults. The main dextral fault zone is relieved by NW-SE oblique segments, dominated by either stretching or shortening structures, which could be interpreted as releasing and restraining bends, respectively. As a whole, the zone is interpreted as a transpressive band developed in the frontal part of the thrust-and-fold belt proper, the “Olistostromic Unit” probably cropping out toward the N.