Page 169 - Carbonate Platforms Facies, Sequences, and Evolution

(b)
The
Fig. 6.
strating
that
ate platforms
kind of elevated
these
grooves, and as thin,
(Schlager,

seamounts
stratigraphic relations and
scattered
the drowning of these seamounts.
had
rim and are simply
veneers
topography
abrupt,
on
at
fringing rims are important features of many carbon­
Sinemurian to earliest Pliensbachian, clearly demon­
The original marginal escarpments and their on­
1981), and as will be dis­
margins (30°-60°), controlled by large normal faults.
of the margins of the seamount tops; they lack any
parts of the escarpment. These exposures allow the
dating of the formation of these seamounts as latest
this
steep
time, as seen in the Sibillini Mountains, are depicted
in Fig. 8. One important feature to note is the nature
abrupt slope
lapping sediments are important not only in dating
other
cussed later, their absence may have contributed to
changes where erosion was taking place. Elevated,
Height from seamount top to base of exposed escarpment is 500 m.
rate
Cecca
minus
in Fig.
plus
seamount
the
seamounts.
60 m Myr- 1 .
et al.
the
A
4, the
obtained from
top
Isolated carbonate seamounts, Italy
The
is
basinal
sediment
the sum
minimum
(1981), the
displacement or subsidence
escarpment
approximately
accumulation
growth
displacement
time scale of
rate
rate
rate
2m Myr-
Haq
sediment accumulation
sediment accumulation rate 1 .
is
on
on
(Cont.) (b) Monte Bove, north face, showing preserved marginal escarpment and remnant of the seamount top.
is important in under­
et at.
constraints on the displacement rates of the faults
of the escarpment growth
the formation of the seamounts, but also in placing
The
the
(1987), and measured thicknesses from the map area
grooves on the marginal escarpment extend = 500 m
estimated at Monte Bove (Fig. 4), where erosional
best
that created these seamounts and basins. The rate of
can be
standing the events that led to the formation of these
seamount top. Using the biostratigraphic results of
the
rate,
155
basinal sediment accumulation rate is the order of