Page 186 - Carbonate Platforms Facies, Sequences, and Evolution

on
®
172
also
older
a
the paper.
older
siliciclastic
ARRUDA
showed not
® TURCIFAL
later
SUB-BASIN
�SUB-BASIN
SUB-BASIN
northwestern
strata,
and Farta Pao
17\ BOMBARRAL
� exposed m cores
strata.
� Oagorda �ormation
only
Megasequence
®
of diapiric structures
Torres
.... ,.,.
<>
facies,
1979; Wilson et al.,
thus
<>
In
Kimmeridgian carbonates
J
o:•
formations
Outcrops of Oxfordian and
margin
l:
3 is
"''
"-r <>
_,,
• the Montejunto,Mem Martins
Cabo
��t
�-
the
of
---
'0
Rey
..
Lo urinha#1
,_ DIAPIR
t'VIMEIRO DIAPIR
<)'(-,�
..,, Sobral#1
TACAES
�� ���
Bombarral Sub-basin (Fig. 2).
indicating
0Aamalhal+ 1
Aptian siliciclastic
Iberia
'
�,r:l
Cereal
equivalent
(1972)
•
Vedras +4 -<..0«;. 0¥- l<.. Benfeito+ l
contains no deep-water sediments.
P.M.
to
r'
'
area,
the
Ellis,
(Sibuet
Town
continued
(F;gure 5)
• ALENQUER
<> Campe los+� SERRA DE
Rey
&
Major fault
suggested
MONTEJUNTO
OTA (Figure 8)
<> Montijo#l
10km
synrift
Exploration well
R. C. L.
'-----...J
locations, exploration wells and structures mentioned in
se­
Ryan,
that
Berriasian strata are missing, and so the siliciclastics
Fig. 3. Map of the southern part of the Lusitanian showing
(1972)
1989), but is much thinner and
activity along this part of the eastern margin of the
the Torres Vedras formation but
of the Torres Vedras formation rest unconformably
tectonic
quences that preceded ocean opening drilled off the
unit cutting across
of
the
over
slope
thick.
The
Caldas
Torres
Seismic
drilling.
(Wilson,
the
Neogene
Wilson and R. R.
carbonate
silts
formations
da
coincident
of
to
Kimmeridgian
basin
with
Vila Franca
sections
Structural setting
the
be
Bombarral
fill
buildup
southern
Rainha
the
Leinfelder
diapiric structures
at
top
show
borehole penetrated =
Fault.
has
half
three sub-basins (Fig. 3).
It
diapir
the
part
containing
yet
of
relatively
Lisbon
1988; Wilson et al.,
sub-basin
is
of
resulted
to
line
the
Barreiro
in
filled
Vedras-Montejunto high,
the
be
Brenha
1989.)
canyon
the
constant
twice the thickness seen at Barreiro.
sediments
along
with
occurs
developed
and
in
but its
up
its
>
ation in this area during the late Jurassic.
as
Lusitanian
a
to
formation.
offshore.
determined
formation
beneath
drawal structure as salt migrated into the Vimeiro­
formations suggest major changes in Basin configur­
with­
E-W trending fault. The nature of its Oxfordian­
Reacti­
by the Torres Vedras-Montejunto anticline (Fig. 2)
indicating little or no differential subsidence during
the Hercynian basement, along with the formation
of
vation of NNE-SSW trending strike-slip faults in
thickness
2 km of
Cretaceous and younger rocks of the Tagus estuary.
variations in the Cabacos, Montejunto and Abadia
Candeiros
margin. To the southeast the sub-basin is bounded
Basin,
the early and middle Jurassic. In contrast, thickness
western
observed on Landsat images, the trend of which is
to the southeast of a major NNE-SSW lineament
which may be a fault-associated salt structure that
lineament probably reflects a major basement fault.
lies on the southern limit of thick Dagorda evaporites
The
The Arruda sub-basin is bounded on the east by
the tectonic setting of the Upper Jurassic sediments
is more difficult to determine. To the southeast, the
a
In the southern-most part of the Lusitanian Basin,
by
the Runa Fault zone, and to the north by an unnamed
The Turcifal sub-basin is bounded to the east by
margin cannot be delineated, as it is obscured by the
formation, and capped by the southward prograding
arkoses of the Castanheira Member of the Abadia
The Barreiro wells are situated immediately
The
1 km
southern
northern margin of the sub-basin is formed by the
setting of the Upper Jurassic sediments brought to
the surface around the late Cretaceous Sintra granite
To the northwest of this lineament, the Monsanto
1000 m of Abadia formation
The tectonic