|This is the surface exploration drill core from the mines' exploration program. There's not as much core as there should've been, but lets not get into that...|
|Each of those core boxes contain about 3-4 m of core.|
Anywho, when I saw the slickensides and slickenlines on this sample, I happily took my rock hammer to the core and pocketed the sample right away. I actually had both sides of the fault, but I gave the other half of it to a geologist friend. What are we looking at and what the heck are slickensides/slickenlines, you ask? Well let me tell ya!
I'm sure you've heard of faults - they often come up when you hear of earthquakes, and there's the ginormous one in California, the San Andreas Fault. Faults are fractures or cracks in the rock where displacement (or movement) occurs, allowing two blocks of rock to slide against each other. The energy released when rocks shift can cause earthquakes if the fault or the displacement is big enough.
|Slickenlines showing the direction of displacement. (source)|
The really cool part of slicklines is that the lines point in the direction of general movement, and other features can actually tell you which side moved what way. This is more difficult to identify in drill core unless you put a lot more work during drilling, but it can give you some idea. Where this is more useful is in outcrops at the surface, where you can get proper azimuth and dip measurements, and is regularly used when discovered to identify fault movement. I saw slicks underground all the time at Wolverine Mine, and always noted the direction of movement on my maps.
2), a little bit of chalcopyrite (the more yellowy copper- and iron-rich mineral, CuFeS2), and some white calcite (CaCO3).
Pretty slick, eh?
Any questions about faults, slicks, or anything else I blathered on about in this post? Is there any type of rock or geological feature you'd like to learn more about? I'm happy to take rock requests!