scholarly journals Middle Miocene Paleoceanography of the Niigata oil field, northern Japan, based on calcareous nannofossils

2021 ◽  
Vol 127 (10) ◽  
pp. 621-633
Author(s):  
Tokiyuki Sato ◽  
Ryo Kato ◽  
Shun Chiyonobu
Keyword(s):  
Middle Miocene ◽  
Oil Field ◽  
Calcareous Nannofossils ◽  
Northern Japan

Lower and Middle Miocene biostratigraphy, Gulf of Suez, Egypt based on dinoflagellate cysts and calcareous nannofossils

Palynology ◽  
2012 ◽  
Vol 36 (1) ◽  
pp. 38-79 ◽  
Author(s):  
Ali Soliman ◽  
Stjepan Ćorić ◽  
Martin J. Head ◽  
Werner E. Piller ◽  
Salah Y. El Beialy
Keyword(s):  
Middle Miocene ◽  
Gulf Of Suez ◽  
Calcareous Nannofossils ◽  
Dinoflagellate Cysts

Middle Miocene planktonic microfossils and lower bathyal foraminifera from offshore southern California

1986 ◽  
Vol 60 (2) ◽  
pp. 249-267
Author(s):  
Ted F. W. Bergen ◽  
Joanne Sblendorio-Levy ◽  
John T. Twining ◽  
Richard E. Casey
Keyword(s):  
New Species ◽  
New Taxa ◽  
Benthic Foraminifera ◽  
Southern California ◽  
Middle Miocene ◽  
Calcareous Nannofossils ◽  
Calcareous Nannofossil ◽  
New Subspecies ◽  
Submarine Ridge ◽  
Age Range

Lower bathyal sediments representing portions of the Luisian and Mohnian stages of Kleinpell (1938) occur on a submarine ridge near Tanner Bank, offshore southern California. The presence of abundant and well-preserved calcareous nannofossils, diatoms, silicoflagellates, radiolarians and foraminifera allows accurate correlations with the onshore type sections of these stages. In terms of the calcareous nannofossil zones, the age range is from the Sphenolithus heteromorphus Zone to the Discoaster kugleri Zone. Although abundant benthic foraminifera indicative of the Luisian and Mohnian are present, they are accompanied by species more characteristic of the Pliocene Repettian Stage of Natland (1952) and the Pliocene-Miocene “Delmontian” Stage of Kleinpell (1938). Many of these latter species live today at lower bathyal depths (below 2,000 m), others occur in lower bathyal sediments as old as Oligocene, but are absent in the onshore type sections of the Luisian and Mohnian stages in coastal California. We ascribe their absence in onshore sequences to deposition at middle bathyal depths. The known chronostratigraphic ranges of several species are extended and five new species and two new subspecies of benthic foraminifera are described.The following new taxa are described: Bolivina pelita n. sp., Cassidulinella inflata n. sp., Globocassidulina undulata n. sp., Cibicidoides mckannai miocenicus n. subsp., C. mckannai sigmosuturalis n. subsp., Pullenia fragilis n. sp., Parafissurina inornata n. sp.

Calcareous nannofossils from Mid-Atlantic basement rocks of DSDP Leg37

1977 ◽  
Vol 14 (4) ◽  
pp. 707-715 ◽  
Author(s):  
Robert C. Howe ◽  
C. Howard Ellis
Keyword(s):  
Deep Sea ◽  
Middle Miocene ◽  
Calcareous Nannofossils ◽  
Early Pliocene ◽  
Basement Rocks ◽  
Late Middle Miocene ◽  
Mid Atlantic Ridge ◽  
Age Limits ◽  
Early Late ◽  
Drilling Project

During Leg 37, Deep Sea Drilling Project, several holes were drilled on the northwest flank of the Mid-Atlantic Ridge. Calcareous nannofossils can be used to define age limits for the upper portion of basement rocks at sites 332 and 334. Nannofossil oozes recovered from immediately above basement basalts in holes 332A and 332B are of early Late or late Early Pliocene age (Discoaster tamalis or D. asymmetricus Subzone). Nannofossil chalks recovered from as deep as 180 m below the top of basalt in these holes are of late Early Pliocene age (D. asymmetricus Subzone). Nannofossils recovered from sediments immediately overlying basement basalts in hole 334 are of early Late Miocene age (D. bellus Subzone). Nannofossil chalks recovered from 50 m below the top of basalt in this hole are of late Middle Miocene age (Catinaster calyculus Subzone). Nannofossils recovered from the calcareous matrix of a gabbro and periodotite breccia occurring 68 m below the top of the basalt are also of late Middle Miocene age (C. coalitus Zone).The results indicate that the upper 180 m of basalt at site 332 were formed during an interval of time not exceeding 1 million years. At site 334 the upper 50 m of basement basalts were formed during an interval of time not exceeding 4.5 million years.

Acid Selection for Volcanic Tuffaceous Sandstone With High Analcime Contents: A Laboratory Study in Kita-Akita Oil Field, Northern Japan

2019 ◽  
Author(s):  
Kenji Ueda ◽  
Ryoichi Matsui ◽  
Murtaza Ziauddin ◽  
Ling Kong Teng ◽  
Wei Kan Wang
Keyword(s):  
Laboratory Study ◽  
Oil Field ◽  
Selection For ◽  
Northern Japan

Petrophysical data analysis using MATLAB tools for the middle Miocene sediments in the Gulf of Suez, Egypt

2020 ◽  
Author(s):  
Douaa Fathy ◽  
Eun Young Lee
Keyword(s):  
Middle Miocene ◽  
Oil Field ◽  
Coarse Grained ◽  
High Resistivity ◽  
Gulf Of Suez ◽  
High Porosity ◽  
Oil Saturation ◽  
Fluid Saturation ◽  
Important Relationship ◽  
Petrophysical Data

<p>Middle Miocene sediments are the most important productive oil zone in the Sidri Member within Belayim oil field. The Belayim oil field is one of well-known oil fields in Egypt, which is located on the eastern side of the Gulf of Suez. The Sidri Member consists of shales, sandstones and limestone with net pay thickness ranges from 5 to 60 m. The oil saturated sandstone layers are coarse grained and poorly sorted, which are classified into sub-litharenite, lithic arkose and arkose microfacies with several diagenetic features. This study measured and collected petrophysical data from the sandstone core samples and well logging of drilling sites to evaluate oil potentiality and reservoir characteristics of the Sidri Member. The collected petrophysical data are porosity, permeability, water and oil saturation, resistivity and grain and bulk density. MATLAB tools were used to analyze the extensive dataset, quantify the correlation trends and visualize the spatial distribution. The porosity values range from 2% to 30%, which show very good positive correlation with horizontal permeability (0 to 1,300 md). The porosity as well as type and radius of pore throats present important relationship with permeability and fluid saturation. The petrophysical characteristics of the Sidri sandstones are controlled by the depositional texture, clay-rich matrix and diagenetic features. This study distinguished poorly, fairly, good to excellent reservoir intervals in the Sidri Member. The best quality reservoir potentiality is recorded in the well sorted sand layers with little clay matrix in the lower part of the Sidri Member. The petrophysical characteristics are high porosity (20% to 30%), high permeability (140 to 1250 md), high oil saturation (20% to 78%), low water saturation (13% to 36%), moderate to high resistivity and relatively low grain density. The hydrocarbon production rates reported from the Sidri reservoirs are greatly correlated with the petrophysical characteristics described in this study.</p>

Reinterpretation of the Miocene Sea-Snake Egg Moniopterus Japonicus as a Boring of Rock-Boring Bivalve Lithophaga (Mytilidae: Mollusca)

2010 ◽  
Vol 84 (5) ◽  
pp. 848-857 ◽  
Author(s):  
Takuma Haga ◽  
Yukito Kurihara ◽  
Tomoki Kase
Keyword(s):  
Middle Miocene ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Sea Snake ◽  
Senior Synonym ◽  
Coleopteran Insect ◽  
Pointed End ◽  
Oval Shape ◽  
Northern Japan

The enigmatic fossil Moniopterus japonicus Hatai et al., 1974 from the early Middle Miocene Moniwa Formation of northern Japan has been described as the only known example of fossil sea-snake eggs and also as fossilized pupal chambers of a coleopteran insect. A reexamination of the holotype provides no evidence in support of these previous interpretations. Scanning electronic microscopy and computed tomography observations on the holotype reveal that the calcareous lining, previously interpreted as eggshell, is instead composed of irregular spherulitic prisms, thin in the middle and becoming thicker toward both ends. In addition to the elongate oval shape and the presence of an opening at the more pointed end, these observations strongly suggest that M. japonicus is a boring of the mytilid boring bivalve Lithophaga isolated from the host rock. This reinterpretation is further supported by the occurrence of similar isolated and in situ borings with Lithophaga shells within the type and a nearby locality. Regarding this fossil as an ichnofossil makes the generic name Moniopterus a junior synonym of Gastrochaenolites Leymerie, 1842 and the species name japonicus is a senior synonym of Gastrochaenolites torpedo Kelly and Bromley, 1984. G. torpedo should thus be replaced with Gastrochaenolites japonicus (Hatai et al., 1974).

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