41 



white clay — and in some cases, both these strata, the olive-coloured 

 being next the Eocene. 



This olive earth is of a fine texture, containing but little gritty sand. 

 Here and there a shark's tooth in a decomposed condition, or the 

 impression of a shell may be discerned. The white stratum 

 abounds in casts, but never presents the shells themselves. It 

 shows a light trace of gypsum, but in neither of these beds does 

 there exist any carbonate of lime. From the character of the 

 organic impressions they contain, they clearly refer themselves to 

 the Miocene formation. 



In some places on the river, particularly where the upper bed of 

 the Eocene contains gypsum, as at a point a little below Piping Tree, 

 a thin layer of ferruginous rock abounding in casts occurs imme- 

 diately in contact with the Eocene ; this also is to be placed among 

 the strata of the Miocene. 



A more distinct conception of the order and extent of the strata 

 of both the tertiary divisions, as they occur at different points along 

 the river, will be obtained from the following summaries derived 

 from observation. 



On the north bank of the river in a cliff about half a mile below 

 Piping Tree, the beds taken in a descending order are, 



Miocene.— 1. White friable sandy clay, containing' fossil impres- 

 sions, - - 10 feet. 



2. White sandy marl with broken shells, - ^ 



3. Ferruginous stratum abounding in casts, and occa- 



sionally containing the shells themselves, £ 



4. Thin band of black pebbles. 



Eocene. — 5. Dark greensand stratum — no shells, - 4 

 C. Rocky shelf of cemented shells of the saddle- 

 shaped oyster, - - ^ 

 7. Dark greensand 6trata with small shells, - 2 



M? 



The highest Miocene bed is not exposed at this point, but occurs 

 a little farther up the river in the character of a dark blue clay with 

 fossil impressions, on which there rests a thin layer of ochreous clay, 

 as brilliant in its tints as the finest chrome yellow. This ochre is of 

 the most impalpable texture when dried, and would be found very 

 valuable in colouring. 



G 



