The Constitution showing is located near the shore of West Thurlow Island at Eden Point. The local geology is composed of Paleozoic and/or Triassic crystalline limestone bands in volcanic rocks (greenstone) in contact with diorite of the Juro-Cretaceous Coast Plutonic Complex. The bands of limestone are found in a shear within the volcanic rocks and range from 1 to 1.5 metres in width. The shear strikes 330 degrees with a dip of 60 degrees north.

Mineralization is composed primarily of sphalerite and pyrite and is found at the limestone-volcanic contacts. The mineralization occurs irregularily and while the continuity along strike is per- sistent, assay values are variable. One sample assayed 36 per cent zinc, 13.7 grams per tonne silver while another assayed 1 per cent zinc and trace lead (Minister of Mines Annual Report 1925, page 280).