TY - JOUR
T1 - The role of mantle-derived volatiles in the petrogenesis of Palaeoproterozoic ferropicrites in the Pechenga Greenstone Belt, northwestern Russia : Insights from in-situ microbeam and nanobeam analysis of hydromagmatic amphibole
AU - Fiorentini, Marco
AU - Beresford, S.W.
AU - Deloule, E.
AU - Hanski, E.
AU - Stone, W.E.
AU - Pearson, N.J.
PY - 2008
Y1 - 2008
N2 - New in-situ trace element and hydrogen isotopic data of hydromagmatic amphiboles from ferropicritic gabbro-wehrlite intrusions and lava flows of the Palaeoproterozoic Pechenga Greenstone Belt (Russia) provide insights into the controversial source of volatiles that are implicated in Precambrian ultramafic magmatism. The intrusions mainly contain oikocrystic kaersutites and pargasites, whereas lava flows generally include idiomorphic Fe-kaersutites and Fe-pargasites. All orthomagmatic amphiboles display slightly LREE-enriched chondrite-normalised patterns. Primitive mantle-normalised patterns of amphiboles from the intrusions display positive Nb-Ta, moderate negative Th-U and distinctive negative Sr-Li anomalies. Conversely, Fe-kaersutites and Fe-pargasites from the lava flows display undepleted Th, U, Sr and Li signatures. Boron and Cl enrichment is primarily observed in secondary edenites, which locally rim orthomagmatic kaersutites. In-situ delta D measurements of hydromagmatic amphiboles from the gabbro-wehrlite intrusions display values ranging between -70 parts per thousand and -170 parts per thousand, and total water contents between 1 and 3 wt. %. Conversely, primary hydromagmatic amphiboles from the Pechenga flows display lighter delta D compositions ranging between -100 parts per thousand and -270 parts per thousand, and lower (
AB - New in-situ trace element and hydrogen isotopic data of hydromagmatic amphiboles from ferropicritic gabbro-wehrlite intrusions and lava flows of the Palaeoproterozoic Pechenga Greenstone Belt (Russia) provide insights into the controversial source of volatiles that are implicated in Precambrian ultramafic magmatism. The intrusions mainly contain oikocrystic kaersutites and pargasites, whereas lava flows generally include idiomorphic Fe-kaersutites and Fe-pargasites. All orthomagmatic amphiboles display slightly LREE-enriched chondrite-normalised patterns. Primitive mantle-normalised patterns of amphiboles from the intrusions display positive Nb-Ta, moderate negative Th-U and distinctive negative Sr-Li anomalies. Conversely, Fe-kaersutites and Fe-pargasites from the lava flows display undepleted Th, U, Sr and Li signatures. Boron and Cl enrichment is primarily observed in secondary edenites, which locally rim orthomagmatic kaersutites. In-situ delta D measurements of hydromagmatic amphiboles from the gabbro-wehrlite intrusions display values ranging between -70 parts per thousand and -170 parts per thousand, and total water contents between 1 and 3 wt. %. Conversely, primary hydromagmatic amphiboles from the Pechenga flows display lighter delta D compositions ranging between -100 parts per thousand and -270 parts per thousand, and lower (
U2 - 10.1016/j.epsl.2007.12.018
DO - 10.1016/j.epsl.2007.12.018
M3 - Article
SN - 0012-821X
VL - 268
SP - 2
EP - 14
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
ER -