Page 163 - Carbonate Sedimentology and Sequence Stratigraphy

154 WOLFGANG SCHLAGER

Fig. 8.8.— Networks of mound
chains mapped by 3D seismics in the
Carboniferous-Permian of the Barents
Sea. Ridges are hundreds of meters
high. After Elvebakk et al. (2002). Copy-
right 2002, reprinted with permission
from Elsevier.

4km

2. TST-FST/HST
Fig. 8.9.— Idealized cross section in
the polygonal mound pattern of Fig.
8.8. Systems tracts can be defined ge-
ometrically. Lowstand tracts are con-
fined to the spaces between the mound
crests; transgressive tracts show gen-
eral retrogradation and local drowning of
mounds; mounds of basal highstand ag-
grade and prograde. Mounds of falling-
1. HST-TST-LST stage systems tract (topmost unit) also
prograde but their tops are truncated by
erosion surfaces. Note that there is no
clear seaward-landward differentiation in
the network of ridges. Systems tracts
need to be defined in relation to the high-
est mounds. After D. Hunt, Norsk Hydro,
written communication.
HST TST LST FST/HST

bedded facies Fig. 8.10.— Convex mud-mound that
built into shallow water and became
patch
framestone reef flat during growth. Concomitant fa-
ca. 40 m flank facies cies change from automicrite to skele-
tal sands and coral patch reefs indi-
mound core cates that the mound reached the sun-
lit and wave-agitated environment. Note
that significant lateral progradation com-
Benifallet Unit menced after the change to skeletal fa-
cies. After Calvet and Tucker (1995),
modified.