The Lower Miocene deposits in Gabal Gharra, Cairo – Suez District, unconformably overlies the Oli... more The Lower Miocene deposits in Gabal Gharra, Cairo – Suez District, unconformably overlies the Oligocene and Eocene deposits. They consist predominantly of regressive and transgressive mixed siliciclastic / carbonate sediments of shallow marine environments. The Lower Miocene deposits are represented lithostratigraphically by the Gharra Formation that comprises four members, from base to top: Agrud, Sadat, Hommath and Genefe members. Two measured sections were described and investigated: Gabal Gharra section and Gabal Agrud section. The coralline red algae are highly abundant in Sadat and Genefe members as fragments, crusts and rhodoliths. Larger foraminifera, corals, echinoids, bivalves, gastropods, bryozoans, benthic and planktonic foraminifers, dasyclades are also present. These two members consist of dolomitized bioclastic packstone, grainstone to floastones / rudstone with rhodoliths (up to 3cm in size). The systematic study led to the recognition of 14 coralline algal species. ...
An integrated biostratigraphical analysis based on the planktonic and larger foraminifera from tw... more An integrated biostratigraphical analysis based on the planktonic and larger foraminifera from two surface sections in the area between Gabal Zeita and Bir Haleifiya, West-Central Sinai region, Egypt, namely, Gabal Zeita and Bir El Haleifiya sections, provides a well-defined zonal scheme of the Miocene successions in the study area. Lithostrtigraphically, the Miocene sequence could be differentiated into four rock units representing shallow and deep marine facies. These are from base to top as follows: Nukhul, Rudeis, Kareem formations (Gharandal Group) and Belayim formation (Ras Malaab Group). The examination of the studied samples has led to the identification of forty four planktonic foraminiferal species belonging to twelve genera. The preserved planktonic foraminifers through the studied sections range from good to moderately well diversified enabled biostratigraphic zonation of the Miocene sequence. On the basis of the vertical stratigraphic distribution of the planktonic foraminiferal species, the studied sections could be subdivided into six planktonic foraminiferal biozones following the Mediterranean (MMi) zonal schemes, from base to top as follows: (1) Globigerinoides primordius Zone (MMi 1) (Early Miocene, Aquitanian), (2) Globigerinoides altiaperturus / Catapsydrax dissimilis Zone (MMi 2b), (3) Globigerinoides trilobus Zone (MMi 3) (Early Miocene, Burdigalian) (4) Praeorbulina glomerosa s.l. Zone (MMi 4) and (5) Orbulina suturalis / Globoratalia fohsi peripheroronda Zone (MMi 5) of (Middle Miocene, Langhian / Serravallian). The Lower / Middle Miocene boundary is defined by the first occurrence (FO) of Praeorbulina glomerosa and is discussed. Two larger foraminiferal zones were recognized in the studied successions from base to top, SB 24 Zone in the Aquitanian and SB 25 Zone in the Burdigalian, according to the European Shallow Benthic Foraminiferal Zonation (SBZ). By integrating the established foraminiferal zonal schemes, the stratigraphical ranges of some larger foraminifera with planktonic foraminiferal zones have been calibrated. Two chronostratigraphic units are detected. The older one is represented by the Early a Miocene and the overlying one is Middle Miocene unit.
The Early Miocene Qom Formation is exposed in Wadi Bagh, Qom area, northern Isfahan, Central Iran... more The Early Miocene Qom Formation is exposed in Wadi Bagh, Qom area, northern Isfahan, Central Iran, where it unconformably overlies the Early Oligocene Lower Red Formation and unconformably underlies the Middle Miocene Upper Red Formation. It is represented mainly by mixed carbonate /siliciclastic deposits. The present paper examines the coralline algal assemblage from the coralline limestone beds of this formation. The systematic studies and taxonomic investigations led to the recognition of fifteen coralline algal species belonging mainly to Rhodophyta (Corallinaceae). Six non-geniculate coralline algal genera belonging mainly to subfamilies Mastrophoroideae, Lithophylloideae and Melobesioideae, are recognized. The geniculated coralline algae (Subfamily Corallinoideae) are relatively scarce and represented by a single genus Corallina sp. The study showed also that Lithophylloids (Lithophyllum) and Melobesioids (Mesophyllum and Lithothamnion) are more dominant coralline algal species than Mastophoroids (Neogonilithon and Spongites) Mastophoroids and lithophylloids characterize the shallow marine water, whereas the melobesioids and the sporolithacean Sporolithon are dominant in deeper-water settings. The recorded coralline red algae are characterized by encrusting, warty, lumpy and fruticose growth morphologies. Two associations of coralline algal assemblages can be distinguished, a Lithophyllum-dominated association and Mesophyllum-dominated association: The first indicating shallow water, high-energy conditions and is developed in the upper part of the section, while the other one suggesting deposition in low-energy conditions characteristic of the lower part of the succession.
The Lower Miocene deposits in Gabal Gharra, Cairo – Suez District, unconformably overlies the Oli... more The Lower Miocene deposits in Gabal Gharra, Cairo – Suez District, unconformably overlies the Oligocene and Eocene deposits. They consist predominantly of regressive and transgressive mixed siliciclastic / carbonate sediments of shallow marine environments. The Lower Miocene deposits are represented lithostratigraphically by the Gharra Formation that comprises four members, from base to top: Agrud, Sadat, Hommath and Genefe members. Two measured sections were described and investigated: Gabal Gharra section and Gabal Agrud section. The coralline red algae are highly abundant in Sadat and Genefe members as fragments, crusts and rhodoliths. Larger foraminifera, corals, echinoids, bivalves, gastropods, bryozoans, benthic and planktonic foraminifers, dasyclades are also present. These two members consist of dolomitized bioclastic packstone, grainstone to floastones / rudstone with rhodoliths (up to 3cm in size). The systematic study led to the recognition of 14 coralline algal species. ...
An integrated biostratigraphical analysis based on the planktonic and larger foraminifera from tw... more An integrated biostratigraphical analysis based on the planktonic and larger foraminifera from two surface sections in the area between Gabal Zeita and Bir Haleifiya, West-Central Sinai region, Egypt, namely, Gabal Zeita and Bir El Haleifiya sections, provides a well-defined zonal scheme of the Miocene successions in the study area. Lithostrtigraphically, the Miocene sequence could be differentiated into four rock units representing shallow and deep marine facies. These are from base to top as follows: Nukhul, Rudeis, Kareem formations (Gharandal Group) and Belayim formation (Ras Malaab Group). The examination of the studied samples has led to the identification of forty four planktonic foraminiferal species belonging to twelve genera. The preserved planktonic foraminifers through the studied sections range from good to moderately well diversified enabled biostratigraphic zonation of the Miocene sequence. On the basis of the vertical stratigraphic distribution of the planktonic foraminiferal species, the studied sections could be subdivided into six planktonic foraminiferal biozones following the Mediterranean (MMi) zonal schemes, from base to top as follows: (1) Globigerinoides primordius Zone (MMi 1) (Early Miocene, Aquitanian), (2) Globigerinoides altiaperturus / Catapsydrax dissimilis Zone (MMi 2b), (3) Globigerinoides trilobus Zone (MMi 3) (Early Miocene, Burdigalian) (4) Praeorbulina glomerosa s.l. Zone (MMi 4) and (5) Orbulina suturalis / Globoratalia fohsi peripheroronda Zone (MMi 5) of (Middle Miocene, Langhian / Serravallian). The Lower / Middle Miocene boundary is defined by the first occurrence (FO) of Praeorbulina glomerosa and is discussed. Two larger foraminiferal zones were recognized in the studied successions from base to top, SB 24 Zone in the Aquitanian and SB 25 Zone in the Burdigalian, according to the European Shallow Benthic Foraminiferal Zonation (SBZ). By integrating the established foraminiferal zonal schemes, the stratigraphical ranges of some larger foraminifera with planktonic foraminiferal zones have been calibrated. Two chronostratigraphic units are detected. The older one is represented by the Early a Miocene and the overlying one is Middle Miocene unit.
The Early Miocene Qom Formation is exposed in Wadi Bagh, Qom area, northern Isfahan, Central Iran... more The Early Miocene Qom Formation is exposed in Wadi Bagh, Qom area, northern Isfahan, Central Iran, where it unconformably overlies the Early Oligocene Lower Red Formation and unconformably underlies the Middle Miocene Upper Red Formation. It is represented mainly by mixed carbonate /siliciclastic deposits. The present paper examines the coralline algal assemblage from the coralline limestone beds of this formation. The systematic studies and taxonomic investigations led to the recognition of fifteen coralline algal species belonging mainly to Rhodophyta (Corallinaceae). Six non-geniculate coralline algal genera belonging mainly to subfamilies Mastrophoroideae, Lithophylloideae and Melobesioideae, are recognized. The geniculated coralline algae (Subfamily Corallinoideae) are relatively scarce and represented by a single genus Corallina sp. The study showed also that Lithophylloids (Lithophyllum) and Melobesioids (Mesophyllum and Lithothamnion) are more dominant coralline algal species than Mastophoroids (Neogonilithon and Spongites) Mastophoroids and lithophylloids characterize the shallow marine water, whereas the melobesioids and the sporolithacean Sporolithon are dominant in deeper-water settings. The recorded coralline red algae are characterized by encrusting, warty, lumpy and fruticose growth morphologies. Two associations of coralline algal assemblages can be distinguished, a Lithophyllum-dominated association and Mesophyllum-dominated association: The first indicating shallow water, high-energy conditions and is developed in the upper part of the section, while the other one suggesting deposition in low-energy conditions characteristic of the lower part of the succession.
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