Controls of the Lithospheric Thermal Field of an OceanContinent Subduction Zone: The Southern Central Andes

RODRIGUEZ PICEDA, CONSTANZA; SCHECK-WENDEROTH, MAGDALENA; BOTT, JUDITH; GÓMEZ DACAL, MARÍA LAURA; CACACE, M.; PONS, MICHAËL; PREZZI, CLAUDIA BEATRIZ; STRECKER, MANFRED

Lithosphere

GeoScienceWorld

Año: 2022 vol. 2022 p. 1 - 26

1941-8264

In an ocean-continent subduction zone, the assessment of the lithospheric thermal state is essential to determine the controls of the deformation within the upper plate and the dip angle of the subducting lithosphere. In this study, we evaluate the degree of influence of both the configuration of the upper plate (i.e., thickness and composition of the rock units) and variations of the subduction angle on the lithospheric thermal field of the southern Central Andes (29°?39°S). Here, the subduction angle increases from subhorizontal (5°) north of 33°S to steep (~30°) in the south. We derived the 3D temperature and heat flow distribution of the lithosphere in the southern Central Andes considering conversion of S wave tomography to temperatures together with steady-state conductive thermal modeling. We found that the orogen is overall warmer than the forearc and the foreland and that the lithosphere of the northern part of the foreland appears colder than its southern counterpart. Sedimentary blanketing and the thickness of the radiogenic crust exert the main control on the shallow thermal field (