The Silver Pond (North) occurrence is located east of Lawyers Creek, approximately 5.5 kilometres southeast of the creek's junction with the Toodoggone River.
The Lower Jurassic Toodoggone Formation (Hazelton Group) volcanics form a northwest-trending belt at least 90 kilometres long and 35 kilometres wide preserved between the undivided Lower Jurassic Hazelton Group to the east and the Upper Cretaceous-Eocene (?) Sustut Group to the west. Where observed, they rest structurally on the Upper Triassic Takla Group. Toodoggone pyroclastic and epiclastic volcanic rocks are a predominantly calcalkaline andesitic to dacitic subaerial succession. The region as a whole resembles a synclinorium in section from northwest to southeast. Potassium-argon studies of hornblende and biotite indicate the age of Toodoggone volcanism ranges from 204 to 182 Ma. This age appears to be divisible into two main groups: an older, lower stage of volcanism dominated by andesitic pyroclastics and flows characterized by widespread propylitic and zeolitic alteration; and a younger, upper stage of volcanism dominated by andesitic ash-flow tuffs which generally lack significant epithermal alteration. All the known epithermal gold-silver deposits and occurrences are restricted to the lower Toodoggone Formation volcanics and underlying units (Fieldwork 1988).
Toodoggone volcanic rocks display broad open folds or homoclines with attitudes generally less than 25 degrees dipping predominantly to the west. The overlying Sustut Group sedimentary rocks are structurally unaffected and are horizontal. A northwest-trending set of younger, steeply dipping faults and synvolcanic half-graben margins are the dominant structure in the region. Major structural breaks are postulated to have been caused, or be the result of, a northwest-trending line of volcanic centres. Small stocks are also aligned northwest, suggesting they were also influenced by the same structural trend. Subsequent to volcanism and intrusion, young faults are recognizable as northwest-trending lineaments. Major north-northwest fault systems are from west to east: Attorney, Moosehorn-McClair and Saunders-Jock. Most prominent gossans are aligned along this configuration of faults. The Attorney fault system passes through the Lawyers property (094E 066).
Two distinct mappable sequences of the Toodoggone volcanics, consisting of an older pyroclastic quartz andesite crystal tuff sequence (Adoogacho Member) and a younger trachyandesite sequence (Metsantan Member), are evident on the Silver Pond property. These volcanics strike northeast and dip 5 to 20 degrees to the northwest. The two sequences are intruded by steeply dipping rhyolite to rhyodacite dikes and are generally associated with steeply dipping fault zones. These are overlain by pyroxene basalt. The volcanic sequence in stratigraphic order consists of: a) quartz andesite crystal tuff, b) fine-grained to aphanitic chocolate brown tuff, c) welded trachyte tuff, and d) trachyte crystal and crystal lapilli tuff with interbedded volcanogenic greywacke. Several north- northwest striking faults have been identified and are slightly offset by younger east-striking faults. The north-northwest striking faults apparently were the conduits for the mineralizing fluids which gave rise to mineralization at the North, Silver Creek (094E 075), Amethyst (094E 160), South (094E 161), Ridge (094E 162) and West (094E 163)) prospects. The Toodoggone volcanics are affected by widespread weak propylitic alteration and weak silicification.
The southern portion of the Silver Pond property is capped by younger Sustut Group conglomerates in slight angular unconformity with the underlying Toodoggone volcanics.
Alteration associated with structurally controlled epithermal mineralization, in the area, consists of pervasive silicification grading outward into weaker silicification, sericitization, argillic and potassic alteration. An alteration zone, two kilometres across, cover much of the area and is marked by a gossan of abundant goethite, jarosite and hematite. Quartz, alunite, kaolinite, montmorillonite, dickite, illite, sericite, and minor amounts of barite, fluorite, limonite and pyrite comprise secondary minerals in intermediate to advanced argillic-altered zones (Forster, 1984).
Two general styles of acid-sulphate type epithermal gold-silver mineralization occur on the Silver Pond property: vein and breccia-type ore shoots and pods; such as the Silver Pond (West) prospect (094E 163) and the Silver Pond (Silver Creek) prospect (094E 075), and high-level stockwork-type mineralization such as the Silver Pond (North) prospect. Gold and silver are generally absent from intensely altered regions in the area, with pyrite and magnetite being the only visible metallic minerals (Forster, 1984).
The Silver Pond (North) prospect is related to the same regional fault that hosts the Silver Pond (West) and Silver Pond (Silver Creek) prospects. It is located 2.4 kilometres north-northwest of the Silver Pond (West) prospect. Initial interest in the area was triggered by identification of a zone of widespread gossan and hydrothermal alteration. Topography, alteration, resistivity and magnetics all show a pronounced north-northwest grain in the area.
A soil geochemical survey, conducted in 1984, outlined a north-northwest trending gold anomaly greater than 800 metres long. The anomaly occurs at the margin of a silica cap which contains the strongest silica-kaolinite-alunite alteration on the North zone.
The predominant rock type underlying the Silver Pond (North) prospect is porphyritic andesitic flows, which are overlain and interfinger with pyroclastics, lapilli tuffs and agglomerates derived from reworked andesitic material, all of the Toodoggone Formation. The bedding attitude of tuffs and agglomerate beds is consistently striking 240 degrees and dipping 10 to 30 degrees northwest. The area is intersected by a suite of dikes ranging from felsic (andesite to rhyolite) to mafic; the mafic dikes being younger and showing no alteration. The felsic dikes are in part hosts for silicification, quartz veining and minor brecciation.
Three types of alteration are observed at the Silver Pond (North) prospect: a) strong silicification, b) phyllic and argillic alteration consisting of clay replacement of phenocrysts, and c) propylitic alteration consisting of calcite-epidote-chlorite- pyrite(-hematite).
Mineralization consists of a stockwork of multistage silica veinlets and stringers with variable amounts of pyrite, epidote, chlorite, barite and laumontite and occasionally traces of chalcopyrite and galena. The mineralization is sporadic and difficult to correlate between adjacent drillholes. Gold is strictly confined to multistage silica stringers and veinlets and not associated with disseminated pyrite. Gold mineralization is closely associated with rhyolite dikes. The alteration and mineralogy observed relative to epithermal models suggest there is potential for economic mineralization deeper in the system.
In 1984, a rock samples (219) taken from the east side of a small creek located approximately 450 metres to the northeast of the Silver Pond (North) occurrence, assayed 3.36 grams per tonne gold and 22.6 grams per tonne silver (Assessment Report 12911).
In 1985, seven trenches and a single diamond drill hole were completed on the North zone. Trench TN-4 exposed a 9-metre-wide silicified zone averaging 0.65 gram per tonne gold with up to 1.37 grams per tonne gold over 1 metre, whereas the entire 22 metre long trench averaged 0.37 gram per tonne gold (Assessment Report 14700).
About 3000 metres of backhoe trenching were conducted on the North zone in 1987. Wide zones of strong pyritic-argillic alteration with an irregular pattern and separated by propylitic andesite, were intersected. Gold mineralization is restricted to millimetre-wide, multistage silica stringers with minor sulphide content. Where trenches were dug on soil gold anomalies and resistivity highs, the trenching yielded widespread low-grade gold mineralization including 1.57 and 1.20 grams per tonne gold over 24 and 38 metres in trenches TR18.50N and TR18.75N, respectively, with sporadic high values ranging up to 28.8 grams per tonne gold over 1 metre (Assessment Report 16952).
In addition to backhoe trenching, approximately 2860 metres of diamond drilling in 19 holes was completed in 1987. The drilling has outlined an area of widespread, low-grade stockwork gold mineralization in the 1 to 2 grams per tonne range (Assessment Report 16952). Silver values are consistently low with weak intersections being noted about 200 metres vertically. Weighted average values, from 25 drillhole intersections with greater than 1 gram per tonne gold and silver, are 1.44 grams per tonne gold and 2.959 grams per tonne silver over 1 metres true width (Assessment Report 16952). Gold values range up to 2.05 grams per tonne over a true width of 3.0 metres including 5.98 grams per tonne over a true width of 0.5 metre (Assessment Report 16952).
In 1992, Even Resources Ltd. optioned the property and explored the northeast portion of the North (MINFILE 094E 069) zone grid. A program of excavator trenching and local blasting identified two north- northwest trending, barren quartz veins and quartz-sericite-pyrite and intensely clay-altered volcanic rock.
In 2018, a float sample (Y445312) from the North zone assayed 5.33 grams per tonne gold and 2.9 grams per tonne silver, whereas a float sample (Y445403), taken approximately 1 kilometre to the northeast, yielded 12.05 grams per tonne gold and 7.9 grams per tonne silver (Assessment Report 38447). Also at this time, a sample (Y445361) from an outcrop located approximately 150 metres south-southeast of the North zone yielded 1.23 grams per tonne gold (Assessment Report 38447).
In 2019 and 2020, rock samples from North zone are reported to have assayed in the range of 5.0 to 10.0 grams per tonne gold (P&E Mining Consultants Inc. [2021-06-28]: Technical Report and Updated Mineral Resource Estimate of the Lawyers Gold-Silver Property, Omineca Mining Division, British Columbia, Canada).
Work History
The area has been explored in conjunction with the nearby Silver Pond (West) occurrence (MINFILE 094E 163) and completed exploration history of the area and property can be found there.
