scholarly journals Climate reconstruction from paired oxygen-isotope analyses of chironomid larval head capsules and endogenic carbonate (Hawes Water, UK) - Potential and problems

2021 ◽  
Vol 270 ◽  
pp. 107160
Author(s):  
Alex Lombino ◽  
Tim Atkinson ◽  
Stephen J. Brooks ◽  
Darren R. Gröcke ◽  
Jonathan Holmes ◽  
...  
2019 ◽  
Vol 489 (2) ◽  
pp. 170-173
Author(s):  
I. Yu. Badanina ◽  
E. A. Belousova ◽  
K. N. Malitch ◽  
S. F. Sluzhenikin

This study presents the first results of oxygen isotope analyses (18O) collected on zircons from the Talnakh economic intrusion within the Norilsk province. Zircons from gabbro-diorite, gabbroic rocks of the layered series and plagioclase-bearing wehrlite have similar mantle-like mean 18O values (5,39 0,49; 5,64 0,48 and of 5,28 0,34, respectively), which differ from 18O in zircons from sulfide-bearing melanocratic troctolite with a taxitic texture in the lower part of the intrusion (mean 18O = 6,50 0,98). These new oxygen isotope data support (i) the mantle-derived origin of the primary magma(s), parental to the Talnakh intrusion, and (ii) possible involvement of a crustal component during the formation of sulfide-bearing taxitic-textured rocks.


1986 ◽  
Vol 50 (355) ◽  
pp. 69-74 ◽  
Author(s):  
A. E. Tsirambides

AbstractMineralogical and oxygen isotope analyses have been performed on nine western Indian Ocean core samples in order to distinguish the detrital from authigenic minerals in the sediments. Following the removal of carbonates, organic constituents and Fe and Mn oxides, the residue was separated into five size fractions, the principal minerals present being feldspar, quartz, clinoptilolite, and clay minerals.Oxygen isotope compositions for two samples reflect an authigenic origin for clinoptilolite by the submarine alteration of volcanic material. Oxygen isotope compositions of two separates (free from feldspar and clays) suggest a detrital origin for the quartz in this area. The same mode of origin is apparent for the other components too, except possibly for some smectite which may have formed authigenically.


2019 ◽  
Vol 33 (14) ◽  
pp. 1185-1195 ◽  
Author(s):  
Nicolas Randazzo ◽  
Sang‐Tae Kim ◽  
Martin Knyf

2020 ◽  
Vol 34 (19) ◽  
Author(s):  
Marco M. Lehmann ◽  
Melanie Egli ◽  
Nadine Brinkmann ◽  
Roland A. Werner ◽  
Matthias Saurer ◽  
...  

1979 ◽  
Vol 43 (327) ◽  
pp. 405-413 ◽  
Author(s):  
Alan Matthews ◽  
Robert D. Beckinsale ◽  
John J. Durham

SummaryOxygen isotope fractionation between rutile and water has been studied from 300 °C to 700 °C, PH2O = 1 kb, using aqueous oxidation of titanium metal as the equilibration reaction. The mechanism of rutile formation (which is critical to the assessment of isotopic equilibrium) is an ‘armouring’ reaction in which rutile grows around grains of titanium metal by solution-precipitation processes. Mean fractionation factors expressed as 103 In αTiO2-H2O obtained in the present study are:−6.20±0.23‰ at 304±5 °C−6.64±0.27‰ at 405±6 °C−6.11±0.16%. at 508±6 °C−4.45±0.28%. at 608±6 °C−3.38±0.15%. at 698±6 °C.These data agree with those obtained at temperatures above 500 °C by Addy and Garlick (1974) but do not accord with theoretical predictions by Bottinga and Javoy (1973). A minimum in the calibration curve 103 ln α versus 106T−2 occurs between 300 °C and 500 °C but from 500 °C to 700 °C 18O fractionation between rutile and water may be expressed by the equation:103 ln α = −(4.72±0.40)106T−2+(1.62±0.53).Oxygen isotope analyses of rutile and quartz from metamorphic eclogites and schists from the Tauern Window, Austria, yield isotopic temperatures at about 550 °C in agreement with results obtained on similar rocks from the Sesia Zone (Western Alps, Italy) and elsewhere by other workers. Petrologic studies indicate that the latest metamorphism of the Tauern eclogites reached about 450 °C Thus the measured partitions of 18O between rutile and quartz indicating temperatures around 550 °C have been inherited from an earlier metamorphic event.


2017 ◽  
Vol 450 ◽  
pp. 199-209 ◽  
Author(s):  
Amélie Didier ◽  
Benita Putlitz ◽  
Lukas P. Baumgartner ◽  
Anne-Sophie Bouvier ◽  
Torsten W. Vennemann

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