The Goldspring occurrences are located south of Fault Creek and west of the Zeballos River at elevations of approximately 440 to 550 metres.
Regionally, the area is underlain by Upper Triassic to Lower Jurassic Bonanza Group basaltic to rhyolitic volcanic rocks. Conformably underlying the Bonanza volcanic rocks are limestones and limy clastics of the Triassic to Lower Jurassic Parson Bay Formation (Bonanza Group) and Upper Triassic Quatsino Formation (Vancouver Group), and the tholeiitic basalts of the Upper Triassic Karmutsen Formation (Vancouver Group). Dioritic to granodioritic plutons of the Zeballos intrusion phase of the Jurassic Island Plutonic Suite have intruded all older rocks. The Zeballos stock, a quartz diorite phase of the Eocene to Oligocene Mount Washington Plutonic Suite, is spatially related to gold-quartz veining in the area. Bedded rocks are predominantly northwest-striking, southwest-dipping and anticlinally folded about a northwest axis. A north-south–striking fault occurs along the Zeballos River valley, north of the rivers junction with the Nomash River.
Locally, three quartz veins are hosted by porphyritic to amygdaloidal andesitic flows of the Karmutsen Formation.
The first vein lies in Fault Creek and is described by Stevenson (Bulletin 27, page 33). It has been traced for 8 metres along a 303 degrees strike. The vein dips 46 degrees north, is 10 centimetres wide and occurs in sheared andesite on the hangingwall side of a major fault near a feldspar porphyry dike. The quartz vein hosts pyrite, pyrrhotite and chalcopyrite.
The main (Eastern, No. 1) vein has been explored by two adits from the 469 and 536 metre levels. The vein strikes 355 degrees and dips 90 to 55 degrees east, and is 2.5 to 20 centimetres wide. It follows a 13 to 30-centimetre wide rusty shear zone, and hosts pyrite, occasional patches of chalcopyrite and minor amounts of sphalerite and galena in quartz gangue. In the lower adit, the vein is hosted by andesite for 18 metres, then follows a quartz porphyry dike for 26 metres before following another shear zone to the face of the adit. The same vein in the upper adit is 2.5 to 7.5 centimetres wide within a 2.5 to 20-centimetre wide shear zone.
In 1938, sampling of opencuts yielded up to 80.0 grams per tonne gold over a width of 10 centimetres (Property File - C.C. Starr [1940-09-30]: Report of Examination of the Gold Streak Group, formerly known as the Gold Spring Group).
In 1940, two samples over 22.5 metres of outcrop averaged 65.7 grams per tonne gold over 10.5 centimetres width, whereas sampling of the tunnels averaged 50.3 grams per tonne gold from four samples over a length of 21.0 metres and a width of 15.6 centimetres from the lower tunnel and 57.8 grams per tonne gold from five samples over a length of 4.8 metres and a width of 11.4 centimetres from the upper tunnel (Property File - C.C. Starr [1940-09-30]: Report of Examination of the Gold Streak Group, formerly known as the Gold Spring Group).
In 1950, a sample of ‘heavy pyrite taken from the vein’ in the creek bed 4.5 metres above the lower adit portal assayed 52.81 grams per tonne gold and 17.15 grams per tonne silver, while three samples taken across 20 centimetres of the vein assayed trace to 13.72 grams per tonne gold and 3.4 grams per tonne silver (Bulletin 27, page 119).
The Third (Western, No.2) vein, as examined in trenches at an elevation of 442 metres and 46 metres above Fault Creek, consists of a 2.5 to 7.5-centimetre wide quartz stringer. The vein occasionally splits into several stringers along a strike of 030 degrees. The shear zone containing the vein dips 70 degrees east and is 2.5 to 13 centimetres wide.
In 1938, a sample from the Third (No.2) vein assayed 4.8 grams per tonne gold across 45 centimetres (Property File - C.C. Starr [1940-09-30]: Report of Examination of the Gold Streak Group, formerly known as the Gold Spring Group).
In 1950, three samples from the vein assayed from trace to 10.29 grams per tonne gold (Bulletin 27, page 119).
The area has been explored in conjunction with the nearby King Midas No. 1 (MINFILE 092L 020) occurrence since the 1930s. By 1940, two tunnels had been driven on the main vein; the lower tunnel was 76.5 metres long and the upper tunnel was 4.8 metres long. In 1999, the area was prospected by the Zeballos Mining Company as the Zeb Au claim. In 2009, Global Silver Producers Ltd. and A25 Gold Producers Corp. prospected the area.
