'THE GEOLOGY AND MINERAL RESOURCES OF DHUFAR PROVINCE, MUSCAT AND OMAN' [‎30r] (49/96)

35
Eocene fossils collected by Bertram Thomas from the^ southern side
of the Rub’al Khali were identified (by L. R. Cox) as ‘all from a
white limestone of Middle Eocene age’. As already shown (para
graph 63) the Eocene is represented in Makalla by middle Eocene
limestones. The Eocene of Masira island and again at Sireir (on
the mainland opposite the island of Hamar an Nafur) on the gulf of
Masira, on the fossil evidence, is middle Eocene. And Eees states
fuage 610 of his paper) : ‘At Dhofar the Cretaceous limestone is over
laid by Eocene limestone with small Nummulites and Alveolina.
At Thaqa and Ras Risut chalky limestones crop out, containing
abundant large Orbitoides, sensu lato. They have not yet been
examined to determine whether they are Lepidocychna or Urmo-
^ 65. There has been some confusion about the Cretaceous
(Cenomanian) limestone and the Eocene limestone. There is no
village called Dhufar or Dhofar, so that the extract quoted m the
previous paragraph is incomplete. And another extract . The
presence of Cenomanian in Dhofar was proved by Carter, whose
fossil collection included Pecten (Vola)^ quadncostata, Saienia
scutigera, Orbitolina concava, and other typical Cenomanian species.
The limestones rest directly, with a slight angular disconformity,
on the Murbat Sandstone. The fossils occur m some marly deposits
at the base of the 1400-foot limestone group which forms the
summit of Jabal Samhan. The upper beds are of Eocene a g e jSo
probablv the various stages of upper Cretaceous are also represented,
but are unfossiliferous.’ Dr. Lees does not claim to have found
anv fossils himself, and I did not find any fossils at all m the
overlving limestones, particularly at their base In his section
(Fig/5 page 622) Dr. Lees ‘. . . shows the ancient crystalline rocks
overlaid by the desert sandstone formation and the Cenomanian-
Eocene limestone series forming the scarp of Jabal Samhan ^ nne
of the fossils described in Dr. Lees paper came from ^hufar produce
and I am therefore assuming that he has depended on the collect o
made by H. J. Carter. I have therefore r ^ e ^ me ^^ r in the
tributions (particularly his revised paper of 185 ^ P-oc 1 ^ 597 a nd
‘Geological Papers on Western India , 1857, pages 585 to 597,
including the section and the sketch from Marbat)
66 Mr H. T. Carter reckoned the scarp section at 3,400 e
(plus another 400 feet to the limestone of the summit northward
on the Samhan hill plateau). He recognized :
i 4 . 0 O feet
White limestone strata. . •• ' ' ’qoo
Argillaceous strata of a red colour / '
Coarse micaceous sandstone, of a yellow brownish
colour, finer higher up •• •• B/uu „
Beginning from the bottom, the sandstones become finer as we