MlNERALOGICAL STUDY OF Mg-SKARNS WITH CLINOHUMITE AT THE OMERLI SITE AGGISTRO, SERRES


Ε. Δήμου
Κ. Κούκουζας
Abstract

Mg-skam occurrences located in the dolomitic marbles at the Omerli site near Aggistro are studied. The dolomitic marbles are gradually enriched in metasomatic minerals, up to the full replacement and the formation of cohesive lenticular beds of skarns in the marbles. The aplito-pegmatitic veins traversing the surrounding marbles as well as the granodiorite occurring in the broader area of Ahladohoho, are considered responsible for the phenomena of thermal metamorphism and metasomatism in the dolomites. On the basis of mineralogical analytical methods (optical microscopy, X-Ray diffraction, microanalysis) the following metasomatic minerals in decreasing order, have been determined: Clinohumite (Mg, Fe +)Q (Si04)4(F,OH)2, forsterite Mg2Si04, spinel MgAb04, hornblende-pargasite NaCa2 (MgFe% AI(SÌ6AI2)022(F,OH)2, clinochlore (MgFe2+)AI(SÌ3AI)Oi0(OH)8, phlogopite KMg3SÌ3AIOio(F, OH)2, dolomite, calcite. The mineral chemistry and petrography of the above assemblages lead to the conclusion that the skarns at Omerli site constitute pure metasomatic concentrations at the expense of the dolomites, with addition of elements from external thermal source and removal of elements from the hosting dolomites. It is, therefore, an open chemical system and not an iso-chemical one.

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  • Mineralogy and Crystallography
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References
Γκάρτζου Ε. Γ. 1981. Σχηματισμός χονδροδίτου εις αλκαλικά καρττονατιτικά συμπλέγματα. Δελτ. Ελλ. Γεωλ. Εταιρίας Τ. XV, σελ. 161-167.
Κατιρτζόγλου Κ. & Παλόγλου Γ. 1991. Κοιτασματολογική μελέτη περιοχών Αγ.Κων/νου και Πότοκα Αγκίστρου Ν. Σερρών. Εσωτ. Εκθεση ΙΓΜΕ, Ξάνθη, σελ.25.
Κούκουζας Κ. 1976. Εττί της κοιτασματολογικής ερεύνης περιοχής Αγ.Κων/νου-Πότοκα Αγκίστρου Σερρών. Εσωτ. Εκθ. ΙΓΜΕ, σελ.57 Αθήνα.
Burnham C. W. 1959. Contact metamorphism of magnesian limestones at Crestmore, California. Bull. Geol. Society of America, 70, 879-920.
Deer W. Α., Howie R. A, Zussman J. 1982. Rock-forming Minerals. V. IA orthosilicates p.p 379-117.
Zachos S. & Dimades E. 1983. The geotectonic position of the Scalotis-Echinos granites and its relationship to the metamorphic formations of Greek Western and central Phodopes. Geol. Bale, 13, 5, p.p. 17-24.
Frey M., Hunziker J. C, Frank W., Bocguet J., Dal Piaz G. V., Jager E. & Niggli E. 1974. Alpine Metamorphism of the Alps-Α Review. SMPM, 54 p.p. 247-290.
Guitard G. & Laffite P. 1958. Les calcaires métamorphiques et les skarns du pic des Costabonne (Pyrenees-Orientales). Sciences de la Terre T. VI No 1-2 p.p. 57-137.
Korzhinskii D. S. 1968. The theory of Metasomatic Zoning. Mineral. Deposita (Beri.) 3, p.p. 222- 231.
Moticska P. 1970. Pétrographie und Strukturanalyse des westlichen Bergeller Massivs und seines Rahmens. SMPM 50, p.p. 355-444.
Papageorgakis J. 1961. Marmore und Kalksilikatfelse der Zone Ivrea-Verbano Zwischen Ascona und Candoglia. Διατριβή επί διδακτορία Zurich ή SMPM 41, p.p. 157-254.
Papanikolaou G. & Papagopoulos A. 1981. On the structural style of Southern Rhodope, Greece.Geol.Balo, 11,3, p.p.13-22.
Tilley C. E. 1951. The zoned contact- skarns of the Broadford area, Skye: a study of boron- fluorine metasomatism in dolomites. Mineral. Magazine Vol. 29 No 214 p.p. 621-667.
Trommsdorff V. 1966. Beobachtungen zur Paragenese Forsterit (Klinohumit, chondrodit) - Klinochlor in metamorphen Dolomitgest einen des Lepontins SMPM 46, p.p.421-429.
Trommsdorff V. & Schwander H. 1969. Brucitmarmore in den Bergelleralpen. SMPM 49, p.p. 333- 336.
Wenk E. 1963. Klinohumit und Chondrodit in Marmoren der Tessineralpen und der Disgrazia- Gruppe. SMPM 43, p.p. 287-293.
Wenk, H.R. 1970. Geologische Beobachtungen in Bergell. I. Gedanken zur Genese des Bergeller Granits. Ruckblick und Ausblick. SMPM 50, p.p. 321-348.
Wenk H. R & Maurizio R. 1970. Geological Observations in the Bergell Area (SE-Alps) II. Contact Minerals from Mt. Sissone-Cima di Vazzeda SMPM 50 p.p. 349-354.
Wetzel R. 1972. Zur Pétrographie und Mineralogie der Furgg-Zone (Monte Rosa-Decke) SMPM 52, p.p.161-236.
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