part 3] L(ES9, ETC. OF THE DURHAM CO.VST. 17> 



at that time, and consequently I did not make an exhaustive 



examination of it. 



About two years later, while I was reading a description of 

 the Continental loess, the similarity of the bed associated with the 

 Scandinavian Drift of the Durham coast to that deposit was 

 forced on my mind, and I paid several visits to the coast in order 

 to observe it more closely, bringing some samples of it away for 

 microscopic and chemical examination. Its similarity to beds of 

 loess that I had seen in New Zealand also occurred to me. 



The following are the results of my continued examination of 

 this deposit : — 



As already stated, it is of a pale-brown or fawn colour, and 

 attains a thickness in the cliff-section of 1 to 10 or 12 feet. 



That portion which I regard as undisturbed kess occurs where 

 the surface of the Magnesian Limestone begins to rise at the 

 south side of the old Preglacial valley, and rests directly upon the 

 underlying rock. It appears to have been banked up against the 

 northward facing slope on the southern edge of the old valley, 

 presumably through the action of wind. The genuine undisturbed 

 loess has a thickness of about 6 feet at this point. It seems to be 

 absent from the corresponding northern slope of the old valley. 

 It passes upwards into a deposit consisting of lcess that has 

 evidently been redeposited to some extent by water, shows con- 

 siderable evidence of horizontal bedding, and has seams of sand, 

 fine gravel, and occasional small boulders in it. 



As already stated, the undisturbed loess occurs towards the base 

 of the section. It is a homogeneous bed, generally shows no 

 trace of stratification, and, unlike the redeposited material overlying 

 it, a fragment if detached cannot be broken along any definite 

 horizontal plane. On the contrary, it betrays a very distinct ten- 

 dency in the cliff to break down along vertical clefts and cracks. 

 The concretions occur more or less throughout this bed, but 

 become more numerous towards the base, although they are rather 

 sparingly and irregularly distributed. They are all more or less 

 elongate-oval in shape, though some are nearly spherical, and 

 measure about 3 to 4 inches in length (see fig. 1, p. 178). 

 In some layers they tend to coalesce one into the other, often 

 forming structures like the so-called ' loess-dolls ' of the Continent. 



Some are barely consolidated, while others are quite hard in the 

 inner portions, requiring a blow of a heavy hammer to break 

 them, when the interior is found to be very dense, and to contain 

 cracks and spaces which are often partly occupied by a few calcite- 

 crystals. 



The bed of undisturbed lcess containing the concretions is very 

 uniform in general colour and appearance, though samples of it 

 taken within a short distance one of the other show that the 

 relative proportion of the chief constituents which compose it 

 varies to some extent. It is quite devoid of sand or stones, and 

 I found no trace of shells or other organic remains in it. 



Although it agrees so closely in chemical and mineralogical 



