400 A, J. JUKES-BROWNE ON THE HESSLE 
§ 1. Hvtension of the Hessle Clay in East Lincolnshire. 
In the first place it will be desirable to identify the Boulder-clay 
in the district examined by me, with the Hessle Clay of the localities 
where the latter is typically developed. Fortunately the well-known 
memoir by Messrs. Wood and Rome renders this an easy task; for 
they have traced the clay southwards through Lincolnshire to the 
mouth of the Steeping valley, where | commenced my survey in 1877. 
The following is their statement regarding the extension of the 
clay in Lincolnshire* :— 
“ At the only spot on the Lincolnshire coast which affords a 
section, namely the low cliff of Cleethorpe, the Hessle clay caps 
the purple; .... From Cleethorpe the Hessle clay extends 
southwards over the belt of undulating ground called ‘The Middle 
Marsh,’ which it envelopes, overlapping the lower part of the 
eastern Wold-slope. It is well shown around Alford, where the 
brick-pits afford good sections, and where it is seen to be overlain 
by 4 or 5 feet of a light-brown silt. ... Four miles south of 
Alford the Wolds terminate, and the East Lincolnshire marsh 
sweeps round to the mouth of the Steeping valley. Fringing that 
marsh and forming a belt between it and the high ground, the 
Hessle clay sweeps round also, and occupies (where it opens on the 
marsh near Firsby) the mouth of the Steeping valley.... The 
southern extension of the Hessle clay beyond the Steeping mouth, 
near the southern extremity of the Wold, is obscure, owing to the 
flat nature of the country.” 
It is its continuation along the borders of this flat fen country that 
I now proceed to indicate. 
From the neighbourhood of Burgh the Boulder-clay dips eastward 
and southward under the soft clays of the Lincolnshire marshland ; 
its surface boundary, indeed, curves round to the 8.W. below Irby, 
Firsby, and Little Steeping; but the clay itself is unquestionably 
prolonged beneath the warp and silt of the fen country to the 
southward ; it is exposed beneath these beds at the bottom of the 
brickyards near Thorpe Culvert Station ; but how far it extends due 
south of this point I have not had any opportunity of ascertaining. 
Returning to the vicinity of Little Steeping, it has been traced 
thence to the 8.W. by Toynton Fenside and Keal Coates to Stickford, 
the course of the Catchwater drain very nearly coinciding with its 
fenward edge, while its northern boundary skirts the high land 
formed by the Kimmeridgian and Neocomian beds between Spilsby 
and Bolingbroke. 
Its westward extension, however, terminates at the mouth of 
the valley in which Bolingbroke its situated; it does not even 
stretch into this valley, but, ceasing to skirt the edge of the fenland, 
it is now prolonged southwards through Stickford and Stickney 
towards Sibsey, forming a narrow ridge or bank which separates the 
two low-lying districts known respectively by the names of West 
Fen and East Fen. 
* Quart. Journ. Geol. Soc. yol, xxiv. p. 152. 
