Iron-boracite from the English Zechstein

Abstract

Iron-boracite from the English Zechstein IRON-BORACITE, (Fe, Mg, Mn)aBTO13CI, has been found in nodules in an anhydritic shale that overlies the sylvinite (sylvine-halite rock) of the third Zechstein Evaporite Cycle at the Boulby Mine, Loftus, Saltburn, Cleveland. This is the first record of the mineral in this country. The succession in the type roadway is:Anhydritic shale with the iron-boracite nodule bed near its base; the Shale and NoduleBeds are cross-cut by red sylvine-halite veins from the sylvinite below: 2 m.Pink-grey sylvinite with red and pink sub-horizontal colour bands; 2 m.Coarse-grained red and white halite with streaked-out fragments of anhydrite at its top; 3 m.

Exceptional Volkovskite Crystals from Zechstein Evaporites at the Boulby Mine, Cleveland, England

“…Borate minerals reported from Boulby mine include a species first described as "iron boracite" (Milne et al 1977), which was later shown to be trembathite or congolite (Green 2005), boracite and hilgardite (e.g., Green and Freier 1994, 1996,2010), and the rare strontium borate p-veatchite (Tindle 2008). As a result of this study volkovskite, which is abundant in the northernmost area of workings approximately 10 kilometers from the access shaft, szaibélyite, and hydroboracite can be added.…”