Several phosphatic limestone bea ring loca lit ies occ ur withi n the Irminio Memb er (Ragusa Forma tion) of the western Hyblean region of southeast Sicily. In a reas of maximum development, suc h as a round Sampieri and Mod ica , the phosphatized, intraclast-dominated dep osits attai n a thickness of up to 0.6 m and a re associated with a phosphatized underlying hardground . Th in and possibly discon t in uo us spreads of phosphatized int raclasts form a broad er zone beyond the central semi-autochtho no us zone. Microfossil analys is of associa te d st rata demonstrates that all occ urre nces of phosphatized st ra ta withi n the Irmin io Member are restricted to a single level of probab le La te Burdigalian (Ear ly Miocen e) age. Th e bed corre la tes well both biostratigrap hica lly and lithologj cally with the "Upper Main Phosphor ite Cong lomerate Bed" of the Maltese Islands, which lie c.95 km south of the Sici lia n pr ovince. Five more distinct phosphorite beds occ ur in the Maltese Islands, being best developed in the western and northern parts of the islands. Th ey ra nge in age from Aquitanian to Late Burdig alian. Th ese are pri ncipa lly francoli te r epl aced micr ite cong lomerates whi ch may be asso ciated with ph osphatized underlyin g hardg rounds in places. A major central Mediterra nea n phosphatogeni c pr ovin ce of Ea rly Miocen e age is postula ted in ord er to account for the simultaneous occ urre nce of phospho r ites in Sicily and Mal ta.
|Titolo:||The distribution and palaeoenvironment of Early Miocene phosphorites of SE Sicily and their relationship with the Maltese phosphorites.|
|Data di pubblicazione:||1987|
|Appare nelle tipologie:||1.1 Articolo in rivista|