420 
THE CRETACEOUS ROCKS OF BRITAIN. 
rough nodular chalk, breaking with an uneven fracture, of which 
between 30 and 40 feet could be reached, and the latter rests on 
about 25 feet of harder and more nodular chalk. At the bottom 
of this chalk Inoceramus mytiloides, Rhynchonella Guvieri and 
Discoidea minima were not uncommon, but the Inoceramus was 
most abundant from 20 to 30 feet up. Between this nodular 
chalk and the Belemnite Marl is about 20 feet of hard white chalk 
with greenish veins. It was not easy to take any plane as a line 
of division between the two zones. 
Professor Barrois estimated the thickness of the beds which 
we include in the Middle Chalk at 40 metres (which is equivalent 
to 132 feet), assigning about 66 feet to each zone. In 1900 Dr. 
Rowe found it impossible to take any measurements at Lulworth. 
In Man-of-War and Durdle Coves the chalk is inverted, crushed, 
and compressed to such an extent that the beds cannot be measured, 
and the cliffs are only interesting as affording examples of slide- 
planes and other incidents of overthrust faulting (see Fig. 75) for 
an account of which the reader is referred to Mr. Strahan’s Memoir. 
Whitenose, or White Notlie, is the next point at which a com¬ 
plete section through the Middle Chalk is displayed, and some 
account of it was given by Professor Barrois in 1876 (Recherches, 
p. 79). He was then able to ascend the cliff by a path which no 
longer exists, and which led up to the Coastguard Station. 
The beach on the east side of the promontory is only accessible 
by boat, and on the west side there is a slope of landslips. The 
Chalk is dipping eastward at angles of from 5° to 8°, and Mi*. Strahan 
states that the basement-bed rises from the beach about 300 
yards east of the ledge formed by the Chert Beds near the point 
and reaches the top of the cliff 280 yards east of Hoi worth House, 
while the bed taken by him at the Chalk Rock rises about 740 
yards east of the ledge and reaches the top of the cliff 600 yards 
west of the Coast guard Station. 
The beds at the junction of the Middle and Uppei* Chalk appear 
to be variable in their aspect at this localit} r , for Mr. Strahan gives 
detailed descriptions of them at two different spots, which differ 
considerably from one another, and neither of them agree 
with Professor Barrois’ account. The following are the particu¬ 
lars given by Mr. Strahan of the beds seen in a fallen mass on the 
east side of White Notlie point. 
Middle 
Chalk. 
Chalk with flints ; a tabular mass of flint (2 to 6 inches 
thick) at the bottom 
(Nodular chalk with a few scattered flints - 
Two layers of green-coated nodules separated by 
nodular chalk -------- 
Nodular chalk. 
Smooth white chalk with an occasional flint - 
V Chalk with wavy laminae of dark marl - 
feet. 
15 
14 
24 
6 
6 
This series of beds seems to correspond very closely with that 
seen in Mupe Bay, the tabular flint occurring at exactly the same 
