Tuesday, May 1, 2012

Morocco part 6: Todra Gorges and Imiter Silver Mine

Heading into the Todra Gorges, the scenic route to the Imiter mine!

Our hotel in the gorge.

Just east of the city of Tinehir, Imiter silver mine is the seventh largest silver mine (in terms of production). It is such a rich deposit that they do not touch the rocks with highest silver content  because it is not cost effective to mine them! They could flood the market with silver but that would drive global prices down.

We had a nice lecture from the mine geologists. The geology is similar to what we saw at Bou Azzer, an east-west trending normal fault creates a contact between the older rocks of Precambrian II with Precambrian III. There are many associated faults, it is a suture zone that in the distant past had hydrothermal activity (lots of hot water flowing through the cracks in the rock). The contact is not mineralized but the faults in Precambrian II do contain the rich ore deposits.

There were two tour options here, underground or above ground. There was some concern that underground would be a bit more unsafe and difficult so only the most adventurous should take this option:

Off they go!  For those who stay above ground, we were treated to a great tour of the surface operations.

We saw one of the larger open pits, in the top photo, the lighter green-grey rocks to the right are Precambrian III, and darker rocks to the left are Precambrian II. The geologist was great, even though our guide Jean-Pierre was there to translate, he was determined to make us understand him! He drew detailed pictures and spoke very clear french and it worked, I think we did understand him fairly well.

They do not use trucks to remove the ore from the pits, they use large elevators and move the ore to the surface and deliver it to the foundries. At this mine (unlike Bou Azzer) they smelt the ore on site and make 99.5% pure silver ingots which are shipped by armored trucks to the port at Tangiers.

This is one of the elevators bringing ore to the surface.  There are cages for people to ride up and down as well!

The adventurers saw the operations from underground:

Seems a little low-tech...

Now we're talking!

In Precambriam II, dolomite limestone veins containing silver, galena, acanthite (silver sulfide) and imiterite (type mineral from this locality, a silver and mercury sulfide).

Back on the surface, security check.

The group came back together for a tour of the foundry. This is the plant where the pure silver metal is extracted from the minerals. This is a multi-stage chemical process involving cyanide and other highly toxic materials. While fascinating, the fumes were very unpleasant and the noise levels were high. A difficult job to have to do every day. Again, it is very valuable to see first hand the process of digging and extracting the materials we need to use in our daily lives.

The finished product, pure silver.  On this cart is approximately one million dollars worth of silver!

On the way out we passed through a village with people on strike.  Apparently the locals are unhappy because they cannot work at the mine.  The mine is one of the only places to work in the area but they bring their employees in from far away.  We don't know the full story but it is sad to see such high unemployment all throughout the country.

No comments:

Post a Comment