Objective DEVELOPMENT OF METHODS TO DISTINGUISH EPISODIC VOLCANIC GROUWTH STAGES AND SYNCHRONOUS TECTONIC AND HYDROTHERMAL PROCESSES DURING ACCRETION OF EXTRUSIVE CRUST IN SULFIDE-DEPOSIT BEARING OPHIOLITES. THIS RESEARCH IS CONCERNED WITH THE GEOLOGICAL AND GEOCHEMICAL ANALYSIS OF THE COUNTRYROCK SURROUNDING THE ORE BODIES WITH THE AIM TO BETTER UNDERSTAND THE PROCESSES OF VOLCANIC CONSTRUCTION AND THE SYNCHRONOUS AND SUBSEQUENT MODIFICATION BY TECTONIC AND HYDROTHERMAL PROCESSES. THE MAIN AIM IS TO DEVELOP CRITERIA FOR SUB-DIVIDING THE THICK EXTRUSIVE CRUST INTO STRUCTURAL AND CHEMICAL UNITS BECAUSE OCEANIC CRUST APPEARS TO GROW PRINCIPALLY BY EPISODIC ERUPTION AND ATTENDANT TECTONISM WITH AT LEAST SOME EPISODIC HYDROTHERMAL ALTERATION. THE IMPRINT OF THE ALTERATION PROCESSES DEPEND NOT ONLY ON THESE DYNAMIC PROCESSES BUT ALSO ON PHYSICAL PROPERTIES SUCH AS PERMEABILITY AND POROSITY OF THE ROCKS WHICH APPEARS TO DIFFER STRONGLY BETWEEN PILLOW AND SHEET FLOW AND BRECCIA UNITS. MOREOVER, THE OCCURRENCE OF FRESH VOLCANIC GLASS THROUGHOUT THE EXTRUSIVE SERIES ON CYPRUS OFFERS THE CHANCE TO QUANTITATIVELY ASSESS ELEMENTAL FLUXES BETWEEN ROCK AND SEA WATER. THE FIRST PHASES OF RESEARCH WILL CONSIST OF MAPPING IN DETAIL A FEW SELECTED PROFILES THROUGH EXTRUSIVE SERIES. SAMPLING WILL CONCENTRATE ON GLASS-CRYSTALLINE ROCK PAIRS OF COOLING UNITS. IN PARTICULAR, GLASS SAMPLES WILL BE SEPARATED INTO CLEAN GLASS CONCENTRATES TO BE ANALYZED BY STANDARD PETROGRAPHIC MICROPROBE AND XRF (MAJOR AND TRACE ELEMENTS) TECHNIQUES AS WELL AS RADIOGENIC SR-, ND-, AND PB- ISOTOPES. DURING THE FINAL PHASE AN ATTEMPT WILL BE MADE TO DEVELOP A MODEL OF SEQUENTIAL GROWTH AND ALTERATION STAGES OF THE EXTRUSIVE CRUST, TO BE COMPARED WITH MODELS OF OCEAN CRUST FORMED AD MID-OCEAN RIDGES. THIS WILL BE BASED ON DATA OF MANY FROUPSGROUPS AND BE DONE IN COLLABORATION WITH SEVERAL COLLEAGUES FROM OTHER COUNTRIES. RESULTS FROM INITIAL WORK IN 1981 AND 1982 INDICATE THAT PERIODS OF ALTERATION MAY HAVE OCCURRED DURING EARLY GROWTH STAGES, OPENING THE POSSIBILITY FOR THE OCCURRENCE OF ORE BODIES DEEP IN THE SECTION. THUS, THE VOLCANOLOGICAL-STRUCTURAL-GEOCHEMICAL ANALYSIS OF THE TYPE PROPOSED HERE, WHEN APPLIED TO APHIOLITE COMPLEXES, WHERE SIMILAR TYPES OF SULFIDE DEPOSITS OCCUR, WILL HELP TO UNDERSTAND THE FORMATION AND THUS LOCALIZATION OF THESE DEPOSITS. Programme(s) PRE-RAWMAT 2C - Research and development programme (EEC) in the raw materials sector, 1982-1985 Topic(s) Data not available Call for proposal Data not available Funding Scheme Data not available Coordinator RUHR-UNIVERSITY BOCHUM EU contribution No data Address Universitätsstrasse 150 44780 Bochum Germany See on map Total cost No data
