Professor Bob Dymek A Little Bit About Me … Mineralogy and Petrology Study rocks and minerals Do geological field work
Where Have I Done Field Work ??? World’s Oldest Rocks West Greenland NW Territories Québec Labrador Adirondacks Central Kansas Virginia SE Missouri
3.8 billion-year-old Metamorphic Rocks at Isua, West Greenland The rocks on the left are older than most of the dark lavas that fill the Mare Basins on the moon !
EPSc118 “Geology of National Parks” EPSc201 “Earth & the Environment” EPSc437 “Igneous & Metamorphic Petrology” EPSc542 “Chemical Petrology” For 12 years, I was the Senior Editor for this research journal
“Secular Magmagenesis” Earth History and Igneous Petrology 4.55-3.8 Ga Hadean ??? 3.8-2.5 Ga Archaean Granite-Greenstone Belts Komatiites Tonalite-Trondjhemite-Granodiorite (TTG) Suite <0.6 Ga Phanerozoic Magmatic arcs Calc-alkaline (CA) batholiths
Phanerozoic CA Suites: Melting of Mantle Wedge Archaean TTG suites: Direct Slab Melting Phanerozoic CA Suites: Melting of Mantle Wedge
Secular Magmagenesis – Earth History and Igneous Petrology 4.55-3.8 Ga Hadean ??? 3.8-2.5 Ga Archaean Granite-Greenstone Belts Komatiites Tonalite-Trondjhemite-Granodiorite (TTG) Suite 2.5-0.6 Ga Proterozoic Massif Anorthosites (~1.0-2.1) Jotunite-Mangerite (AJM) Suite <0.6 Ga Phanerozoic Magmatic arcs Calc-alkaline batholiths
Massif Anorthosites Rocks consisting mostly of intermediate plagioclase feldspar (An40-60) Plutons ranging from ~10 to >1,000 km2 Associated cogenetic/comagmatic plutons Jotunite – mafic to intermediate, green, opx-bearing monzodiorite Mangerite – intermediate to felsic, green, opx-bearing granodiorite Elongate “belts” across Laurentia and Gondwana Continental rifts, continent-continent collision, continental margin arcs Approximaely half of global occurrences are found in Québec
Distribution of Anorthosite Massifs, NE North America Forêt Montmorency
Jotunites and Mangerites
J-M
Summary Compared with Phanerozoic Calc-Alkaline plutonic rocks, the Proterozoic Jotunite-Mangerite suite – found only in association with massif anorthosites – is enriched in Fe-Ti-P, as well as high-field-strength elements (Ga, Ce, Y, Zr, Nb, Zn), but is depleted in transition-metal trace elements (V, Cr, Ni), and large-ion-lithophile trace elements (Rb, Th, U). Should you join our Department, you can learn more about acquiring, interpreting, and understanding such data in “Chemical Petrology.”