Arkell.1956.Jurassic..

240 THE IBERIAN PENINSULA
from over 100 m. of alternating marls and limestones, and still longer
lists are published for western Algarve (Choffat, 1887, pp. 247-53). Until
the ammonites have been revised and figured nothing useful can be said
about the succession. The list from Algarve contains 9 species of
Phylloceratids. Among the other genera several anomalies appear:
Am. macrocephalus and Am. anceps are said to occur together from the
bottom to the top at Cape Mondego, and Am. modiolaris only at the top.
A macrocephalitid from the Sharpe collection has been figured as
Nothocephalites mondegoensis Spath (Cutch, p. 206, pi. xxxvi, fig. 16),
and presumably indicates about Koenigi Zone. Parapatoceras, Cadomites,
Erymnoceras, Bullatimorphites, Distichoceras and other interesting genera
are present, to judge by Choffat's specific records, together with a large
fauna of other invertebrates. Posidonia alpina occurs throughout.
BATHONIAN
As Choffat considered the Bathonian a facies of the Lower Callovian,
it is difficult to disentangle the two from his accounts. In some places
north of the Tagus he described up to 70 or 80 m. of white oolites with a
Bathonian fauna and no ammonites (1880, pp. 46, 71), but at Cape
Mondego the Bathonian seems to be absent. White limestones believed
to be Bathonian also occur in Algarve.
BAJOCIAN
The Bajocian is fully developed in the country north of the Tagus,
comprising up to 80 m. of highly ammonitiferous limestones and marls
forming steep scarps. In the south and in Algarve is developed an Alpine
facies of homogeneous sybcrystalline limestone, in which mainly Upper
Bajocian fossils have been found. In the north Choffat (1880) recognized
seven zones:
7. Beds with Parkinsonia parkinsoni, Strigoceras, Garantiana, Oppelia,
Cadomites, Stephanoceras, Spiroceras, Morphoceras, etc. (list 1880, p. 43)
6. Horizon of Skirroceras bayleanum (Oppel)
5. Horizon of Teloceras blagdeni (Sow.)
4. Horizon of Acrocoelites blainvillei
3. Horizon of Otoites sauzei (d'Orb.)
2. Horizon of Sonninia sowerbyi (Sow.)
1. Beds with Ludwigia murchisonae and Leioceras opalinum
Compared with areas in NW. Europe, the order of 5 and 6 is noteworthy;
it seems likely that Teloceras blagdeni will turn out to be a misidentified
Stemmatoceras. Among other fossils, Cancellophycus occurs. Posidonia
alpina is confined to the southern, or Alpine, facies. No. 1 is not
clearly differentiated from the 'Lower Aalenian' with Dumortieriae and
Hammatoceras (Choffat, 1908, pp. 156-9, a critical discussion of the
ammonites).
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