RT Journal Article
T1 The effects of source rocks and chemical weatheringon the petrogenesis of siliciclastic sand from the Neto River(Calabria, Italy): implications for provenance studies
A1 Le Pera, Emilia
A1 Arribas Mocoroa, José
A1 Critelli, Salvatore
A1 Tortosa, A.
AB Plutonic and gneissic rocks of the Sila Massif in the uppermost portion of theNeto drainage basin (Calabria, Southern Italy) weather and erode under ahumid Mediterranean climate. During the development of weathering pro®les,a combination of chemical weathering and granular disintegration processesoccurred. Chemical weathering involves a loss of both plagioclase (mainlyduring grus generation) and K-feldspar (mainly during soil formation). Thisloss is attributed to transformation of plagioclase to clay minerals and toleaching and dissolution of K-feldspar. Sand composition is quartzofeldspathicand nearly homogeneous along the main channel of the Neto River, even wherethe river cuts across a blanket of sedimentary cover. Thus, ¯uvial transportdoes not alter sand composition within the Neto drainage basin. Petrographicindices are effective in (1) discriminating between contributions from similar(granite and gneiss) source rocks (Qm/F); (2) relating the provenance ofplutoniclastic and gneissiclastic sand found in the headwaters to grus horizons(Qm/F; Q/Rg); and (3) distinguishing between upstream ®rst-cycle anddownstream multicycle sand (Q/Rg). This last distinction is furtheremphasized by considering both aphanitic and phaneritic varieties of rockfragments (RgRmRs diagram). Chemical weathering is the main sand producerwithin the regolithic environment in northern Calabria. In addition, rapiderosion resulting from steep slopes removes weathered products, and rapid andshort transport leads to minimal sediment maturation. In general, the F/Qindex is climate and relief dependent; thus, it should be used in conjunctionwith palaeoclimatic and palaeophysiographic evidence for provenanceinterpretations of ancient quartzofeldspathic sandstones.
PB Blackwell Publishing Ltd
SN 0037-0746
YR 2001
FD 2001
LK https://hdl.handle.net/20.500.14352/59248
UL https://hdl.handle.net/20.500.14352/59248
LA eng
DS Docta Complutense
RD 21 sept 2024