Arkell.1956.Jurassic..

228 THE IBERIAN PENINSULA
judging by the figures by Mengaud (1920, p. 83). Towards the west and
south the marine Aptian wedges out and the later beds of similar facies
continue up to the Cenomanian and transgress on to Lower Jurassic
and Trias.
In the southern basin (Valencia) the Wealden Beds rest on pale grey
or white marine limestones of Kimeridgian age, which have yielded
Physodoceras lallierianum (d'Orb.) of the Tenuilobatus Zone (Schlosser,
1919). An upper limit is firmly imposed by succeeding marine Aptian.
The usual thickness is about 150 m., but a section of 410 m. has been
measured (Brinkmann, 1931, pp. 16-17). Here the age of the lowest
Wealden Beds is more debatable. The lower part contains, near the base,
some marine bands with Trigonia gibbosa (Sow.) and numerous Isognomon
and other mollusca, which have been taken to indicate equivalence with
the Portland Beds (Royo y Gomez, 1927). With and above these marine
beds are freshwater beds with trunks and branches of trees and a rich
vertebrate fauna. The vertebrates (saurians, fish, etc.) give no definite
indication of age beyond 'Upper Jurassic or Lower Cretaceous.' While
Royo y Gomez published only one identification of a gastropod from the
marine beds, Natica elegans, which occurs in the Portland Beds, Brinkmann
(1931, p. 16) identified five species of gastropods (10-38 m. above
the base), all Naticae of Lower Cretaceous species. On the other hand, in
another section and from a higher level, he recorded Trigonia truncata Kg.,
a species of the Gravesia Zones of the Boulonnais (Middle Kimeridgian).
This is sufficiently like T. oviedensis Lycett to make one wonder whether
it was not in fact the Asturian species. There is also considerable resemblance
to T. freixialensis Choffat (1885, pi. x) of the highest Jurassic of
Portugal, the Freixial Beds, which Choffat regarded as Portlandian. High
up in the same section Brinkmann found isolated Cidarids and corals.
Near the coast SW. of Barcelona dolomites of unknown date are
succeeded by 30 m. of bituminous lacustrine limestone with Paludestrina,
Bythinia and Physa (Almera, 1896).
The problems of the Spanish Wealden clearly require much further
work (see Saenz Garcia, 1952).
KIMERIDGIAN
In the former 'Gulf of Aragon', in the plateau of Teruel and in Tarragona,
on both sides of the lower Ebro valley, limestones and dolomites
occur with the Lower Kimeridgian fauna typical of Crussol in the Rhone
valley (Tenuilobatus Zone). This is the latest Jurassic fauna so far discovered,
but similar beds devoid of fossils continue upwards for considerable
thicknesses (about 35 m. in the plateau of Teruel), until overlain by
Upper Cretaceous or Tertiary formations. In Teruel the lowest 5 m.
of limestone yields in abundance the Ataxioceras and Taramelliceras
assemblage of Crussol, with A. polyplocus (Rein.), A. lictor (Font.), A.
lothari (Oppel), T. trachynotum (Oppel), while the upper 15 m. yields
instead an assemblage of Aspidoceratids: A. acanthicum (Oppel), A.
http://jurassic.ru/