Jeffrey Mine, Val-des-Sources, Les Sources RCM, Estrie, Québec, Canadai

Regional Level Types
Jeffrey Mine	Open-Cast Mine (Inactive)
Val-des-Sources	Town
Les Sources RCM	Regional County Municipality
Estrie	Administrative Region
Québec	Province
Canada	Country

Formerly: Jeffreymine (Johns-Manville Mine), Asbestos, Les Sources RCM, Estrie, Québec, Canada.

Formerly: Jeffreymine (Johns-Manville Mine), Asbestos, Asbestos RCM, Estrie, Québec, Canada.

Formerly: Jeffreymine (Johns-Manville Mine), Asbestos, Shipton Township, Richmond Co., Québec, Canada.

The town voted to change the name from "Asbestos" to "Val-des-Sources" in October 2020.

"Jeffreyquarry" in earlier locality strings has no trace in the literature and should not be propagated. The "Johns-Manville mine" is also a misused name, as it was not officially used; Johns-Manville was the corporate owner and operator of themine for most of its history.

Mine: Open-pitchrysotile asbestosmine, measuring some 2 km in diameter and eventually reaching a depth of 350 m. Mining began in 1879. In 1950 an attempt was made to switch toblock caving, but this method was abandoned after 10 years. In 1969 thepit was expanded, requiring the relocation of the adjacent town. However, world demand forasbestos fell drastically in the 1980s when its carcinogenic properties became known and worldwide bans were implemented on its use as a building material. In 1996, in an attempt to mine a high-grade area at the bottom of thepit, another attempt was made to switch to underground methods, but government subsidies were exhausted in 2001, and since then the mine has been inactive.

Regional Geology: While theultramafics of the Thetford-Ham area are a typicalophiolitecomplex, their origin remains controversial. "Ophiolite" is a term referring to an assemblage ofultramafic andmaficintrusive andextrusive rocks, widely believed to represent oceaniccrust. Suchcomplexes are characteristic of many orogenicfold mountain chains and are sometimes preserved when anisland arc system is scraped off of onetectonic plate as it collides with and is subducted under anotherplate, creatingfold mountains. However, others have concluded that theultramafic rocks of southern Quebec and Vermont are not oceaniccrust remnants because many areintrusive, withperidotite the most common. Furthermore, Precambrianoutcrops in the area appear to be continental, not oceaniccrust. They suggest instead that theultramafic rocks are from the uppermantle, emplaced as solidintrusions duringdeformation of the Appalachians. Still others propose that perhaps the Quebecultramafic rocks represent gigantic submarineextrusions orfeederconduits for submarine eruptions.



The geological map is copied from Horváth et al. (2013)

Local Geology: TheSerpentineTectonicBelt of the Lower Ordovician rocks of the Appalachians comprise serpentinizeddunite,chromitite,pyroxenite andperidotite, all intruded bydiorite,syenite,granite,gabbro andultramafic tointermediate volcanic rocks. Thedunite andperidotite that are associated with theasbestosdeposits were heavily serpentinized in successive stages soon after crystallization, especially where sheared and intruded bygranitic to dioritic masses. In a later phase of serpentinization,shear zones andfractures channelled theasbestos-formingsolutions. Laterdikeintrusions into thedunite andperidotite formed irregularly and, as at thedioritecontact zone with the serpentinizedzones, they tended to facilitatereplacement mineralization. Calcium- and aluminium-richfluids were deposited injoints andshears in thediorites andultramafics, and occasionally were intruded as discretedikes calledrodingites.

Other Databases

Wikipedia:	https://fr.wikipedia.org/wiki/Mine_Jeffrey
Wikidata ID:	Q21834551

Mindat Articles

Colour relationship to composition in alumovesuvianite/vesuvianite from the Jeffrey Mine, Quebec, Canada by Richard Gunter

Other Regions, Features and Areas containing this locality

References