Host Rock Mineralogy
Host Rock Mineralogy: The host rocks around the I-2 dyke rocks are intensely foliated and altered, and contain many minerals that are not characteristic of the host rocks at Thor. These rocks are fine-grained and the mienrals can be very difficult to identify with the naked eye. TEM scans at the Colorado school of mines provides some insight into the alteration surrounding the dykes, and the minerals that form the rock are primarily albite, amphibole, chlorite and epidote. These minerals give the rock a distinctive green color. Magnetite is also present in the I-2 dykes making them traceable using magnetometer surveys. Although these dykes do not contain any metals of economic interest, they are important because they are the waning phase of the I-1 intrusion. They also bracket the entire I-1 body and were emplaced along the outside margin of the I-1 Intrusive and also intruded the Thor epithermal deposit, cutting it off at depth. |