نتایج جستجو برای: alkali feldspar

تعداد نتایج: 17765  

Journal: :فصلنامه زمین شناسی محیط زیست 0
اسماعیل درویشی استادیار گروه زمین شناسی، دانشگاه آزاد اسلامی، واحد الیگودرز

the dehno granite massive is located in the east dehno village and southern khomein city and within themetamorphic sanandaj–sirjan zone. the composition of these rocks include: granodiorite, quartzdiorite(tonalite), monzogranite and leucogranite. quartz, alkali feldspar, plagioclase, biotite, andalusite, hornblendemuscovite, tourmaline, zircon and apatite are examples of the existing major and ...

2006
J. E. GARCIA HERNANDEZ J. S. NOTARIO

-The chemical and the mineralogical composition of a group of pumiceous tufts associated with recent salic volcanic episodes from Tenerife (Canary Islands) have been studied. The investigation focused on the two main types of pyroclastic deposits of the zone: ash-flows and ash-falls. The samples can be classified chemically as trachytic and phonolitic rocks with an intermediate silica content a...

2017
KAREN S. TAYLOR

The internal layering and provenance of feldspar in 3 tills and in one outwash deposit at Gahanna, Ohio, were studied by determining pebble lithologies and Rb-Sr dates of feldspar. Variations in lithology of pebbles and in the Rb-Sr ratios of feldspar in the 125—250 micrometer fractions reveal discontinuities which divide the upper 2 tills into 2 subunits each. Each of the lower subunits appear...

Journal: :SADJ : journal of the South African Dental Association = tydskrif van die Suid-Afrikaanse Tandheelkundige Vereniging 2010
A R Le Roux N Lachman

INTRODUCTION Flexure of a dental composite can be detrimental to the success of a restoration. Flexibility considerations are thus important when comparing dental materials to optimize the success of resin restorations. AIMS AND OBJECTIVES Flexibility of 5.6 x 18.0 x 2.0 mm3 experimental alumina/feldspar and SR ADORO dental composites specimens were compared. It was hypothesized that alumina/...

2008
DANIEL FERNÁNDEZ MOSQUERA SANJURJO SÁNCHEZ

In the dating of sediments by luminescence methods, to obtain a sample the purest possible as to its mineralogy determines the rest of the analytical procedures. The isolation of the sample minerals is a critical stage due to the impossibility of quantifying the relative contributions to the dose from the different minerals. In this paper we propose a non chemical method to isolate quartz from ...

Journal: :geopersia 2013
amir ali tabbakh shabani reza zarei sahamieh zohre keshavarz

tourmaline can be found as an accessory mineral in a variety of rocks including leucogranite, pegmatite, quartz veins, and metamorphiccountry rocks in hajiabad-dehgah area in se of boroujerd city. tourmaline in pegmatites is coarse-grained, subhedral to euhedral, anddisplays strong to moderate pleochroic blue rimmed by olive green. in contrast, tourmalines from leucogranite, quartz-veins, and h...

Journal: :Minerals 2021

The study reports petrography, mineralogy and carbonate geochemistry stable isotopy of various types ocelli (silicate-carbonate globules) observed in the lamprophyres from Chadobets Uplift, southwestern Siberian craton. are related to REE-bearing Chuktukon carbonatites. On basis their morphology, relation with surrounding groundmass, we distinguish three ocelli: carbonate-silicate, containing c...

1999
P. TROPPER

The eclogite facies assemblage K-feldspar–jadeite–quartz in metagranites and metapelites from the SesiaLanzo Zone (Western Alps, Italy) records the equilibration pressure by dilution of the reaction jadeite+quartz=albite. The metapelites show partial transformation from a pre-Alpine assemblage of garnet (Alm63Prp26Grs10)–K-feldspar–plagioclase–biotite±sillimanite to the Eo-Alpine high-pressure ...

2001
M. WILKINSON KITTY L. MILLIKEN STUART HASZELDINE

Systematic patterns of detrital K-feldspar decline with increasing burial depth are revealed during deep burial (1.5–4.5 km) of sandstones in diverse sedimentary basins from three rift and two passive margin settings in the North Sea and USA Gulf Coast. K-feldspar destruction is predominantly by dissolution, though in-situ alteration to albite also occurs. Dissolution can remove up to 15% solid...

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