Abstract

The Neogene sedimentary record of the Madrid Basin, central Spain, comprises three major stratigraphic units (the Lower, Intermediate and Upper Miocene Units), separated by sedimentary discontinuities which were linked with variations in the tectonic activity of the basin margins. The distribution of the depositional systems that formed the Lower Unit was, to a large extent, controlled by the emplacement of the Altomira Range during the Late Oligocene and Early Miocene. The sedimentation that formed the Intermediate Unit during most of the Middle Miocene and part of the Late Miocene was mainly controlled by uplift of the Central System. Finally, the sedimentary features of the Upper Unit reveal clearly a drastic change in regional stress tensors affecting the area. The stress fields became extensional in the Late Miocene, in contrast to the compressional fields that existed during the deposition of the earlier units.

Introduction

The general evolution of the sedimentary basins and ranges of the central Iberian peninsula (see Chapter Cl) provides the context within which the sedimentary filling of the Madrid Basin may be easily related to the deformation of its borders (the Central System, Toledo Mountains, Iberian and Altomira Ranges). In this chapter, we describe briefly the main features of the Neogene sedimentary record of the Madrid Basin, placing emphasis on the distribution of major depositional systems and their control by the various macrostructures that were active during each period of regional deformation.