The Paco 11-12 occurrence is located on steep southeast facing slopes, northwest of Hesquiat Lake.
In the Hesquiat Lake area, northwest striking limestones and volcanics previously assigned to the Quatsino and Karmutsen Formations (Geological Survey of Canada Map 53-17) have more recently been included with the Pennsylvanian to Permian Sicker Group (Geological Survey of Canada Map 1537A). The rocks are intruded by felsic granitic rocks of the Early to Middle Jurassic Island Plutonic Suite, Muchalat batholith. A dioritic to gabbroic border phase is 500 metres wide.
Locally, mineralization occurrence lies along a northwest striking contact between limestones and volcanic rocks. The mineralization consists of massive magnetite which is streaked and spotted with garnet in a garnet-altered grey limestone. Un-mineralized skarned or altered- limestone is on strike with, and continues to the Violet (MINFILE 092E 029) occurrence.
Two lenses of magnetite have been exposed by hand trenching. The lenses are 30 metres apart and the largest is 1.5 by 0.6 metres. In 1962, a selected sample assayed 56.11 per cent iron, 0.03 per cent copper, 0.05 per cent sulphur and 0.01 per cent phosphorus (Assessment Report 464). Another sample assayed 51.61 per cent iron (Assessment Report 462).
In 1962, Paco Resources completed a program of geological mapping on the area. In 1982, Cominco completed a program of prospecting and geochemical sampling on the area as the Basin and Lake claims. In 1984, Flow Resources completed a program of geological mapping, soil sampling, trenching, a ground electromagnetic survey and 13 diamond drill holes, totalling 643.2 metres. The drill program explored a strike length of 84 metres and a total down dip extension of 28.5 metres on the Brown Jug structure, approximately 3.3 kilometres south of Paco 11-12.