Surface exposure is minimal. Gold mineralization is mainly contained within two steeply dipping ore zones that are neither stratabound nor stratiform. Protoliths for the ore include all host rock types, but consist dominantly of metasediments and with lesser amounts of QFP rocks and mafic fragmental rocks. This unit is pervasively altered and locally attains ore grade. Aplitic dykes are altered and mineralized, but are rare and possibly limited to the central and eastern portions of the deposit.
Ore mineralogy is complex.
The metamorphic history of the Hemlo deposit is the subject of a Ph.D. project by Martin Heiligmann , also at McGill University. The official objective of the project was to develop a descriptive and genetic model of the Hemlo deposit . It does not include news items, press releases or mining reports. It is intended for geologists.