MIDDLE CHALK—SOUTH DORSET. 
417 
Mr. Strahan mentions several exposures of the Melbourn Rock 
and a pit near Woolgarston which exposes the uppermost nodular 
chalk including the layer of green-coated nodules, and from this 
layer Mr. Rhodes obtained a number of fossils. He remarks also 
that “ A good section [of the Middle Chalk] is afforded in the rail¬ 
way cutting at Corfe Castle, though the freshly exposed surface 
does not exhibit the characteristic aspect of the various rock-bands 
so clearly as the old quarries; the Chalk Rock* crops out on the 
east side of the cutting 74 yards north from the centre of the 
bridge at the Manse.” At this place the total thickness of nodular 
chalk from the layer of green nodules to the base of the Upper 
chalk appeal's to lie only 154 feet. 
At Ivnowle, in some quarries north-east of the church, Mr. 
Strahan saw “ massive chalk in bands of 1 to 3 feet in thickness, 
with occasional small grey cylindrical Hints and with nodular bands, 
resting upon about 30 feet of nodular chalk.” The latter doubt¬ 
less belongs to the zone of Rhynchonella Cuvieri and the higher 
beds to the Terebratulina zone. In the marl pits at Krnowle Hill 
still lower beds were seen, the section being as follows : — 
feet. 
Zone of [Hard nodular chalk ... 20 
Rh. Cuvieri. fShaly nodular chalk - 6 
Belemnite \ Chalk and marl interbcdded - - - - 3 
Marl. i Marl -------- 12 
The cliff section of the Middle Chalk in W arborrow Bay is described 
by Mr. Strahan as not easily accessible, but the beds am on the 
whole mom nodular than those at Ballard cliff. The layer of green- 
coated nodules can be reached, and there is 15 feet of nodular chalk 
above it, while below his measurements gave a thickness of 113 feet 
to the base of the nodular chalk in the zone of Rhyne. Cuvieri, 
but below this them is about 20 feet of chalk which is not 
nodular, consisting of smooth homogeneous chalk in regular beds 
with partings of greenish mail. Here, therefore, the total thick¬ 
ness of Middle Chalk seems to be 148 feet ; but Dr. Rowe found 
it impossible to measure the section in 4900. 
In Mupe Bay the beds are mom accessible, but as they dip north 
ward at increasing angles till they are actually vertical, very small 
portions of them can be reached and few fossils can be obtained. 
Mr. StraliaiTs account gives a thickness of 97 feet from the top 
of the Belemnite marl to the lower of two layers of green-coated 
nodules. Above this am about 17 feet of nodular chalk, which 
must be included in the Terebratulina zone, and these thicknesses 
make a total of 114 feet. 
Mr. W. Hill took some measurements here in 1897 which con¬ 
firm those of Mr. Strahan and make the succession as follows : — 
feet. 
A layer of flints (base of Upper Chalk). 
Rough nodular chalk without flints - - - - - 15 
x By this term Mr. Strahan means the layer of green nodules and about 
2 feet of nodular chalk beneath it. 
