Page 383 - Global Tectonics

CHAPTER 11
366
10
15
30
90
70
50
0
0
East
Extent of Phanerozoic cover
B-41
Cordilleran Front
Shot points
P-56
0 300 km Yellowknife Ft. Providence Junction Hwy. 1 & 3 E 12000 11000 10000 Rae 9000 8000 7000 6000 5000 0 5 Time (s) 20 25 30 Slave Province Wopmay Orogen (3.5–2.6 Ga) Yellowknife Basin Great Bear Magmatic Arc Hottah Terrane Upper crust Upper crust Upper crust Upper crust Lower crust Lower crust Lower crust Lower crust Moho Moho ? Hottah Mantle ? Archean Mantle Archean and/or Proterozoic ? Deformed Mantle Deformed Mantle 40 0 Proterozoic (?) Proterozoic (?) km Approx
60 4000 West
63 Underthrusted lower crust of Fort Simpson
Rae 111
Contwoyto Fort Simpson Accretion
1100 Yellowknife 1101 Taltson 114 3000 Fort Simpson Terrane
Anton Slp. Dragon 1104 A 1105 1107 GSLsz Buffalo Head Lower crust Lower crust Proterozoic mantle of Fort Simpson Terrane and Basin
Great Bear B 117 2000 Upper crust Upper crust ~400 km convergence minimum
Coronation
1108 AB Terrane (1.85–0.6 Ga)
Hottah 1110 C BC 120 Ft. Simpson Fort Simpson

Fort Simpson Moho rise due to Middle Proterozoic extension
D 1112 1000
CANADA NWT 123 Cordillera Phanerozoic Phanerozoic Proterozoic Mantle
Nahanni butte Nahanni 100 km
Cordillera YK
1113 126 W 0 5 10 15 20 25 30 0 15 30 50 70 90 Approx. Depth (km) 110

(a) (b) Time (s) (c) (d)
Fig. 11.15