Anorthosite complexes

Farquhar J, Chacko T, Frost BR (1993) Strategies for high-temperature oxygen isotope thermometry A worked example from the Laramie Anorthosite Complex, Wyoming USA Earth Planet Sci Lett 117 479-492... 

Figure 11. Isotope Exchange Trajectories (lET) for magnetite from six rocks from the Sybille Fe-Ti-oxide quarry, Laramie anorthosite complex. The average temperature of intersection, 1077+25°C, is higher than Tc for any mineral in these rocks, and it is interpreted as the solidus temperature of the magma (from Farquhar et al. 1993).

In 2004, nearly 90% of the titanium minerals mined in the world today came either directly from igneous magnetite-ilmenite ore bodies associated with primary anorthosite complexes or secondary placer deposits derived from the weathering of these complexes. 

M. D. Schmitz, S. A. Bowring, and T. R. Ireland. Evaluation of Duluth Complex Anorthositic Series (AS3) Zircon as a U-Pb Geochronological Standard New High-Precision Isotope Dilution Thermal Ionization Mass Spectrometry Results, Geochim. Cosmochim. Acta, 67(2003) 3665-3672. 

In an attempt to upgrade the siliceous bauxites and other aluminous materials, such as clay where the alumina usually is in the form of complex silicates, Skow and Conley (Si 9) considered the removal of the silica by caustic digestion. Prior to leaching, the aluminuous materials were calcined at 970°C, resulting in an optimal removal of silica with little loss in alumina content in the subsequent leaching step. The desilication step is necessary prior to using the raw materials as feed to the standard Bayer process (E3). The pilot plant operation to extract alumina from an anorthosite ore has been reported by St. Clair et al. (S24). 

SCHARER, U., WiLMART, E. DUCHESNE, J, C. 1996. The short duration and anorogenic character of anorthosite magmatism U-Pb dating of the Rogaland complex, Norway. Earth and Planetary Science Letters, 139, 335-350. 

Ilmenite from massive hard-rock anorthosite Magmatic complexes always contains less TiO, than segr tion... 

Within the Stillwater Complex, fine-scale layering is only locally well developed. It is found associated with chromite-bearing rocks and, in the most extensive developments, with layered norites associated with anorthosites in the middle portions of the complex. Where best developed, as in figure 1, the layering may be present over a stratigraphic distance of several tens of meters. 

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