Tracking the evolution of mantle sources with incompatible element ratios in stagnant-lid and plate-tectonic planets

2017 ◽  
Vol 213 ◽  
pp. 47-62 ◽  
Author(s):  
Kent C. Condie ◽  
Charles K. Shearer
Keyword(s):  
Incompatible Element ◽  
Plate Tectonic ◽  
Element Ratios ◽  
Mantle Sources

The occurrence of niobian zirconolite, pyrochlore and baddeleyite in the Kovdor carbonatite complex, Kola Peninsula, Russia

1996 ◽  
Vol 60 (401) ◽  
pp. 639-646 ◽  
Author(s):  
C. Terry Williams
Keyword(s):  
Kola Peninsula ◽  
Incompatible Element ◽  
Fluid Composition ◽  
Carbonatite Complex ◽  
Compositional Zoning ◽  
Accessory Minerals ◽  
Element Ratios ◽  
Backscattered Electron ◽  
Oxide Minerals ◽  
High Concentrations

AbstractThe compositions and textural relationships of the oxide minerals zirconolite, pyrochlore and baddeleyite are described. These occur as accessory minerals, often intergrown with each other, from a phoscorite rock associated with the Kovdor carbonatite complex. Both the zirconolite and baddeleyite have relatively high concentrations of Nb and Ta; the pyrochlore is rich in U and Ta. Backscattered electron images, coupled with detailed microprobe analyses, reveal complex compositional zoning in zirconolite and pyrochlore which reflect changes in the fluid composition during growth of these minerals. A comparison is made of incompatible element ratios Zr/Hf, Nb/Ta and Th/U between the three accessory minerals.

A comparative geochemical study of Mars and Earth basalt petrogenesis

2013 ◽  
Vol 50 (1) ◽  
pp. 78-93 ◽  
Author(s):  
John D. Greenough ◽  
Avee Ya’acoby
Keyword(s):  
Incompatible Element ◽  
A Priori ◽  
Correlation Coefficients ◽  
Small Sample ◽  
Geochemical Data ◽  
Data Set ◽  
Element Ratios ◽  
Highly Correlated ◽  
Small Sample Sizes ◽  
Priori Information

Geochemical data, from the Mars Meteorite Compendium web site, for 13 basaltic meteorites, possibly from only four localities on Mars, are used to study Martian petrogenetic processes. To achieve this goal, an exploratory data analysis technique, multidimensional scaling (MDS), is used to quantitatively assess the relative behavior (measured with correlation coefficients) of 160 incompatible element ratios involving 25 “trace” elements. The ratios behave as in Earth basalts, suggesting that relative element incompatibility is similar in both planets. Because mineralogy controls incompatibility, the mineralogy of Earth and Mars mantles appears similar. In addition, results suggest that ratios involving elements with highly different incompatibility (e.g., La/Yb) are dominantly controlled by % melting. Plots of SiO2 (pressure proxy; decreases with increasing pressure) versus La/Yb and Nb/Y (decrease as melting increases) imply that Mars basalts, like Earth tholeiites, reflect high percentages of melting, but opposite to Earth, % melting appears to increase with increasing pressure. The moderately correlated, positive, SiO2–La/Yb Mars relationship parallels highly correlated Lunar KREEP data and contrasts with Earth’s negative correlation. The positive relationships may reflect restricted mantle convection in some (Mars and the Moon are smaller) planetary bodies. Using similarly incompatible element ratios that are sensitive to source composition, to compare Mars and Earth with MDS, Mars sources most resemble depleted Earth mantle. Additionally, these ratios group Mars sources into enriched, depleted, and intermediate types. The groupings are the same as those suggested by isotopes, and we conclude that trace element data support the hypothesis that chemical variation in Mars may reflect crystallization of a Mars magma ocean. The natural patterns in ratios and samples revealed using MDS, which has no a priori information about relationships, support integrity of the geochemical data set, despite potential shortcomings such as small sample sizes, alteration, and weathering. However, whether the meteorites are representative of Mars as a whole is unknown.

Petrological and geochemical constraints on the genesis of Mesozoic–Cenozoic magmatism of King George Island, South Shetland Islands, Antarctica

1991 ◽  
Vol 3 (3) ◽  
pp. 293-308 ◽  
Author(s):  
K. Birkenmajer ◽  
L. Francalanci ◽  
A. Peccerillo
Keyword(s):  
Incompatible Element ◽  
South Shetland Islands ◽  
Geochemical Data ◽  
King George Island ◽  
Island Arcs ◽  
Calc Alkaline ◽  
Constant Composition ◽  
Shetland Islands ◽  
Element Ratios ◽  
Incompatible Trace Elements

Petrological and geochemical data are reported for a series of Late Cretaceous-Middle Miocene volcanic, hypabyssal and intrusive rocks from King George Island (KGI) and from nearby Ridley Island, South Shetland Islands. Major element data indicate a calc-alkaline, basic to intermediate composition for the analysed samples. Although emplaced on a continental margin, the KGI rocks generally display low abundances of incompatible trace elements, close to those typically observed in calc-alkaline suites erupted in intraoceanic island arcs. A few samples have a significant negative Ce anomaly. Many incompatible elements define smooth positive trends on interelemental variation diagrams which suggests that magmas erupted at different times on KGI maintained a rather constant composition in terms of incompatible element ratios. Geochemical modelling, based on Sr isotope ratios and incompatible element ratios, suggests that the primary calc-alkaline magmas of KGI were all generated in an upper mantle modified by addition of small amounts of pelagic sediments dragged down by subduction processes.

Isotopic study of basaltic dikes in the Nain Plutonic Suite: evidence for enriched mantle sources

1993 ◽  
Vol 30 (6) ◽  
pp. 1141-1146 ◽  
Author(s):  
R. W. Carlson ◽  
R. A. Wiebe ◽  
R. I. Kalamarides
Keyword(s):  
Mantle Source ◽  
Incompatible Element ◽  
Isotopic Study ◽  
Major Element Composition ◽  
Enriched Mantle ◽  
Mantle Sources ◽  
Mineral Isochron ◽  
Lithospheric Mantle Source ◽  
Nain Plutonic Suite ◽  
Alkalic Basalts

Basaltic dikes cutting the Nain Plutonic Suite (NPS) of Labrador include two chemically distinct groups. One is a high-Fe tholeiitic to transitional alkalic composition similar to some of the magmas involved in the formation of the NPS. The other, distinguished by high phosphorus and incompatible element contents, is similar in major element composition to intraplate oceanic alkalic basalts. A Rb–Sr mineral isochron for one high-P2O5 sample defines an age of 1276 ± 23 Ma indicating that it is similar in age to, or only slightly younger than, the circa 1305 Ma anorthosites.Compositional and isotopic characteristics of the high- and low-P2O5 dikes show that the gross features of their initial isotopic characteristics (i.e., low 87Sr/86Sr, negative εNd, nonradiogenic Pb) probably derive from a distinct lithospheric mantle source with similar characteristics. To have developed these isotopic characteristics by the time of dike emplacement, their mantle source must have formed and separated from oceanic-type upper mantle well prior to Nain anorthosite genesis, possibly between 2.0 and 2.6 Ga.

New insights for the mantle source components of the most primitive recent basaltic rocks from central and western Anatolia: Evidences for the involvement of pyroxenite and the peridotite source domains

2020 ◽  
Author(s):  
Biltan Kurkcuoglu ◽  
Tekin Yurur
Keyword(s):  
Mantle Source ◽  
Incompatible Element ◽  
Central Anatolia ◽  
Spinel Peridotite ◽  
Western Anatolia ◽  
The West ◽  
Cinder Cones ◽  
Basaltic Rocks ◽  
Mantle Sources ◽  
Source Component

<div> <p>Basaltic activities  developed  extensively in central and western Anatolia since middle –Miocene to quaternary time, the most primitive lavas are  situated at  the eastern end of  central Anatolia, (southern Sivas) and the most recent ones  are situtated in central (basaltic cinder cones at south of Hasandağ) and also in western Anatolia (Kula region),  Among those  primitive recent  lavas, mantle sources that are responsible for the generation of basaltic rocks is  still a matter of a debate.          </p> <p>Previous studies suggested  that  spinel peridotite source   is the dominant source  component  for many of the basaltic rocks which are situated in several different locations in central Anatolia, including, Erciyes and Hasandağ stratovolcanoes,  Erkilet, Develidağ, Karapınar vents and Salanda fissure eruptions while Sivas fissure basalts in the east,  Gediz and Kula  basalts in the west, were  derived  mostly  from  the  garnet peridotite sources, but , the  specific  incompatible element ratios  and the melting model based on Rare Earth Elements obviously  indicate that  these basaltic rocks could not be solely generated  from  the garnet- spinel transition zone,   instead another mantle source component need to be involved  in the generation of the basaltic rocks.</p> <p>Tb/Yb(N) and Zn/Fe  ratios provide significant values   in order to constraint for the magmas  generated from the asthenosphere.  Tb/Yb(N) ratio seperates  garnet – spinel transition [1]  and Zn/Fe  ratio  displays separation between the peridotite-derived (Zn/Fe <12, [2,3]) and pyroxenite-derived (13-20 [2,3]) melts.  Zn/Fe, as well as  the  Tb/Yb(N) ratios and the melting model display  that single spinel  source   component  is not solely   responsible for  the generation of  the basaltic rocks,   pyroxenite  source domain  should    also  be involved in   during  the genesis of these rocks as well, besides, the  contributions from  the both of the  mantle source domains also explain the  depleted  magma nature that is observed  in some of recent basaltic rocks ( e.g, Salanda  and  Hasandağ  volcanic  systems) which is diffrent  from the dominated alkaline character,  generally observed  as  the   final products  of central Anatolian  magmatism   </p> <p><em>1.Wang et al., 2002, J.Geophys.Res.vol:107,ECV 5 1-21</em></p> <p><em>2 .Le Roux, et al.,2011,EPSL, vol:307, 395-408</em></p> </div><p><em>3. Ducea, et al.,2013, GEOLOGY, Vol:41, 413-417</em></p><p><em>This study   is financially supported by Hacettepe University, BAB project no: FHD-2018-17283</em></p>

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