Κοιτάσματα Επιθερμικού τύπου = Epithermal type deposits.

Ευρύκλεια Α. Τσονίδου

Κοιτάσματα Επιθερμικού τύπου = Epithermal type deposits.

Ευρύκλεια Α. Τσονίδου

Περίληψη

Η παρακάτω εργασία αποτελεί μια σύνοψη όλων των γνωρισμάτων που χαρακτηρίζουν ένα κοίτασμα επιθερμικού τύπου. Η εμφάνισή τους λαμβάνει χώρα σε ένα γεωτεκτονικό περιβάλλον υποβύθισης μίας ωκεάνιας τεκτονικής πλάκας κάτω από μια άλλη ηπειρωτική, και την ταυτόχρονη άνοδο μάγματος και μεταφορά ρευστών, ώστε τέλος να προκύψουν αυτού του είδους τα κοιτάσματα. Επιπλέον, αναφέρονται όλα τα ιδιαίτερα χαρακτηριστικά τους, όπως ορυκτά της μεταλλοφορίας, μορφή των μεταλλοφόρων σωμάτων, πηγή προέλευσης των ρευστών, μητρικό πέτρωμα ξενιστής κ.ά., στοιχεία τα οποία είναι και αυτά που οδηγούν στην κατηγοριοποίηση των επιθερμικών κοιτασμάτων σε τρεις μεγάλες ομάδες. Στη συνέχεια, γίνεται λόγος για τις υδροθερμικές εξαλλοιώσεις που είτε προϋπάρχουν στα ορυκτά του πετρώματος ξενιστές, είτε αναπτύσσονται κατά τη δημιουργία της μεταλλοφορίας. Τέλος, παρατίθενται μερικά παραδείγματα τόσο παγκόσμιων όσο και Ελληνικών εμφανίσεων των κοιτασμάτων επιθερμικού τύπου.

The following diploma thesis is a summary of all the features that characterize an epithermal type deposit. They appear in a tectonic environment with the subduction of an oceanic lithosphere below a continental lithospheric slab, causing a contemporaneously rise of magma and fluid circulation. All these lead to the formation of epithermal deposits. Their special features such as the ore and hydrothermal minerals, the form of the ore bodies, the origin of the fluids, the host rocks etc. are further discussed. All these data that are used in order to separate them from other types of deposits and also to discriminate the epithermal deposits in subtypes based on the sulfidation state. Subsequently, the different types of hydrothermal alteration are mentioned, whether they pre-existed in the minerals of the host rocks, or they were formed during the mineralization process form the hydrothermal fluids. Last but not least, several examples of worldwide and Greek epithermal type deposits, are briefly described.

Πλήρες Κείμενο:

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Αναφορές

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