VOLCANO MADNESS: Re: [Geology2] Diatomaceous Earth In That Volcanic Province?

Wednesday, January 30, 2013

Re: [Geology2] Diatomaceous Earth In That Volcanic Province?

Okay, Kimmer.. got it. Wherever these folks are digging must have been an ancient body of water. Volcanoes produce ash which is high in silicates. The ash falls into the water and the phytoplankton eat it, which produces those hard shells. The creatures die off after the food source is depleted, fall to the bottom. The cycle is repeated on a bell curve for population growth with each successive eruption. When the volcanoe goes dormant or becomes extinct, the diatoms die off, the water recedes and then you get a sedimentary bed of diatoms.

Think that's what you are asking.

Lin

On Wed, Jan 30, 2013 at 1:56 PM, Kenneth Quinn <mosasaur47@email.msn.com> wrote:

This is speculation, since I am not familiar with the area, and also is based on what I remember from taking sedimentology in the 80s. Diatomite is formed a considerable depth, so on-land deposits are rare; California is one of the few areas where they are known. I would expect such a deposit in the Costal Range, though, not near Redding.

I could not find Lake Briton in my road atlas, and will try to do some more research.

Kenneth Quinn

----- Original Message -----

From: Kim Noyes

To: Geology2 ; NorCal-Rocks ; goldcountryrocks

Sent: Wednesday, January 30, 2013 1:34 PM

Subject: [Geology2] Diatomaceous Earth In That Volcanic Province?

Would somebody be able and willing to explain to me how this material formed in such an otherwise volcanic region?

From the pages of the Redding Record-Searchlight 50 years ago:

1963: Diatomaceous earth would be mined near Lake Briton by a Covina company.
The D and F Mining Co. bought rights to 1,200 acres of diatomaceous earth.
The company was the only bidders when the U.S. Forest Service offered the deposit for sale.