Messinian and Pre-Messinian Sediments from ODP Leg 107 Sites 652 and 654 in the Tyrrhenian Sea: Sedimentologic and Petrographic Study and Possible Comparisons with Italian Sequences

Abstract

Sedimentology, mineralogy, and petrology of the pre-Pliocene sediments drilled at ODP Sites 652 and 654 in the Tyrrhenian Sea (Leg 107) have been studied with emphasis on the lower Messinian to pre-Messinian intervals. Messinian at Site 652 is essentially turbiditic and basinal in character; it was deposited during the syn-rift phase in a strongly subsiding half-graben and is correlatable with emerged coeval sequences; in part with the Laga Formation of the foredeep of Apennines, and in part with the filling of grabens dissecting that chain in the Tyrrhenian portion of Tuscany. The sequence found in Site 654 indicates an upper Tortonian to Messinian transgression accompanying crustal stretching in the western Tyrrhenian Sea and is perfectly correlatable with the so-called "Sahelian cycle" and with "postorogenic" cycles recognized in peninsular Italy and in Sicily.

Environments and tectonic instability in central Italy (Garigliano Basin) during the late Messinian Lago–Mare episode: New data from the onshore Mondragone 1 well

“…Similar deposits have been also recovered in the central Mediterranean Basin from the ODP sites 975 (Balearic Basin, Iaccarino and Bossio, 1999), 654 (Tyrrhenian Basin, Cita et al, 1990), 652 (Borsetti et al, 1990;Robertson et al, 1990) and 974 (Tyrrhenian Basin, Iaccarino and Bossio, 1999). From the eastern Mediterranean Basin, upper Messinian Lago-Mare deposits were recorded in the DSDP sites 375 and 376 (Benson, 1978), and more recently in the ODP site 968 (Shipboard Scientific Party, 1996;Blanc-Valleron et al, 1998;Rouchy et al, 2001).…”

“…The occurrence in the Unit 4 of the ODP Site 652 of scarce A. beccarii tepida and Cyprideis sp. (Borsetti et al, 1990;Robertson et al, 1990) together with its magnetostratigraphy (Channell et al, 1990) allows to correlate the ODP Site 652 pre-Pliocene deposits with those drilled at Mondragone 1 (Fig. 6).…”

Palaeoenvironments of the Mediterranean Basin at the Messinian hypersaline/hyposaline transition: evidence from natural radioactivity and microfacies of post-evaporitic successions of the Adriatic sub-basin

“…Fine‐laminated deposits, generally barren in benthic biota, are well known from the Messinian deposits of the whole Mediterranean Basin. These types of deposits were recovered in several western Mediterranean ODP sites (Iaccarino and Bossio, 1999) and in the Tyrrhenian abyssal plain (ODP Site 652; Borsetti et al. , 1990; Cita et al.…”

“…The stratigraphy of ODP Site 652 allows for the palaeoenvironmental reconstruction of the Central Mediterranean Basin at the end of the MSC to be compared with the results presented in this paper. According to Borsetti et al. (1990) and Kastens and Mascle (1990), the pre‐Pliocene succession drilled at Site 652 belongs to the Messinian.…”

“…A conglomerate body of 10 m thickness separates an upper portion characterised by light mudstone/silt couplets containing rare brackish water forms ( Cyprideis sp. and Ammonia beccarii tepida ) from a lower portion consisting of dark shales with sand and silt interbeds and completely barren in autochthonous fossils (Borsetti et al. , 1990).…”