Lithospheric evolution of the Andean fold-thrust belt, Bolivia, and the origin of the central Andean plateau

摘要: We combine geological and geophysical data to develop a generalized model for the lithospheric evolution of central Andean plateau between 188 208 S from Late Cretaceous present. By integrating results upper mantle structure, crustal thickness, composition with recently published structural, stratigraphic, thermochronologic data, we emphasize importance both crust in plateau. Four key steps are as follows. 1) Initiation mountain building by ~70 Ma suggested associated foreland basin depositional history. 2) Eastward jump narrow, early fold–thrust belt at 40 through eastward propagation 200–400-km-long basement thrust sheet. 3) Continued shortening within Eastern Cordillera 15 Ma, which thickened established eastern boundary modern Removal excess delamination Cordillera–Altiplano during Miocene appears necessary accommodate underthrusting Brazilian shield. Replacement lithosphere hot asthenosphere may have provided heat source pulse mafic volcanism Altiplano 24–23 further recorded 12–7 ignimbrites. 4) After ~20 deformation waned Interandean zone began be transferred into Subandean zone. Long-term rates indicate that average rate has remained fairly constant (~8–10 mm/year) time possible slowing (~5–7 last 15–20 myr. suggest Cenozoic been focused where most likely continues removed piecemeal delamination. D 2005 Elsevier B.V. All rights reserved.