Open questions: East Sussex

Where sources disagree, MineArchive keeps both accounts rather than picking one; where a fact could not be settled, the record says so. 3 such claims on 1 records. All regions.

Brightling and Mountfield Gypsum Mines

• Mountfield Mine closed in the early 1990s with its reserves virtually exhausted, having latterly used a heavy media separation plant to work anhydrite-contaminated gypsum. (disputed)
• Mountfield Mine is reported to have closed in 1998. (disputed)
• Brightling is reported as accessed by a 420 m drift at a 1:8 decline, with working depths from about 100 m to 350 m. (uncertain)