Trill (Troll) Quarry SSSI, Thornford.
Fuller’s Earth Rock.
ST 593 126
This is a key locality in studies of Bathonian (Middle Jurassic) stratigraphy. It shows sections through the Thornford Beds of the Fullers Earth Rock.
This has been defined as the type locality for the base of the standard Tulites subcontractus zone. The zonal index ammonite T . subcontractus is very common at the site.
Pholadomya lirata
| Zone | Subzone | Group | Formation | Member | ||
| Callovian | Macrocephalites herveyi | Macrocephalites kamptus | Kellaways | |||
| Macrocephalites terebratus | ||||||
| Great Oolite | Cornbrash | Upper Cornbrash | ||||
| Keppleritis keppleri | ||||||
| Upper Bathonian | Clydoniceras discus | Clydoniceras discus | Lower Cornbrash | |||
| Clydoniceras hollandi | Forest Marble | |||||
| Oxycerites orbis
| ||||||
| Boueti Bed | ||||||
| Frome Clay | ||||||
| Procerites hodsoni | ||||||
| Wattonensis Beds | ||||||
| Fuller’s Earth | Upper Fuller’s Earth | |||||
| Fuller’s Earth Rock | Ornithella Beds | |||||
| Middle Bathonian | Morrisiceras morrisi | Linguifera Bed | ||||
| Tulites subcontractus | Thornford Beds | |||||
| Procerites progracilis | Lower Fuller’s Earth | Acuminata Beds | ||||
| Lower Bathonian | Asphinctites tenuiplicatus | |||||
| Zigzagiceras zigzag
| Oppelia (Oxycerites) yeovilensis | Lenthay Beds | ||||
| Inferior Oolite | Crackment Limestones | |||||
| Parkinsonia convergens | ||||||
Great Oolite Group stratigraphy in the Sherborne area
The quarry face is now located within a Wessex Water operated sewage treatment works.
G C Rowland June 2021