A new natural occurrence of zirconolite (CaZrTi₂O₇) and baddeleyite (ZrO₂) in basic cumulates: the Laouni layered intrusion (Southern Hoggar, Algeria)

Abstract

Four grains of zirconolite and baddeleyite have been found in two plagioclase-rich adcumulates from the Laouni layered intrusion (Southern Hoggar, Algeria). Zirconolite is poor in REE; baddeleyite is chemically close to ZrO 2 and contains minor amounts of Hf. They are considered to be crystallization products of pockets of intercumulus liquid. The preferential distribution of zirconolite in anorthosite is explained in terms of expulsion of the intercumulus liquid by sintering or annealing of plagioclase. The crystallization of baddeleyite reflects the sharp increase of Zr in the trapped intercumulus liquid.

Baddeleyite: new occurrences from two mafic-ultramafic layered intrusions, Russia

“…Additional trace elements were sought (AI, Mg, Mn, Na, K, V, Zn, Ce, La, Nd, Pr, Y, U, Th, Nb, Ta) but were not detected. The composition differs from samples reported from two other localities (Keil and Fricker, 1974;Lorand and Cottin, 1987) by having higher Hf contents. It is particularly noteworthy that in the Lukkulaisvaara baddeleyite there are significant differences in the Ti contents from earlier (ultramafic) cumulates compared with those from the more evolved meta-anorthositic cumulates.…”

“…-... similar to baddeleyite from some other reported localities (e.g. Lorand and Cottin, 1987), and does not support a possibility that it crystallized early as a cumulus phase. We suggest that a genetic link exists between the presence of a volatile-rich fluid phase circulating through the lower Lukkulaisvaara cumulates and sporadic baddeleyite occurrences in them.…”

“…The presence of baddeleyite was recorded in the UG-2 chromitite layer, Bushveld igneous complex (McLaren and De Villiers, 1982) and in the Koitelainen layered intrusion, northern Finland (Tarkian and Mutanen, 1987), but compositions were not given. Another baddeleyite occurrence from basic cumulates was reported from the Laouni layered intrusion, Algeria (Lorand and Cottin, 1987). Hf-bearing baddeleyite has also been identified in the Penikat layered intrusion, northern Finland, although full analytical data were not given (Halkoaho et al, 1989).…”

Zr- AND Ba-RICH MINERALS FROM THE PONTE NOVA ALKALINE MAFIC-ULTRAMAFIC MASSIF, SOUTHEASTERN BRAZIL: INDICATION OF AN ENRICHED MANTLE SOURCE

“…The spectrum of host rocks includes carbonatites, kimberlites, alkaline intrusions, pegmatites, skarns, potassic lavas, metacarbonates, granulites, lunar basalts, and alluvial deposits (Williams & Gieré 1996, Gieré et al 1998. However, most of the occurrences of zirconolite and baddeleyite are associated with carbonatite and mafic to ultramafic SiO 2 -undersaturated magmas (Lorand & Cottin 1987, Chakhmouradian & Zaitsev 1999, Zaccarini et al 2004.…”

Detrital and authigenic(?) baddeleyite (ZrO2) in ferromanganese nodules of Central Indian Ocean Basin

“…In terrestrial environment it occurs mainly as an accessory mineral in alkaline, silica-undersaturated rocks such as sanidinites, kimberlites, carbonatites, and syenites, as well as in hydrothermal and alluvial deposits, altered pyroxenite and some metamorphic rocks (Keil and Fricker, 1974;Williams, 1978;Raber and Haggerty, 1979;Scatena-Wachel and Jones, 1984;Lorand and Cottin, 1987). The mineral has also been recorded from extra-terrestrial rocks such as lunar basalts, breccias, tektites, and meteorites (Bukovansk a et al, 1997;Kuehner et al, 2007).…”