The Recycled Orogenic Sand Provenance from an Uplifted Thrust Belt, Betic Cordillera, Southern Spain

The Betic Cordillera of southern Spain represents an uplifted fold–thrust belt. Source rock types of the Betic Cordillera metamorphic (mainly phyllite, schist, quartzite, and ), sedimentary (siliciclastic and carbonate), volcanic (felsic to intermediate ), and mantle-derived (peridotite, gabbro, serpentinite, serpentine schist) rocks. The fluvial systems range that transect Betic Cordillera are the major detrital source of sediment the southern Spanish coast, supplying sand to beaches and offshore systems in the Alboran Sea basin. key sand petrofacies derived from the Betic mountain belt the main clastic contribution of known source rocks. All the are quartzolithic, ranging from quartz-rich to lithic-rich. systems draining the Sierra de Los Filabres, the Sierra Nevada, Sierra de Gador, and the Ma´laga Mountains, and their related constitute a metamorphic–sedimenticlastic quartzolithic petrofacies (Qm34610 F463 Lt6269; Lm72614 Lv264 26613), derived dominantly from the Nevado–Fila´bride, Alpuja´rride, Mala´guide complexes. This quartzolithic petrofacies extends northeast of Almeria to Torremolinos (southwest of Ma´laga), and of Algeciras. Only one beach sand sample, east of Cabo de , is volcanolithic. Volcanic detritus (mainly having felsitic textures) derived from Miocene (15–7 Ma) pyroclastic sequences cropping out the southeast of the chain. metamorphic–sedimenticlastic quartzolithic petrofacies in the coastal stretch from Torremolinos to Marbella, drainage systems cut across the Serrania de Ronda. Here rock types include peridotite, gabbro, and serpentinite of the Peridotite Massif, and metamorphic rocks of the Ma´laguide Alpuja´rride units. The fluvial and beach sands of this area are (Qm32612 F1063 Lt58611), and include abundant and serpentinite grains. The latter quartzolithic petrofacies abruptly from Algeciras to Ca´diz, where the sand quartz-rich (Qm7765 F462 Lt1964). This sand petrofacies derived predominantly from recycling of sedimentary sequences, the quartzarenite turbidite units of the Gibraltar (the Algeciras Flysch). This petrofacies is characterized by proportion of quartz grains and abundant sedimentary lithic (Lm163 Lv161 Ls9863). three onshore petrofacies plot in the recycled-orogen provenance field and the lithic to transitional to quartzose subfields of Dickinson (1985). They vary from lithic, to transitional quartzose depending on their source lithologies in the Betic fold–thrust belt. These actualistic petrofacies best describe the and distribution of sand petrofacies derived from a collisional –thrust belt where primary and recycled source rocks are interfingered. -marine turbidites of the Alboran Basin have basinwide sands having close compositional relations with Betic onshore sand petrofacies. Comparison of detrital modes mainland to deep-marine environments provides a suitable for interpreting the Miocene to Pleistocene sand dispersal history the Alboran Basin. These modern quartzolithic petrofacies used to interpret analogous ancient collisional sandstone petrofacies the Alpine orogenic belt of the western-central Mediterranean and of other collisional orogenic systems, as a broader of view.