Millennium Gallery, Sheffield, 9th July - 26th August 2013

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How the texture forms

The swarf, created by the grinding process, is composed of tiny steel particles, abraded by the grindstone, with a little stone and tiny wood splinters (from the flatstick).It is fused together by heat due to friction, which is then cooled by water, from which it has been deposited.

The water flow, which runs down the squat board after being picked up from the ‘trow’ and thrown against it by the grindstone, creates a cyclical system of flow, which allows a sedimentary deposit to form and “grow”, on the squat board, or on any object placed in front of the grindstone.

Technically, the texture of the surface of the swarf deposit is created by ”lag” effects, due to the hydrological system, or hydrosphere, implicit in the working process. The resultant fluvial process, of deposition, creates a “bedload” of coarse fragments on the surface of the squat board, or target. A deposit can only be made when the velocity of the fragments (entrainment velocity) in suspension, is low enough to enable “lithification” – the creation of a lithological unit, an alluvial deposit. Lithification applies to rock formation usually.

The sediment then undergoes “diagenesis”. Diagenesis is any chemical, physical or biological change undergone by a sediment, after its initial deposition, and during or after its lithification, exclusive of surface alteration (weathering) and metamorphism.

A concretion occurs, with strata, which appears to form some kind of “pseudo-fossil”. The concretion “grows” as successive layers of mineral “accrete” are held at the surface.

It could be called a “ferruginous concretion”.

Professor Antonin Horsin Dept of Sedimentary Mechanics and Swarfological Studies Utrecht Psalter