Coeval compressional deformation and volcanism in the central Andes, case studies from northern Chile (23°S-24°S)
Abstract
In this contribution we examine the relationship between active compression and construction of Pleistocene volcanoes in the present-day magmatic arc of the central Andes (23°S-24°S). Deformation produced several N-S striking, ∼40 km long subparallel ridges. These ridges formed by folding of Pliocene ignimbrites and upper Pliocene and Pleistocene lavas; they are asymmetrical in profile and have a gentle back limb and steeper frontal limb. Andesitic monogenetic volcanoes show a close spatial relationship with the ridges; some volcanoes are on the hinge zone, whereas others lay on the sides of the ridges. We interpret this spatial pattern as a result of magma storage and migration along a system of subhorizontal reservoirs and reverse faults. Magma reservoirs probably formed along flat portions of reverse faults between ramp structures that serve as episodic magma transport pathways.
- Publication:
-
Tectonics
- Pub Date:
- December 2009
- DOI:
- 10.1029/2009TC002538
- Bibcode:
- 2009Tecto..28.6003G
- Keywords:
-
- Tectonophysics: Tectonics and magmatism;
- Tectonophysics: Volcanic arcs;
- Structural Geology: Folds and folding;
- Geographic Location: South America;
- Information Related to Geologic Time: Cenozoic;
- structural geology;
- volcanism;
- tectonics