A combined study of noble gases, trace elements, and Sr-Nd isotopes for alkaline and tholeiitic lava from the Hyblean Plateau (Italy)

The occurrence of carbonatites in oceanic settings is very rare if compared with their continental counterpart, having been reported only in Cape Verde and Canary Islands. This paper provides an overview of the main geochemical characteristics of oceanic carbonatites, around which many debates still exist regarding their petrogenesis. We present new data on trace elements in minerals and whole-rock, together with the first noble gases isotopic study (He, Ne, Ar) in apatite, calcite, and clinopyroxene from Fuerteventura carbonatites (Canary Islands). Trace elements show a similar trend as Cape Verde carbonatites, almost tracing the same patterns on multi-element and REE abundance diagrams. 3He/4He isotopic ratios of Fuerteventura carbonatites reflect a shallow (sub-continental lithospheric mantle, SCLM) He signature in their petrogenesis, and they clearly differ from Cape Verde carbonatites, i.e., fluids from a deep and low degassed mantle with a primitive plume-derived He signature are involved in their petrogenesis.

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Pb-Sr-Nd Isotopes and Trace Elements of Granitoids in the Qinling Orogenic Belt, Central China: Implications for Evolution of Deep Crust Composition and Continental Subduction

Mineralogical Magazine ◽

10.1180/minmag.1998.62a.3.219 ◽

1998 ◽

Vol 62A (3) ◽

pp. 1691-1692

Author(s):

H.-F. Zhang

Keyword(s):

Trace Elements ◽

Orogenic Belt ◽

Central China ◽

Nd Isotopes ◽

Qinling Orogenic Belt ◽

Continental Subduction ◽

Deep Crust

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Noble gases as trace elements in magmatic processes

Chemical Geology ◽

10.1016/0009-2541(94)90120-1 ◽

1994 ◽

Vol 117 (1-4) ◽

pp. 37-56 ◽

Cited By ~ 56

Author(s):

Michael R. Carroll ◽

David S. Draper

Keyword(s):

Trace Elements ◽

Noble Gases ◽

Magmatic Processes

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Petrological and geochemical (trace elements and Sr–Nd isotopes) characteristics of the Paleozoic Kovdor ultramafic, alkaline and carbonatite intrusion (Kola Peninsula, NW Russia)

Lithos ◽

10.1016/s0024-4937(99)00072-9 ◽

2000 ◽

Vol 51 (1-2) ◽

pp. 1-25 ◽

Cited By ~ 52

Author(s):

A Verhulst ◽

E Balaganskaya ◽

Y Kirnarsky ◽

D Demaiffe

Keyword(s):

Trace Elements ◽

Kola Peninsula ◽

Nd Isotopes

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Assessing the Natural Performance of Felsic Tuffs Using the Rb-Sr and Sm-Nd Systems-A Study of the Altered Zone in the Topopah Spring Member, Paintbrush Tuff, Yucca Mountain, Nevada

MRS Proceedings ◽

10.1557/proc-212-687 ◽

1990 ◽

Vol 212 ◽

Cited By ~ 2

Author(s):

Zell E. Peterman ◽

Richard W. Spengler ◽

Kiyoto Futa ◽

Brian D. Marshall ◽

Shannon A. Mahan

Keyword(s):

Trace Elements ◽

Drill Hole ◽

Yucca Mountain ◽

Sr Isotope ◽

Nd Isotopes ◽

Minor And Trace Elements ◽

High Silica ◽

Altered Zone ◽

Nd Systems ◽

Isotope System

ABSTRACTCore samples of the Topopah Spring Member of the Paintbrush Tuff from drill hole UE25A#1 were analyzed for Sr and Nd isotopes and selected minor and trace elements to constrain the origin of a zcolitized zone associated with the lower vitrophyre. The Sm-Nd radiogenic isotope system was unperturbed by the alteration, but the Rb-Sr system was severely disturbed in the altered zone. The thick, densely welded high-silica rhyolite is remarkably uniform in composition with only a slight decrease in initial 87Sr/86Sr ratios with depth (0.7129–0.7125). Quartz latite in the upper part of the Topopah Spring has significantly lower initial Sr isotope ratios (0.7095–0.7114). Locally in the altered zone, Sr and Ca were gained in substantial amounts, and K, Rb, and Y were removed. Ti, Zr, Nb, Ba, La, Ce, Sm, and Nd were relatively immobile during the alteration. Sr added to the altered zone had an isotopic composition of 0.7119 ± 0.0002 and was probably derived from dissolution of glass in the bulk Topopah Spring (high silica rhyolite + quartz latite) and transported downward by infiltration.

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