Magmatism and structure
The Carboneras Fault Zone (CFZ) of SE Spain separates the volcanic Cabo de Gata terrain to the SE (accumulated over 18 to 6 Ma BP) from the tract of uplifted Alpine metamorphic basement blocks and post-orogenic basins that comprise the Betic Cordilleras to the NW. The CFZ cuts metamorphic basement and folded post-orogenic sediments and volcanic rocks, and acted as a conduit for upper Miocene calc-alkaline volcanic rocks to the surface. NW of the CFZ, unconformities and deformation episodes affect successive sedimentary formations of upper Miocene age (upper Serravallian through Messinian). CFZ movements are constrained stratigraphically by an unconformity within the volcanic sequence. Older, pre-faulting volcanic rocks are uptilted against the CFZ whilst the youngest volcanic rocks step across it. 40Ar–39Ar age determinations on amphibole crysts from the volcanic rocks show the main CFZ movements began 11–12 Ma BP and ended about 6 Ma. Lesser movement rates continue today. The CFZ is interpreted as part of a transform fault system separating NE–SW stretched and NW–SE shortened crust deformed above a southwestward-retreating subducted slab, from a less deformed terrain lying to the SE. Locally, total offset on the CFZ may be up to 40 km but is at least 15 km.
Figures & Tables
Deformation Structures and Processes within the Continental Crust
This volume presents a selection of papers showing the current focus of studies of deformation structures and processes within the continental crust. The selected contributions use a large range of analytical techniques suited to the full range of structure sizes and fine-tuned to the physical process that controls the deformation, from the grain boundary at the micro-scale, the lithological contact at the meso-scale to the plate boundary at the global scale.
The papers in the volume are grouped into three sections relating to specific lines of research within the analysis of rock deformation structures and processes, in particular in respect to the continental crust: structures within shear zones and faults; magmatic structures, and microstructures and rheology. These sections include papers describing field studies, experimental rock deformation and numerical modelling of deformation processes.