 |
| The Grotto |
From the Trout Stream, I continued with the exploration of the gardens of Chatsworth House by heading south along the main path, which runs parallel to the escarpment of Chatsworth Grit that rises above it.
 |
| The Grotto |
The Grotto is essentially a very large rock arch made of rough rectangular blocks of gritstone, with a cylindrical summer house with a conical roof rising up behind it, and was originally built by White Watson for the Duchess Georgiana in 1798.
 |
| The Grotto |
A first impression is that it is of very crude dry stone construction, given the very irregular nature of the flanks to the structure but, when viewing the entrance to the Grotto from the west, it can be seen that the arch and its surrounds are made with alternate rough blocks of gritstone and large sections of flowstone and tufa that have been shaped to fit tightly together.
 |
| Flowstone and tufa alternating with gritstone |
I have seen tufa used locally in vernacular architecture in Matlock Bath and Alport, but I had never seen flowstone used as a building stone. The Grotto was much altered by the 6th Duke in the 1820s and its use might reflect his love of stone in many forms, with Poole’s Cavern being a possible source.
 |
| Flowstone and tufa alternating with tufa |
Just beyond the Grotto, several large blocks of Chatsworth Grit litter the lower slopes, which are one of the constituents of a loose geologically recent sedimentary deposit known as head, which usually forms beneath the gritstone edges.
 |
| Boulders of Chatsworth Grit |
Although I have never seen crags at Chatsworth like in other places further north along the Derwent Valley, like Curbar Edge, these large blocks will have detached themselves from the escarpment by the process of cambering and then slipped with other rock debris down the slope.
 |
| A general view of the Grotto and Chatsworth Grit boulders |
No comments:
Post a Comment