NOTES ON THE GEOLOGY OF DEKBVSHIRE. ;^^ 



used to tlie utmost. The great value of Kent's cavern, near 

 Torquay, consisted not only in the quantity and variety of the 

 deposits found in it, but also in the fact that the cave had not 

 been previously tampered with. We should, therefore, try to 

 impress upon people in the county the great importance of 

 guarding such treasures from those who might, tlirough ignorance, 

 help to destroy valuable evidence. 



Good work has been done lately on the glacial drifts in the 

 southern part of the county, which the then president of the 

 Geological Society characterised as " a most useful contribution 

 towards the correlation of the drift deposits of the British 

 Islands." In his paper on the Pleistocene succession in the 

 Trent basin, read before the Geological Society in 1886, 

 Mr. Deeley discussed a large number of exposures of glacial drift, 

 and succeeded in establishing a definite sequence amongst the 

 deposits. There is still much work of a similar nature to be done 

 in the county, and it is of that detailed kind that only those 

 living in the district will be able to do it thoroughly. Authorities 

 say that the work in tiie valleys is easier than that on the hills, 

 and should be attempted first. What has been done is only an 

 instalment of the data required for the solution of an interesting 

 problem, viz., the explanation of the unequal distribution of the 

 drift on opposite sides of the southern part of the Pennine 

 Chain. Mr. Deeley mentions good exposures of drift in clay pits 

 at Spondon and Chellaston, and at the latter place blocks of 

 limestone are to be found scratched and polished by being rubbed 

 against others, owing to the action of ice. But it is not even 

 necessary to leave our own town for observations. Many good 

 exposures have been opened out in excavating for cellars. On 

 Normanton Road, at the top of Hartington Street, a very good 

 section was seen by Mr. Deeley. " Nine feet of boulder clay, 

 consisting of red marl, rested upon a violently contorted bed of 

 sand in the Keuper. The boulder clay had evidently been thrust 

 over the sand by a force acting from west or north." Some 

 streets on the Burton Road were lately cut in the boulder clay, 

 which contained boulders of limestone, millstone grit, rocks from 

 4 



