scholarly journals Seismic slip history of the Pizzalto fault (central Apennines, Italy) using in situ-produced36Cl cosmic ray exposure dating and rare earth element concentrations

2016 ◽  
Vol 121 (3) ◽  
pp. 1983-2003 ◽  
Author(s):  
J. Tesson ◽  
B. Pace ◽  
L. Benedetti ◽  
F. Visini ◽  
M. Delli Rocioli ◽  
...  
Author(s):  
E. Blereau ◽  
C. Clark ◽  
P. D. Kinny ◽  
E. Sansom ◽  
R. J. M. Taylor ◽  
...  

2016 ◽  
Vol 53 (8) ◽  
pp. 788-794
Author(s):  
Živilė Žigaitė ◽  
Alexandre Fadel ◽  
Alberto Pérez-Huerta ◽  
Teresa Jeffries ◽  
Daniel Goujet ◽  
...  

In situ rare-earth element (REE) compositions have been measured in early vertebrate microremains from the Lower Devonian basin of Andrée Land (Svalbard), with the aim of obtaining information about their early depositional environment and potential reworking. Vertebrate microremains with different histology were used for the analyses, sourced from two different localities of marginal marine to freshwater sediments from geographically distant parts of the Grey Hœk Formation (Skamdalen and Tavlefjellet members). We selected thelodont and undescribed ?chondrichthyan scales, which allowed us to define potential taxonomic, histological, and taphonomic variables of the REE uptake. Results showed REE concentrations to be relatively uniform within the scales of each taxon, but apparent discrepancies were visible between the studied localities and separate taxa. The compilation of REE abundance patterns as well as REE ratios have revealed that thelodont and ?chondrichthyan originating from the same locality must have had different burial and early diagenetic histories. The shapes of the REE profiles, together with the presence and absence of the Eu and Ce anomalies, equally suggested different depositional and diagenetic environments for these two sympatric taxa resulting from either stratigraphical or long-distance reworking. The REE concentrations appear to have visible differences between separate dental tissues, particularly between enameloid and dentine of thelodonts, emphasizing the importance of in situ measurements in microfossil biomineral geochemistry.


1989 ◽  
Vol 26 (7) ◽  
pp. 1356-1367 ◽  
Author(s):  
A. D. Fowler ◽  
L. S. Jensen

The Archean tholeiitic Kinojévis suite is characterized by an iron-enrichment trend and abundant Fe–Ti oxides in its evolved basalts, andesites, and rhyolites. The rare-earth-element (REE) patterns of the suite remain flat from the basalts through to the rhyolites, with the development of small, negative Eu anomalies. Quantitative modelling of the trace elements from little-altered samples is consistent with the mineralogy, suggesting that the suite was produced through fractional crystallization of olivine, pyroxene, plagioclase, and Fe–Ti oxides. The evolved rhyolites are interpreted as having developed by greater than 90% fractional crystallization in a high-level magma chamber.The calc-alkaline Blake River Group conformably overlies the Kinojévis rocks and is characterized by enrichment in alkalis and silica. The REE patterns are light rare-earth-element (LREE) enriched, and the felsic rocks have prominent negative Eu anomalies. Geochemical modelling shows that the suite could have developed either through fractional crystallization dominated by plagioclase and clinopyroxene or by assimilation of tonalite, coupled with fractional crystallization.


2016 ◽  
Vol 31 (8) ◽  
pp. 1680-1687 ◽  
Author(s):  
X. X. Ling ◽  
Q. L. Li ◽  
Y. Liu ◽  
Y. H. Yang ◽  
Y. Liu ◽  
...  

SIMS Th–Pb dating technique of bastnaesite avoids the excess radiogenic206Pb problem and constrains mineralization time of the Himalayan Mianning–Dechang rare earth element deposits.


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