Geology of the Mine-

This is a simple explanation of the geology of the Humming Bird Mine…

One half mile to the east of the mine, a layer of pre-Cambrian granite rises up out of the valley floor – getting taller as it continues west. At the point where the claim is, it is 200 tall above the highway. As it heads west it rises even further to 500, then 1000 feet. I think at some point further up the canyon it is close to 1500 foot tall!

This granite is:
– 1.6 BILLION years old!
– It is full of pegmatites ( coarse grains of quartz, mica and feldspar) .
– Has VERY OLD faults and fissures in it.

Some of these faults date back a billions years! Our claim sits on one of those ancestral faults. Since then several continental events caused the land under the claim to go from sitting at the equator at sea level, to where it sits today in Colorado at 6200 feet in elevation. Many of these large continent-shifting events caused “flows” to rise up inside the faults and fissures of the area.

To date, there are 8 recorded “flows” of minerals within the fault we are digging. This explains the wide variety of minerals found at our mine. The following list of minerals are currently being mined:

1- Granite Intrusion (1.6 million years old)
2 - Mica - Schist (Basement rock)
3 - 7 Quartz - 5 types - (Amethyst, Clear, Milky, Smoky & Citrine)
8 & 9 - Fluorite (Green and Purple)
10 - Calcite
11 - Hematite
12 - Pyrite
13 - Limonite
- 13A - Limonite after Pyrite (pseudomorph)
14 - Malachite
- 14A - Malachite after Brochantite (pseudomorph)
15 - Azurite
16 - Shattuckite
17 - Chalcopyrite
18 - Tenorite
19 - Barite
20 & 21 - Beryl (Blue and Green)
22 & 23 - Topaz (Brown and Blue)
24 - Aquamarine
25 - Bornite
26 - Molybdenum
27 - Chrysocolla
28 - Chalcocite

I believe three are of pegmatite origin. Since no other similar material has been found in the immediate area (there is a blue beryl deposit 15 miles away in same granite), I think that one or more pegmatitic veins bisect (cross) the fault and cause a shift in the chemistry that makes up the gemstones found at that contact point. It is obvious that the miners of the 1890s hit it, because those beryls, topaz and aquamarine were found in their debris. I just have not reached it myself yet!

We have been working with Colorado Mesa University over the last couple of years. One of their graduate students did his thesis on the Nancy Hanks District. He used samples from our mine as part of his April 2018 research paper. “Relative Age Dating of Faulting Episodes by Determination of the Mineralization Sequence in Unaweep Canyon, Colorado” by Timothy Bowers is a 50-page, well-written research paper that puts approximate dates to the various mineral “flows” that happened in the district. I would like to point out a couple of things from that research.

Mineralization Sequence -35 to 80 million years ago, the first two mineralization events occurred. First, we have Calcite and Hematite. As the Calcite formed large crystals, it indicates this mineralization occurred over a long period of time. Trace elements in this calcite include: Silica (Si), Phosphorus (P), Potassium (K), Iron (Fe), and Nickel (Ni).

The second hydrothermal solution within this time period was rich in Silica (Si), Hematite and Manganese (Mn). This generated the first Quartz (Amethyst) mineralization.

XRF analysis of the Humming Bird Mine Amethyst indicates relatively high concentrations of Iron (Fe) and Manganese (Mn) within the samples of the dark purple quartz. Other common trace elements present include: Nickel (Ni), Copper (Cu), Zinc (Zn) and Chromium (Cr), which are found in relatively moderate concentrations. Relatively small concentrations of Aluminum (Al), Titanium (Ti) and Cobalt (Co) are also present. Vanadium (V) has been observed in concentrations ranging from low to moderate. The color variations within the Amethyst is directly correlated to the concentrations of both iron and manganese.

The third phase of mineralization was the Fluorite. It can be dated to 30 – 35 million years ago. Trace elements in the Fluorite include: Phosphorus (P), Sulfur (S), and Potassium (K). It is obvious there was some fault movement prior to this hydrothermal solution flow, as the Fluorite cemented fractures separating the Calcite from the Quartz crystals in brecciated zones. One thing to note is that the Fluorite fluoresces under LW UV lighting.

The fourth mineralization in this sequence was a second crystallization of Amethyst Quartz. This solution contained lower concentrations of Manganese (Mn). As crystallization continued, Iron (Fe) and Manganese (Mn) continued to decrease until almost clear Quartz crystallized.

The fifth phase of mineralization, which can be dated to 23 million years ago (San Juan Sulfur intrusion), consisted of a Sulfur-rich solution. It is responsible for the generation of Pyrite and Chalcopyrite. Trace elements in this mineral deposit include: Calcium, Cobalt, Copper, Sulfur, Zinc, Silica, Aluminum.

The sixth mineralization phase occurred with the precipitation of copper carbonates Malachite and Azurite (and probably a few more copper-related minerals yet to be found). These minerals don’t appear to be the product of hydrothermal mineralization, but the oxidation of the Chalcopyrite. This precipitation has caused the Malachite to find its way into cracks and broken crystals, filling the damage caused from brecciation and fault movement over the millions of years.

These have been at least 2 more “flow” events that I have documented since this paper was written. But it is debatable if they are actual mineralizations or meteoric calcite cement generated by groundwater sapping.