Sheppard : Geology of B rough, East Yorkshire. 141 



traced for long- distances in the sides of the railway cuttings. 

 Fossils, however, are provokingly scarce in this middle chalk, 

 which, perhaps, accounts for it not having- received the attention 

 that has been paid to the other beds. 



The Upper Chalk does not occur near Broug-h. 



St. Austin's Stone should be briefly mentioned here. It 

 forms a prominent feature in Drewton Dale. It is a hug-e mass 

 of chalk and flint breccia which protrudes from the dale side, 

 and has evidently at one time filled up a fissure, as it can be 

 traced some distance down the dale side. 



The Chalk, which we have just referred to, is the last of the 

 solid rocks we have to deal with. In the Wolds and Dales it 

 reaches the surface and forms the subsoil. . After the Chalk we 

 have another great break, as the Tertiaries are not represented 

 at all, neither here nor elsewhere in Yorkshire. 



Capping- and skirting' the Chalk in one or two places are 

 beds of Glacial ag-e. At North Cave, Sancton, Market Weig-hton, 

 Broug-h, and other places in the vicinity are beds of gravel, all 

 strongly current-bedded, but all have been formed by water 

 flowing in a southerly direction, and apparently they are con- 

 nected in some way, as they resemble each other in general 

 appearance and composition very much, varying, of course, 

 according to local surroundings. 



In a field at South Cave is a series of four or five gravel 

 terraces resting on the Oolites. They are principally composed 

 of chalk debris, but also contain boulders of Lias, Oolite, basalt, 

 porphyrite, etc. Their contour is very marked and clear, and 

 they are probably contemporaneous with the formation of the 

 various current-bedded gravels just referred to. 



As already pointed out these gravels are well distributed 

 over this part of the country, but I will confine my remarks to 

 those at Brough. There are two main sets, one on the low 

 ground skirting the Humber and one capping Mill Hill. 



The gravel on the top of Mill Hill appears to consist of two 

 distinct beds of different ages. The upper gravel is, as usual, 

 false-bedded, and chiefly composed of angular and sub-angular 

 chalk and flint fragments, with occasional pebbles of other local 

 rocks and a large proportion of sand. No mammalian remains 

 occur in this gravel except such as have been included by human 

 agency since its formation. 



In the lower part of this Mill Hill section, however, in 

 a shallow depression, there are relics of an older and entirely 

 different bed preserved. It is composed of ferruginous sand, 



1901 May 



