Carbonatite complexes of circular (ring) and linear structural-morphological type: the comparison of fenite haloes at the example of Alno (Sweden) and Chernigovka (Ukraine) massifs

• Main Authors: Yu. Ye. Nykanorova, I. I. Lazareva, S. Ye. Shnyukov, O. V. Kovtun
• Format: Article in Journal/Newspaper
• Language: English; Russian; Ukrainian
• Published: Ukrainian Geological Company (UGC) 2015
• Subjects: carbonatite massifs; fenitization; pre-azov region; ukrainian shield; fennoscandian shield; Geology; QE1-996.5; Fennoscandian
• Online Access: https://doaj.org/article/7e285ae7dca6438185a9318d6f5676bf

Mineralogical, petrographic and geochemical features of fenitization halos of circular (ring) and linear carbonatite complexes, Alno (Sweden) and Chernigovka (Ukraine), respectively, have been investigated. Similar features of mineral associations changes during host rocks fenitization in both complexes have been identified. They are: (1) gradual disappearance of relict minerals (quartz, plagioclase An10-30, hornblende); (2) increasing of aegerine minal in clinopyroxene; (3) emergence of newly formed paragenesis: albite, microcline, alkaline pyroxene and amphibole, phlogopite, calcite; (4) increasing of apatite and titanite content. According to the character of major and trace elements behavior during fenitization three groups of elements have been distinguished for both Alno and Chernigovka complexes, they are: elements are lost, elements are gained and elements are redistributed. Using elements whose behavior is characterized by stable gaining (Sr, Ba) a single for both complexes multiplicative geochemical zonation index has been suggested. This index objectively displays the increasing of host rocks transformation level and allows to observe changes of main ore components concentrations.