96 CALCAREOUS ALGAE OF THE MIDDLE EAST 



In Iraqi Kurdistan the fossils occur in two principal intergrading formations of the 

 same age. These are the Sinjar limestones and marls, with a rich and varied dasy- 

 clad and other algal flora, and the Kolosh elastics, a coarse green-rock sand with a 

 much more restricted flora of which only two species, only one a dasyclad, are 

 common. Van Bellen (1959) considered the Sinjar as marking the reef-like facies of 

 the Palaeocene (and Lower Eocene), which occurred to seaward of the near-shore 

 Kolosh accumulation-zone of clastic detritus from the land. The Sinjar reefs and 

 shoals did not form a continuous barrier, but a broken line of separate reef-banks and 

 islands, sometimes backed by developments of the lagoonal Khurmala Formation, 

 whose altered deposits sometimes contain indeterminate algal debris. 



The Kolosh has yielded occasional examples of such dasyclads as Cymopolia and 

 Dissocladella, and the codiacid Halimeda, etc., but the only common algae are the 

 dasyclad Trinocladus perplexus and the codiacid Ovulites morelleti. These are 

 presumably the descendants of the species-pair of the same genera recorded above 

 for the lithologically similar underlying Cretaceous Tanjero, but they are much more 

 abundant in the succeeding Kolosh. Presumably they were littoral algae from the 

 coast : some indirect support for this is found in the complete absence of Trinocladus 

 from the Sinjar, although Ovulites is common there. I would suggest this as possibly 

 evidence that Trinocladus for some reason only grew along the coast, whence its 

 broken tubes were wafted into the sandy offshore sedimentation, and that Sinjar 

 shoal-conditions were unfavourable to it. By inference, the bulk of Kolosh fossils of 

 Ovulites came likewise from the coastal population, and only a minority from the 

 Sinjar shoals : no more in fact than the odd Kolosh Cymopolia etc. (unless indeed 

 these came from a minority population on the coast). 



Possibly Trinocladus perplexus was restricted to littoral waters with fresh-water 

 dilution from the land drainage : Teredo-bored wood is not uncommon in the Kolosh 

 Formation (Elliott 1963b), and this is a familiar indication of adjacent coastal or 

 estuarine conditions, as in the English Lower Eocene London Clay. 



The richer Sinjar flora seems to have been buried where it lived, more or less, 

 amongst the pockets, pools and channels of the shoal and reef belt. Sedimentation 

 here was more varied and irregular, and fossils are sporadically more abundant. In 

 submerged channels and on submerged shoals, and in sheltered waters between and 

 to the landward of the barrier-components, the dasyclads found conditions congenial 

 to them : they are often very well-preserved and seem to have been buried where 

 they grew, although rolled and broken material is also not uncommon. In these 

 happy conditions a considerable variety of algae grew together : the last abundance 

 of endospore dasyclads (Trinocladus, Dissocladella, Thyr sopor ella) and the rare 

 Broeckella co-existing with choristospore genera (Indopolia, Cymopolia), together 

 with Clypeina and the more problematic Fur copor ella. Codiaceae were represented 

 by abundant Ovulites, an extinct relation of the modern Penicillus, and by Halimeda, 

 not yet swamping the flora. But also in the Sinjar environment was a rich variety 

 of calcareous red algae : melobesioids such as Archaeolithothamnium spp., Litho- 

 phyllum, Mesophyllum, Lithothamnium and Lithoporella, with surviving soleno- 

 poroids (Parachaetetes and Solenomeris) , and the problematic Pseudolithothamnium 



