An interim report on some New Zealand Scheelites.

Barraclough, D

Up-to-date geochemical information about New Zealand scheelite is lacking; the last recorded analyses were published in 1945.
New methods of analysis such as Atomic Absorption are now available and 14 new analyses are presented, the results of which can be used to correlate between the scheelite fields but only to a limited extent.
Atomic Absorption has been used to determine tungsten, the results of which have been checked gravimetrically. Molecular absorption is reported by sodium carbonate.
Large variations in the iron and magnesium results indicate absorption of the sediments by platinum.
Interference is reported in the colourimetric determination of silica.
A petrographic investigation suggests that early-formed quartz and scheelite have crystallised more or less simultaneously and were followed by calcite. Fracturing and cataclasis have introduced new solutions which have partially replaced the early formed minerals.

49 leaves. ill. 27 cm.

1969Barraclough