Efficiency of compaction and compositional convection during mafic crystal mush solidification: the Sept Iles layered intrusion, Canada

in Contributions to Mineralogy & Petrology (in press)

Experimental investigation of the alluaudite + triphylite assemblage, and development of the Na-in-triphylite geothermometer: applications to natural pegmatite phosphates

in Contributions to Mineralogy & Petrology (2011), 161

Ilmenite composition in the Tellnes Fe–Ti deposit, SW Norway: fractional crystallization, postcumulus evolution and ilmenite–zircon relation

in Contributions to Mineralogy & Petrology (2007), 154(2), 119-134

Major and trace element XRF and in situ LA-ICP-MS analyses of ilmenite in the Tellnes ilmenite deposit, Rogaland Anorthosite Province, SW Norway, constrains a two stage fractional crystallization model of ... [more ▼]

Major and trace element XRF and in situ LA-ICP-MS analyses of ilmenite in the Tellnes ilmenite deposit, Rogaland Anorthosite Province, SW Norway, constrains a two stage fractional crystallization model of a ferrodioritic Fe-Ti-P rich melt. Stage 1 is characterized by ilmenite-plagioclase cumulates, partly stored in the lower part of the ore body (Lower Central Zone, LCZ), and stage 2 by ilmenite-plagioclase-orthopyroxene-olivine cumulates (Upper Central Zone, UCZ). The concentration of V and Cr in ilmenite, corrected for the trapped liquid effect, (1) defines the cotectic proportion of ilmenite to be 17.5 wt% during stage 1, and (2) implies an increase of D VIlm during stage 2, most likely related to a shift in fO2. The proportion of 17.5 wt% is lower than the modal proportion of ilmenite (ca. 50 wt%) in the ore body, implying accumulation of ilmenite and flotation of plagioclase. The fraction of residual liquid left after crystallization of Tellnes cumulates is estimated at 0.6 and the flotation of plagioclase at 26 wt% of the initial melt mass. The increasing content of intercumulus magnetite with stratigraphic height, from 0 to ca. 3 wt%, results from differentiation of the trapped liquid towards magnetite saturation. The MgO content of ilmenite (1.4–4.4 wt%) is much lower than the expected cumulus composition. It shows extensive postcumulus re-equilibration with trapped liquid and ferromagnesian silicates, correlated with distance to the host anorthosite. The Zr content of ilmenite, provided by in situ analyses, is low (<114 ppm) and uncorrelated with stratigraphy or Cr content. The data demonstrate that zircon coronas observed around ilmenite formed by subsolidus exsolution of ZrO2 from ilmenite. The U-Pb zircon age of 920 ± 3 Ma probably records this exsolution process. [less ▲]

Experimental study of a jotunite (hypersthene monzodiorite) : constraints on the parent magma composition and crystallization conditions (P, T, fO2) of the Bjerkreim-Sokndal intrusion (Norway)

in Contributions to Mineralogy & Petrology (1994), 118

Fluid inclusions in charnockites from the Bjerkreim-Sokndal massif (Rogaland, southwestern Norway): fluid origin and in situ evolution

in Contributions to Mineralogy & Petrology (1991), 108

Petrogenesis of monzonoritic dykes in the Egersund-Ogna anorthosite (Rogaland, SW Norway)

in Contributions to Mineralogy & Petrology (1985), 90