8 
LOCAL OCCURRENCES IN NATURAL HISTORY. 
transported detritus so prevalent in the surrounding parts of Great Britain, the 
region cannot have been visited by a great deluge flowing from other countries, 
after its features had been determined and its present vallies excavated .”* In 
the local drift of the region as previously limited, it does not appear that any 
fossil bones have hitherto been met with. But on approaching the great valley 
of the Severn and the New-Bed-Sands tone formation, “ we enter districts where 
a large portion of the accumulations are associated with others which have been 
transported from Cumberland , and probably even from Scotland” It is in gravel 
associated with this “Northern drift” that the fossil bones formerly alluded to 
have been found. The “ Northern drift” is traced by Mr. Murchison from the 
coast of Lancashire, where, as at Preston, it is 150 feet thick, over a very large 
portion of Cheshire, Staffordshire, and Shropshire, “ until it reaches the vale of 
Worcester, where it occurs in the form of a Delta, included between the Silurian 
[Malvern and Abberley] hills on the one side, and the Cotteswolds on the other, 
both of those hilly ranges being entirely free from it.”f Throughout its course 
the “Northern drift” is distinguished by Granite boulders, precisely similar to 
rocks in Cumberland and Scotland, and it is also associated in many spots with 
marine shells of existing species ; so that Mr. Murchison remarks,—“ so numer¬ 
ous, indeed, are the localities over the region in question, where Northern boulders 
and modern sea-shells are grouped together, that no doubt can exist that the 
phenomena were due to a submarine agency extending over a very large region.” 
This “ recently-submerged tract” comprehends the Eastern parts of Lancashire, 
all Cheshire, the North of Salop, and large portions of Stafford, Worcester, and 
Gloucester, which, forming an arm of the sea between Siluria and other portions 
of Britain, communicated with the main ocean Southward, by what Mr. Mur¬ 
chison denominates the “ Straits of Malvern.” Thus we are presented with a 
great Delta extending GO or 80 miles Southward from the shores of the ancient 
Cumberland, and acting upon the disintegrating members of the New-Bed-Sand- 
stone and Lias ; and “ in which blocks of Granite, as well as other ancient rocks, 
were commingled with the marine shells at the bottom of the sea.”J 
I have adduced the deliberate and recorded opinion of Mr. Murchison as 
confirmatory of preceding statements; and explanatory of-the aspect the district 
I am examining must have formerly had, and which in several localities it still 
displays, as in the case of Mitton Common , mentioned in the commencement of 
this letter, of a sandy tract but little elevated above the sea, and recently exposed 
to its occasional incursions at high tides.§ Under such circumstances it is easy to 
* Murchison, p. 522. + Ibid., 528. J Ibid., 537. 
§ Even now, at Spring-tides, the Severn is affected so much by what is commonly called the 
“ boar,” or rush of the water up the stream from the sea, that at the Lower Lode Ferry, half a 
mile only from my residence, and above fifty miles from the Bristol Channel, at King-road, the 
