Plate Tectonics and Mineralization Structural features of the Earth Major plates & Plate boundaries Plate tectonic cycle Mineralization
Lithosphere vs Asthenosphere
Conservative (Transform) Divergent Convergent 3 Types of Plate Boundaries
Divergent Boundaries Conservative
Convergent Boundaries
Transform Boundaries
Plate Motion
Hot spot and origin of island chains
Intra-plate Volcanism (Hot Spots)
Continental Drift & Sea-floor Spreading
Plate Tectonics’ Cycle
Plate Tectonics and Rock Cycle
Mineralization and Divergent Boundary (Mid-oceanic ridge)
Submarine hydrothermal vent or “Black Smoker”
Cyprus type: associated with tholeiitic basalts in ophiolite sequences copper rich withgold. e.g. Troodos Massif (Cyprus). Besshi-type: associated with volcanics and continental turbidites, copper/zinc with gold and silver.e.g. Sanbagwa (Japan). Kuroko-type: associated with felsic volcanics particularly rhyolite domes copper/zinc/lead with gold and silver, e.g. Kuroko deposits (Japan).
Ophiolites are pieces of oceanic plate that have been thrusted (obducted) onto the edge of continental plates. They provide models for processes at mid-ocean ridges.
Ophiolites are thought to represent slices of oceanic crust that have been thrust or obducted onto a continental margin during collision. They are characterised by a sequence of rock types, consisting of deep sea sediments overlying basaltic pillow lavas, sheeted dykes, gabbros and peridotites.
Ophiolite Complex Pillow Basalts Sheeted dikes (Diabase) Gabbros Peridotites
Podiform chromite deposits are irregular but fundamentally lenticular chromite-rich bodies that occur within Alpine peridotite or ophiolite complexes. Thus, they generally occur in orogenic settings.
Chromite: FeCr2O4 Podiform chromite deposit, Cyprus
Mineralization at Convergent Boundaries Geological Processes Calcalkaline Magma Series Volcano-plutonic complexes Subaerial / Submarine volcanism Porhyry / Massive sulphide deposits Plutonism: Granitic batholiths / Stocks Pegmatitic/ Hydrothermal / Skarn / Greisen/ deposits Regional Metamorphism (High P/ Low T and Low P/High T ) Some gemstone deposits e.g. jade and corundum
The ASARCO Mission Mine near Tucson, Arizona
Detailed Cross - Section of a Porphyry Copper Deposit
Intraplate Mineralization
Lopolith Sill Bushveld stratiform chromite deposit
Schematic model of a fully grown kimberlite pipe
MASTER LIST OF ALL DEPOSIT GROUPS A - Organic B - Residual/Surficial C - Placer D - Continental Sediments and Vocanics E - Sediment-Hosted F - Chemical Sediment G - Marine Volcanic Association H - Epithermal I - Vein, Breccia and Stockwork J - Manto K - Skarn L - Porphyry M - Ultramafic / Mafic N - Carbonatites O - Pegmatite P - Metamorphic-hosted Q - Gems and Semi-precious Stones R - Industrial Rocks S - Other
Genetic Classifications of Mineral Deposits Syngenetic deposits layered mafic intrusion type deposits volcanogenic massive sulphide deposits sedimentary massive sulphide deposits placer deposits Epigenetic porphyry deposits skarn deposits pegmatitic deposits hydrothermal deposits
Classifications Based on Geological Processes Hydrothermal/Pegmatitic mineral deposits form in association with hot water- or gas-rich fluids Magmatic mineral deposits concentrated in igneous rocks; Metamoprhogenic mineral deposits concentrated by metamorhism / metasomatism Sedimentary mineral deposits are precipitated from a solution, typically sea water; Placer minerals are sorted and distributed by flow of water (or ice); Residual mineral deposits formed by weathering reactions at the earth's
Classifications Based on Host Lithology Unconsolidated Deposits Sedimentary Rocks Volcanic Rocks Intrusive Rocks Regionally Metamorphosed Rocks