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Browsing Геология России by Author "Yapp C.J."

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A MODEL FOR 18O/16O VARIATIONS IN CO2 EVOLVED FROM GOETHITE DURING THE SOLID-STATE α-FEOOH TO α-FE2O3 PHASE TRANSITION

Yapp C.J. (2003)

“Plateau” δ18O values of CO2 that evolved from the Fe(CO3)OH component during isothermal vacuum dehydrations (200–230 °C) of 18 natural goethites range from 8.2 to 28.1‰. In contrast, the measured δ18O values of the goethite ...
CARBON ISOTOPES IN CONTINENTAL WEATHERING ENVIRONMENTS AND VARIATIONS IN ANCIENT ATMOSPHERIC CO2 PRESSURE

Yapp C.J.; Poths H. (1996)

Abundance and carbon isotope data from an Fe(CO3)OH component in apparent solid solution in oolitic goethites have been used to infer ancient atmospheric CO2 pressures. A test of the validity of these estimates might be ...
CLIMATIC IMPLICATIONS OF SURFACE DOMAINS IN ARRAYS OF D AND 18O FROM HYDROXYL MINERALS: GOETHITE AS AN EXAMPLE

Yapp C.J. (2000)
CLIMATIC IMPLICATIONS OF SURFACE DOMAINS IN ARRAYS OF δD AND δ18O FROM HYDROXYL MINERALS: GOETHITE AS AN EXAMPLE

Yapp C.J. (2000)

Paired D/H and 18O/16O analyses of natural goethites range from -224%% to -93%% for δD and from -15.5%% to +2.8%% for δ18O. The isotopic systematics of these goethites seem to be most closely mimicked by the goethite-water ...
COEXISTING GOETHITE AND GIBBSITE FROM A HIGH-PALEOLATITUDE (55°N) LATE PALEOCENE LATERITE: CONCENTRATION AND 13C/12C RATIOS OF OCCLUDED CO2 AND ASSOCIATED ORGANIC MATTER

Tabor N.J.; Yapp C.J. (2005)

A Late Paleocene (~60 Ma BP) lateritic soil from Northern Ireland (the Antrim paleosol, herein referred to as Nire) contains coexisting goethite, gibbsite, phyllosilicate, and hematite. The Fe(III) oxides exhibit pisolitic ...
FLUX BALANCE MODELS FOR THE OXYGEN AND CARBON ISOTOPE COMPOSITIONS OF LAND SNAIL SHELLS

Balakrishnan M.; Yapp C.J. (2004)

A simple flux balance model with a diffusive, evaporative boundary layer indicates that the time constant (characteristic time) for approach to oxygen isotope steady state in the body fluid of land snails is ~19 min or ...
GOETHITE, CALCITE, AND ORGANIC MATTER FROM PERMIAN AND TRIASSIC SOILS: CARBON ISOTOPES AND CO2 CONCENTRATIONS

Tabor N.J.; Yapp C.J.; Montanez I.P. (2004)

Pedogenic goethites in each of two Early Permian paleosols appear to record mixing of two isotopically distinct CO2 components—atmospheric CO2 and CO2 from in situ oxidation of organic matter. The δ13C values measured for ...
MIXING OF CO2 IN SURFICIAL ENVIRONMENTS AS RECORDED BY THE CONCENTRATION AND δ13C VALUES OF THE FE(CO3)OH COMPONENT IN GOETHITE

Yapp C.J. (2001)

Measured values of mol fraction (X) and δ13C in the Fe(CO3)OH component of 49 samples of goethite (α-FeOOH) from a wide variety of environments range from 0.0015 to 0.0182 and from -21.7 to +3.3%%, respectively. The ...
STABLE HYDROGEN ISOTOPES IN IRON OXIDES: III. NONSTOICHIOMETRIC HYDROGEN IN GOETHITE

Yapp C.J.; Poths H. (1995)

Hydrogen isotope exchange experiments between goethite and water vapor were performed at 22°C after vacuum ''outgassing'' at temperatures ranging from 100 to 140°C. The results for five natural and one synthetic goethite ...
THE ABUNDANCE OF FE(CO3)OH IN GOETHITE AND A POSSIBLE CONSTRAINT ON MINIMUM ATMOSPHERIC OXYGEN PARTIAL PRESSURES IN THE PHANEROZOIC

Yapp C.J. (1996)

Concentrations of the Fe(CO3)OH component in goethites from Phanerozoic oolitic ironstones appear to record information on the partial pressures of soil CO2 in ancient subaerial weathering environments. Application of a ...

Browsing Геология России by Author "Yapp C.J."

Browsing Геология России by Author "Yapp C.J."

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