566
Chapter 12 Basin Evolution and Sediments
SW
GOBAN SPUR TRANSECT
NE
----4--4-- - ----- - - ~- - .-:---- ---- - ---- ...... ----I i
: ALBYA'N
FAULTS
I NEOGENE
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OCEANIC
CRUST
TRA NSITIONAL
CRUST
WNW
BAJA CALIFORNIA
d
CONT. CRUST
(HERCYNIAN
BARR.-HAUT.
BASEMENT)
SHAllOW -WATER
MAR l S:AND LlMEST.
4
6
km
ESE
RIFT GRABEN
2
o
2
4
Fig. 12.13. a,b Sediment-starved passive continental
margin of the eastem Atlantic. (After de Graciansky
et al. 1985). c,d Y oung, rapidly subsided passive
ingly cold climate and subarctic ocean currents, while the
northwest African basins more or less remained in a zone
ofwarm, relatively dry climate.
The eastern margin of the Grand Banks in the northwestern Atlantic and the Galicia Bank margin of Spain display a similar Mesozoic-Cenozoic tectonic-sedimentary
history (Grant et al. 1988; cf. Sect. 12.1.6 and Fig.
12.7a,c). Another, weH described example of conjugate
marginal basins is the Campos basin of Brazil and the
margin of the southem Gulf of Califomia. (After
Currayet al. 1982a). Note the different vertical and
horizontal scales. See text for explanation
Gabon basin of West Africa (Edwards and Santogrossi
1990); one basin is the mirror image of the other.
As a result of differential subsidenee and/or uplift of
the landward side of the stretehed eontinental erust,
many Atlantie-type eontinental margin basins beeame
partially emerged. These parts of the basins are referred to as coastal basins. The sediments of these