Reviews—Geology of Mesopotamia. 283 
about Arabia, Armenia, Kurdistan, and Persia. The pioneers of 
Persian geology, Ainsworth (1838) and Loftus (1853), made long 
journeys in Mesopotamia and Persia. They give clear accounts of 
the formations and are remarkably correct in their determination 
of age and relation, but it was left to later travellers, of whom 
De Morgan i is the best know n, to work out the structure of this part 
of the sword From the aries of these explorers and geologists 
this book has been compiled, and we suspect that the author, whose 
name is not given, has an intimate knowledge of at least part of this 
country. 
The first seven chapters deal with the stratigraphy, structure, and 
geological history of the area; the latter part with the economic 
geology. A great part of Mesopotamia is covered with alluvial 
deposits of the Tigris and Euphrates. The underlying beds are for 
the most part of Miocene or Pliocene age. In Mesopotamia proper 
the oldest rocks exposed are Cretaceous, but in Kurdistan, Armenia, 
and Persia Jurassic, Permian, Carboniferous, Devonian, and Lower 
Palzozoic occur, Some oranites and metamorphic rocks are referred 
to Archean. Igneous rocks of Pliocene age also occur. 
The most interesting and best known formation is the gypsiferous 
series, known in Persia as ““ Lower Fars”’. It crops out over a large 
part of Northern Mesopotamia and in South-West Persia chiefly 
in anticlines. In Armenia similar beds were described by Oswald. 
With regard to the age of these beds there is much difference of 
opinion, as Oswald correlates them with Tortonian, and Pilgrim 
in Southern Persia considers them Helvetian or Burdigalian. This 
is fully discussed pp. 77-83. Since this book was written, Ostrea 
latimarginata, which is looked upon as a zone fossil of the Burdigalian 
by the Indian paleontologists, has been found in the Lower Fars 
of Mesopotamia. This supports Pilgrim’s views expressed in “ The 
Geology of the Persian Gulf and adjoining portions of Persia and 
Arabia’, Mem. Geol. Surv. India, vol. xxxiv, pt.iv, p. 31. There- 
fore we do not agree with the author when he states that Suess’ 
suggestion that the gypsum beds (of Mesopotamia, Persia, etc.) repre- 
sent the south-east extension of the Schlhier (a special shallow water 
phase of the Burdigalian) cannot be maintained. 
The structure of Mesopotamia is simple, and intimately connected 
with that of Persia. The important factor is a thrust from the north- 
east, which has caused rocks of all ages to be folded on an axis 
north-west-south-east. In Persia this thrust has caused tightly 
compressed and contorted folding, but in Mesopotamia the force 
seems to have spent itself with the result that more and more 
gentle folding is seen as one travels from east to west. The greatest 
period of folding took place in later Pliocene times, but we suspect 
that it had been going on along the same lines since Cretaceous 
times. 
Chapter viii deals with economic geology. Plate viii gives all the 
recorded occurrences of minerals in the area covered by this book. 
