MODIFICATION OF CRUST
AND LITHOSPHERE
BY
CONTINENTAL RIFTING/BREAKUP
AND BY
TERRANE ACCRETION
William A. Thomas
Geological Survey of Alabama
GROWTH OF
CONTINENTAL LITHOSPHERE
Accretion of continental
crustal terranes
long the Iapetan rifted
southern margin of Laurentia
uring assembly of Pangaea
Gulf Coastal Plain
S
Ouachita thrust belt
a
Benton
uplift
forearc
basin
entia
continentalmargin
arc
Gulf Coastal Plain
Sabine terrane
AlabamaOklahoma
transform
100 km
VE 4x
–309 Ma
Atoka Formation
eland basin
accretionary prism
forearc basin
–260 Ma
ma
entia
Guadalupian
Desmoinesian
Ouachita
thrust belt
successor
basin
Sabine terrane
S
alladega
ate belt
Piedmont
chian
accreted
belt
terranes
entia
km
Pine Mtn.
basement
massif
Triassic
South Georgia
basin
Gulf Coastal Plain
Suwannee terrane
S
3/530 Ma
restored
Talladega
slate belt
d minimum
f
e-margin shelf
restored
Pine Mtn.
basement
massif
Argentine
Precordillera
accretionary prism,
arc-continent collision
continentcontinent
MODIFICATION OF
CONTINENTAL LITHOSPHERE
ough two Wilson cycles:
sembly of Rodinia
ntinental rifting and breakup of Rodinia,
and opening of Iapetus
sembly of Pangaea, and
the Appalachian-Ouachita orogen
ntinental rifting and breakup of Pangaea,
and opening of the Atlantic Ocean
mas, 1993
Allen et al., 2009
Green Mountains
Berkshire
Hudson Highlands
Reading Prong
Honey
Brook
Avondale
Baltimore