U–Pb zircon age, geochemical and isotopic characteristics of carbonatite and syenite complexes from the Shaxiongdong, China

Xu, Cheng; Campbell, Ian H.; Allen, Charlotte M.; Chen, Yanjing; Huang, Zhilong; Qi, Liang; Zhang, Guishan; Yan, Zeyu

doi:10.1016/j.lithos.2008.03.002

Cited by 57 publications

(31 citation statements)

References 45 publications

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“…This mineral forms characteristic hexagonal crystals, either co-genetic with calcite in calcite carbonatites (e.g., Bear Lodge and Shaxiongdong; Xu et al 2008;Moore et al 2015) or in later REE-rich pegmatites (e.g., Khibiny; Zaitsev et al 1998). The primary nature of burbankite is supported by its stable (O and C) isotope composition, which is within the range of values for primary magmatic carbonatites (Zaitsev et al 2002).…”

Section: Electronic Supplementary Materialsmentioning

confidence: 99%

Deducing the source and composition of rare earth mineralising fluids in carbonatites: insights from isotopic (C, O, 87Sr/86Sr) data from Kangankunde, Malawi

Broom-Fendley

Wall

Spiro

et al. 2017

Contrib Mineral Petrol

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Section: Electronic Supplementary Materialsmentioning

confidence: 99%

Deducing the source and composition of rare earth mineralising fluids in carbonatites: insights from isotopic (C, O, 87Sr/86Sr) data from Kangankunde, Malawi

Broom-Fendley

Wall

Spiro

et al. 2017

Contrib Mineral Petrol

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“…much higher than the measured levels of this element dolomite (grey diamonds) from Aley (this work). In addition to the publications cited above, diagrams (a) and (b) were constructed the data from Hornig-Kjarsgaard (1998), Ionov and Harmer (2002), Dawson and Hinton (2003), Xu et al (2007Xu et al ( , 2008a ( Table 2). The equivalent content of P would be about twice as low, but above the detection limit of WDS (~0.03 wt.% P 2 O 5 ).…”

Section: Trace Elements In Carbonatitic Calcite: a Synthesis Of Publimentioning

confidence: 99%

“…The former type of patterns is predominant among the samples examined in the present work, i.e.~70 % of the analyses give (La/Yb) cn ≥25. The dataset of published calcite analyses contains a large proportion of data for (post)orogenic Chinese carbonatites characterized by very low (La/Yb) cn ratios ranging from 0.5 to 2.8 at Miaoya (Xu et al 2010) to 17-29 at Maoniuping (Xu et al 2008a). If the number of localities, rather than the number of analyses, is taken into account, about 50 % of the calcite compositions are strongly dominated by LREE.…”

Section: Trace Elements In Carbonatitic Calcite: a Synthesis Of Publimentioning

confidence: 99%

“…Without this knowledge, it is impossible to interpret correctly much of petrologic data used routinely for tracking the origin of carbonatitic magmas (e.g., radiogenic isotope ratios, or textural interrelations between silicate and carbonate minerals). This information is also important from a practical standpoint: for example for the study of igneous and hydrothermal rare-earth deposits associated with carbonatites (Xu et al 2008a(Xu et al , 2010. Despite all this, there is a limited amount of published data on the trace-element chemistry of carbonate minerals from igneous rocks.…”

Section: Introductionmentioning

confidence: 99%

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Calcite and dolomite in intrusive carbonatites. II. Trace-element variations

et al. 2015

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The composition of calcite and dolomite from several carbonatite complexes (including a large set of petrographically diverse samples from the Aley complex in Canada) was studied by electron-microprobe analysis and laserablation inductively-coupled-plasma mass-spectrometry to identify the extent of substitution of rare-earth and other trace elements in these minerals and the effects of different igneous and postmagmatic processes on their composition. Analysis of the newly acquired and published data shows that the contents of rare-earth elements (REE) and certain REE ratios in magmatic calcite and dolomite are controlled by crystal fractionation of fluorapatite, monazite and, possibly, other minerals. Enrichment in REE observed in some samples (up tõ 2000 ppm in calcite) cannot be accounted for by coupled substitutions involving Na, P or As. At Aley, the REE abundances and chondrite-normalized (La/Yb) cn ratios in carbonates decrease with progressive fractionation. Sequestration of heavy REE from carbonatitic magma by calcic garnet may be responsible for a steeply sloping Bexponential^pattern and lowered Ce/Ce* ratios of calcite from Magnet Cove (USA) and other localities. Alternatively, the low levels of Ce and Mn in these samples could result from preferential removal of these elements by Ce 4+ -and Mn 3+ -bearing minerals (such as cerianite and spinels) at increasing f(O 2 ) in the magma. The distribution of large-ion lithophile elements (LILE = Sr, Ba and Pb) in rock-forming carbonates also shows trends indicative of crystal fractionation effects (e.g., concomitant depletion in Ba + Pb at Aley, or Sr + Ba at Kerimasi), although the phases responsible for these variations cannot be identified unambiguously at present. Overall, element ratios sensitive to the redox state of the magma and its complexing characteristics (Eu/Eu*, Ce/Ce* and Y/Ho) are least variable and in both primary calcite and dolomite, approach the average chondritic values. In consanguineous rocks, calcite invariably has higher REE and LILE levels than dolomite. Hydrothermal reworking of carbonatites does not produce a unique geochemical fingerprint, leading instead to a variety of evolutionary trends that range from light-REE and LILE enrichment (Turiy Mys, Russia) to heavy-REE enrichment and LILE depletion (Bear Lodge, USA). These differences clearly attest to variations in the chemistry of carbonatitic fluids and, consequently, their ability to mobilize specific trace elements from earlier-crystallized minerals. An important telltale indicator of hydrothermal reworking is deviation from the primary, chondrite-like REE ratios (in particular, Y/Ho and Eu/Eu*), accompanied by a variety of other compositional changes depending on the redox state of the fluid (e.g., depletion of carbonates in Mn owing to its oxidation and sequestration by secondary oxides). The effect of supergene processes was studied on a single sample from Bear Lodge, which shows extreme depletion in Mn and Ce (both due to oxidation), coupled with enrichment in Pb and U, po...

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“…The Aeronian/Telychian boundary is currently dated at 436 ± 1.9 Ma (Ogg 2004). The Osmundsberg K-bentonite, lying (Peccerillo 2005, Mourão et al 2010, Nelson Eby et al 2009, Xu et al 2008. Black quadrangle -Ol Donio Lengai natro-carbonatite (Zaitsev & Keller 2006).…”

Section: Time Of the Anomalous High-ree Eventmentioning

confidence: 99%

The Geniai Tuff in the southern East Baltic area - a new correlation tool near the Aeronian/Telychian stage boundary, Llandovery, Silurian

Kiipli¹,

Radzievičius²,

Kallaste³

et al. 2012

Bull. Geosci.

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In three drill cores in Latvia and Lithuania a thin (1 cm thick) altered volcanic ash bed with high concentrations of phosphorus (up to 3%), cerium (1%), lanthanum (0.5%) and strontium (2.5%), has been found close to the Aeronian/Telychian boundary (Llandovery, Silurian, ca 438 Ma). Small, millimetre-thick lenses within the ash bed contain up to 12% P and Sr, up to 6% Ce and 3% La. These elements occur as a solid solution of goyazite-florencite mineral. Additionally, authigenic K-feldspar and kaolinite occur in this ash bed. The high concentrations of REE elements, strontium and phosphorus suggest a carbonatite source magma, but the strontium isotope ratio contradicts that origin. Such a unique composition in a volcanic ash layer is a good basis for using it as a marker horizon for correlation of sections.

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U–Pb zircon age, geochemical and isotopic characteristics of carbonatite and syenite complexes from the Shaxiongdong, China

Cited by 57 publications

References 45 publications

Deducing the source and composition of rare earth mineralising fluids in carbonatites: insights from isotopic (C, O, 87Sr/86Sr) data from Kangankunde, Malawi

Deducing the source and composition of rare earth mineralising fluids in carbonatites: insights from isotopic (C, O, 87Sr/86Sr) data from Kangankunde, Malawi

Calcite and dolomite in intrusive carbonatites. II. Trace-element variations

The Geniai Tuff in the southern East Baltic area - a new correlation tool near the Aeronian/Telychian stage boundary, Llandovery, Silurian

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