Rare-earth and minor element distribution and petrographic features of fluorites and associated Mesozoic limestones of northwestern Sicily

1981 ◽  
Vol 32 (1-4) ◽  
pp. 255-269 ◽  
Author(s):  
A. Bellanca ◽  
P. Di Salvo ◽  
P. Möller ◽  
R. Neri ◽  
F. Schley
1970 ◽  
Vol 78 (3) ◽  
pp. 304-325 ◽  
Author(s):  
Tom Simkin ◽  
J. V. Smith

1973 ◽  
Vol 3 (2) ◽  
pp. 307-315 ◽  
Author(s):  
M.J. Dudas ◽  
M.E. Harward ◽  
R.A. Schmitt

AbstractPrimary mineral phenocrysts from eight different late Quaternary pyroclastic deposits were fractionated for neutron-activation analysis with the purpose of characterizing each of the deposits on the basis of trace and minor element compositions. In hornblende separates, contents of several rare earth and transition elements were found to be distinctive for the Mazama, Glacier Peak, and several St. Helens deposits. In magnetites, abundances of transition elements are characteristic and serve as good discriminants for the pyroclastic deposits examined in this investigation. Contents of transition and rare earth elements in hyperthenes also appear useful in distinguishing volcanic ash deposits. Trace and minor element abundances in plagioclase phenocrysts did not appear adequate for identification of pyroclastics due to elemental depletion and similarity of contents for feldspar separates. It was found that contents of Sm and Yb in hornblende phenocrysts would serve to distinguish between several pyroclastic deposits from the Pacific Northwest.


1984 ◽  
Vol 48 (349) ◽  
pp. 495-505 ◽  
Author(s):  
P. Mitropoulos

AbstractRock samples from the various metabasic hornfelses of the Land's End granite aureole were analysed for major elements by X-ray fluorescence analysis and for rare-earth elements (REE) by instrumental neutron activation analysis (INAA). The REE patterns of the unaltered dolerites of the area seem to be analogous to those of the alkali basalts, taking into account a slight mobilization of the light REE during low-grade metamorphism.The REE content of the metabasic rocks of the aureole has increased relative to that of the unaltered dolerites due to the introduction of REE, along with K, from the granite by the action of hydrothermal solutions. The parallel increase in REE with the increase in K is demonstrated.The metasomatic hornfelses of igneous origin form two groups showing slightly different REE patterns and different rates of increase in REE content. The REE patterns of the two groups show a Eu anomaly increasing with the increase in REE content for the first group and decreasing with the increase in REE content for the second group, A qualitative model of the distribution of the REE in the metabasic aureole rocks is given.


1982 ◽  
Vol 45 (337) ◽  
pp. 211-218 ◽  
Author(s):  
J. J. Fawcett ◽  
J. Gittins ◽  
J. C. Rucklidge ◽  
C. K. Brooks

AbstractWhole-rock, minor element, rare earth, and electron microprobe data are presented for basaltic lavas from the western Kangerdlugssuaq area of East Greenland. Samples were obtained from Professor W. A. Deer's 1936 collection at Triangular Nunataks and Gardiner Plateau, and additional material obtained by sampling moraines on the surface of Kangerdlugssuaq Glacier. Both undersaturated and tholeiitic lavas are present at the Triangular Nunatak locality but the glacier suite is dominantly tholeiitic. The tholeiitic suite is less evolved than tholeiites from the Scoresby Sund area. Undersaturated lavas show enrichment in light rare earth elements and tholeiitic lavas show fiat chondrite-normalized patterns. Tholeiites from the Gardiner Plateau show no Eu anomaly but others show a slight negative Eu anomaly. Chemical data and considerations of regional geology are consistent with Cox's (1980) model of flood basalt vulcanism.


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