Premium
Origin of silicate minerals in carbonatites from Alnö Island, Sweden: magmatic crystallization or wall rock assimilation?
Author(s) -
Vuorinen Jaana Hode,
Skelton Alasdair D. L.
Publication year - 2004
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2004.00557.x
Subject(s) - carbonatite , silicate , geology , silicate minerals , geochemistry , wall rock , electron microprobe , crystallization , mineralogy , mantle (geology) , chemical engineering , engineering
Textural, electron microprobe and whole rock geochemical evidence from carbonatites and associated silicate rocks on Alnö Island, Sweden, suggest that the carbonatite, at the time of emplacement, could have been an (almost) pure CaCO 3 liquid with a high volatile (H 2 O–CO 2 ) content and that most silicate minerals, which are ubiquitously present, are either (1) assimilated from the surrounding wall rock, by progressive and coupled fragmentation and corrosion; or (2) by‐products of corrosive interaction between the carbonatite liquid and the wall rock. This interpretation is supported by balancing a reaction to describe interaction between carbonatite and a cpx + ne‐bearing (ijolite) wall rock. Although our analysis does not preclude the possibility that fenitizing agents (e.g. Na, Fe) were transported by the carbonatite liquid, these components are not required to drive the observed mineralogical changes in the carbonatite.