Naslov
Eocene clastics of the Rab island - Lopar peninsula, Rab
(Eocene clastics of the Rab island - Lopar peninsula, Rab)

Autori
Marjanac, Tihomir ; Marjanac, Ljerka

Izvornik
Harold Readinǵs IAS Lecture Tour ́99 - Field-trip guidebook: Some Carbonate and Clastic Successions

Vrsta, podvrsta
Ostale vrste radova, ostali članci/prilozi

Godina
1999

Ključne riječi
Eocene; clastics; sequence stratigraphy;

Sažetak
The Lopar-Sandstones on the Island of Rab are unique in the Eastern Adriatic realm by their silicic composition and shallow-marine origine. The sediment succession documents several episodes of sea level rise and fall, so we can distinguish transgressive and regressive intervals. Sandstones which build sandstone bodies were deposited by currents and we interpret them as sandwaves or complex dunes which have been deposited in an outer estuary setting. The provenance of sand was outside the present Dinaric range, probably in the Alps. Sandstones that occur as sheet-like bodies, composed of numerous storm beds, are interpreted in terms of a shoreface deposit, that was incised by the base of sandstone bodies. The shoreface sandstones document facies progradation by gradual increase of thickness of individual beds and reduction of the number of marl interbeds. In those cases where thick shoreface sandstones overlie offshore marls, and their base is sharp and marked by thick tempestites, we have interpreted the forced regression. Sandy marls were deposited in a lower shoreface where relicts of storm sandstones are preserved, or offshore where the sand was admixed by a pervasive bioturbation. Succession of offshore sediments and overlying shoreface is interpreted as a regressive interval, whereas succession of estuarine sandstones and offshore sediments is interpreted as a transgressive interval. Both are parts of complete depositional sequences. Frequent oscillations in sea level forced basinward and landward shifts of facies, so we believe the depositional environment was a paralic sea where a succession of incised valleys was formed during relative sea-level falls.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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