Speleothem Stable Isotope Records from Eastern Europe & Turkey

The region of Eastern Europe & Turkey contributed to the SISAL (Speleothem Isotopes Synthesis and AnaLysis) global database with stable carbon- and oxygen isotope time-series from 18 entities from 14 cave systems. The currently available oldest record from this region is the ABA-2 flowstone record (Abaliget Cave; Hungary) reaching back to MIS 6. The temporal distribution of the compiled 18 entities points out a ~20-kyr-long period, centering around 100 ka, lacking speleothem stable isotope record in the region. The regional subset of SISAL_v1 records displays a continuous coverage for the past ~90 kyr for both δ18O and δ13C, with a mean temporal resolution of ~12 yr for the Holocene, and >50 yr for the pre-Holocene period. The highest temporal resolution both for the Holocene and the pre-Holocene was achieved in the So-1 record (Sofular Cave; Turkey). Assessing the data, an important split was found regarding the climatic interpretation of speleothem δ18O. While the oxygen isotope composition of more continental formations is thought to reflect mainly temperature variations and changes in moisture transport trajectories, it may strongly reflect fluctuations of precipitation amount in the southern part of the region. Variations of δ13C primarily interpreted as humidity changes reflecting dry/wet periods across the region. Elevation gradients from three non-overlapping time periods from the region - for the last 5kyr - indicated systematically prevailing elevational gradients around -0.26&permil; 100m-1 in δ18O. The regional comparison of SISAL_v1 speleothem δ18O and the temporal distribution of coarsely crystalline cryogenic cave carbonate occurrences back to 45ka does not appear to confirm the finding that occurrence of the latter coincides with the warming from stadial to interstadial conditions.

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Application of the Data on δ13C and δ18O of Carbonates for the Study of Unconventional Reservoirs on the Example of the Bazhenov Source Rocks, Western Siberia, Russia

Geosciences ◽

10.3390/geosciences11070264 ◽

2021 ◽

Vol 11 (7) ◽

pp. 264

Author(s):

Anna Yurchenko ◽

Andrey Voropaev ◽

Elena Kozlova ◽

Nikita Morozov ◽

Mikhail Spasennykh

Keyword(s):

Carbon Dioxide ◽

Stable Isotope ◽

Oxygen Isotope ◽

Isotope Exchange ◽

Isotope Composition ◽

Source Rocks ◽

Distribution Area ◽

Exchange Reactions ◽

Bazhenov Formation ◽

Carbon And Oxygen Isotope

This paper addresses potential application of data on stable carbon and oxygen isotope composition of carbonates for study of organic rich source rocks on the example of the Late Jurassic–Early Cretaceous Bazhenov Formation (West Siberian petroleum basin, Russia). Geochemical studies were conducted for sections located in central (most productive) and peripheral (northern and southern) regions of the Bazhenov Formation distribution area, containing deposits formed under different conditions. We identified key factors impacting stable isotope composition of carbonate minerals and established relation of their isotope composition to the formation conditions. Using a thermodynamic model of carbon and oxygen isotope exchange in the carbonate–water–carbon dioxide system, it is shown that variations in the isotope composition of secondary carbonates are affected by isotopic composition of primary carbonates in sediments and by the isotope exchange reactions with water and carbon dioxide, generated during the source rocks transformation. Our results demonstrate that stable isotope data for carbonates in the Bazhenov Formation together with standard geochemical methods can be efficiently applied to determine sedimentation conditions and secondary alteration processes of oil source rocks.

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Speleothem Records from the Eastern Part of Europe and Turkey—Discussion on Stable Oxygen and Carbon Isotopes

Quaternary ◽

10.3390/quat2030031 ◽

2019 ◽

Vol 2 (3) ◽

pp. 31 ◽

Cited By ~ 7

Author(s):

Zoltán Kern ◽

Attila Demény ◽

Aurel Perşoiu ◽

István Gábor Hatvani

Keyword(s):

Oxygen Isotope ◽

Central Europe ◽

Temporal Resolution ◽

Elevation Gradients ◽

East Central Europe ◽

East Central ◽

East Europe ◽

The Holocene ◽

South East Europe ◽

Precipitation Δ18o

The region comprising of East Central Europe, South East Europe and Turkey contributed to the SISAL (Speleothem Isotopes Synthesis and AnaLysis) global database with stable carbon and oxygen isotope time-series from 18 speleothems from 14 caves. The currently available oldest record from the studied region is the ABA-2 flowstone record (Abaliget Cave; Hungary) reaching back to MIS 6. The temporal distribution of the compiled 18 records from the region points out a ~20 kyr-long period, centering around 100 ka BP, lacking speleothem stable isotope data. The regional subset of SISAL_v1 records displays a continuous coverage for the past ~90 kyr for both δ13C and δ18O, with a mean temporal resolution of ~12 yr for the Holocene, and >50 yr for the pre-Holocene period. The highest temporal resolution both for the Holocene and the pre-Holocene was achieved in the So-1 record (Sofular Cave; Turkey). The relationship between modern day precipitation δ18O (amount weighted annual and winter season mean values; 1961–2017) and climatological parameters was evaluated. The strong positive correlation found in East Central Europe reinforces the link between modern day precipitation δ18O, temperature and large-scale circulation (North Atlantic Oscillation) expected to be preserved in the speleothem δ18O record; while a negative relationship was documented between precipitation amount and oxygen isotope compositions in South East Europe. Variations of δ13C values are primarily interpreted as reflecting dry/wet periods across the region. Elevation gradients from three non-overlapping periods of the last ~5 kyr indicated elevation gradients around −0.26‰ per 100 m−1 for calcite δ18O.

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Investigating late Holocene variations in hydroclimate and the stable isotope composition of precipitation using southern South American peatlands: an hypothesis

Climate of the Past ◽

10.5194/cp-8-1457-2012 ◽

2012 ◽

Vol 8 (5) ◽

pp. 1457-1471 ◽

Cited By ~ 12

Author(s):

T. J. Daley ◽

D. Mauquoy ◽

F. M. Chambers ◽

F. A. Street-Perrott ◽

P. D. M. Hughes ◽

...

Keyword(s):

Stable Isotope ◽

Air Temperature ◽

Regional Differences ◽

Late Holocene ◽

Isotope Composition ◽

Precipitation Amount ◽

Surface Air Temperature ◽

Global Network ◽

Stable Isotope Composition ◽

Δd And Δ18o

Abstract. Ombrotrophic raised peatlands provide an ideal archive for integrating late Holocene records of variations in hydroclimate and the estimated stable isotope composition of precipitation with recent instrumental measurements. Modern measurements of mean monthly surface air temperature, precipitation, and δD and δ18O-values in precipitation from the late twentieth and early twenty-first centuries provide a short but invaluable record with which to investigate modern relationships between these variables, thereby enabling improved interpretation of the peatland palaeodata. Stable isotope data from two stations in the Global Network for Isotopes in Precipitation (GNIP) from southern South America (Punta Arenas, Chile and Ushuaia, Argentina) were analysed for the period 1982 to 2008 and compared with longer-term meteorological data from the same locations (1890 to present and 1931 to present, respectively). δD and δ18O-values in precipitation have exhibited quite different trends in response to local surface air temperature and precipitation amount. At Punta Arenas, there has been a marked increase in the seasonal difference between summer and winter δ18O-values. A decline in the deuterium excess of summer precipitation at this station was associated with a general increase in relative humidity at 1000 mb over the surface of the Southeast Pacific Ocean, believed to be the major vapour source for the local precipitation. At Ushuaia, a fall in δ18O-values was associated with an increase in the mean annual amount of precipitation. Both records are consistent with a southward retraction and increase in zonal wind speed of the austral westerly wind belt. These regional differences, observed in response to a known driver, should be detectable in peatland sites close to the GNIP stations. Currently, insufficient data with suitable temporal resolution are available to test for these regional differences over the last 3000 yr. Existing peatland palaeoclimate data from two sites near Ushuaia, however, provide evidence for changes in the late Holocene that are consistent with the pattern observed in modern observations.

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Changes in carbon and oxygen isotope composition during limestone diagenesis

Sedimentology ◽

10.1111/j.1365-3091.1980.tb01161.x ◽

1980 ◽

Vol 27 (1) ◽

pp. 107-118 ◽

Cited By ~ 118

Author(s):

J. A. D. DICKSON ◽

M. L. COLEMAN

Keyword(s):

Oxygen Isotope ◽

Isotope Composition ◽

Oxygen Isotope Composition ◽

Carbon And Oxygen Isotope

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Paleoenvironmental Traces of Carbon and Oxygen Isotopes in Carbonate Rocks: An Example From Dengying Formation in Xichuan Area, Henan Province

10.21203/rs.3.rs-17072/v1 ◽

2020 ◽

Author(s):

Lan Zhang ◽

Hong Xie ◽

Qingguang Li ◽

Zhenghao Lu ◽

Yang Bai ◽

...

Keyword(s):

Oxygen Isotope ◽

Carbonate Rocks ◽

Isotope Composition ◽

Salinity Range ◽

Carbon And Oxygen Isotopes ◽

Accurate Analysis ◽

Average Value ◽

Dengying Formation ◽

Three Samples ◽

Carbon And Oxygen Isotope

Abstract The carbon and oxygen isotope composition of carbonate rocks is an important index for accurate analysis of the paleo-sea environment, which depends on Mn/Sr, δ 18 O > -10‰, correlativity of δ 13 C and δ 18 O and “age effect” of δ 18 O. This study reports carbon and oxygen isotope data of carbonate rocks from the Dengying Formation in the Xichuan area. δ 13 C values range -1.58‰ to 3.76‰, with an average value of 1.55‰, and δ 18 O values are -14.91‰ to -1.88‰, with an average value of -6.95‰. The δ 18 O values of three samples are less than -10‰, so they are excluded and taken to be correlative with the cracking of the Rodinia supercontinent during the Neoproterozoic. The paleotemperature range 7.40°C to 35.05°C, with an average value of 21.09°C. Paleo-salinity range 8.38‰ to 19.30‰, with an average value of 13.89‰. Z values range 127.80 to 135.03 and thus all exceeded 120, with an average value of 131.25. These calculations indicate that the Xichuan area had deposited marine carbonate rocks, with the hot and dry tropical monsoon climate, and a transgressive process overall during the Dengying age.

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An Oxygen Isotope Study of Seasonal Trends in Jinxiuchuan River of Jinan South Mountain

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.522-524.954 ◽

2014 ◽

Vol 522-524 ◽

pp. 954-957 ◽

Cited By ~ 1

Author(s):

Yong Sen Wang ◽

Zheng He Xu ◽

Si Fang Dong

Keyword(s):

Stable Isotope ◽

Oxygen Isotope ◽

River Water ◽

Oxygen Isotopes ◽

Water Cycle ◽

Climatic Factors ◽

Isotope Composition ◽

Stable Isotope Composition ◽

Isotope Study ◽

Isotopic Variations

The stable isotope composition of river water contains some information of water cycle and climatic factors, such as precipitation, evaporation and temperature. Oxygen isotopes in river water were monitored at one site in Jinxiuchuang basin of Jinan southern mountain.δ18O values of river water show a variation from-7.82 on July 6 to-9.98 on June 6. The result reveals that the river water was mainly supplied by the precipitation. The isotopic variations at Jinxiuchuan river have strong precipitation patterns owning to different rainfall in summer.

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