RT Journal Article
T1 Influence of granitoid textural parameters on sediment composition: Implications forsediment generation
A1 Caracciolo, Luca
A1 Tolosana Delgado, Raimon
A1 Le Pera, Emilia
A1 Eynatten, Hilmar von
A1 Arribas Mocoroa, José
A1 Tarquini, Simone
AB The aim of this study is to determine and characterise the control exerted by parent rock texture on sandcomposition as a function of grain size. The sands investigated were generated from granitoid parent rocksby the Rhone, Damma and Sidelen glaciers, which drain the Aar Massif in the Central Alps (Switzerland),and were deposited in glacial and fluvio-glacial settings. Mechanical erosion, comminution (crystal breakdownand abrasion) and hydraulic sorting are the most important processes controlling the generation ofsediments in this environment, whereas chemical and/or biochemical weathering plays a negligible role.By using a GIS-based Microscopic Information System (MIS), five samples from the glacier-drained portionsof the Aar basement have been analysed to determine textural parameters such as modal composition, crystalsize distribution and mineral interfaces (types and lengths). Petrographic data of analysed sands includetraditional point counts (Gazzi-Dickinson method, minimum of 300 points) as well as textural counts todetermine interface types, frequency, and polycrystallinity in phaneritic rock fragments. According toPettijohn's classification, grain‐size dependent compositions vary from feldspathic litharenite (0φ fraction)via lithic arkose (1φ and 2φ) to arkose (3φ and 4φ). Compositional differences among our data set were comparedto modern plutoniclastic sands from the Iberian Massif (Spain) and the St. Gabriel Mts. (California,USA), which allowed us to assess the role exerted by glaciers in generating sediments. By combining datafrom the MIS with those from petrographic analysis, we outlined the evolution of mineral interfaces fromthe parent rocks to the sediments.
PB Elsevier
SN 0037-0738
YR 2012
FD 2012
LK https://hdl.handle.net/20.500.14352/42524
UL https://hdl.handle.net/20.500.14352/42524
LA eng
DS Docta Complutense
RD 9 abr 2025