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XXI. — Notices and Extracts from the Minute-Book of the Geolog^ical 



Society. 



1. — Observations on the Cliffs in the neighbourhood of Harwich, made in De- 

 cember 1832. % James Mitchell, LL.D., P.G.S. [Read May 15th, 1833.] 



Harwich is situated upon a peninsula, which is defended from the ac- 

 tion of the sea by a promontory on the north-east; and on the east and south- 

 east it is partially protected by walls and lines of posts or groins. 



About 300 yards to the south of the light-house begins a cliff consisting of 

 London clay. Where it first appears it is low, but as it projects towards the sea 

 it rises in the course of 300 yards to 35 feet ; but for the next 300 yards it re- 

 cedes from the sea, and declines to the height of 15 or 20 feet. Prom that spot 

 it again rises to 30 feet^ and extends for nearly three quarters of a mile, when 

 it sinks to a level with the shore. 



At the point where the cliff is highest, is a small remnant of a battery, which, 

 about twenty years ago, was 30 yards from the edge of the cliff. A whole 

 farm on this part of the coast is said to have been swept away ; and within the 

 last twenty-five years a piece of land, called the Vicar's Field, has been totally 

 removed. 



At the highest part the cliff presents the following section : 



Vegetable soil. 

 Chalk flints, rolled pebbles, and clay ; the two first predominating 1 ft. 

 Red clay, in beds, from six inches to four feet thick, and separated 



by seams of whitish or greenish clay, not calcareous ; about . 20 

 Blue " cement marl," or indurated clay, two beds separated by a 



bed of clay ; about , 2 



Cement stone, consisting of flattened spheroids about three feet in 



diameter 10 in. 



Blue clay, divided into two beds by a whitish streak; about . . 7 ft. 



These measurements were taken by the eye, but the height being small, it 

 is presumed that they are tolerably correct. The lines of stratification are 

 parallel; but, at the point where the section was taken, they are not horizontal, 

 having a gentle anticlinal dip. 



A second bed of cement stone is visible on the shore at low water, and about 



2l 2 



