Ok i'm not a miner by any means but learning a few things here and there,But am an ammetuer history buff, I was thinking the other day that Nevada at one time was pretty much covered by a lake that covered 25000 square miles and included parts of California, Oregon,Utah. Now with a lake that large as it reciedes and the waves and water washing Material from the mountains that were below this sea what would the possabilitys be that where you find alot of your major hard rock mines if you were to go to the lower areas below the mines and dig down till you hit Gravel from this old lake or bedrock and follow that downward that you could get the gold that was washed down by this massive lake. I wonder how far down you would have to dig to hit gravel or bedrock,would there be any course gold or would it have been ground down into little flakes, Any ideas if this would make any sence.
And Rex love the sight especially the tidbits from the 30's
rehab
ocean, not lake
regional differences abound throughout the area you described. while many areas are more limestone based bedrock, others have experienced upwellings of ore minerals due to volcanic action and receding subduction zones from colorado to the present pacific coast shelf.
while it is possible that minerals you seek would be found at depth, you're looking at a shaft of 2 miles or more, deep, and heat so intense as to defy human miners. miners in nevada had trouble enough with heat in the comstock and gold field mines, and those were only several hundred feet deep. theoretically, it may not be economical to mine. However, gold mines in south africa are now approaching 2+ miles in depth, so there may be hope yet.
Instead of looking at the area as part of some big lake (there were some like that like lake mannix, Lake Lahontan, and lake bonneville), many of these were remnant water bodies from one of the last inland oceans on teh north american continent, an area that comprises most of southern nevada and parts of other states.
Sklybones
Thank you for the quick reply and Lake Lahonton was what I was talking about..damn didnt realize someone would have to go that deep.Thats deffinately out of the question for me..I was trying to think of how the Majuba placers may have been distributed and thought maybe the waters may have helped but maybe it was just geothermal and the right elements at the right times....Ive been looking for awhile and finding very little ,guess I need to go back and hit the books and studie some more..
Hope everyone out there has a great Holiday season and may next year be even better..
My thanx to all Mike
RexB
Re: ocean, not lake
rehab wrote:
you're looking at a shaft of 2 miles or more, deep, and heat so intense as to defy human miners. miners in nevada had trouble enough with heat in the comstock and gold field mines, and those were only several hundred feet deep. theoretically, it may not be economical to mine. However, gold mines in south africa are now approaching 2+ miles in depth, so there may be hope yet.
I think the mines in S. Africa are in old cratons (archons) while Nevada sits on a younger proton land mass. Since the African land mass is much older I assume it is cooler at depth, but that also depends on the thickness of the crust. I believe the crust over Nevada is significantly thinner and I imagine it may be hotter at depth than in S. Africa, how much hotter I don't know, it may only be an insignificant amount.
Boise Ron
Sklybones wrote:
Thank you for the quick reply and Lake Lahonton was what I was talking about..damn didnt realize someone would have to go that deep.Thats deffinately out of the question for me..I was trying to think of how the Majuba placers may have been distributed and thought maybe the waters may have helped but maybe it was just geothermal and the right elements at the right times....Ive been looking for awhile and finding very little ,guess I need to go back and hit the books and studie some more..
Hope everyone out there has a great Holiday season and may next year be even better..
My thanx to all Mike
If you look at this picture of the Majuba placers (from Google Earth), you will see the Lake Lahontan shorelines on the right side of the picture. There may be gold in that area, but I have never prospected there, nor have I seen anyone else there. The high water shoreline is at an elevation of about 4360-4370 ft. The Rye Patch "push pin" is at an elevation of about 4600 ft, so I don't believe the placers were ever touched by the lake. That doesn't mean there are no other places below the old shoreline where gold can be found.
