Page 358 - Global Tectonics

OROGENIC BELTS 341

(a)
Laurentia (Proterozoic)

50°N
X
arc and
Gulf of St. oceanic rocks
Lawrence
Passive margin sequences
X
Avalonia
Magdalen
Magdalen
Basin
Basin
Newfoundland
Avalonia
Meguma Canso
0 200 Fault
Nova Scotia
km

(b) X X
NW SE
0 0
2 6
4 12
6 18
Time (s) 10 8 24 Approximate depth (km)
30
12 36
14 44
16 52
18 60
suture
suture
(c) NW SE
0 ?? ? ? 0
2 ?? ? ? ? ? ? ? Avalonia 6
4 6 ?? ?? Ganderia ? ? ? ? ? ? ? ? 12
18
Time (s) 10 8 Laurentia ?? ? ? ? ? ? ? 24 Approximate depth (km)
30
12 Moho Moho 36
10
14 Mantle Mantle 0 0 10 20 44
20
Mantle
Mantle
16 km 52
km
18 60
Laurentia Gondwana
Passive margin sequences suture Notre Dame arc and obducted Clastic sedimentary rocks
and Taconic allochthons oceanic rocks of lapetus
suture
Microcontinental blocks and
Proterozoic basement
arc terranes
Avalonia
Figure 10.34 (a) Tectonic provinces of Newfoundland in eastern Canada and plot (b), and interpretation (c), of seismic
reflection data (after van der Velden et al., 2004, with permission from the Geological Society of America). Migrated

−1
data are plotted with no vertical exaggeration and an assumed average velocity of 6 km s .