Search results for " ROC"
showing 10 items of 951 documents
The holocene marine record of unrest, volcanism, and hydrothermal activity of campi flegrei and somma-vesuvius
2020
Abstract This chapter illustrates the marine record of a spectrum of volcanic, hydrothermal, and sedimentary features that characterize the Latest Pleistocene–Holocene evolution of the Naples Bay offshore Campi Flegrei and Somma–Vesuvius. The work is based on review of previous literature integrated with interpretation of new high-resolution marine Digital Terrain Models (DTMs) derived from swath bathymetry surveys and high-resolution reflection seismic profiles calibrated with marine gravity core data. Seismic profiles from Pozzuoli Bay provide detailed images of the ring fault system and resurgent dome associated with the evolution of the Neapolitan Yellow Tuff (NYT) collapse caldera and …
Subsurface geometries in central sicily FTB as a premise for hydrocarbon exploration
2008
The study concerns a sector of the Maghrebian Sicilian Fold and Thrust Belt (FTB), located in central Sicily between the southern edge of the Madonie Mts. and the Caltanissetta trough. Interpretation of recently acquired seismic profiles, constrained by joint detailed stratigraphy and field investigation, revealed the structure of the study area as formed by a thick pile of deep water carbonate (Imerese and Sicanian) thrusts lying on carbonate platform imbricates. In the forward migration of the FTB, two main tectonic events were envisaged; shallow and deep seated thrusts occurred during the Miocene-early Pleistocene time interval that deformed the former sedimentary cover of the continenta…
Using high-resolution stratigraphy and structural analysis to constrain a “polyphase” tectonics in wedge-top basins. Inferences from the Late Tortoni…
2012
Abstract The present paper aims to show, both from a stratigraphic and structural points of view, the main features of a wedge-top syntectonic basin which evolved recording polyphase and non-coaxial tectonics. The study area is the Scillato Basin ( SB ), a roughly N–S-oriented structural depression located in the central-northern sector of the Sicililian Maghrebides. There, an approximately 1300 m-thick upper Serravallian to upper Tortonian succession of clastic units outcrops as a portion of the Neogene syntectonic covers of the Sicilian fold and thrust belt. Within the outcropping succession the upper Tortonian Terravecchia Fm represents the main topic of this paper. A multidisciplinary a…
Tectono-Magmatic Evolution, Age and Emplacement of the Agardagh Tes-Chem Ophiolite in Tuva, Central Asia: Crustal Growth by Island arc Accretion
2004
Publisher Summary The Agardagh Tes–Chem ophiolite in Tuva, Central Asia, is part of the Central Asian Mobile Belt which formed during subduction–accretion processes lasting from the early Neoproterozoic to the late Palaeozoic. The Agardagh Tes–Chem ophiolite marks the northwestern border of the Tuva–Mongolian Massif (TMM), which comprises several intrusive and metamorphic complexes. These complexes consist of metatonalites, gneisses, migmatites, amphibolites, marbles, quartzites, low-grade metasedimentary rocks and minor ultramafic lenses, and radiometric ages range between 536 and 464 Ma. Field observations suggest that the southwestern part of the Tes–Chem unit represents the lower to int…
Late Archaean foreland basin deposits, Belingwe greenstone belt, Zimbabwe
2001
Abstract The c. 2.65 Ga old sedimentary Cheshire Formation of the Belingwe greenstone belt (BDB), central Zimbabwe, has been studied in detail for the first time to shed some light on the much debated evolution of this classical belt. The Cheshire Formation rests sharply on a mafic volcanic unit (Zeederbergs Formation) and comprises a basal, eastward-sloping carbonate ramp sequence built of shallowing-upward, metre-scale sedimentary cycles. The cycles strongly resemble Proterozoic and Phanerozoic carbonate cycles and might have formed by small-scale eustatic sea level changes. The top of the carbonate ramp is represented by a karst surface. The carbonates are overlain by and grade laterally…
Sedimentation in a tropical, microtidal, wave-dominated coastal-plain estuary
1996
The Mono estuary is an infilled, microtidal estuary located on the wave-dominated Bight of Benin coast which is subject to very strong eastward longshore drift. The estuarine fill comprises a thick unit of lagoonal mud deposited in a ‘central basin’between upland fluvial deposits and estuary-mouth wave-tide deposits. This lagoonal fill is capped by organic-rich tidal flat mud. In addition to tidal flat mud, the superficial facies overlying the ‘central basin’fill include remnants of spits resting on transgressive/washover sand, an estuary-mouth association of beach, shoreface, flood-tidal delta and tidal inlet deposits, and a thin sheet of fluvial sediments deposited over tidal flat mud. Af…
A possible tsunami deposit around the Jurassic–Cretaceous boundary in the Boulonnais area (northern France)
2005
Abstract An unusual succession of facies locally deposited around the Jurassic–Cretaceous boundary in the Boulonnais (northern France) is attributed to a tsunami event by comparison with recent tsunami deposits. This sedimentary succession includes basal erosion with reworked lithified blocks, soft-sediment deformations, an erosional conglomerate overlain by wood fragments and clays containing continental and marine fossils in one setting and conglomerate with mixed fauna in an other setting. The tsunami probably affected the coast of the Boulonnais area of the London–Brabant Massif. The origin of the event is unknown. It was most probably triggered by an earthquake, but other origins such …
Nearshore, temperate, carbonate depositional systems (lower Tortonian, Agua Amarga Basin, southern Spain): implications for carbonate sequence strati…
1997
Abstract The bryozoan-rich lower Tortonian carbonates of the Agua Amarga Basin in southern Spain (Province of Almeria) provide an example of sediments formed in a nearshore, non-tropical depositional setting. Based on data derived from logging of sections and from field mapping, these lower Tortonian carbonates form a depositional sequence, which is subdivided into several depositional systems. A lowstand systems tract, which consists of volcaniclastic fan deltas and washover deposits, formed on the leeward side of a basement shoal which delimited the basin towards the south. A transgressive systems tract, which is characterised by a landward encroachment of deposits, is represented by subm…
Eclogites within the Menderes Massif / western Turkey
1997
Metagabbros in the core series of the Menderes Massif, for some time considered as post orogenic Miocene intrusives, revealed a strong poly-metamorphic history. The metagabbro bodies exhibit a pronounced zonation. Within their cores, igneous minerals are still preserved. Coronitic textures are interpreted as results of a high temperature, possibly granulitic overprint. The outer parts of the metagabbro bodies mostly consist of strongly to completely retrograded gamet-amphibo-lites, but occasionally contain relies of eclogites. Petrologic investigations confirmed a high pressure overprint and allowed preliminary P, T estimates (650 degrees C, equal to or greater than 1.3 GPa). The intensity …
Mesozoic tectono-sedimentary evolution of Rocca Busambra in western Sicily
2008
The Rocca Busambra ridge in western Sicily is a shallow to pelagic Meso-Cenozoic carbonate structural unit of the Sicilian fold and thrust belt with a variety of tectono-sedimentary features. Palaeofaults, unconformities (buttress unconformity, onlap, downlap), a network of neptunian dykes with several infilling generations, several large hiatuses, different facies and lateral facies changes, and erosional submarine and subaerial surfaces are observed. Detailed fieldwork and structural analyses have indicated the occurrence of fault planes with different orientations. These data, combined with facies studies and physical-stratigraphy analyses, allow for the distinction of different depositi…