Monterey Excursion Events in the Middle Miocene Carbonate Rock Succession, Eastern Iraq

2021 ◽  
Author(s):  
Mustafa A. Ali ◽  
Sa'ad Z. Al-Mashaikie ◽  
Arsalan Ahmed Othman
Keyword(s):  
Shallow Water ◽  
Middle Miocene ◽  
Depositional Environments ◽  
Arabian Plate ◽  
Tethys Sea ◽  
Carbon Isotopic ◽  
Lithostratigraphic Units ◽  
Platform Margin ◽  
Δ 13C ◽  
The Relationship

Abstract The global Monterey excursions are recognized in many deep-sea, and recently in shallow water depth records during the Miocene epoch. We analyzed the δ 13C and δ 18O to investigate the relationship between the lithostratigraphic units and the deviation of the stable isotopes. The results show that there is a significant relationship between the depositional energy changes and both of δ 13C and δ 18O. The present paper is deals with variability of the primary isotopic composition of seawater in the shallow water zone. Sedimentary successions of middle Miocene outcropping in the eastern part of Iraq provide an excellent archive of the oxygen isotope events (Mi‐events), additional details about Mi 2 and Mi 3 zones of glaciations and refine the Monterey Excursion, carbonate isotope maxima (CM‐events). Facies analysis revealed several microfacies could be distinguished, reflecting depositional environments including; lagoon, back reef-reef, shallow open marine, and shoal environments. The Jeribe Formation is a transgression unit belonging to the stage Ap11 tectonostratigraphy Megasequence. The Formation was deposited in the outer platform margin of unstable shelf of the Arabian Plate and significant of this formation, which is deposited during the final phase of Tethys sea closure. The stable isotope (18O/16O and 13C/12C) provide an excellent archive of the paleoceanography for the Neogene (middle Miocene Transgression) of the Neo-Teythys. Oxygen and carbon isotopic stratigraphy for bulk-rock were analyzed in order to distinguished Monterey Event and climate optima.

Biostratigraphically constrained Neogene palaeoenvironments of the Red Sea rift

2021 ◽  
Author(s):  
Geraint Hughes ◽  
Osman Varol
Keyword(s):  
Sea Level ◽  
Red Sea ◽  
Debris Flows ◽  
Middle Miocene ◽  
Depositional Environments ◽  
Early Miocene ◽  
Arabian Plate ◽  
Tectonic Activity ◽  
Gulf Of Suez ◽  
Gulf Of Aden

<p>Marine sediments deposited in response to the Neogene opening of the Red Sea during divergence of the African-Arabian plate margin provide micropalaeontological chronological evidence to calibrate synchronous palaeoenvironmental events from the Gulf of Suez to the Gulf of Aden. This facility provides insights to the timing and relative rates of tectonic subsidence associated with the rifting episodes of the region. Biostratigraphic index forms include planktonic and benthonic foraminifera and calcareous nannofossils. These, combined with various associated microfossils and macrofossil fragments, permit interpretation of a range of depositional environments that span intertidal to bathyal regimes. Onset and recovery from various hypersaline events are similarly interpreted by integrating microfossils and lithology. Following an episode of emergence and sporadic volcanicity, subsidence and the first Neogene marine transgression created brackish to shallow marine lagoons during the Early Miocene (Foraminiferal Letter Stage Upper Te). Rapid subsidence and accumulation of deep marine mudstones, of local hydrocarbon source-rock quality, with thinly interbedded siliciclastic and calciclastic debris flows commenced in the Early Miocene (Planktonic foraminiferal zones N5-N8; Nannofossil zones NN3-NN5). The debris flows increased in abundance and provide good hydrocarbon reservoirs. The Gulf of Suez and Red Sea experienced episodic isolation from the Indian Ocean during the latest Early Miocene and earliest Middle Miocene (Planktonic foraminiferal zones N8-N9; Nannofossil zone NN5 Foraminiferal Letter Stage Middle-Upper Tf1), resulting in hypersaline events with precipitation of submarine gypsum and halite. The isolation is attributed to constriction of the southern Red Sea, in the vicinity of the Bab El Mandab Straits, by eustatic sea level fall as well as probable tectonic activity; the synchronous Gulf of Aden succession does not display evidence for such hypersaline events. A prolonged hypersaline phase extended over most of the Middle Miocene, for which absence of biostratigraphic data precludes age control. During the latest Middle Miocene to Late Miocene, rejuvenation of the hinterland cause rapid deposition of terrestrial and fluviatile coarse and fine siliciclastics, with similar biostratigraphic paucity except for rare diatoms and palynomorphs. Renewed subsidence, associated with opening of the Aqaba Fault, combined with eustatic sea level rise caused marine deposition to recommence in the Pliocene.</p>

Gypsum facies in the Badenian (Middle Miocene) of southern Poland

1993 ◽  
Vol 30 (9) ◽  
pp. 1799-1814 ◽  
Author(s):  
Alicja Kasprzyk
Keyword(s):  
Shallow Water ◽  
Sea Level ◽  
Water Depth ◽  
Middle Miocene ◽  
Climatic Factors ◽  
Peripheral Part ◽  
Southern Poland ◽  
Lithostratigraphic Units ◽  
Peripheral Area ◽  
Maximum Water

Middle Miocene sulfate sediments south of the Holy Cross Mountains, southern Poland, comprise deep- and shallow-water as well as subaerial facies, accompanied by carbonates and siliciclastics. In the gypsum section, 18 lithostratigraphic units have been distinguished. The facies variety reflects distinct sedimentary conditions in the peripheral area of the evaporitic basin, where the maximum water depth never exceeded some tens of meters. The succession of facies is regressive and comprises six sedimentary cycles that reflect relative changes in sea level and in the physicochemical regime of the basin, both of which were controlled by tectonic and climatic factors. Sea level fell five times during sulfate sedimentation; the last sea-level drop led to the almost total desiccation of the sea in the peripheral part of the basin.

scholarly journals CARBONATE CLASTS FROM CRETACEOUS CONGLOMERATE DEPOSITS OF THE POSTĂVARU MASSIF (SOUTHERN CARPATHIANS, ROMANIA) – DEPOSITIONAL ENVIRONMENTS AND BIOSTRATIGRAPHIC REMARKS

2020 ◽  
pp. 27-39
Author(s):  
Sergiu Șerban ◽  
Cristian Victor Mircescu ◽  
Razvan Ungureanu ◽  
Ioan I. Bucur
Keyword(s):  
Shallow Water ◽  
Depositional Environments ◽  
Thin Sections ◽  
Depositional Settings ◽  
Platform Margin ◽  
Southern Carpathians

The objective of this study is to describe the composition of the carbonate elements from the upper Albian–Cenomanian Postăvaru Conglomerates. Eight sections were studied. Two major types of conglomerates are identified in the field and thin sections: polymictic orthoconglomerates and paraconglomerates. Carbonate clasts are dominant in both types of conglomerates. Other subordinated clasts are composed of quartzites, sericite-chlorite schists and gneisses. Facies data allow reconstructing the depositional environments, while microfossil assemblages were used to establish the age of the studied carbonate clasts. The identified microfacies characterize a large variety of depositional environments, ranging from basin to shallow water environments (platform margin and inner platform depositional settings). The identified microfossil associations are indicative for three biostratigraphic intervals: Kimmeridgian–Tithonian, Tithonian–Berriasian and Berriasian–? lower Valanginian.

scholarly journals The middle Miocene palynofloras of the Salihpaşalar lignite mine (Yatağan Basin, southwest Anatolia): environmental characterisation and comparison with palynofloras from adjacent basins

2018 ◽  
Vol 99 (4) ◽  
pp. 591-636 ◽  
Author(s):  
Johannes M. Bouchal
Keyword(s):  
Shallow Water ◽  
Middle Miocene ◽  
Depositional Environments ◽  
Temporary Ponds ◽  
Woody Vegetation ◽  
Lake Shore ◽  
The Third ◽  
Lignite Mine ◽  
Angiosperm Pollen ◽  
Algal Spores

Abstract As the third part of an ongoing investigation of middle Miocene palynofloras in the Yatağan Basin (YB), southwestern Anatolia, the palynofloras of the Salihpaşalar lignite mine in the main YB were studied. Seven types of algal spores, aplanospores/zygospores or cysts, six types of lycophyte and fern spores, 12 types of gymnosperm pollen and 90 types of angiosperm pollen were identified. Of a total of ca. 140 plant taxa described from the YB, over 10% are confined to the Salihpaşalar assemblage. Differences between coeval palynofloras of the Sekköy Member might reflect changing or prograding depositional environments. A number of rare accessorial taxa reflect these local differences: Pilularia, Valeriana, Drosera and Persicaria aff. amphibia only occur at Salihpaşalar and are typical of shallow water or temporary ponds associated with a lake shore. Apart from this, all the palynofloras, originating from the lignite seams and overlying limnic limestones (uppermost Turgut and Sekköy Member), of the YB are strongly indicative of extensive woody vegetation with a dominance of diverse Fagaceae and Pinaceae. In addition, a list comparing the well-documented YB palynomorphs to morphologically similar palynomorphs of published late early to middle Miocene plant assemblages of western Anatolian was compiled. Such a comparison reveals that in many instances different taxon names have been used to denote the same taxa. Hence, resolving these synonymies is a prerequisite of any meaningful comparison of palynofloras in the region.

Oxygen-18 and carbon-13 in the carbonates of the Salina formation of southwestern Ontario

1988 ◽  
Vol 25 (2) ◽  
pp. 182-194 ◽  
Author(s):  
K. J. O'Shea ◽  
M. C. Miles ◽  
P. Fritz ◽  
S. K. Frape ◽  
D. E. Lawson
Keyword(s):  
Water Balance ◽  
Isotopic Composition ◽  
Shallow Water ◽  
Depositional Environment ◽  
Carbon Isotopic Composition ◽  
Depositional Environments ◽  
Michigan Basin ◽  
Anoxic Conditions ◽  
Carbon Isotopic ◽  
Upper Silurian

The oxygen and carbon isotopic composition of the carbonates of the Upper Silurian Salina formation of the Michigan Basin was investigated to aid in interpretation of depositional environments.13C results indicate that a change from generally anoxic bottom conditions to oxic conditions occurred during deposition of the B evaporite unit. The organic-rich A carbonate units were deposited in a shallow-water, evaporitic setting, most likely adjacent to a sabkha-type environment. A positive water balance maintained the anoxic conditions and buffered the carbon isotopes.Above the B evaporite, the isotopic composition suggests that the development of a similar depositional environment, a subaerial prograding sabkha, occurred over wide areas of the basin.18O results support the conclusion that Silurian oceans were depleted in 18O with respect to modem oceans by 5–6‰.

Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Near Surface ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Platform Margin ◽  
Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

A new tool to detect exposure surfaces in shallow water carbonate depositional environments

2002 ◽  
Vol 45 (3) ◽  
pp. 301-317 ◽  
Author(s):  
Andrea Mindszenty ◽  
J. Ferenc Deák ◽  
Mária Fölvári
Keyword(s):  
Shallow Water ◽  
Depositional Environments ◽  
Water Carbonate ◽  
Shallow Water Carbonate

scholarly journals How Does Diet Influence Our Lives? Evaluating the Relationship between Isotopic Signatures and Mortality Patterns in Italian Roman Imperial and Medieval Periods

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3895
Author(s):  
Marica Baldoni ◽  
Alessandra Nardi ◽  
Flavio De Angelis ◽  
Olga Rickards ◽  
Cristina Martínez-Labarga
Keyword(s):  
Middle Ages ◽  
Dietary Habits ◽  
Roman Period ◽  
Survivorship Analysis ◽  
Linear Effect ◽  
Isotopic Signatures ◽  
Carbon Isotopic ◽  
Religious Aspects ◽  
The Relationship ◽  
Source Of Information

The present research investigates the relationship between dietary habits and mortality patterns in the Roman Imperial and Medieval periods. The reconstructions of population dynamics and subsistence strategies provide a fascinating source of information for understanding our history. This is particularly true given that the changes in social, economic, political, and religious aspects related to the transition from the Roman period to the Middle Ages have been widely discussed. We analyzed the isotopic and mortality patterns of 616 individuals from 18 archeological sites (the Medieval Latium sites of Colonna, Santa Severa, Allumiere, Cencelle, and 14 Medieval and Imperial funerary contexts from Rome) to compile a survivorship analysis. A semi-parametric approach was applied, suggesting variations in mortality patterns between sexes in the Roman period. Nitrogen isotopic signatures influenced mortality in both periods, showing a quadratic and a linear effect for Roman Imperial and Medieval populations, respectively. No influence of carbon isotopic signatures has been detected for Roman Imperial populations. Conversely, increased mortality risk for rising carbon isotopic values was observed in Medieval samples.

New equation to decipher the relationship between carbon isotopic composition of methane and maturity of gas source rocks

2021 ◽  
Vol 64 (3) ◽  
pp. 470-493 ◽  
Author(s):  
Jianping Chen ◽  
Xulong Wang ◽  
Jianfa Chen ◽  
Yunyan Ni ◽  
Baoli Xiang ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Carbon Isotopic Composition ◽  
Source Rocks ◽  
Carbon Isotopic ◽  
Gas Source ◽  
New Equation ◽  
The Relationship
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