Results 211 to 220 of about 5,174 (245)

In vacuo crushing experiments and K-feldspar thermochronometry

Earth and Planetary Science Letters, 1993
Using in c, acuo crushing methods, both C1- and K-correlated components of trapped 4°At have recently been identified in hypersolvus alkali feldspar and K-feldspar-bearing 'chert' and stromatolite samples. If these components re-emerge during the late stages of thermal degassing, interpretation of 4°Ar/39Ar age spectra could be complicated.
T. Mark Harrison, Matthew T. Heizler, Oscar M. Lovera   +2 more
openaire   +1 more source

Cosmogenic chlorine-36 production in K-feldspar

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997
The high production rate of in-situ cosmogenic 36Cl from potassium allows K-rich minerals to be dated with high sensitivity and precision. K-rich minerals, such as K-feldspar and biotite are commonly associated with quartz in which 26Al and 10Be are produced, allowing three cosmogenic nuclides, with half-lives ranging from 0.3 Ma to 1.5 Ma, to be ...
J.M. Evans, J.O.H. Stone, L.K. Fifield, R.G. Cresswell   +3 more
openaire   +1 more source

K-Feldspar Cement in the Jacobsville Sandstone

SEPM Journal of Sedimentary Research, 1978
ABSTRACT Authigenic, monoclinic, potassium feldspar has been found in the Jacobsville sandstone. The feldspar is chert-like in appearance or recrystallized in an adularia habit. It contains < 0.1% Na2O and
openaire   +1 more source

How late are K-feldspar megacrysts in granites?

Lithos, 2008
Abstract Various petrologists have suggested that K-feldspar megacrysts grow in granites that are extensively crystallized, even at subsolidus conditions. However, experimental evidence indicates that, though K-feldspar nucleates relatively late in the crystallization history, abundant liquid is available for development of large crystals.
R.H. Vernon, S.R. Paterson
openaire   +1 more source

Tunneling radiative recombination in K-feldspar sanidine

Nuclear Tracks and Radiation Measurements, 1993
Abstract A study has been made of the afterglow from three sanidine samples following beta irradiation. The temperature was lowered to 77 K, then raised to 750 K and the emission spectra were measured from ultraviolet (u.v.) to 890 nm. An intense emission is observed at liquid nitrogen temperature, entirely in the red and infrared (i.r.) part of the ...
openaire   +1 more source

Temperature effects on the electrical conductivity of K‐feldspar

Geophysical Prospecting
AbstractK‐feldspar, which constitutes about 60 of the Earth's crust, is crucial for understanding electrical conductivity in porous rocks. Its electrical properties are vital for applications in ceramics, electrical insulation and conductive polymers.
Supti Sadhukhan, Tapati Dutta
openaire   +1 more source

Stability of the assemblage cordierite +K feldspar+quartz

Contributions to Mineralogy and Petrology, 1976
Under hydrous conditions the stability field of the assemblage Mg-cordierite+K feldspar+quartz is limited on its low-temperature side by the breakdown of cordierite+K feldspar into muscovite, phlogopite and quartz, whereas the high-temperature limit is given by eutectic melting.
openaire   +1 more source

K-feldspar megacrysts in granites — Phenocrysts, not porphyroblasts

Earth-Science Reviews, 1986
Abstract K-feldspar megacrysts in granitoid plutons have been interpreted as either phenocrysts or porphyroblasts. Most of the microstructural, mineralogical and chemical evidence (e.g., shape, alignment, concentration, Ba content, zoning, inclusions, and twinning) favours a phenocryst origin.
openaire   +1 more source

K-Feldspar-Rich Aplite Dykes in the Yolcular Metamorphics (Bitlis Massif): A Potential Source for K-Feldspar

2015
  Bitlis Masifi'ndeki Yolcular Metamorfitleri içinde gözlenen aplit daykları feldispat minerallerince zenginleşme göstermektedirler. Bu çalışmada Bitlis Masifi'nin alt birliğini kesen aplit dayklarının K-feldispat kaynağı olarak kullanılabilirliği araştırılmıştır.
Oyan, Vural, Özdemir, Yavuz
openaire   +1 more source

Coccolith in a K-feldspar: A note.

Journal of Nannoplankton Research, 2000
K. Salis, D. Bernoulli
openaire   +1 more source