Drainage pattern as a tectonic footprint: A case study of Riedel
conjugate systems in the Laguna del Maule Volcanic Complex, Southern
Andean Volcanic Zone (Chile)
Abstract
The tectonic movement along faults is often reflected by geological
lineaments, appearing as geomorphological features caused by relief. The
detection and quantification of geological lineaments raises interest as
it provides information on tectonic processes. During the last decade,
remote sensing data has been used as a source of information for the
detection of geological lineaments; however linear features acquired via
different GIS techniques are usually not consistent. Based on the
drainage pattern, this study provides a new approach to envisage the
tectonic footprint on the Earth surface, that has been successfully
tested and compared with field structural characterizations. The
tectonic framework of the Laguna del Maule Volcanic Complex (LdMVC), in
the Southern Andean Volcanic Zone, is distinguished by local structural
domains characterized by diverse but coherent fault geometries and
kinematics that accommodate bulk crustal deformation, coexisting with
high local uplift rates related to magma ascend. The analysis of local
lineament populations suggests the interaction between two conjugate
Riedel systems sharing the LdMVC as a depocenter: An orogenic scale
dextral system, that has favored the formation of wide ENE oriented
extensional areas, is intersected by another sinistral WNW-NW Riedel
system, likely favored by the reactivation of ancient Andean transverse
faults (ATF). The coexistence of both Riedel systems creates a positive
feedback for their related deformation areas, and therefore, favoring
the formation of intense damage zones, which in turn, promote the
structural conditions for the migration and emplacement of magma and
geofluids.