Arkell.1956.Jurassic..

CUTCH 387
Table 18, opposite, shows the formations and their correlation as
established by Waagen (1873) and as now accepted, chiefly as the result
of the revision by Spath (here modified as to terminology). The column
on the left shows original and subsequent spellings. Thicknesses apply
only to the main southern outcrop, where they were measured by Dr
Allison. His ammonites are now in the Sedgwick Museum.
[APTIAN AND LATER CRETACEOUS
Succession in Cutch
Bhuj Series (Umia Plant Beds), yielding a Ptilophyllum flora comparable
with, and having a number of forms identical with, the Jabalpur group of
the highest Upper Gondwanas (Fox, 1931, pp. 235-8).
Ukra Beds. Calcareous shales with large Australiceras, already correctly
assigned to the Aptian by Waagen. (30 m.).]
[? NEOCOMIAN
Umia Beds (about 500 m. excluding the ammonite beds below).
Unfossiliferous shales and sandstones, 300 m. or more (Nath, 1932,
P- I7 1
)-
Trigonia Beds of Umia, composed mainly of T. crassa Kitchin, with
T. ventricosa Krauss, a form found in the Valanginian Uitenhage Beds
of South Africa. At least four of the species of Trigonia (including
T. smeei Sowerby) figured by Kitchin (1903) as from these beds were
misplaced owing to faulty stratigraphical information and have proved
to belong to beds of either highest Oxfordian or lowest Kimeridgian age
(Spath, 1935). T. smeei has thus turned out to be Upper Jurassic,
instead of Cretaceous, in both Cutch and Tanganyika (see p. 335).
Under the Trigonia Beds are up to 90 m. of sandstones (Nath, 1932,
p. 170).]
TITHONIAN
Umia Ammonite Beds (c. 15 m.). Three beds of green oolite, highly
fossiliferous, with abundant ammonites, also brachiopods, etc., and a
coral (Stylina). The chief element is large Virgatosphinctes, some up to
2 ft. in diameter, especially V. denseplicatus (Waagen) with four named
varieties, also Aulacosphinctes occultefmeatus (Waagen), Micracanthoceras
aff. microcanthum (Oppel), M. sp. aff. fraudator (Zittel), Umiaites rajnathi
Spath, U. minor Spath, Ptychophylloceras tithonicum Spath, Holcophylloceras
silesiacum (Oppel), Hemilytoceras cf. montanum (Oppel), H. aff.
sutile (Oppel). (For list see Spath, 1933, p. 797). With these occur
Trigonia retrorsa Kitchin and a form hardly (if at all) separable from
T. ventricosa Krauss of the Valanginian.
Upper Katrol Shales with Hildoglochiceras. These shales were formerly
(Spath, 1933, p. 865) called the Zamia Shales, but according to Raj Nath
(1932, pp. 167, 172) the true Zamia Shales form the base of the Umia
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