The Arrhenius plot for 39At released uring step heating of a sample containing a distribution of diffusion domains will depart from a straight line in ways that depend on the domain size distribution and the heating schedule used to extract he 39At. In a new series of experiments we make use of the heating schedule effect to confirm the multidomain nature of several alkali feldspar samples. We ...

Introduction: The Mars Science Laboratory (MSL) rover Curiosity recently completed its fourth drill sampling of sediments on Mars. The Confidence Hills (CH) sample was drilled from a rock located in the Pahrump Hills region at the base of Mt. Sharp in Gale Crater. The CheMin X-ray diffractometer completed five nights of analysis on the sample, more than previously executed for a drill sample, a...

We explore the potential effects of magmatic assimilation on mineral growth and mineral zoning in an alkali olivine basaltic magma using both equilibrium thermodynamics and kinetics. The equilibrium-model calculations simulate fractional crystallization alone (closed system) and coupled assimilation fractional crystallization (AFC) (open system); the models predict the assemblages ofmagmatig mi...

or the length of time which the process requires. The allanite replacements in the Tan-y-Grisiau microgranite suggest that unmixing was completed before hydrothermal minerals began to crvstallize and suggests, therefore, that in some instances, at least, unmixing ma.v belong to an early, relatively high temperature post-magmatic phase' The reason for the selective replacement of K-feldspar b.v ...

Experimental studies show that K replacement of Na in triclinic plagioclase under hydrothermal conditions results directly in triclinic microcline without forming intermediate monoclinic orthoclase. These experiments bring laboratory and field evidence into agreement for the K-metasomatic origin of granites which contain exclusively microcline as the potash feldspar. Such replacements of a more...

New heat capacity data obtained on 12 samples of the low albite–low microcline series are presented. They were measured by relaxation and differential scanning calorimetry between 5 and 773 K. Two series, differing in their starting materials, were investigated, both of which were prepared via molten salt and solid-solid ion-exchange techniques in previous studies. The heat capacity of both ser...

Feldspars are ubiquitous natural dosimeters widely used in luminescence dating. Despite decades of research, the lattice defects as well mechanisms involved production feldspars remain poorly understood. The recently developed method infrared photoluminescence (IRPL) excitation-emission spectroscopy has revealed presence two electron trapping centres emitting IRPL at 1.3 eV and 1.41 (IRPL1.3 IR...

Abstract Petrographic, organic, and inorganic geochemical analysis of the solid bitumen host shales from Middle Late Jurassic-age Sargelu Naokelekan Formations Banik section, northernmost Iraq, was undertaken. The aim to understand their derivation preservation, as well examine carbon oxygen isotopes, paleoredox proxies under which sediments were deposited. Petrographic both formations revealed...

Feldspar is a domain specific language, embedded in Haskell, for programming digital signal processing algorithms. The final aim of a Feldspar program is to generate low level code with good performance. Still, we chose to provide the user with a purely functional DSL. The language is implemented as a minimal, deeply embedded core language, with shallow extensions built upon it. This paper pres...