historical geology lecture 11 the proterozoic eon
TRANSCRIPT
Historical Geology
Lecture 11
The Proterozoic Eon
Historical Geology
I Proterozoic TimelineII Tectonics Overview
A) Continental GrowthB) Wilson Cycle Tectonics
III Paleoproterozoic Laurentia (North America)A) Orogenies (Convergence)B) Rifting (Divergence)C) SedimentationD) Climate
IV Mesoproterozoic Laurentia (North America)A) Orogenies (Convergence)B) Rifting (Divergence)C) SedimentationD) Climate
V Neoproterozoic Laurentia (North America)A) Orogenies (Convergence)B) Rifting (Divergence)C) SedimentationD) Climate
VI The Proterozoic Outside Laurentia
Outline
Historical Geology
The Proterozoic Eon
1.0 bya
2.5 bya
1.6 bya
0.545 bya
Historical Geology
The Proterozoic EonTectonics Overview
growing cratons
lateral plate tectonic movements
rifting and sea-floor spreading
wide continental shelves
epeiric seas
Historical GeologyThe Proterozoic Eon
Aggregating Cratons
accretion - addition of crustal materials to continental margins
aggregation – bringing together and consolidation of cratonic elements
Historical GeologyThe Proterozoic Eon
Early Epeiric Seas
epeiric sea - a shallow sea flooding the continental craton
Erikkson, et al., 1998
Historical GeologyThe Proterozoic Eon
Sedimentation Overview
Carbonates appear
Banded Iron Formations peak/disappear
Red Beds
Passive Margin Sedimentation
Historical GeologyThe Proterozoic Eon
Carbonate Sedimentation
Historical GeologyThe Proterozoic EonBanded Iron Formations
Historical GeologyThe Proterozoic Eon
Red Beds
oxidation4Fe + 3O2 ---> 2Fe2O3
iron + oxygen -> iron oxide
hematite
limonite
laterite soils
Red ShaleChuar Group (Grand Canyon)
Historical GeologyPaleoproterozoic Laurentia
Orogenies
Torngat (2.1-1.75 Ga)
Taltson-Thelon (2.0-1.9 Ga)
Penokean (2.0-1.8 Ga)
Wopmay (1.97-1.84 Ga)
Cape Smith-New Quebec (1.9-18 Ga)
Trans-Hudson (1.88-1.79 Ga)
Historical GeologyPaleoproterozoic Laurentia
Slave Province
Historical GeologyPaleoproterozoic Laurentia
Slave Province Aulacogens
Athapuscow Aulacogen
Bathhurst Aulacogen
Irving, et al., in press
Historical GeologyPaleoproterozoic LaurentiaSlave Province - Wopmay Orogen
Historical GeologyPaleoproterozoic Laurentia
Superior Province
Young, 2002
Ojakangas, et al., 2001
Historical GeologyPaleoproterozoic LaurentiaSuperior Province - Huronian Supergroup
Young, 2002
2.5 - 2.2 Ga
Gowganda FormationHuronian Supergroup
Gowganda Tillite
Historical GeologyPaleoproterozoic LaurentiaGlaciation
Historical GeologyPaleoproterozoic Laurentia
Superior Province - Animikie Group2.2 - 1.8 Ga Young, 2002
Banded Iron FormationAnimikie Group
Kona DolostoneAnimikie Group
Ajubik QuartziteAnimikie Group
Historical GeologyPaleoproterozoic Laurentia
Superior Province - Penokean Orogeny
Historical GeologyPaleoproterozoic LaurentiaSuperior Province Cross Section
Historical Geology
Paleoproterozoic LaurentiaTrans-Hudson Orogen
Schwerdtner and Cote, 2001
Historical Geology
Mesoproterozoic LaurentiaEvents
Elsonian Orogeny
Yavapai Orogeny
Mazatzal Orogeny
Mid-Continent Rifting
Grenville OrogenyAssembly of Rodinia
Historical GeologyMesoproterozoic Laurentia
Yavapai and Mazatzal Orogenies
Series of orogenies
~1.8 - 1.6 Ga
Vishnu Schist
Historical GeologyMesoproterozoic LaurentiaGrand Canyon Region
Historical GeologyMesoproterozoic LaurentiaGrand Canyon Region
Historical GeologyMesoproterozoic Laurentia
Mid-Continent Rift~1.2-1.0 Ga
Keweenawan Supergroup
Ojakangas and Dickas, 2002
Historical GeologyMesoproterozoic Laurentia
Grenville Orogeny
Historical GeologyMesoproterozoic Era
Rodinia
S W E A T
A U S W U S
Historical GeologyMesoproterozoic Era
Rodinia – SWEAT
Historical GeologyMesoproterozoic Era
Rodinia – AUSWUS
Historical GeologyNeproterozoic Laurentia
Breakup of Rodinia
Panthalassic Ocean (proto-Pacific)
Iapetus (proto-Atlantic)
Varangian Glaciation
Eykes and Januszczak, in press
Historical GeologyNeproterozoic Laurentia
Breakup of Rodinia
Historical GeologyNeproterozoic Laurentia
Panthalassa
Historical GeologyNeproterozoic Laurentia
Late Proterozoic Rifting
Grand Canyon Supergroup
Historical GeologyNeproterozoic LaurentiaGrand Canyon Supergroup
Historical GeologyNeproterozoic Laurentia
Late Proterozoic Rifting
Breakup of Rodinia
Panthalassic Ocean (proto-Pacific)
Varangian Glaciation
Historical GeologyNeproterozoic Laurentia
Late Proterozoic Rifting
Historical GeologyNeproterozoic Laurentia
Varangian Glaciation
Historical GeologyNeproterozoic Laurentia
Varangian Glaciation
OXYGENHeavy Oxygen-18 is incorporated into minerals. More Oxygen 18 during low temperatures.
STRONTIUMIncreased Sr86/87 ratio due to increased weathering during glaciation.
CARBON 12/CARBON 13Plants use the lighter isotope Carbon 12 in photosynthesis. The lower relative abundance of Carbon 13 means the plants were worse off (dying). Evidence in “cap” carbonates
Jacobson and Kaufmann, 1999Knoll, 2000Knoll, 2000
Historical GeologyNeproterozoic Era
Snowball Earth
Historical GeologyNeproterozoic Era
Snowball Earth
Historical GeologyNeproterozoic Era
Snowball Earth
Historical GeologyThe Precambrian Outside North America