No abstract

The Late Cretaceous fill of the Oman Mountains foredeep is subdivided into four sub-sequences using seismic stratigraphic principles based on seismic, well and outcrop data. Sub-sequence FD-a (Late Coniacian to Early Santonian) was overriden by the Hawasina allochthon on the sea bed of the foredeep. FD-b (Early to Late Santonian) was deposited during thrusting and slices of foredeep sediment were tectonically accreted onto the allochthon during the final stages of thrusting. FD-c and FD-d (Late Santonian to Late Coniacian) were deposited after the emplacement of the allochthon into the foredeep. Subsidence curves for the foredeep area show that an emergent peripheral bulge bounded the cratonic side of the foredeep throughout the Late Cretaceous. There is no evidence that the forebulge migrated with time ahead of the advancing Hawasina thrust sheets. Instead the bulge remained in situ while the basin narrowed during thrusting. During the Maastrichtian, after infill of the foredeep, the Oman Mountains area subsided beneath sea level. Clastic supply from the drowned hinterland ceased and carbonate deposition followed. The main Oman Mountain building episode was during the Late Miocene when continent-continent collision occurred in the Zagros Mountains.

No abstract

No abstract

Blueschists in Corsica represent a continuation of the internal Alpine PenninicZone schistes lustrés nappe, metamorphosed during the Eoalpine (late Cretaceous) collision of a Tethyan subduction complex with the European continental plate. Although extremely complex, the Corsican schistes lustrés preserve some semblance of a coherent stratigraphy and have been divided into several units, the most important of which are the Castagniccia, Inzecca, and Santo Pietro Groups. The metasedimentary and ophiolitic rocks associated with the Inzecca and Castagniccia Groups have been correlated with similar Liguro-Piemontais units in the Western Alps and interpreted as representing Tethyan oceanic basement and cover. The nature of the basement to the Santo Pietro Group is, however, more controversial and could be oceanic, continental or both.The Corsican blueschists have suffered syn-metamorphic polyphase folding and thrusting, generally externally (WNW) directed, although SSW-directed nappe displacement has been described in western Cap Corse. The onset of high-pressure metamorphism is at least mid-Cretaceous in age, but a spread of younger radiometric dates has led authors to suggest that blueschist metamorphism has continued through the late Cretaceous and even into the Eocene, when the Adria microplate collided with Corsica. The highest metamorphic grades are recorded by undated eclogite relics which are overprinted by a pervasive blueschist metamorphism. The highest blueschist pressures are recorded along the eastern margin of Alpine Corsica. A later phase of (late Eocene?) SE-verging folding and backthrusting occurred under greenschist facies conditions. Late (post-Miocene) upright folding about N-S axes has greatly influenced the present outcrop pattern.Most recent work on these blueschists has concentrated on Cap Corse in NE Corsica where several nappes have been identified. Two of these, the Ersa-Centuri and Farinole Nappes, have been correlated with Austro-Alpine basement, with the Ersa-Centuri nappe being emplaced from the west. Various tectonic models have attempted to refine the 'Eoalpine obduction' model, but there remains considerable disagreement over the timing of individual tectonometamorphic events. There is as yet no record of blue-