Four Corners Gem and Mineral Show

This weekend there was the Four Corners Gem and Mineral show hosted by the Four Corners Mineral Club of Durango. Every year there are tons of amazing rocks, crystals, jewelery and other neat things to see. I highly recommend going to a rock show like this where you live.

  

 

Large Amazonite (blue) and Smokey Quartz crystals (black)

 This guy is the miner who found all of these

 Thunderegg Agate

 I didn't find out the name of this neat mineral

 A large sample of Crinoid fossils

 Fishy fossils

 Trilobites!

So many things to look at!!

 The items I purchased for my own collection.

The Purple Cilffs of the McDermott Formation

South of Durango lies this striking maroon cliff band of strata known locally as the Purple Cliffs and geologically as the McDermott Formation. It is believed by most geologist to be a fluvial deposit with debris flows and some volcaniclastic deposits from the La Plata Volcanic Intrusions to the northwest.. The deposit can be found throughout the Four Corners area and is dated to be on the Upper Cretaceous-Tertiary boundary (66 Million years old) and some fossils have been found in the formation here in Durango and also in exposures in New Mexico. I find them to be one of my favorite exposures in all of the Durango area.

Silver Mountain

 Silver Mountain is one of the more prominent peaks of the La Plata Mountains seen from Durango. As its name suggests, it was found to host veins of the precious metal. While mining of the mountain is now a thing of the past, one may still find traces of galena, lead, pyrite and traces of gold and silver in the mountain.

Unconformity

Just west of Baker's Bridge, One may view the contact between the Precambrian Baker's Bridge Granite and the overlying Upper Devonian Elbert Formation. The contact between these two rock types exhibits a gap of time known as an uncomformity which here represents 1.2 to 1.3 Billion years missing from the geological record of the area. During this lost time, it is believed there was no sediment deposition and erosion reigned supreme. Below is an annotated picture of the same outcrop.

Purple Cliffs

  

" How much paint did it take to make the cliffs purple?" An actual question asked by a tourist visiting Durango. Geologically, the Purple Cliffs are known as the McDermott Formation. They are the  stream and mudflow deposits that washed off the La Plata Mountains as they started to uplift during the late Mesozoic Era (66 Milion years ago).

Snow and Sun

The view spreads south over the agricultural fields of the Florida Mesa and the forested foothills of the Hogback Monocline, which bounds the San Juan Mountains to the north and the San Juan Basin to the south