titoli, abstracts, parole chiave >>>
Tectonic and litho-stratigraphic controls on kaolin deposits within volcanic successions: insights from the kaoliniferous district of North-Western Sardinia (Italy)

Oggiano, Giacomo and Mameli, Paola (2012) Tectonic and litho-stratigraphic controls on kaolin deposits within volcanic successions: insights from the kaoliniferous district of North-Western Sardinia (Italy). Ore Geology Reviews, Vol. 48 , p. 151-164. eISSN 1872-7360. Article.

Full text not available from this repository.

DOI: 10.1016/j.oregeorev.2012.03.002

Abstract

In northwestern Sardinia, a Tertiary calc-alkaline volcanic succession, linked to the subduction of Insubric oceanic crust and subsequent post-collisional slab break-off, crops out and hosts several kaolindeposits. We have undertaken field and laboratory studies to establish how the Tertiary geodynamic setting of the western Mediterranean, and the composition and texture (especially porosity) of the volcanic rocks, control the geometry and quality of the deposits. Massive andesites, dacites, and mildly welded rhyodacitic ignimbrites are the precursors of the kaolin. Kaolindeposits from the andesites contain pyrite and jarosite, and the deposits which formed from the dacites contain up to 5% alunite. The amounts of pyrite and alunite are negligible in deposits which formed from ignimbrite. Fracture-controlled fluid-dominated systems (Izawa, 1986), responsible for the formation of the deposits, are linked to NNW–SSE-trending normal faults which formed during Burdigalian to Serravallian extension following on from collision between Adria and Europe (Corsica–Sardinia crust). Four types of deposit morphology (bedform, mushroom, fault parallel and funnel) are recognised, based on the attitude, fracturing, and porosity of the precursor rock. The remarkable funnel morphology was generated by repeated hydrothermal eruptions.

Item Type:Article
ID Code:7383
Status:Published
Refereed:Yes
Uncontrolled Keywords:Kaolin, tectonics, volcanic successions, Sardinia
Subjects:Area 04 - Scienze della terra > GEO/09 Georisorse minerarie e applicazioni mineralogico- petrografiche per l'ambiente ed i beni culturali
Area 04 - Scienze della terra > GEO/03 Geologia strutturale
Divisions:001 Università di Sassari > 01-a Nuovi Dipartimenti dal 2012 > Scienze della Natura e del Territorio
Publisher:Elsevier
eISSN:1872-7360
Deposited On:16 Apr 2012 09:33

I documenti depositati in UnissResearch sono protetti dalle leggi che regolano il diritto d'autore

Repository Staff Only: item control page