Laverdiere Prospects, Hoboe Creek, Atlin Lake Area, Atlin Mining Division, British Columbia, Canadai

Regional Level Types
Laverdiere Prospects	Group of Prospects
Hoboe Creek	- not defined -
Atlin Lake Area	- not defined -
Atlin Mining Division	Division
British Columbia	Province
Canada	Country

The Laverdiere Prospects are located on the west side of Hoboe Creek, about 3 kilometres south of Willison Bay (Torres Channel, Atlin Lake) and 46 kilometres south-southwest of Atlin, British Columbia.
There are descriptions of these prospects on the British Columbia “Minfile” site, current to 2021. Relevant portions are quoted below:
“The prospect occurs in an area if (sic) limestone, marble, and calcareous sedimentary rocks of the Devonian to Middle Triassic Boundary Ranges Metamorphic Suite. This unit is surrounded by tuffaceous non-calcareous sediment (?) and lesser biotite schist of the Boundary Ranges Metamorphic Suite. Dolomitic limestone and underlying thin-bedded calcareous siltstone, quartzite, and schist dip moderately west along the western edge of Hoboe Creek valley. These are intruded by Cretaceous granite that forms high bluffs west of the valley wall.
A series of semi-conformable skarn deposits occupy a horizon in dolomitic limestone near the siltstone contact and are explored by several adits. Mineralization consists mainly of magnetite or magnetite-serpentine (chlorite, epidote, tremolite) skarn with disseminated to massive chalcopyrite. Three separate mineralized sections total over 265 metres in length, with widths of 3 to 12 metres, reaching a maximum of 55 metres. In addition to magnetite and chalcopyrite, specularite, tetrahedrite, pyrite, pyrrhotite, molybdenite, scheelite, cobaltite, erythrite, bornite and malachite have been reported in skarn, with molybdenite and scheelite occurring locally in fractured zones in the intrusives.”
At this point, I (Giles Peatfield) think it appropriate to present some additional information regarding the mineral occurrences of the property. There are two distinct styles of metallization. The copper-bearing skarns are located in the northern part of the area, and are better studied. To the south, there are quartz veins with precious and base metal values. There are also occurrences of disseminated and fracture controlled chalcopyrite, scheelite and molybdenite mineralization in intrusive rocks; it does not appear, contrary to what is stated in Minfile, that scheelite and molybdenite occur in the various skarns. The differences between the skarn and quartz vein occurrences were described by Cairnes (1911), although he did not recognize the disseminated copper and tungsten mineralization. It is also important to point out that the granitic rocks are much more diverse than indicated in the Minfile write-up – see comments below for rock types.
There has been no production from the Laverdiere property, and there are no quantified resources reported.

Comments by Giles Peatfield on several of the minerals reported from the locality:
Amphibole group: Carswell (1974) in his petrographic studies identified ‘hornblende’.
Apatite: Carswell (1974) reported small amounts of apatite in quartz monzonite.
Bornite: No workers until Rodway (2019) mentioned bornite. A photo in Rodway’s report, of massive magnetite from the French Adit, shows strong bornite mineralization.
Clinopyroxene subgroup: Carswell (1974) identified possible pigeonite; Macdonald (1981) and Savell (1982) both reported diopside.
Cobaltite: Early workers in the area (Cairnes, 1913; Clothier, 1919) reported ‘cobalt bloom’ (erythrite), but it was not until 1950 that Livingston described cobaltite, in polished section examination. Frustratingly, Livingston did not give any firm information on how he identified cobaltite; there is no mention of X-ray confirmation, so presumably the identification was based solely on ore microscopy. Thompson (1954) reported cobaltite from this locality, based on samples collected by Livingston; presumably he was satisfied with Livingston’s work, which he in fact supervised. Finally, the Pacific Museum of Earth at the University of British Columbia has in their collection two (small) fist-sized lumps of dark, mixed sulfide material with abundant erythrite crusts, specimen catalogue number 1727. According to the Museum’s records, these specimens were donated to the collection by Livingston.
Erythrite: The earliest reference to erythrite was by Cairnes (1911), and it was reported by numerous other workers in successive years. See note above for cobaltite.
Feldspar group: Carswell (1974), in his petrographic studies, reported orthoclase in several rock types; other workers simply used “K-feldspar”. Carswell also described plagioclase, with compositions generally between An20 and An30.
Galena: Cairnes (1911) reported galena in a quartz vein in granitic rocks, with tetrahedrite (q.v.)
Garnet group: Cairnes (1913) reported a garnet that he thought might be grossularite. Savell (1982) described a ‘reddish’ garnet. Livingston (1950) reported that “The south end of the property is more sparsely mineralized and a few small bodies of garnetite are found in the limestone.” There are no more specific data for garnets.
Gold: Mentions of native gold are not common for the area. Cloutier (1919) mentioned, regarding one of the adits toward the southern part of the property, that “It is said that free gold was found in an open-cut just above this tunnel.” Fustos (1974) reported possible free gold in drill core. Macdonald (1981), listing the underground workings on the property, mentioned that the southern-most adit, driven on a quartz vein in granodiorite, was known as the “Free Gold’ adit – does this hark back to the work of Cloutier?
Scheelite: Macdonald (1981) confirmed the presence of scheelite in drill core by ultra-violet radiation.
Siderite: Savell (1982) reported siderite in drill core, but gave no details.
Silver: Cairnes (1911), describing a quartz vein on the Alvine claim, noted that “. . . small particles and flakes of native silver also occur.” No other worker has reported native silver.
Specularite: This variety of hematite was described in polished sections by Livingston (1950) and subsequently reported by Thompson (1954).
Sphalerite: This mineral is apparently not common on the property; it was reported in a single polished section by Livingston (1950), who noted that it was found in contact with chalcopyrite, and also that “The usual [ex-solution?] inclusions of chalcopyrite are seen in the sphalerite, but they are exceedingly small and can only be seen by use of a high power oil immersion lens.”
Tetrahedrite subgroup: This was reported by early workers (e.g. Cairnes (1911, 1913) and Cloutier (1919), generally as “grey copper”. Cairnes (1911) mentioned that it contained “more or less” silver but gave no further details. Subsequent workers did not mention the mineral.
Titanite: “Sphene” was identified by Carswell (1974) in his petrographic studies.
Tremolite: This was reported in drill core by Savell (1982), who gave no further details.
Valleriite: This was reported as possible by Macdonald (1981).
Wollastonite: This was reported as possible by Macdonald (1981).
Zeolite group: Carswell (1974) described a dark rock that he thought might be a lava, based on the presence of amygdules filled by possible analcite (sic) Note that the currently accepted name is analcime (Back, 2018). Carswell also reported a high percentage of what he tentatively identified as ‘pigeonite’. The geologic setting makes lava an unlikely rock. Savell (1982) described, in drill core, several thin, highly altered mafic dykes, but it is not likely that these are equivalent to Carswell’s ‘lava’ – might they, however, be related?
Zircon: This was identified by Carswell (1974) in his petrographic studies.

Comments by Giles Peatfield on the rock types reported from the locality:
Note that many of the rocks listed have field names; only a few of these are derived from petrographic studies. These include arkose, monzonite, quartz diorite, quartz monzonite and syenite, described by Carswell (1974). White (1969) described the siltstone as “calcareous” and some of the limestone as “dolomitic”. Savell (1982) in his diamond drill core logs described some of the marble as “dolomitic” – this is probably White’s dolomitic limestone. Savell’s logs mention several different varieties of “skarn”, viz magnetite, magnetite-serpentine, serpentine, impure limestone, and chlorite-serpentine skarn.

Other Databases

Link to British Columbia Minfile:	104M++022

Other Regions, Features and Areas containing this locality

References