Page 190 - Carbonate Platforms Facies, Sequences, and Evolution

- 176
�
1985)
of the
f �
Middle
Oxfordian
�R �de� vant � ig_u_r�
-r�18
?
�
indicating
n
Sintra
a
-_-_-_
''''
�
�
>l
� facies # 1 #1 basinal s Ramalhal Montejunto M �f 1 ejunto P.M. Ellis, R. C. L.
�20�-r-- -17
Lower Kimmeridgian age.
5I=1 Shallow
topmost
Bolhos-
l:l:::J:::j limestones
���1
siliciclastics
��;���o�:; ine
?
�
lagoonal
r-:- Mixed siliciclastic-
Upper
� 2�
L:J dommated limestones
Grainstone /packstone­
�Predominantly terrestrial
l_.= limestones ICabayOS fm.l
fYl Predominantly lacustrine
(inclined>: slope seen on
Deeper marine shales,silts
� calcareous lagoonal facies
4� - 17 .�2��5�
Oxfordian
-,'"'and turbiditic sandstones seismicsl
The dating of the shallow-water shelf carbonates
(Atrops & Marques, 1986) and foraminifera (Starn,
to
a
precise dating of the Tithonian successions is not possible.
Montejunto formation exposed to the north
r;.�ti��
ow
,9
� .
..-........-..
[]
�. 7 ����5� ,6� . �7-,-i --�8 � �
mation.
Ota
10
8�:):J
ld
�
underlain
(Zbyszewski
by
et
#1
m Limestone
the
+-------
E
"'
Karstification
0
However,
at.,
Wilson and R.R. Leinfelder
breccia
Sub - aerial exposure
Middle
1966)
Deep water Garbonates
-+--------
Montalegre Monsanto
!:::;:::1 Metamorphosed limestones
and
Micrite - dominated limestones
�1�1�1�3
#4
characteristic
are
I
0
Barreiro
Oxfordian
E
.�2 �2-;
"'
0
"'
believed
0
0
sequence
Caba�os
See note
\��� � et al
boundaries
..,.
in caption
Sea-level &
N
assemblages
to
Basin. The correlation between the sea-level curve and sequence boundaries of Haq eta/. (1987) with the Portuguese
N
...J
ci:J
sequences cannot be made precisely due to lack of good biostratigraphic control. It is particularly difficult to identify the
Fig. 4. Summary chart showing the stratigraphic distribution of the Upper Jurassic carbonate formations of the Lusitanian
for­
Oxfordian-Kimmeridgian boundary in shallow-water carbonate sequences. No attempt is made to show LZB-1 cycles, as
of the Montejunto anticline is less certain. They are
conventionally placed entirely within the Oxfordian
of
be