Rare earth abundances were determined by neutron activation in twenty Hawaiian lavas and one diabase of known chemical and mineralogical compositions. These results demonstrate a systematic relationship between the absolute or relative rare earth abundances and the petroehemistry of these rocks. Three distinct lava groups are recognized. These correspond to: (1) tholeiites, (2) alkali series, (...

New crystallization temperatures for four eruptions from the Northern Volcanic Zone of Iceland are determined using olivine-spinel aluminum exchange thermometry. Differences in the olivine crystallization temperatures between these eruptions are consistent with variable extents of cooling during fractional crystallization. However, the crystallization temperatures for Iceland are systematically...

salafchegan-khorhe volcanic rocks are exposed within urumieh-dokhtar magmatic belt. different kinds of volcanic and subvolcanic rocks of calc-alkaline to alkaline character have been reported throughout this magmatic belt. since, isotopic investigations are very useful for detection of magma petrogenesis and because no isotopic studies have been done in this area, so a geochemical and isotopic ...

This study reassesses the development of compositional layering during the growth of granitic plutons, with emphasis on fractional crystallization and its interaction with both injection and inflationrelated deformation. The Dolbel batholith (SW Niger) consists of 14, kilometre-sized plutons emplaced by pulsed magma inputs. Each pluton has a coarse-grained core and a peripheral layered series. ...

-A new general method for the preparation of 2-alkyl-pipecolic acids has been developed. The syntheses of 2-methyl-, 2-benzyland cis-6-methylpipecolic acids are described. ( ) S and (+)R-2-methylpipecolic acids were resolved by fractional crystallization of the quinine salt of their N-carbobenzoxy derivative. Isolation of (-)S-cis-6-methylpipecolic acid required the use of 4-phenylbenzyloxycarb...

Introduction: We have developed a model to calculate the cooling rate (or burial depth) by using the Fe-Mg chemical zoning profile of olivine, considering diffusional modification of zoning profiles as crystals grow by fractional crystallization from a melt [e.g., 1]. We applied the model to calculating cooling rates of olivines in the Semarkona (LL3.00) chondrite [2]. In this abstract, we appl...

has been obtained in pure form from baker 's yeast by a method based chiefly on fractional precipitation with alcohol. 1 mg. of the pure protein catalyzes the transfer of 4.2 mg. P per minute at 30 ° and pH 7.5. The reported crystallization of the protein from dilute alcohol is not readily reproducible. Crystallization from ammonium sulfate (Fig. 1) according to the procedure of Kunitz and McDo...

New empirical calibrations for the fractionation of oxygen isotopes among zircon, almandine-rich garnet, titanite, and quartz are combined with experimental values for quartz-grossular. The resulting A-coefficients (‰K) are: for the relation 1000 ln Y-X AY-X (10 /T). The fractionation of oxygen isotopes between zircon and coexisting minerals can provide otherwise unavailable evidence of magmati...

clinopyroxene phenocrysts and microphenocrysts in potassic and sodic eosen alkaline volcanic rocks from the northern lahrud (nw iran) record various stages in the crystallization and evolution history of the alkaline melt as well as its origin. the rock series hosting the clinopyroxene phenocrysts is phonolitic tephrite and tephritic phonolite composition. theses rocks generally show porphyriti...