Micro Rhombic Calcite of a Giant Barremian (Thamama B) Reservoir Onshore Abu Dhabi - Clumped Isotope Analyses fix Temperature, Water Composition and Timing of Burial Diagenesis

2014 ◽  
Author(s):  
Volker Vahrenkamp ◽  
Joao Barata ◽  
Pierre Joseph Van Laer ◽  
Peter Swart ◽  
Sean Murray
Keyword(s):  
Abu Dhabi ◽  
Burial Diagenesis ◽  
Water Composition ◽  
Clumped Isotope ◽  
Isotope Analyses ◽  
Temperature Water

scholarly journals Reconstruction of drip-water δ<sup>18</sup>O based on calcite oxygen and clumped isotopes of speleothems from Bunker Cave (Germany)

2013 ◽  
Vol 9 (1) ◽  
pp. 377-391 ◽  
Author(s):  
T. Kluge ◽  
H. P. Affek ◽  
T. Marx ◽  
W. Aeschbach-Hertig ◽  
D. F. C. Riechelmann ◽  
...  
Keyword(s):  
Variation Method ◽  
Clumped Isotopes ◽  
New Approach ◽  
Drip Water ◽  
The Holocene ◽  
Water Composition ◽  
Kinetic Isotope ◽  
Cave Drip Water ◽  
Clumped Isotope ◽  
Kinetic Fractionation

Abstract. The geochemical signature of many speleothems used for reconstruction of past continental climates is affected by kinetic isotope fractionation. This limits quantitative paleoclimate reconstruction and, in cases where the kinetic fractionation varies with time, also affects relative paleoclimate interpretations. In carbonate archive research, clumped isotope thermometry is typically used as proxy for absolute temperatures. In the case of speleothems, however, clumped isotopes provide a sensitive indicator for disequilibrium effects. The extent of kinetic fractionation co-varies in Δ47 and δ18O so that it can be used to account for disequilibrium in δ18O and to extract the past drip-water composition. Here we apply this approach to stalagmites from Bunker Cave (Germany) and calculate drip-water δ18Ow values for the Eemian, MIS3, and the Holocene, relying on independent temperature estimates and accounting for disequilibrium. Applying the co-variation method to modern calcite precipitates yields drip-water δ18Ow values in agreement with modern cave drip-water δ18Ow of −7.9 ± 0.3‰, despite large and variable disequilibrium effects in both calcite δ18Oc and Δ47. Reconstructed paleo-drip-water δ18Ow values are lower during colder periods (e.g., MIS3: −8.6 ± 0.4‰ and the early Holocene at 11 ka: −9.7 ± 0.2‰) and show higher values during warmer climatic periods (e.g., the Eemian: −7.6 ± 0.2‰ and the Holocene Climatic Optimum: −7.2 ± 0.3‰). This new approach offers a unique possibility for quantitative climate reconstruction including the assessment of past hydrological conditions while accounting for disequilibrium effects.

Clumped isotope geothermometry of an Ordovician carbonate mound, Hudson Bay Basin

2020 ◽  
Vol 178 (1) ◽  
pp. jgs2020-102
Author(s):  
Josué J. Jautzy ◽  
Martine M. Savard ◽  
Denis Lavoie ◽  
Omid H. Ardakani ◽  
Ryan S. Dhillon ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Oil And Gas ◽  
Fission Track ◽  
Hudson Bay ◽  
Apatite Fission Track ◽  
Burial Diagenesis ◽  
Carbonate Mound ◽  
History Of ◽  
Homogenization Temperatures ◽  
Clumped Isotope

The Hudson Bay sedimentary basin was overlooked geologically until two decades ago. Recent efforts to understand the palaeogeothermal history of this basin have led to the evaluation of fluid inclusion microthermometry, apatite fission track, organic matter reflectance and Rock–Eval analyses. Although apatite fission track and organic maturity indicators tend to show relatively low maximum burial temperatures (60–80°C), evidence of potential oil slicks on the sea surface and oil and gas shows in offshore wells have been reported across Hudson Bay. Fluid inclusion microthermometry in a carbonate mound sequence suggests homogenization temperatures of 118 ± 25 and 93 ± 10°C for recrystallized synsedimentary marine calcite and late pore-filling burial calcite, respectively. This sequence provides an interesting geological framework to test the application of clumped isotope thermometry against independent geothermometers. Here, we present clumped isotope data acquired on the late calcite cements and diagenetically altered early marine phases. The integration of clumped isotopic data with other thermal indicators allows the reconstruction and refinement of the thermal–diagenetic history of these carbonates by confirming an episode of heating, probably of hydrothermal origin and prior to normal burial diagenesis, that reset both fluid inclusions and the clumped isotope indicators without recrystallization.

The continental Middle Miocene Climatic Transition in Southern Europe as derived from clumped isotope analyses

2020 ◽  
Author(s):  
Niklas Löffler ◽  
Andreas Mulch ◽  
Wout Krijgsman ◽  
Emilija Krsnik ◽  
Jens Fiebig
Keyword(s):  
Late Miocene ◽  
Middle Miocene ◽  
Middle Eocene ◽  
Time Interval ◽  
Suitable Model ◽  
Southern Europe ◽  
Carbonate Formation ◽  
Carbon And Oxygen Isotope ◽  
Clumped Isotope ◽  
Isotope Analyses

&lt;p&gt;Reconstructing Cenozoic terrestrial paleoclimate is frequently limited by temporal resolution and suitable quantitative tools to reliably assess changes in temperature and aridity. The dynamics of ocean temperatures&lt;sup&gt;1&lt;/sup&gt; and chemistry&lt;sup&gt;2&lt;/sup&gt;, varying &lt;em&gt;p&lt;/em&gt;CO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;3&lt;/sup&gt;, and faunal assemblages are known to a certain extent, however, terrestrial data on temperatures, which are mostly indirectly derived from fossil assemblages and palynologycal data&lt;sup&gt;4&lt;/sup&gt;&amp;#160;are rare. This study contributes to the understanding of the dynamics and variability of terrestrial temperatures during one of the most extreme Neogene climate changes, the Middle Miocene Climate Transition (MCT). The comparison of &lt;em&gt;p&lt;/em&gt;CO&lt;sub&gt;2&lt;/sub&gt; forecasts for the coming century and reconstructed Mid-Miocene &lt;em&gt;p&lt;/em&gt;CO&lt;sub&gt;2&lt;/sub&gt; levels suggest that the Mid-Miocene is an important time interval for ascertaining suitable model projections of the future anthropogenic impact on climate. In order to establish an appropriate understanding and modeling of the natural variability of the European/Mediterranean climate system, quantitative climate information of the European continental Mid-Miocene is mandatory. This would facilitate the identification of main drivers of climate evolution in an area which is exposed to the present climate change and its subsequent natural hazards.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;This study presents a profound and well-dated terrestrial clumped isotope (&amp;#916;&lt;sub&gt;47&lt;/sub&gt;) paleosoil carbonate dataset from Spain that ranges from 13.0 to 15.1 Ma (100 kyr resolution) and hence covers an interval that was previously classified as the MCT. The &amp;#916;&lt;sub&gt;47 &lt;/sub&gt;data is supported by stable carbon and oxygen isotope analyses that are in agreement with previously published continental and oceanic records. A distinct decline in apparent &amp;#916;&lt;sub&gt;47&lt;/sub&gt;-based temperatures between 13.7 and 14.1 Ma reveals a substantial drop in continental temperatures and indicates changes in seasonality of pedogenic carbonate formation. The major cooling thereby coincides with a change in Milankovi&amp;#263; periodicities and can be linked to oceanic isotope records&lt;sup&gt;5&lt;/sup&gt;. While the transition into the MCT shows a high temperature variability indicating varying environmental conditions, calculated oxygen isotopic values of the soil water point to a rather stable moisture source across the MCT in Southern Europe.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;1: Super, J. R., Thomas, E., Pagani, M., et al. (2018) North Atlantic temperature and pCO&lt;sub&gt;2&lt;/sub&gt; coupling in the early-middle Miocene. Geology, 46(6), 519-522.&lt;/p&gt;&lt;p&gt;2: Pearson, P. N., and Palmer, M. R. (1999) Middle Eocene seawater pH and atmospheric carbon dioxide concentrations. Science, 284(5421), 1824-1826.&lt;/p&gt;&lt;p&gt;3: Pagani, M., Freeman, K. H., and Arthur, M. A. (1999) Late Miocene atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentrations and the expansion of C4 grasses. Science, 285(5429), 876-879.&lt;/p&gt;&lt;p&gt;4: Lewis, A. R., Marchant, D. R., Ashworth, A. C., et al. (2008) Mid-Miocene cooling and the extinction of tundra in continental Antarctica. Proceedings of the National academy of Sciences.&lt;/p&gt;&lt;p&gt;5: Holbourn, A., Kuhnt, W., Clemens, S., et al. (2013) Middle to late Miocene stepwise climate cooling: Evidence from a high resolution deep water isotope curve spanning 8 million years. Paleoceanography, 28(4), 688-699.&lt;/p&gt;

scholarly journals Carbonate clumped isotope analyses with the long-integration dual-inlet (LIDI) workflow: scratching at the lower sample weight boundaries

2017 ◽  
Vol 31 (12) ◽  
pp. 1057-1066 ◽  
Author(s):  
Inigo A. Müller ◽  
Alvaro Fernandez ◽  
Jens Radke ◽  
Joep van Dijk ◽  
Devon Bowen ◽  
...  
Keyword(s):  
Sample Weight ◽  
Clumped Isotope ◽  
Isotope Analyses

scholarly journals Optimizing sampling strategies in high-resolution paleoclimate records

2020 ◽  
Author(s):  
Niels de Winter ◽  
Tobias Agterhuis ◽  
Martin Ziegler
Keyword(s):  
Sample Size ◽  
Oxygen Isotope ◽  
Temperature Cycle ◽  
Size Optimization ◽  
Seasonal Temperature ◽  
Proxy Data ◽  
Water Composition ◽  
Combining Data ◽  
Wide Range ◽  
Isotope Analyses

Abstract. The aim of paleoclimate studies to resolve climate variability from noisy proxy records can in essence be reduced to a statistical problem. The challenge is to isolate meaningful information on climate events from these records by reducing measurement uncertainty through a combination of proxy data while retaining the temporal resolution needed to assess the timing and duration of the event. In this study, we explore the limits of this compromise by testing different methods for combining proxy data (smoothing, binning and sample size optimization) on a particularly challenging paleoclimate problem: resolving seasonal variability in stable isotope records. We test and evaluate the effects of changes in the seasonal temperature and hydrology cycle as well as changes in accretion rate of the archive and parameters such as sampling resolution and age model uncertainty on the reliability of seasonality reconstructions based on clumped and oxygen isotope analyses in 33 real and virtual datasets. Our results show that strategic combinations of clumped isotope analyses can significantly improve the accuracy of seasonality reconstructions if compared with conventional stable oxygen isotope analyses, especially in settings where the isotopic composition of the water is poorly constrained. Smoothing data using a moving average often leads to a dampening of the seasonal cycle, significantly reducing the accuracy of reconstructions. A statistical sample size optimization protocol yields more precise results than smoothing. However, the most accurate results are obtained through monthly binning of proxy data, especially in cases where growth rate or water composition cycles dampen the seasonal temperature cycle. Our analysis of a wide range of natural situations reveals that the effect of temperature seasonality on isotope records almost invariably exceeds that of changes in water composition. Thus, in most cases, isotope records allow reliable identification of growth seasonality as a basis for age modelling and seasonality reconstructions in absence of independent chronological markers in the record. These specific findings allow us to formulate general recommendations for sampling and combining data in paleoclimate research and have implications beyond the reconstruction of seasonality. We discuss the implications of our results for solving common problems in paleoclimatology and stratigraphy, including cyclostratigraphy, strontium isotope dating and event stratigraphy.

scholarly journals Impact of diagenesis on the spatial and temporal distribution of reservoir quality in the Jurassic Arab D and C members, offshore Abu Dhabi oilfield, United Arab Emirates

GeoArabia ◽  
2012 ◽  
Vol 17 (3) ◽  
pp. 17-56
Author(s):  
Sadoon Morad ◽  
Ihsan S. Al-Aasm ◽  
Fadi H. Nader ◽  
Andrea Ceriani ◽  
Marta Gasparrini ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
United Arab Emirates ◽  
Temporal Distribution ◽  
Abu Dhabi ◽  
Reservoir Quality ◽  
Second Phase ◽  
Burial History ◽  
Burial Diagenesis ◽  
Thin Sections ◽  
The Impact

ABSTRACT This study is based on petrographic examination (optical, scanning electron microscope, cathodo-luminescence, backscattered electron imaging, and fluorescence) of 1,350 thin sections as well as isotopic compositions of carbonates (172 carbon and oxygen and 118 strontium isotopes), microprobe analyses, and fluid inclusion microthermometry of cored Jurassic Arab D and C members from 16 wells in a field from offshore Abu Dhabi, United Arab Emirates. The formation was deposited in a ramp with barrier islands and distal slope setting. Petrographic, stable isotopic and fluid-inclusion analyses have unraveled the impact of diagenesis on reservoir quality of Arab D and C within the framework of depositional facies, sequence stratigraphy, and burial history. Diagenetic processes include cementation by grain rim cement and syntaxial calcite overgrowths, formation of moldic porosity by dissolution of allochems, dolomitization and dolomite cementation, cementation by gypsum and anhydrite, and stylolitization. Partial eogenetic calcite and dolomite cementation has prevented porosity loss in grainstones during burial diagenesis. Dolomitization and sulphate cementation of peritidal mud are suggested to have occurred in an evaporative sabkha setting, whereas dolomitization of subtidal packstones and grainstones was driven by seepage reflux of lagoon brines formed during major falls in relative sea level. Recrystallization of dolomite occurred by hot saline waters (Th 85–100°C; and salinity 14–18 wt% NaCl). Anhydrite and gypsum cements (Th 95–105°C; fluid salinity 16–20 wt% NaCl), were subjected to extensive dissolution, presumably caused by thermal sulfate reduction followed by a major phase of oil emplacement. The last cement recorded was a second phase of anhydrite and gypsum (Th 95–120°C; 16–22 wt% NaCl), which fills fractures associated with faults.

CLUMPED ISOTOPE ANALYSES OF OYSTERS FROM THE MAASTRICHTIAN TYPE SECTION IN SOUTHEAST NETHERLANDS

2020 ◽  
Author(s):  
Heidi O'Hora ◽  
◽  
Sierra Petersen ◽  
Johan Vellekoop ◽  
Serena Scholz
Keyword(s):  
Type Section ◽  
Clumped Isotope ◽  
Isotope Analyses
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