Post-Paleozoic activity - Lamont-Doherty Earth Observatory ...
Post-Paleozoic activity - Lamont-Doherty Earth Observatory ...
Post-Paleozoic activity - Lamont-Doherty Earth Observatory ...
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DETRITAL BASINS<br />
:'->: SALT BASINS<br />
0 0 rn<br />
"moo" POTASH SALT BASINS<br />
CARBONATE BASINS<br />
@ LAND<br />
y/1 DDLERITE DIKES<br />
fl mNT FR-RE , TRANSFER FAULTS<br />
WHITE MOUNTAIN MAGMA<br />
' SERIES NEW ENGLAND<br />
SEAMOUNT CHAIN<br />
<strong>Post</strong>-<strong>Paleozoic</strong> <strong>activity</strong><br />
THICKNESS On nnim)<br />
MAIN SOUTH GEORGIA RIFT 20 ATLANTIS BASIN<br />
RIDDLEVILLE-DUNBARTOM-FLORENCE 21 GEORGES BANK<br />
DURHAM-SANFORO-WADESBOROCROWBUffi 3,000 22 SCOTIAN-SABLE IS. SUBBASIN<br />
FARMVILLE-ROAHOK&SCOTTSBUffi 23 SCOTIAHABENAKI SUBBASIN<br />
DAN RNER-OAtMLLE-OAVIE M. 3,200 24 AVALCTWABSON SUBWIN<br />
RCHMONC-TAYLWLLE 1,870+ 25 LDSFTANIA<br />
CUEPER 6,600 26 J E W<br />
GETTYSBURG 9.000 27 BERKANE<br />
NEWARK 7.200 28 GUERCIF<br />
WRTFORMEERFIM 5.600 29 MOU8A ON SALAUTAMDAFELT<br />
GULF OF WNE 30 KEflOUCMEN<br />
FUNDY 1,100 31 CENTRAL HIGH ATLAS<br />
SCOTlAN-OflPHEUS QRABEN 6.000 32 TBI N'TEST<br />
BLAKE PLATEAU S.OOO 38 ARSANA-ES8AOUIRA<br />
CAROLINA TROUGH 7.000 34 DOUKKALA<br />
BALTIMORE CANYON 8.000 38 BERRICHID<br />
N.Y. BIGHT BASIN 8,000 38 KIJEFfWt.KHEM1886T<br />
LONG ISLAND BASIN 3.500 37 MIUM<br />
NANTUCKET 3.000 38 SENEOU.<br />
Figure 3. Lat ikic-~arl~ Jurassic reconstruction of eastern North America and northwestern Africa,<br />
outlining the named basins and lithofacies that developed on the Variscan-Alleghany-Mauritanide<br />
orogen. Modified from Manspeizer, 1980. Line A-B marks the trend of cross section given in Figure 12.<br />
of evaporation and precipitation of gypsum, aragonite, and halite.<br />
Although information on precise paleoaltitudes is lacking, this<br />
model (orographic) suggests that Triassic-Liassic lacustrine and<br />
paludal sedimentation occurred in high-altitude basins, while<br />
evaporites formed concurrently in adjacent low-altitude troughs<br />
(see Fig. 3).<br />
According to the Milankovitch astronomical theory of cli-<br />
mate change, periodic climate changes are caused by cycles in the<br />
seasonal distribution of sunlight reaching the earth; these cycles,<br />
in turn are controlled by the astronomical cycles of celestial me-<br />
chanics (Milankovitch, 1941). The periodicity inferred for Trias-<br />
sic lacustrine cycles is described later in this chapter by Olsen.<br />
NEWARK SUPERGROUP: LATE<br />
TRIASSIC-EARLY JURASSIC<br />
Figure 3, a pre-drift reconstruction of eastern North Amer-<br />
ica and northwest Africa, outlines the major Early Mesozoic<br />
basins and lithofacies on the broad Alleghanian, Variscan, and<br />
Mauritanide orogenic belt. Two major basin types and lithofacies<br />
are recognized: (1) Newark-type detrital rift basins, which typi-<br />
cally are exposed onshore as half grabens containing a thick (4 to<br />
8 km) continental clastic-lacustrine and volcanic facies; and<br />
(2) evaporite basins, which occur on rift-stage crust seaward of<br />
the string of detrital basins (e.g., Georges Bank basin) and/or on a