Moho depth inferred from gravity and topography in an intraplate area (Iberian Chain)

Abstract

This paper discusses variations in Moho depth beneath an intraplate area, including the Iberian Chain thrust belt and the surrounding Cenozoic basins, based on topography and Bouguer anomaly data analysis. Two models of Moho depth mapping were used: Airy Moho depth maps and a Moho depth map derived from the Bouguer anomaly map. According to these models, a minimum Moho depth of 32 to 36km was calculated beneath the Iberian Chain and the Central System, and a maximum Moho depth ranging from 37 to 44km for the central part of the Iberian Chain. This crustal thickening (at least 5 to 7km) was generated during the Cenozoic contraction. Subsequent to these analyses, a new 2D density model was built across the entire Iberian Chain. This model showed a thickening of the upper crust, which is consistent with a Cenozoic thrust system involving only the upper crust.