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Azmy, Karem; Veizer, Ján; Wenzel, Bernd; Bassett, Michael G.; Copper, Paul

doi:10.1130/0016-7606(1999)111<0475:ssis>2.3.co;2

Cited by 57 publications

(1 citation statement)

References 22 publications

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“…Variations of up to 50 10 6 have been observed in pristine brachiopods within the same stratigraphical level (e.g. Azmy et al 1999). The diagenetically altered specimen (OM48-15) from this bed yielded a significantly higher ratio although the Sr content appeared to be unaffected lending credence to the suggestion that dense puncta may have diagenetically altered fillings.…”

Section: Strontium Isotope Datasupporting

confidence: 53%

Lower Permian brachiopods from Oman: their potential as climatic proxies

Angiolini¹,

Darbyshire

Stephenson

et al. 2007

Earth and Environmental Science Transactions of the Royal Socie

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The Lower Permian of the Haushi basin, Interior Oman (Al Khlata Formation to Saiwan Formation/lower Gharif member) records climate change from glaciation, through marine sedimentation in the Haushi sea, to subtropical desert. To investigate the palaeoclimatic evolution of the Haushi Sea we used O, C, and Sr isotopes from 31 brachiopod shells of eight species collected bed by bed within the type-section of the Saiwan Formation. We assessed diagenesis by scanning electron microscopy of ultrastructure, cathodoluminescence, and geochemistry, and rejected fifteen shells not meeting specific preservation criteria. Spiriferids and spiriferinids show better preservation of the fibrous secondary layer than do orthotetids and productids and are therefore more suitable for isotopic analysis. 18 O of 3·7 to 3·1‰ from brachiopods at the base of the Saiwan Formation are probably related to glacial meltwater. Above this, an increase in 18 O may indicate ice accumulation elsewhere in Gondwana or more probably that the Haushi sea was an evaporating embayment of the Neotethys Ocean. 13 C varies little and is within the range of published data: its trend towards heavier values is consistent with increasing aridity and oligotrophy. Saiwan Sr isotope signatures are less radiogenic than those of the Sakmarian LOWESS seawater curve, which is based on extrapolation between few data points. In the scenario of evaporation in a restricted Haushi basin, the variation in Sr isotope composition may reflect a fluvial component.

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Section: Strontium Isotope Datasupporting

confidence: 53%

Lower Permian brachiopods from Oman: their potential as climatic proxies

Angiolini¹,

Darbyshire

Stephenson

et al. 2007

Earth and Environmental Science Transactions of the Royal Socie

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The Silurian red beds of Tarim Basin: Signals of palaeoenvironment, palaeoclimate, and sea‐level change

Liu

Lin

et al. 2019

Geological Journal

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The Silurian red beds of the Tarim Basin were formed in a coastal tidal and fluvial delta environment. They consist of red mudstone layers of the lower Tataaiertag Formation and separate the grey-green muddy sandstones of the Kalpintag Formation from the red sandstones of the upper Tataaiertag Formation. These mudstones are regarded as the most important regional seal for Silurian oil reservoirs. They contain a significant record of palaeoenvironmental and palaeoclimate changes which is related to global sea-level changes. Based on a systematic and continuous sedimentary study and multiple geochemistry analyses of samples taken from the Sishichang outcrop profile in west of the Tarim Basin, the Early-Middle Silurian palaeoclimate and sea-level curve have been reconstructed. The Early-Middle Silurian Tarim Basin encountered five intervals of climate change, from humid transitioning to semi-humid and dry-hot climate which shows signs of generally increasing oxidation. The reconstructed sea-level curve indicates five sea-level cycles throughout the Early-Middle Silurian succession. The most significant sea-level drop occurred during the early Telychian stage, which represents the onset of the red mudstone section of the Tataaiertag Formation. This new sealevel curve shows some differences compared with the earlier proposed global sealevel curves. The dry-hot climate occurred during the late Telychian stage and the beginning of Wenlock age. The Early-Middle Silurian sea-level change of the TarimBasin was mostly synchronical to the eustacy. However, regional tectonic activities during the early Telychian stage further enhanced the effect of the global sea-level fall and lead to a dry-hot climate trend which also caused the creation of the red beds of the Silurian period.

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Early–Middle Permian strontium isotope stratigraphy of marine carbonates from the northern marginal areas of South China: Controlling factors and implications

Azmy

Yang

et al. 2020

Geological Journal

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The radiogenic strontium isotope (87Sr/86Sr) system is a powerful tool for constraining sea‐level change and palaeoclimatic variations as well as tectonic activities. The Permian is a period that records the lowest seawater Sr‐isotopic ratios in the Earth's history. The near‐primary geochemical signatures retained in the micritic carbonates of the Luduba section (uppermost lower to Middle Permian) on the northern margin of the South China Block allowed the reconstruction of reliable carbon and Sr‐isotope profiles for global chemostratigraphic correlations. The investigated interval (~300 m) spans the Chihsia and overlying Maokou formations (Kungurian to Capitanian series). The 87Sr/86Sr values decrease consistently upward from 0.70833 to 0.70684, and their trend correlates well with a long‐term increase in the carbon isotope (δ13C) values. The negative correlation between the 87Sr/86Sr and δ13C values suggests that the sea‐level change, climatic conditions, opening of the Neo‐Tethys Ocean, and accretion of the Pangean Supercontinent are among the factors that might have contributed to the consistent depletion of the 87Sr/86Sr values. The rate of upward decrease in 87Sr/86Sr values throughout the Chihsia Formation is generally higher than that of the overlying Maokou Formation, which provides a possible marker for intra‐ and interbasinal basin stratigraphic correlations. The general increase in the δ13C values of the Luduba profile peaks at ~5‰, which correlates with the distinct lowest 87Sr/86Sr value (~0.70684) near the top of the Maokou Formation (Upper Capitanian). The δ13C values decrease to 3.6‰ at the top of the Maokou Formation, that correlates with the rapid sea‐level drop in the Late Guadaualupian worldwide. Meanwhile, the87Sr/86Sr ratios remain low values, probably due to the development of cold climate, increasing input of hydrothermal flux and low terrestrial runoff.

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Cited by 57 publications

References 22 publications

Lower Permian brachiopods from Oman: their potential as climatic proxies

Lower Permian brachiopods from Oman: their potential as climatic proxies

The Silurian red beds of Tarim Basin: Signals of palaeoenvironment, palaeoclimate, and sea‐level change

Early–Middle Permian strontium isotope stratigraphy of marine carbonates from the northern marginal areas of South China: Controlling factors and implications

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