Mesozoic siliciclastic mudrocks ('continental redbeds') at the base of the Stilo Unit of the northern sector of the Calabria-Peloritani Arc (southern Italy) are mainly composed of quartz, phyllosilicates (illite, illite/smectite mixed layers, kaolinite, chlorite), Fe-oxide (hematite) and feldspars. The <2 mu m grain-size fraction shows high percent of I/S mixed layers, characterized by R value ranging from R0 to R3. The Kubler Index values indicate temperatures ranging from 130 degrees C to 160 degrees C. The source areas of the studied sediments were mainly characterized by metasediments of the Paleozoic basement with plutonic bodies. The limited importance of a mafic supply is confirmed by the La/Sc, Th/Sc, Th/Co, Th/Cr and Cr/Th ratios, that suggest a provenance from source areas fairly felsic rather than basic in composition. The CIA index indicates moderate weathering in the sediment source areas. The Al-Ti-Zr diagram and the Th/Sc vs. Zr/Sc plot indicate sedimentary sorting and recycling effects for the studied sediments. Preliminary geological and compositional data of these siliciclastic deposits suggest close similarities with the well studied Mesozoic continental redbed successions of the Internal domains of the circum-Mediterranean orogenic belts.
Links between composition and provenance of Mesozoic siliciclastic sediments from western Calabria (southern Italy)
Belviso C
2011
Abstract
Mesozoic siliciclastic mudrocks ('continental redbeds') at the base of the Stilo Unit of the northern sector of the Calabria-Peloritani Arc (southern Italy) are mainly composed of quartz, phyllosilicates (illite, illite/smectite mixed layers, kaolinite, chlorite), Fe-oxide (hematite) and feldspars. The <2 mu m grain-size fraction shows high percent of I/S mixed layers, characterized by R value ranging from R0 to R3. The Kubler Index values indicate temperatures ranging from 130 degrees C to 160 degrees C. The source areas of the studied sediments were mainly characterized by metasediments of the Paleozoic basement with plutonic bodies. The limited importance of a mafic supply is confirmed by the La/Sc, Th/Sc, Th/Co, Th/Cr and Cr/Th ratios, that suggest a provenance from source areas fairly felsic rather than basic in composition. The CIA index indicates moderate weathering in the sediment source areas. The Al-Ti-Zr diagram and the Th/Sc vs. Zr/Sc plot indicate sedimentary sorting and recycling effects for the studied sediments. Preliminary geological and compositional data of these siliciclastic deposits suggest close similarities with the well studied Mesozoic continental redbed successions of the Internal domains of the circum-Mediterranean orogenic belts.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
