Page 365 - Carbonate Facies in Geologic History

352 Summary

Manlius 8 7·8 \ kalkb.rg 2 New Scotland :2
a'gili.

9' roo -"..-,.. .... - ~
Tranaer ... i.,. Aggf"odation during IUbm.rgence

\ d.bri, pile. 6 \ • "c:r'nlt. 2' bract'll.b,.,.. 2 \

30 ..
. :'IIIt:::~ .. _
MISSISSIPPIAN . WilliSTON IASIN

7 \ . \ 3 \
. . 100 .. 30 ..
... ~ ~, "
WOLfCAMPIAN • TOWNSEND . KEMNITZ

Houp.dolomll 8 \ Doch,tein 6.1 \ Doch.tel" r •• f .s .. \ \ HolI.toll :2
\i,amuton. fin. groin \o,gill.
-~.,. 7~~~ ---~-
§
I~"",=--
LA TE TRIAS. AUSTRIA 30m

Fig. XII-2. Examples of stratigraphic profiles showing variations from the idealized and com-
plete sequence of numbered facies belts. Note that steep profiles have narrower belts. The
sections are from 160-300 km long. All the examples are discussed in the text except the
Devonian Helderberg of New York (Laporte, 1969)

The Marathon-Ouachita geosyncline contains a 700 m thick record of such
limestones and argillites of Ordovician age, capped by a dark cherty limestone
(Maravillas Formation). The sections contain dark micritic limestones, micro-
breccias, shales, beds of conglomerates and exotic blocks, and some cherts. The
whole Ordovician section has been described by McBride (1969, 1970) and Young
(1970). Similar Ordovician strata are known in the interiors of both the Appa-
lachian and Cordilleran geosynclines.
b) Leptogeosynclinal troughs: These do not contain extensive allodapic lime-
stones, but remained deep during their history and were only intermittently sites
of sediment from outside the basin. Their sediment is chiefly pelagic. Mostly
siliceous sediment accumulated when protected from argillaceous influx and in
water deep enough for extensive solution of calcium carbonate (modern compen-
sation depth for calcium carbonate is 3000--4000 m). These sediments have much in
common with those occurring in quiet cratonic basins (see below).
The Alpine-Mediterranean Tethyan troughs of Mesozoic age contain several
special types of continental margin sediments which are discussed in Chapter IX