NBRI Chief Geological Consultant for the Ruby Mine, Gary Clifton, Western Resource Group LLC, was guest speaker at the recent Geological Society of Nevada (GSN) membership meeting. The subject of Gary's presentation was 'The Ruby Tertiary Channel, Sierra County, California'. In attendance were approximately 100 GSN members, a mix between consultants, prospectors (mine owners) and suppliers. Gary's presentation lasted for an hour and included a slide show.
The presentation began with a detailed geological overview of the old California motherload and her tertiary channels, focusing to those channels and mines found in Sierra Co. and concluding with the complex found in Ruby mine. The CL Best story, the abrupt mine closure and pictures of the Ruby Mine gold nugget collection was shared as an entry point to the Ruby's geological discussions and investigations. This captured the attention of the crowd of course and everyone was all ears, Lots of of pictures and maps were showed, many the same as provided on the NBRI website.
The presentation was basically a review of an ongoing geological study and investigations of underground alluvial channels. The effort is directed to maintain the continuation of and exploration new prospects from within a known channel complex. The subject complex of course, is the Ruby drift mine and her tertiary channels. Gary first reviewed the known channel information available in the form of existing mapping from previous mine operators. From that information he described his work to proceed forward using existing and innovative geosciences.
As we are aware, the Ruby is in process to survey the existing channels, layers and use 3-D modeling of that information to predict legacy channels and prospects (geophysics). The surveying effort and 3-D mapping that has been completed was shared. I was certainly impressed with the product completed so far. In one instance, the mapping has shown that the spacing of 'pools' are closer in the Ruby channels than theoretically predicted. This is good.. Gold is heavy and falls out in the low spots. Gold is found all along the channels, but we want to concentrate on the richer pools or at least know when we will hit those as part of our operations. There are some unique conditions for the pay layers in that were deposited outside of normal stream dynamics. Some of these included debris fields from volcanic actions, hanging 'perched' alluvial benches, and overlay of the channels. The different layers found in the mine, from the basement volcanic base layer, the pay layer and those above were discussed including old 20-30' burnt trees that are sometimes found growing out of the different layers. Different layers predict the different conditions from which they were placed helping us concentrate efforts where the pay is profitable. He discussed the finding of isolated water and stalactites in the roof of the main tunnel.. indicators of previously unexplored target channels found due to the porous nature of alluvial channels (aquifers) and the effort to drill these targets to make a determination before we expend the cost of an exploratory raise.
Gary shared some pictures of the inside Big Bend area of the Black Channel, an important target as that is where the big gold nuggets we see today were found, the CL Best Collection. Gary provided a discussion on the dynamics of this particularly rich area, and shared a real world comparison of the same conditions in the adjacent N Yuba River. Understanding the nature of where gold has been found helps us find future prospects. I previously mentioned benches and 3-D mapping. Every miner in this area is aware of the rich alluvial benches 'above' the rivers in this area on the hillsides. Remember we are basically mining a river that has been buried over thousands of years and we are basically blind in knowing whats where when standing underground in a dark tunnel unless we let the geological sciences work for us. Gary has found in his survey work and 3-D mapping, along with his study of river dynamics and 'knick' points, a way to predict elevation and direction of alluvial benches (paydirt to you and me). Knick points basically are the top of rapids in a river, from which the river back up against it depositing alluvial materials in the slow moving water. Knick points migrate up river and tributaries over time and with erosion. A connection has been made in our 3-D mapping to known knick points.. an important discovery in our quest to better identify, not guess, where to find future prospects in the Ruby.
We can't move forward blind when drift mining and be successful. The more you know the better. Gary has mining experience worldwide, in his presentation he connected how he applied his experience to his work at the Ruby and how he is being innovative learning around the unique challenges presented. The miners working for us are experienced lifelong miners some of who had previously worked in the Ruby when Brush Creek ran it. The energy exhibited during Gary's presentation and his portrayed interactions and relationship with our miners leads me to believe we have some of best working for us in our effort to rediscover the California Motherload... NBRI & RGI
