The zircon SHRIMP chronology and trace element geochemistry of the Carboniferous volcanic rocks in western Tianshan Mountains

2005 ◽  
Vol 50 (19) ◽  
pp. 2201-2212 ◽  
Author(s):  
Yongfeng Zhu ◽  
Lifei Zhang ◽  
Libing Gu ◽  
Xuan Guo ◽  
Jing Zhou
Keyword(s):  
Trace Element ◽  
Volcanic Rocks ◽  
Tianshan Mountains ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Western Tianshan

A petrological and geochemical study of the volcanic rocks of the Crowsnest Formation, southwestern Alberta, and of the Howell Creek suite, British Columbia

2006 ◽  
Vol 43 (11) ◽  
pp. 1621-1637 ◽  
Author(s):  
Melissa Bowerman ◽  
Amy Christianson ◽  
Robert A Creaser ◽  
Robert W Luth
Keyword(s):  
British Columbia ◽  
Trace Element ◽  
Isotope Geochemistry ◽  
Source Region ◽  
Volcanic Rocks ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Geochemical Study ◽  
Geological Sciences ◽  
Ree Patterns

Alkaline igneous rocks of the Crowsnest Formation in southwestern Alberta and in the Howell Creek area in southeastern British Columbia have been suggested previously to be cogenetic. To test this hypothesis, samples of both suites were characterized petrographically and their major and trace element geochemistry was determined. A subset of the samples was analyzed for whole-rock Sr and Nd isotope geochemistry. The samples of the two suites are latites, trachytes, and phonolites based on the International Union of Geological Sciences (IUGS) total alkalis versus silica (TAS) diagram. Samples from both suites show similar patterns on mantle-normalized trace element diagrams, being enriched relative to mantle values but depleted in the high field-strength elements Nb, Ta, and Ti relative to the large-ion lithophile elements. The chondrite-normalized rare-earth element (REE) patterns for both suites are light REE enriched, with no Eu anomaly and flat heavy REE. The isotope geochemistry of both suites is characterized by low initial 87Sr/86Sr (SrT = 0.704 to 0.706) and low εNdT (–7 to –16). The Howell Creek samples have lower εNdT and higher SrT than do the Crowsnest samples. Based on the intra- and intersuite differences in the isotope geochemistry, we conclude that these samples are not cogenetic, but rather represent samples that have experienced similar evolutionary histories from a heterogeneous source region in the subcontinental lithospheric mantle.

Trace element geochemistry of Cenozoic volcanic rocks in Shandong Province

1989 ◽  
Vol 8 (3) ◽  
pp. 254-266
Author(s):  
Chen Daogong ◽  
Li Binxian ◽  
Zhang Xun
Keyword(s):  
Trace Element ◽  
Volcanic Rocks ◽  
Shandong Province ◽  
Trace Element Geochemistry ◽  
Element Geochemistry

scholarly journals Trace-Element Geochemistry of Volcanic Rocks from Site 786: The Izu-Bonin Forearc

1992 ◽  
Author(s):  
B.J. Murton ◽  
D.W. Peete ◽  
R.J. Arculus ◽  
J.A. Pearce ◽  
S. van der Laan
Keyword(s):  
Trace Element ◽  
Volcanic Rocks ◽  
Trace Element Geochemistry ◽  
Element Geochemistry

Trace element geochemistry of the Meen-Dempster greenstone belt, Uchi subprovince, Superior Province, Canada: back-arc development on the margins of an Archean protocontinent

2000 ◽  
Vol 37 (7) ◽  
pp. 1021-1038 ◽  
Author(s):  
Pete Hollings ◽  
Greg Stott ◽  
Derek Wyman
Keyword(s):  
Trace Element ◽  
Greenstone Belt ◽  
Volcanic Rocks ◽  
Tholeiitic Basalt ◽  
Pyroclastic Flows ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Lree Enrichment ◽  
Compositional Diversity ◽  
Back Arc

Comprehensive trace element analyses of mafic and felsic volcanic rocks from the 2.85-2.74 Ga Meen-Dempster greenstone belt reveal a wide compositional diversity. The ~2.85 Ga Kaminiskag assemblage is dominated by mafic tholeiite characterized by predominantly unfractionated REE (La/Smn = 0.8-1.1). Rare intermediate and felsic pyroclastic flows (SiO2 = 62-74) with moderate to pronounced LREE enrichment are intercalated with the tholeiite. The Kaminiskag assemblage is overlain by the ~2825 Ma Meen assemblage, comprising dominantly dacitic tuffs and pyroclastic breccia, displaying enriched LREE (La/Smn = 3.7-7.2) and moderately fractionated HREE, in conjunction with pronounced negative Nb anomalies. Five distinct suites have been recognized in the ~2740 Ma Confederation assemblage: (1) tholeiitic basalt with flat to smoothly depleted REE, (2) tholeiite with flat to weakly depleted LREE in conjunction with pronounced negative Nb anomalies, (3) Fe-rich basalt with elevated Ti and P contents, LREE enrichment, and fractionated HREE, (4) LREE enriched basalt and andesite with negative Nb anomalies, and (5) dacite and rhyolite with enriched LREE, moderately fractionated HREE, and variable high field strength element anomalies. The geochemistry and geochronology of the Kaminiskag and Meen assemblages are consistent with the formation of an oceanic back arc (Kaminiskag assemblage), which formed the basement for a subduction-related arc complex (Meen assemblage) after a 15 Ma hiatus. The Confederation assemblage is interpreted to represent an Archean back arc, where the complex interplay of mantle sources allows for the eruption of tholeiite, subduction-modified tholeiite, ocean island basalt-like basalt, and subduction-related arc-type volcanic rocks. The recognition of back-arc basins within the Meen-Dempster greenstone belt emphasizes a continuity of crustal growth processes from the Archean to the present day.

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