190 Geological Observations. 



to that formation, it may be asked, What are the true beds of tlie 

 red ground ? by which term 1 mean that deposit which, as to the 

 sera of its formation, is later than all the coal strata in England, and 

 of course than their inclosing rocks, and which lies immediately 

 under the lyas. As far as I have seen, the lowest stratum of 

 the red ground is a very coarse breccia, or rather conglomerate, 

 which becomes finer as we ascend. The contained masses 

 are rounded and angular, and consist of limestone, hornstone, 

 quartzv sandstone, &c. To this succeeds a fine-grained cal- 

 careous sandstone, which is sometimes of a deep red and some- 

 times of a white colour. Above these, I believe, lies the great 

 deposit of red clay, abounding in many districts with gypsum 

 both foliated and fibrous, and sometimes containing sulphate of 

 strontites. I do not pretend to saylhat no other beds can with 

 propriety be referred to this formation ; but, as far as I may be 

 allowed to speak from my own experience, and the descriptions 

 of others, these only appear to me to belong to this formation. 

 It may be worth while mentioning, that the conglomerate which 

 I have formerly described as one of the red ground beds near 

 Bristol, has also been noticed by writers as occurring in other 

 districts. In a short account of the stratification of Glamor- 

 ganshire in the xlivth vol. of the Philosophical Magazine there is 

 the following passage: — " About a mile west of Dunraven, a cal- 

 careous breccia similar to that described by Mr. Gilby underlies 

 the lyas." The following is a note which I have extracted from 

 some author, but unfortunately have neglected to take down the 

 name, but I think it is from Dr. Kidd. — "A circumstance in 

 the history of rock marl is its alternating with and transition 

 into beds which would usually be called conglomerate. Thus 

 the red cliffs at Budleigh, Saltstoun near Teignmouth, and those 

 also of Teignmouth itself, consist of argillaceous beds with beds 

 of sandstone and breccia." 



The calcareous sandstone has also been noticed by other au- 

 thors. I have mentioned above Mr. Horner's description of its 

 occurrence in his account of the Quantock Hills. 



Mr. Buckland, in the paper above referred to, on the rock* 

 situated to the east of Appleby, mentions that on the west part 

 of the range there occur strata of limestone, either by themselves, 

 or with thin seams of coal interposed nearly vertical. Then 

 comes in a sandslone in nearly horizontal beds, forming, in hrs* 

 opinion, part of the great deposit which overspreads the vale of 

 Carlisle, a largij part of Cheshire, and vale of York, in which are 

 contained the great quarries of gypsum and beds of rock salt. 



Before closing this paper, it may be interesting to state the' 

 occurrence of a trap rock in the neighbourhood of Bristol. I 

 had frequently remarked, in travelling from Bristol to Gloucester, 



that 



