Selandian-Thanetian larger foraminifera from the lower Jafnayn Formation in the Sayq area (eastern Oman Mountains)

The larger foraminifera of the lower part of the Jafnayn Formation outcropping in the Wadi Sayq, in the Paleocene series of the eastern Oman Mountains, have been studied and described in detail. The analysis have allowed us to develop a detailed systematic description of each taxa, constraining their biostratigraphic distribution and defining the associated foraminifera assemblages. The taxonomic study has permitted us to identify each morphotype precisely and describe three new taxa, namely, Ercumentina sayqensis n. gen. n. sp. Lacazinella rogeri n. sp. and Globoreticulinidae new family. The first assemblage is characterized by the presence of Coskinon sp., Dictyoconus cf. turriculus Hottinger and Drobne, Anatoliella ozalpiensis Sirel, Ercumentina sayqensis n. gen. n. sp. Serra-Kiel and Vicedo , Lacazinella rogeri n. sp. Serra-Kiel and Vicedo, Mandanella cf. flabelliformis Rahaghi, Azzarolina daviesi (Henson), Lockhartia retiata Sander, Dictyokathina simplex Smout and Miscellanites globularis (Rahaghi). The second assemblage is constituted by the forms Pseudofallotella persica (Hottinger and Drobne), Dictyoconus cf. turriculus Hottinger and Drobne, Lacazinella rogeri n. sp. Serra-Kiel and Vicedo, Azzarolina daviesi (Henson), Keramosphera? cf. iranica Rahaghi, Lockhartia haimei (Davies), Lockhartia retiata Sander, Sakesaria trichilata Sander, Kathina delseota Smout, Elazigina harabekayisensis Sirel, Daviesina khatiyahi Smout, and Miscellanea juliettae Leppig. The first assemblage can be considered to belong to the Shallow Bentic Zone SBZ2 (early Selandian age), and the second assemblage to the SBZ3 (late Selandian-early Thanetian age).This paper shows, for the first time in the Middle East area, a correlation between the Selandian larger foraminifera and planktonic foraminifera biozones

Forward seismic modeling as a guide improving detailed seismic interpretation of deltaic systems: Example of the Eocene Sobrarbe delta outcrop (South-Pyrenean foreland basin, Spain), as a reference to the analogous subsurface Albian Cenomanian Torok-Nanushuk Delta of the Colville Basin (NPRA, USA)

A forward seismic model of the Middle Eocene Sobrarbe delta outcrop (South-Pyrenees, Spain) has been made to investigate its seismic signature. The Sobrarbe delta complex corresponds to a syntectonic sedimentary wedge locally thicker than 1000 m. This 15 km-long, highly-progradational and moderately aggradational sedimentary system presents sigmoid and oblique clinoforms, characterized by slopes ranging from 0.2° to 5.7°. Along the clinoforms, the classical deltaic depositional environments grade progressively from one to the other: alluvial plain, delta plain, delta front and prodelta. Locally, specific carbonate deposits occur, corresponding to transgressive pulses. The transition from delta front to prodelta is locally marked by large slide scars affecting clinoform morphology. A detailed outcrop transect of the Sobrarbe delta was converted to an acoustic impedance model by assigning petrophysical properties to each geological facies. This model was then used to create synthetic seismic lines characterized by various input wavelets. The resulting various peak frequency synthetic seismic lines have been interpreted, and the seismic interpretation compared to the outcrop description to calibrate the seismic interpretation and assess the 'limits' of that interpretation. This work shows that the 'seismic stratigraphy' methodology is consistent and allows the correct interpretation of most seismic sequences. However, composite reflections from rapid lateral facies transitions and higher-frequency sequence boundaries can clearly lead to seismic interpretation mistakes. The seismic facies of seven facies associations have been described, providing guidelines to recognize them on actual seismic lines. The synthetic seismic image of four selected systems tracts comprising good reservoir bodies has been analyzed to highlight recognition criteria which can be used to interpret analog deltaic systems in the subsurface, and therefore enhance the prediction and characterization of the reservoir bodies that they hold. These guidelines were systematically applied to a direct subsurface analog: the Torok-Nanushuk Delta (Colville Basin, NPRA, USA)

Selandian-Thanetian larger foraminifera from the lower Jafnayn Formation in the Sayq area (eastern Oman Mountains)

The larger foraminifera of the lower part of the Jafnayn Formation outcropping in the Wadi Sayq, in the Paleocene series of the eastern Oman Mountains, have been studied and described in detail. The analysis have allowed us to develop a detailed systematic description of each taxa, constraining their biostratigraphic distribution and defining the associated foraminifera assemblages. The taxonomic study has permitted us to identify each morphotype precisely and describe three new taxa, namely,Ercumentina sayqensis n. gen. n. sp. Lacazinella rogeri n. sp. and Globoreticulinidae new family. The first assemblage is characterized by the presence of Coskinon sp., Dictyoconus cf. turriculus Hottinger and Drobne, Anatoliella ozalpiensis Sirel, Ercumentina sayqensis n. gen. n. sp. Serra-Kiel and Vicedo ,Lacazinella rogeri n. sp. Serra-Kiel and Vicedo, Mandanella cf. flabelliformis Rahaghi, Azzarolina daviesi(Henson), Lockhartia retiata Sander, Dictyokathina simplex Smout and Miscellanites globularis(Rahaghi). The second assemblage is constituted by the forms Pseudofallotella persica (Hottinger and Drobne), Dictyoconus cf. turriculus Hottinger and Drobne, Lacazinella rogeri n. sp. Serra-Kiel and Vicedo, Azzarolina daviesi (Henson), Keramosphera? cf. iranica Rahaghi, Lockhartia haimei (Davies), Lockhartia retiata Sander, Sakesaria trichilata Sander, Kathina delseota Smout, Elazigina harabekayisensis Sirel, Daviesina khatiyahi Smout, and Miscellanea juliettae Leppig. The first assemblage can be considered to belong to the Shallow Bentic Zone SBZ2 (early Selandian age), and the second assemblage to the SBZ3 (late Selandian-early Thanetian age).This paper shows, for the first time in the Middle East area, a correlation between the Selandian larger foraminifera and planktonic foraminifera biozones