1011 
upper-triassic deposits overlying permian deposits conformably ; in 
the case of Noil Tobee it would appear that an upper-cretaceous 
deposit is superposed conformably on an upper-triassic sediment. In 
such a case certain characteristics of the plane of contact between 
the two formations often reveal it to be a tectonic plane. In fact in 
such cases the plane is as a rule more or less polished, slickensided 
or plastered over with a thin layer of gouge. No mention is made 
of it by Jonker in his notes about the geology of the place. Pro- 
bably he conceived the plane cc’ between the red clay and the 
bedded limestone to be a normal partition between two deposits in 
normal succession. 
Secondly it is possible, that the section after all represents a true 
undisturbed succession; if so, the red clay with nodules of manga- 
nese would embody the sum total of all that has been deposited 
here, in the deep-sea, from upper-triassic to uppercretaceous time. 
In such a case one might expect the fish-teeth, described above, 
not to occur in the lowermost part of the section. The notes on 
hand do not settle the question. An a priori rejection of this solu- 
tion would not be warrantable either. True, the thickness of the red 
clay (in the section rather more than 3 m.) is small if compared 
with the enormous time its deposition must have taken, but then 
also the process of sedimentation must have been extremely slow 
in the deepest parts of the oceans far removed from the land, i.e. 
in the areas of the red clay. 
EXPLANATION OF THE PLATES. 
PLATE ‘I. 
Fig. 1. Section of a manganese nodule from the cretaceous deep-sea 
clay of Noil Tobee. 
K. Nucleus, consisting of modified radiolaria-chert. 
CC Concentric shales of manganese ore. 
B.O. Outer surface of the nodule. 
Fig. 2. Fragment of red deep-sea clay of Noil Tobee, containing a small 
manganese nodule with a large, white nucleus. Natural size. 
PLATE II. 
Fig. 1 and Fig. 2. Broken nodules manganese of Noil Tobee, clearly showing 
concentric arrangement. 
Fig. 3. Nodule of manganese showing concentric layers and a white nucleus. 
Fig. 4. Nodule of manganese seen from the outside. The surface is mam- 
millated and is like shagreen in appearance by numerous little rugosities. 
