Re: Quartz Crystal With Lava?

Matalog wrote:
> A friend of mine found a little area In Ireland where a 20' x 20'
> vein of quartz crystal lies. He was looking at the area and found that
> there was a piece of the vein where what looked to be lava had covered some of
> the crystals. There is no history of volcanic activity in the area that
> I am aware (at least not reorded history) and no signs of volcanoes close
> around the area. Anybody have any ideas what might have caused this lava?
> I can supply a photo of the crystal he gave to me - upon request.

Paul wrote:
> > We could use definitions and better descriptions:
> >
> > What is a "20' x 20' vein of quartz crystal"? What is its third
> dimension?
> > How is it oriented?
>
> I have not seen this site.
>
> > What exactly are you calling "lava"? (granite, basalt, diorite, etc.?)
> I don't know what type of lava it is.
>
> > What are "glacial mountains"? Please describe.
> Mountains that were shaped by glaciers flowing past in the years gone by.

Ireland is very pretty. I have not been there in a long time and
would like to go back some day. The geology is great. Quite varied.

The little biting black flies are not so great though. Thats mainly where
there are sheep...

> > What do you mean the mtns are qtzite? Please describe.
> I hear that the mountains consist mainly of quartzite.

The common useage of quartzite usually refers to metamorphosed sandstone.
Ireland has everything: sedimentary, volcanics, plutonics, & metamorphs.
Go here and download a small geological map of Ireland:
http://www.gsi.ie/everyone/simplegeol/ireland/ireland.htm
http://www.gsi.ie/everyone/simplegeol/ireland/GSI_GeolIreland_A4.pdf
It will help show what rocks are where.

> I am no geologist (apart from the fact that it interests me).
Good interest to have!
Continue to ask questions and we will try to answer them.
Paul.
.