Mineral occurrences from the Neogene-Quaternary volcanic chain Cálimani-Gurghiu-Harghita (Eastern Carpathians, Románia)

Abstract

Derive from the geological structure of Seclerland, the mineral occurrences from here are numerous
and very diversified. In respect of genesis, these mineralisations are linked to the Neogene-Quaternary
calc-alkaline volcanism, to the Alkaline Massif of Ditráu and to the Crystalline-Mesozoic Zone of Eastern
Carpathians. Because of the number of mineral occurrences are very large, this work is focused only on
the Cálimani-Gurghiu-Harghita Neogene-Quaternary volcanic chain.
In the Cálimani-Gurghiu-Harghita mountain's area and in the immediate neighbourhood there are
many mineral occurrences which are linked geneticaly to the Neogene-Quaternary volcanism. These
mineralizations are the result of the hydrothermal activities with sulphur deficit, rarely with sulphur
excess. They are present as impregnations, coatings, massive deposits and as veins (Pb-Zn, Cu, Sb, As,
Au-Ag, Hg), and as a porphyry copper mineralizations (Cu-Mo, Au). Together with the ore minerals
many silicate, carbonate, sulphate and phosphate presence can be observed. Beside these mineralisations
there are hydrothermal-metasomatic siderite deposits (Fe), or many minerals resulted from the
exhalations activity. Finally, the secondary minerals which are the result of the primary minerals exposed
to the supergene weathering processes, are in a very great diversity.
From the more than fifty mineral occurences described in this paper, only the Hanko stream
(Covasna), from Sf. Ana crater, from Sántimbru-Bái (Southern Harghita Mountains), from Harghita-Bái
(Northern Harghita Mountains), from Ivo-Cocoizas volcano (Northern Harghita Mountains), from
Corund, from Zebrac stream (Stánceni-Calimani Mountains) and from Cálimani caldera (Cálimani
Mountains) are the best, but insufficiently known mineralized zones. Only a few minerals from the Sf.
Ana crater's, the Sántimbru-Bái's, the Harghita-Bái's, the Corund's and the Fáncel-Lápusnea crater's
occurrences were studied with modern analytical methods
Because of the lack of the linked work to this subject, in the mineral occurrences presented in this
study many primary and mainly secondary minerals are waiting for descriptions.