architecture of a distal skarn system: calamita fe-skarn ... removal of low‐solubility components...
TRANSCRIPT
03.05.17
Master ès Sciences in geology
Architecture of a distal skarn system: Calamita Fe-skarn deposit, Elba Island, Italy
Contact persons: Kalin Kouzmanov (Department of Earth sciences, University of Geneva); Andrea Dini (Institute of Geosciences and Earth Resources, CNR Pisa); [email protected]; Phone +41 (0)22 379 68 93
Context Distal skarns constitute a particular group in the skarn family and their formation away from a causative magmatic body suggests that probably the mineralizing fluids travel over long distances resulting in cooling and selective removal of low‐solubility components prior to skarn formation. Classical hedenbergite‐ilvaite‐garnet distal skarn deposits in Tuscany are systematically associated with, but spatially separated from, the underlying Late Miocene‐Pliocene felsic intrusions. Although mineralogically similar, Tuscan skarns host different ore types (Fe, Pb‐Zn, Cu‐Zn‐Pb) which genetic relationships with skarnification processes are still debated. Major goal of the project is to characterize the architecture of a distal skarn body at Calamita (Elba Island) as an ore‐forming environment performing: i) quantitative field study combining a careful three‐dimensional reconstruction of the skarn body morphology and a precise quantitative analysis of the internal skarn structure, resulting in generation of 2D and 3D maps of the skarn body; ii) textural and quantitative mineral analysis; and iii) trace element characterization of the samples to study the use of major and trace element composition as a vectoring tool.
Objectives and Methods The Master project aims to apply a combination of analytical techniques for quantitative mineralogy, textural analysis and geochemical tracing in order to establish detailed paragenesis of both skarn and ore mineralization. Methods to be applied: i) Detailed field mapping and sampling; ii) Transmitted/reflected‐light petrography; iii) QEMSCAN; iv) Cathodoluminescence (SEM‐CL and cold‐CL); v) EPMA and LA‐ICP‐MS.
Literature Dünkel I (2002) The genesis of East Elba iron ore deposits and their interrelation with Messinian tectonics. PhD Dissertation, Universität Tübingen. Meinert L, Dipple G, Nicolescu S (2005) World skarn deposits. Economic Geology 100th anniversary volume: 299–336. Tanelli G, Benvenuti M, Costagliola P, Dini A, Lattanzi P, Maineri C, Maineri C, Mascaro I, Ruggieri G (2001) The iron mineral deposits of Elba Island: state of the art. Ofioliti 26: 239‐248.
http://cms.unige.ch/sciences/terre/research/Groups/mineral_resources/mineral‐resources.php http://www.igg.cnr.it/en/organization/igg‐personnel/andrea‐dini/
Choice of orientation : (supprimer les orientations qui ne conviendraient pas) Geochemistry, Alpine tectonics, Ore Deposits