13G 
THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
PART I. 
The Middle Lias of Northamptonshire considered 
Stratigraphically. 
There is considerable difference of opinion amongst 
geologists as to the vertical limits of the Middle Lias, par¬ 
ticularly downwards, so it is necessary for me at the outset 
to state explicitly what I consider to be Middle Lias in 
Northamptonshire, and my reason for claiming this and no 
other as belonging to the period in question. 
To all who have studied the Lias deposits in England it 
must be evident that there was no great break in the con¬ 
tinuity of the series at any time, and it is more than probable 
that, so far as the Lower and Middle Lias are concerned, a 
break at one place is represented by a continuous deposit at 
another. Such being the case, it appears to be only neces¬ 
sary to accurately state where the line is drawn in any 
locality by the local geologists. Professor Judd, in his 
“ Geology of Rutland, &c.,” places this matter, which is still 
one of controversy, in a very clear light; and I am sure I 
need offer no apology for quoting some of his remarks on 
the matter. 
The Lias formations were first divided into “ Upper,” 
“ Middle,” and “ Lower,” by Phillips, in a book published in 
1829 :—“ Illustrations of the Geology of Yorkshire.” Part I., 
“ The Yorkshire Coast.”* 
Louis Hunton was probably the first geologist who made the 
attempt to localise fossils, and so divide formations into zones 
characterised by a particular fauna ; and a paper of his on 
this subject was published in Yol. Y. of the second series of 
the “ Geological Transactions,” in 1836. This was followed 
by another paper in the same volume, by W. C. Williamson, 
which was an attempt to divide the whole of the Lias into 
zones. 
■Quenstedt, in 1843, divided the Lias into six stages, 
a j8 y 5 e f. Dr. Albert Oppel, in 1856, published a work as 
the result of his study of the German and English Lias 
(chiefly Yorkshire, I think), in which Hunton’s ideas of Palae¬ 
ontological zones was more completely developed; and since 
then this method of dividing the various formations, particu¬ 
larly the Lias and Oolites, has been largely followed. 
* “ The Yorkshire Lias,” by Messrs. Tate and Blake. 
