Ice-sheet and sea-level fluctuations during the Early and Middle Pleistocene are as yet poorly understood. A stalactite from a karst cave in North West Sicily (Italy) provides the first evidence of four marine inundations that correspond to relative sea-level (RSL) highstands at the time of the Middle Pleistocene Transition. The speleothem is located ~ 97 m above mean sea level (msl) as result of Quaternary uplift. Its section reveals three marine hiatuses and a coral overgrowth that fixes the age of the fourth and final marine ingression at 1.124 ± 0.2 million years ago, thus making this speleothem the oldest stalactite with marine hiatuses ever studied to date. Scleractinian coral species witness lightlimited conditions and water depth of 20-50 m. Integrating the coral-constrained depth with the geologically constrained uplift rate and an ensemble of RSL scenarios, we find that the age of the last marine ingression most likely coincides with Marine Isotope Stage 35 on the basis of a probabilistic assessment. Our findings are consistent with a significant Antarctic ice-sheet retreat.

An Early Pleistocene benthic community, discovered inside the Rumena Cave in NW Sicily, Italy, was studied. Analysis of the community led to the recognition of several encrusting species – notably scleractinians, bryozoans, serpuloideans, cirripeds, foraminifera and brachiopods – and borings mostly referable to the ichnogenus Gastrochaenolites. All fossils detected are typical of the present‐day hard‐surface submarine cave biota, at both high taxonomic rank and species level. The biogenic crust, restricted to a few sectors of the cave but locally up to few centimetres thick, largely consist of scleractinians, mainly represented by dendrophylliids. Bryozoans and serpuloideans are also present with Hippaliosina depressa and Spiraserpula massiliensis, locally forming multi‐layered sheets and dense specimen aggregates, respectively. Basing mostly on the composition of the encrusting community and on morphological/morphometric features of some species, it has been hypothesized that at least part of the cave was blind when the crust formed, possibly at relatively shallow depth in a sheltered setting or, more probably, at higher depths, below the fair weather swell zone. Encrustations and borings on the rocky cave ceiling and on occasional speleothems broken surfaces document subsequent phases of cave submersion/colonization separated by emersion/erosion phases. The importance of the Early Pleistocene fossils of the Rumena Cave for the knowledge of submarine cave communities through time and for the understanding of sea‐level variations and the uplift of the area has been remarked.

censke jame tipa flank margin pri Custonaci (Trapani, SZ Sicilija) in spreminjanje morske gladine Za polotok San Vito Lo Capo 50 km zahodno od Palerma so značilne številne sledi preteklega spreminjanja morske gladine: morske terase, niše, morske in obalne jame s freatičnimi prerastki na sigi ter kopenski in morski sedimenti. Na osnovi izjemno ohranjenih oblik in sedimentov, so v preteklosti različni avtorji določili spreminjanje morskega nivoja in neotektonske premike. Med številnimi obravnavanimi jamami jih je večina morskega izvora, z ohranjenimi nišami in morskimi oz. kopenskimi sedimenti. Dve jami, Fantasma in Falesia Rocca Rumena I, pa kažeta značilnosti jam tipa flank margin. Obe jami imata sledove dviganja in spuščanja morske gladine. Njun položaj, z ozirom na morske terase, kaže na starost med 0,8 in 1,1-1,2 Ma. Naša študija pokaže, da v stratigrafskem in geomorfološkem zapisu niso ohranjeni vsi visoki nivoji morske gladine. Ključne besede: telogenetski apnenec, obalni kras,speleogeneza v območju mešanja, spremembe morske gladine, kvartar.

No abstract

No abstract