Showing papers in "Chemical Geology in 1972"

TL;DR: In this article, four rare earth element microprobe standards have been prepared, and the compositions of the standards were independently confirmed by instrumental neutron activation analysis. The base is a synthetic Ca-Alsilicate glass to which 3-4 weight percent REE have been added.

TL;DR: In this paper, it has been shown that amorphous hydroxides of Al, Fe, Mg, etc are capable of co-precipitating silica even from very dilute surface solutions.

TL;DR: Examination of the thermal changes occurring in spore exines is presented including stable carbon isotope studies, and the potential of sporopollenin as a major progenitor of natural petroleum is discussed.

TL;DR: In this paper, a detailed analysis of the deep-water sediments of the Black Sea during Late Pleistocene and Holocene time is presented, including three sedimentary units: (1) a microlaminated coccolith ooze mainly consisting of Emiliania huxleyi ; (2) a sapropel; and (3) banded lutite.

TL;DR: In this paper, the authors characterized cathodoluminescence and X-ray induced luminescence in the visible range of the spectrum for Mn2+ activated carbonate minerals.

TL;DR: Considering all known phosphatic substances in animal hard parts, it is found that amorphous constituents are far more common in invertebrates than crystalline compounds.

TL;DR: Petrological and geochemical studies of the metasediments in the central part of the Chitaldrug schist belt, Mysore, India indicate that these metsediments, most probably were supplied from an area of predominantly basic composition.

TL;DR: In this paper, the isotopic composition of carbon and oxygen in the carbonates, the amount of acid insoluble residue, as well as the concentrations of P 2 O 5, Ca, Mg, Sr and Fe were determined.

TL;DR: The sodium content of dolomite crystals from the Middle Devonian Pine Point lead-zinc district of northern Canada is related to the diagenetic history of the crystals as discussed by the authors.

TL;DR: In this article, the ratio FeO/MgO is used as an indicator of the degree of fractionation in oceanic tholeiites, in which plagioclase crystallized first and showed higher concentrations of Sr and lower concentrations of Cr, Ga, Ni, Pb and V.

TL;DR: In this article, it was shown that the Bernal liquid model of random close packing does not apply to silicate glasses and that measurements on these glasses cannot provide reliable information about coordination numbers in silicate liquids.

TL;DR: In this paper, the distribution of the elements Fe and Mn, Sr-isotopes, and inorganic deep sea carbonates in sediments along active ridges and possibly also deep sea pH support the hypothesis that shallow hydrothermal leaching of basalt is a major source of active ridge sediments.

TL;DR: The dependence of luminescence on Fe/Mn concentration and in heating of the host mineral was instrumental in allowing the use of emission intensity for the detection, in a general manner, of the location of a hydrothermal ore body in a limestone sequence as discussed by the authors.

TL;DR: In this paper, chemical analyses of some 406 widely scattered samples of Archean shale from the Superior province of the Canadian Shield have been performed and it was shown that mobile elements were removed by weathering during the Archean in approximately the same relative proportion as during later periods; and that the calcium thus liberated has not been redeposited with the shales.

TL;DR: The metal-solubilizing properties of quinones, together with their unusual stability in the geological column, may play a significant role in the concentration of metals in the substrate enriched with organic compounds containing quinone groups as discussed by the authors.

TL;DR: In this article, the boron content of travertines can be related to the Boron concentration in the travertine-depositing thermal waters in terms of the Freundlich adsorption isotherm.

TL;DR: Platinum and gold have been determined simultaneously in 43 chondrites by neutron activation analysis as discussed by the authors, using a rapid radio-chemical procedure employing a substoichiometric separation of gold was used.

TL;DR: In the presence of kaolinite and at temperatures not exceeding 80°C, polysaccharides were synthesized from aqueous solutions of paraformaldehyde; pentoses and hexoses were preferentially formed as discussed by the authors.

TL;DR: The chemistry of two different types of granitic rocks from a polymetamorphic Precambrian basement complex is described in the light of their metamorphic and tectonic history as mentioned in this paper.

TL;DR: The average K, Rb, T1 abundances in 26 Mid-Atlantic Ridge basalts are 2,660 p.p.m., 6.6 p.m. as mentioned in this paper.

TL;DR: In this article, the abundance of iodine and uranium in sedimentary rocks was determined by neutron activation analyses, showing that the iodine content is higher in the sediments than in igneous rocks and the iodine concentrations follow the same general pattern as chlorine and bromine.

TL;DR: In this article, the geochemistry of the non-carbonate fraction of sediments from the continental shelf and slope off northwest Africa has been investigated using R-mode factor analysis, which is governed by a small number of factors controlled quantiatively by glauconite, phosphorite, quartz, clay minerals and secondary iron oxides.

TL;DR: In this article, the effect of sodic-phosphate solutions on calcite is studied and it is shown that it is not a replacement of calcite by phosphate, but a dissolution of calcites followed by a precipitation of phosphate from ions in solution.

TL;DR: The contents of uranium in mineral fractions from some basic rocks and peridotite nodules have been measured as mentioned in this paper, and it appears that peridotsite nodule range in uranium content, between 48 · 10−2 to 82 · 10 −3 ppm.

TL;DR: In this paper, the oxygen Kα emission spectra from ten simple oxides have been investigated using an A.R.L. electron microprobe and it is found that these spectra can be satisfactorily interpreted using qualitative molecular orbital theory.

TL;DR: Oxygen isotope ratios of twenty samples from a cut surface of a barite slab have been measured and from various considerations it is concluded that the barite probably originated by the reaction between ascending magmatic solutions containing dissolved barium and the interstitial water of sediments.

TL;DR: In this article, a suite of rocks and minerals from the Skaergaard intrusion, east Greenland, was determined by atomic absorption spectrophotometry using a pre-concentration technique.

TL;DR: In this paper, the authors used neutron activation procedures for the determination of rhenium in sea water and sediments, and found that water from the North Atlantic was found to contain 2.7-5.8 ng 1−1 of Re (average 4.0 ng 1 −1 Re).

TL;DR: A soluble fraction of organic matter was extracted from the salt-free sediment with benzene-methanol, and after chemical treatment with hydrochloric acid, hydrofluoric acid and lithium aluminium hydride, an insoluble organic sample was also obtained.