Distribution of Ca in highly fractionated peralkaline magmas

Marsh, Julian S

Title: Distribution of Ca in highly fractionated peralkaline magmas
Creator: Marsh, Julian S
Date Issued: 1976
Date: 1976
Type: text
Type: article
Identifier: http://hdl.handle.net/10962/132974
Identifier: vital:36914
Identifier: https://doi.org/10.1016/0012-821X(76)90106-0
Description: Many peralkaline rhyolites and granites contain less than 0.15 wt.% CaO. In contrast, strongly fractionated peralkaline nepheline syenites and phonolites usually contain greater than 0.5 wt.% CaO. Consideration of known distributions of Ca between crystals and liquid in conjunction with crystal fractionation does not provide an adequate explanation of the contrasting levels of Ca depletion observed. Examination of the suites of late-crystallizing accessory phases in peralkaline rocks suggests that Ca is more soluble in undersaturated magmas than in over-saturated magmas. Activities for CaO in silicic and phonolitic rocks are calculated and the latter have higher CaO activities than the former and this may manifest itself in the different suites of accessory phases and levels of Ca depletion noted in natural rocks.
Format: 8 pages
Format: pdf
Language: English
Relation: Earth and Planetary Science Letters
Relation: Marsh, J.S., 1976. Distribution of Ca in highly fractionated peralkaline magmas. Earth and Planetary Science Letters, 31(1), pp.153-160.
Relation: Earth and Planetary Science Letters volume 31 number 1 153 160 June 1976 0012-821X
Rights: Elsevier
Rights: Use of this resource is governed by the terms and conditions of the Elsevier Terms and Conditions Statement (https://www.elsevier.com/legal/elsevier-website-terms-and-conditions)

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Marsh, Julian (Goonie)(Prof)

RU Department of Geology

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