The Rioanda 15W occurrence is located on a hill between George Creek and the Loughborough Inlet, approximately 1.7 kilometres south of George Lake.
The area is underlain by a persistent band, greater than 12 kilometres long, of stratified metavolcanic and metasedimentary rocks of the Upper Triassic Quatsino and Karmutsen formations (Vancouver Group). The band trends north- west and separates Jurassic to Cretaceous Coast Plutonic Complex rock of two different compositions:, diorite and granodiorite.
Locally, random pods, seams and disseminated molybdenite-chalcopyrite mineralization occurs in contact zone rocks containing complex mixtures of quartz diorite and granitized to dioritized pendant rocks with random veins and irregular masses of chert, quartz, aplite and pegmatite. No rock sample assays were reported.
The area was originally prospected and staked in 1964 as the Rioanda claims. Over the next two years, minor programs of prospecting, geological mapping, geochemical sampling and a preliminary magnetometer survey were completed.
