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EVIDENCE FOR MOLECULAR SIZE DEPENDENT GAS FRACTIONATION IN FIRN AIR DERIVED FROM NOBLE GASES, OXYGEN, AND NITROGEN MEASUREMENTS

Huber C.; Beyerle U.; Leuenberger M.; Schwander J.; Spahni R.; Weiler K.; Kipfer R.; Severinghaus J.P. (2006)

We present elemental and isotopic measurements of noble gases (He, Ne, Ar, Kr, and Xe), oxygen and nitrogen of firn air from two sites. The first set of samples was taken in 1998 at the summit of the Devon Ice Cap in the ...

EVIDENCE FOR MONAZITE- , BARITE- , AND AGMNO4 (DISTORTED BARITE)-TYPE STRUCTURES OF CASO4 AT HIGH PRESSURE AND TEMPERATURE

Crichton W.A.; Parise J.B.; Antao S.M.; Grzechnik A. (2005)

Using laser-heated diamond-anvil cells, we have observed CaSO4 undergoing phase transitions from its ambient anhydrite structure to the monazite type, and at highest pressure and temperature to crystallize in the barite-type ...

EVIDENCE FOR RAPID ENVIRONMENTAL CHANGES IN LOW LATITUDES DURING THE LATE SILURIAN LAU EVENT: THE BURGEN-1 DRILLCORE, GOTLAND, SWEDEN

Calner M.; Eriksson M.J. (2006)

Erosional outliers are an important component of the Ludlow (Late Silurian) stratigraphy of Gotland, Sweden. However, due to the poor degree of exposure, outcrop studies have not revealed a detailed section from any of ...

EVIDENCE FOR REACTIVATION OF EOCENE JOINTS AND PRE-EOCENE FOLIATION PLANES IN THE OKANAGAN CORE-COMPLEX, BRITISH COLUMBIA, CANADA

Eyal Y.; Feinstein S.; Osadetz K.G. (2006)

We studied the brittle deformational history of the Okanagan metamorphic core complex, and its hanging wall carapace, in the Canadian Cordillera, in southern British Columbia by an extensive structural investigation at ...

EVIDENCE FOR SOLAR NEBULA SIGNATURES IN THE MATRIX OF THE ALLENDE METEORITE

Brenker F.E.; Palme H.; Klerner S. (2000)

Carbonaceous chondrites of type 3 (e.g. Allende) are among the most primitive meteorites. They contain components that formed prior to the accretion of a parent asteroid and thus record conditions of the ambient nebular ...

EVIDENCE FOR SUBDUCTION-RELATED COMPONENTS IN THE SUBCONTINENTAL MANTLE FROM LOW 3HE/4HE AND 40AR/36AR RATIO IN MANTLE XENOLITHS FROM FAR EASTERN RUSSIA

Yamamoto J.; Kaneoka I.; Nakai S.; Kagi H.; Prikhod'ko V.; Arai S. (2004)

By applying both vacuum crushing and stepwise heating methods for the extraction of the noble gases, we have discovered ³He/⁴He ratios much lower than the atmospheric ratio (∼0.3 RA; RA is the atmospheric ³He/⁴He ratio of ...

EVIDENCE FOR SVECONORWEGIAN (GRENVILLIAN) MAGMATIC ACTIVITY IN THE NORTHWESTERN BALTIC SHIELD

Arzamastsev A.A.; Arzamastseva L.V.; Fedotov Zh.A.; Montero P.; Bea F.; Travin A.V. (2006)

The crustal structure in the Baltic Shield is determined by a system of geological blocks, which formed at different evolutionary stages of this largest stable Precambrian domain. Cratonization of the Archean Karelian, ...

EVIDENCE FOR THE EARLY DIFFERENTIATION OF THE CORE FROM PT-RE-OS ISOTOPE SYSTEMATICS OF 2.8-GA KOMATIITES

Puchtel I.S.; Humayun M.; Walker R.J.; Brandon A.D. (2005)

Komatiite samples from the 2.8-Ga Kostomuksha greenstone belt in the Baltic Shield define Pt–Os and Re–Os isochrons with ages of 2816 ± 190 and 2880 ± 83 Ma, respectively. The mean initial 186Os / 188Os and 187Os / 188Os ...

EVIDENCE FOR THE EMPLACEMENT OF CA. 3.0 GA MANTLE-DERIVED MAFIC-ULTRAMAFIC BODIES IN THE UKRAINIAN SHIELD

Gornostayev S.S.; Walker R.J.; Hanski E.J.; Popovchenko S.E. (2004)

The Archean bedrock of the Ukrainian Shield is divided into western and central blocks by a N–W trending tectonic zone known as the Golovanevsk suture zone. Within this zone, there are numerous mafic-ultramafic bodies ...

EVIDENCE FOR THE EXISTENCE OF A SIMPLE RELATION BETWEEN EARTHQUAKE MAGNITUDE AND THE FRACTAL DIMENSION OF SEISMOGENIC FAULTS: A CASE STUDY FROM CENTRAL ITALY

Cello G.; Marchegiani L.; Tondi E. (2006)

Fault data from the central Apennines (Italy) were integrated with earthquake information from seismic catalogues in order to derive an empirical relation between the magnitude of the strongest historical earthquake and ...

EVIDENCE FOR THE LEADING ROLE OF TEMPERATURE VARIATIONS RELATIVE TO GREENHOUSE GAS CONCENTRATION VARIATIONS IN THE VOSTOK ICE CORE RECORD

Vakulenko N.V.; Kotlyakov V.M.; Monin A.S.; Sonechkin D.M. (2004)

Dependence of concentrations of green-house gases in atmosphere on long-term variations of temperature has been considered. It is assumed that technogeneous factor plays the main role in the global warming. However, that ...

EVIDENCE FOR THE NUCLEATION AND EPITAXIAL GROWTH OF ZN PHYLLOSILICATE ON MONTMORILLONITE

Schlegel M.L.; Manceau A. (2006)

Zinc uptake in suspensions (≤3.7 g L-1) of MX80 montmorillonite was investigated at pH 4.0 and 7.3, a total Zn concentration ([Zn]total) of 500 μM, and dissolved Si concentrations ([Si]aq) of ~70 and ~500 μM in 0.5 M NaCl, ...

Evidence for the submarine weathering of silicate minerals in Black Sea sediments: possible implications for the marine Li and B cycles.

Bohrmann, Gerhard (PANGAEA, 2004-09-21)

The role of sediment diagenesis in the marine cycles of Li and B is poorly understood. Because Li and B are easily mobilized during burial and are consumed in authigenic clay mineral formation, their abundance in marine ...

EVIDENCE FOR THE TRANSITION ZONE ORIGIN OF SOME [MG,FE]O INCLUSIONS IN DIAMONDS

Gasparik T. (2000)

Inclusions of [Mg,Fe]O (fPc, ferropericlase, magnesiowüstite) were found in natural diamonds from several localities worldwide. fPc is typically absent from upper-mantle assemblages, but expected to be common in the lower ...

EVIDENCE FROM ANTARCTIC MANTLE PERIDOTITE XENOLITHS FOR CHANGES IN MINERALOGY, GEOCHEMISTRY AND GEOTHERMAL GRADIENTS BENEATH A DEVELOPING RIFT

Foley S.F.; Jacob D.E.; Andronikov A.V.; Melzer S. (2006)

Garnet and spinel peridotite xenoliths associated with the Phanerozoic Lambert-Amery Rift in eastern Antarctica contain evidence for several stages in the development of the mantle beneath the rift. Despite the fact that ...

EVIDENCE FROM FE- AND AL-RICH METAPELITES FOR THRUST LOADING IN THE TRANSANGARIAN REGION OF THE YENISEY RIDGE, EASTERN SIBERIA

Likhanov I.I.; Polyansky O.P.; Reverdatto V.V.; Memmi I. (2004)

In the Transangarian region of the Yenisey Ridge in eastern Siberia (Russia), Fe- and Al-rich metapelitic schists of the Korda plate show field and petrological evidence of two superimposed metamorphic events. An early ...

EVIDENCE FROM NORTHWEST EUROPEAN BOGS SHOWS 'LITTLE ICE AGE' CLIMATIC CHANGES DRIVEN BY VARIATIONS IN SOLAR ACTIVITY

Mauquoy D.; Van Geel B.; Blaauw M.; Van der Plicht J. (2002)

Fluctuations in Holocene atmospheric radiocarbon concentrations have been shown to be due to variations in solar activity. Analyses of both 10Be and 14C nuclides confirm that production-rate changes during the Holocene ...

EVIDENCE FROM OLIVINE/MELT ELEMENT PARTITIONING THAT NONBRIDGING OXYGEN IN SILICATE MELTS ARE NOT EQUIVALENT

Mysen B.O.; Shang J. (2005)

Partitioning of Ca, Mn, Mg, and Fe2+ between olivine and melt has been used to examine the influence of energetically nonequivalent nonbridging oxygen in silicate melts. Partitioning experiments were conducted at ambient ...

EVIDENCE FROM OPHIOLITES, BLUESCHISTS, AND ULTRAHIGH-PRESSURE METAMORPHIC TERRANES THAT THE MODERN EPISODE OF SUBDUCTION TECTONICS BEGAN IN NEOPROTEROZOIC TIME

Stern R.J. (2005)

Earth is the only known planet with subduction zones and plate tectonics, and this fact demonstrates that special conditions are required for this mode of planetary heat loss. Sinking of cold, dense lithosphere in subduction ...

EVIDENCE FROM P-TO-S MANTLE CONVERTED WAVES FOR A FLAT "660-KM" DISCONTINUITY BENEATH ICELAND

Du Z.; Vinnik L.P.; Foulger G.R. (2006)

Iceland is the type example of a ridge-centered hotspot. It is controversial whether the seismic anomaly beneath it originates in the lower mantle or the upper mantle. Some recent studies reported that the 660-km discontinuity ...

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