Trill (Troll) Quarry SSSI

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

CallovianMacrocephalites herveyi

Macrocephalites kamptusKellaways
Macrocephalites terebratus

Great OoliteCornbrashUpper Cornbrash
Keppleritis keppleri
Upper BathonianClydoniceras discus

Clydoniceras discusLower Cornbrash
Clydoniceras hollandiForest Marble
Oxycerites orbis



Boueti Bed
Frome Clay
Procerites hodsoni
Wattonensis Beds
Fuller’s EarthUpper Fuller’s Earth
Fuller’s Earth RockOrnithella Beds
Middle BathonianMorrisiceras morrisiLinguifera Bed
Tulites subcontractusThornford Beds
Procerites progracilisLower Fuller’s EarthAcuminata Beds
Lower BathonianAsphinctites tenuiplicatus 
Zigzagiceras zigzag


Oppelia (Oxycerites) yeovilensisLenthay Beds
Inferior OoliteCrackment 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

Preserving our geological heritage