276 H. B. Maufe — Coastal Series of Sediments, E. Africa. 



At the station of Maji-ya-Chumvi (mile 33) Fraas notes greasy 

 brown marls, said to be of Oxford and Kimmeridge age (group 5), 

 which without doubt are a part of my Maji-ya-Chumvi Beds. Fraas 

 saw no fossils here, but identifies them with a part of the marine 

 fossiliferous Changamwe Shales of Mombasa Harbour. Not only are 

 they distinct lithologically, in being dull greenish mudstones with 

 numerous thin beds of very hard sandstone, but in place of the 

 Ammonites and Belemnites found in the Changamwe Shales I obtained 

 Estheria near Maji-ya-Chumvi. After the description by Mr. R. B. 

 Newton of a new species of Estheriella discovered by Messrs. Andrew 

 and Bailey in the Karroo rocks of Nyassaland, 1 Mr. Newton kindly 

 examined the Maji-ya-Chumvi specimens, and wrote : "I am inclined 

 to regard them as carapaces of a form closely allied to Estheria greyi, 

 T. Rupert Jones, from Cradock, South Africa. I should regard them 

 also as of similar age to those found by Molyneux in Rhodesia, as 

 well as those discovered by Andrew & Bailey in Nyasaland." This 

 I think makes it clear that the Maji-ya-Chumvi Beds cannot be 

 correlated with the marine Changamwe Shales of Upper Jurassic age. 



Above the Maji-ya-Chumvi Beds come sandstones, which Fraas, 

 as a result of his identification discussed in the preceding paragraph, 

 places above the Changamwe Shales and calls Cretaceous. These 

 sandstones were divided by me into two groups, the Mariakani 

 Sandstones below and the Mazeras Sandstones above. I found that 

 the Mazeras Sandstones dipped below the Changamwe Shales, a clear 

 section being seen in the estuary of the Mwachi River, south of the 

 railway. Fraas' statement that the sandstones overlie the shales and 

 cap the ridge along which the railway runs from Mazeras down to 

 Changamwe is contrary to fact. The Shales at Changamwe are 

 covered only by 6 or 8 feet of loam, which extends in this manner 

 inland for 5 miles. The shales then appear on the surface and in 

 cuttings for about 2 miles, when the upper beds of the Mazeras 

 Sandstones rise from beneath them. The dip of the shales in this 

 section is much above the average, being often 25° instead of the 

 usual 10°. Shortly after passing on to the Mazeras Sandstone the dip 

 flattens and is less than the normal. The overlooking of this change 

 of dip has probably been the cause of the error in supposing that 

 the sandstones overlay the shales with marine fossils. The presence 

 of silicified wood, as noted above, in these sandstones, and their 

 interstratification with bright green and purple sandstones point to 

 the persistence of lagoonary or continental conditions until the close 

 of the period of their deposition. Marine conditions come on for the 

 first time on this coast with the Changamwe Shales, for near their 

 base are two beds of limestone, the upper of which contains an 

 unidentified lamellibranch. It is quite possible that this limestone 

 is on the same horizon as the fossiliferous Bathonian limestone, 

 apparently faulted in amongst Upper Jurassic shales, about 5 kilo- 

 metres inland from Tanga, German East Africa. 2 The fossils which 

 Fraas actually obtained all came from the well-known locality on the 



1 Quart. Journ. Geol. Soc, vol. lxvi, p. 244, 1910. 



2 W. Koert, Zeitsch. cler deutsch. geol. Ges., vol. lxi, p. 150, 1904. 



