Premium
Neotectonic development of western Nicaragua
Author(s) -
Weinberg Roberto Ferrez
Publication year - 1992
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/92tc00859
Subject(s) - geology , neogene , anticline , graben , volcano , paleontology , subduction , fault (geology) , seismology , outcrop , quaternary , neotectonics , volcanism , pleistocene , tectonics , geomorphology , structural basin
This study presents a reconstruction of the Neotectonic evolution of western Nicaragua by means of structural analysis of outcrop scale joints, faults and bedding planes integrated with macroscale structures. The results indicate three clearly separable deformation phases which are closely related to specific volcanic events and account for the major tectonic features of Nicaragua. The first deformation phase was a Late Miocene to Early Pliocene shortening that produced the Pacific Plain anticlines and controlled the contemporaneous extrusion of the El Coyol Group volcanic rocks. The second phase, active between the Pliocene and the Pleistocene, resulted in extensional structures such as the 500‐km‐long and 50‐km‐wide NW‐SE trending Nicaragua Depression. This phase was accompanied by a gradual trenchward migration of the volcanic activity responsible for the formation of the Las Sierras Group. The third deformation phase is still active and is responsible for the present shallow focus‐seismic activity associated with N‐S trending volcanic vents and the N‐S Managua pull‐apart Graben. The Neotectonic development of western Nicaragua, as interpreted here, is closely related to the contemporaneous evolution of the neighboring areas of Guatemala (south of the Jocotan Fault), Honduras, El Salvador and Costa Rica (north of the Valle Central). The Valle Central of Costa Rica represents the southern boundary of this structurally homogeneous domain and may indicate the southern boundary of the Neogene Chortis Block. Changes in deformation style and the trenchward migration of volcanism which occurred during the Pliocene may indicate an increase in the subduction angle of the Cocos Plate and may also be correlated to Pliocene shortening of Jamaica and Hispaniola.