Carbon and oxygen isotopic composition of carbonatite dikes and metamorphic country rock of the Haast Schist terrain, New Zealand
✍ Scribed by Peter Blattner; A. F. Cooper
- Publisher
- Springer
- Year
- 1974
- Tongue
- English
- Weight
- 759 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0010-7999
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✦ Synopsis
A lamprophyre dike swarm intruding the Haast Schist terrain of Southern New Zealand includes Ba-, Sr-, and REE-rich carbonatitcs with carbon and oxygen isotopic compositions quite distinct from those of the country rock. In the light of more recent literature data it is argued that the field of carbon and oxygen isotopic compositions defined by Taylor et al. (1967) as pertaining to "primary igneous carbonatites" (PIC), is still relevant. The Haast carbonatite isotopic compositions are readily derived from the PIC field, if assimilation of and isotopic exchange with the known country rock by the magma is allowed for. The Haast Schist terrain is very poor in carbonate rocks and may directly overlie oceanic crust. Hence ~C TM values typical of lower crust or upper mantle sources are preserved in the Haast carbonatites, and only 50 TM has been modified during intrusion. * Institute of Nuclear Sciences contribution no. 639.