Wednesday 30 June 2010

Can anyone help please?

A teacher has sent this photo taken at Shap. What are the elongate, dark coloured inclusions in the granite at the contact with the host rock? Please put your replies in 'comments' on this post or send them by email.
Many thanks.

3 comments:

Anonymous said...

Are they xenoliths? - Broken-off portions of cold rock/minerals in the molten magma.

I seem to remember seeing something of the sort on a Shap trip in the 80s

Alan said...

Hi, it's Alan. I do not pretend to be a mineralogist, and there may be someone out there who knows this for sure. Also. of course, there are serious pitfalls intrying to identify miknerals from photos alone.

However, I though it might be useful to draw your correspondent's attention to the following useful article:

Wirth, Max M, & Green, David I, 2002: "The Shap Granite Quarry, Cumbria". UK Journal of Mines and Minerals No 22, pp 43 - 52. This contains details of all minerals known from the quarry up to that time, with nice clour pics and a very full backup reference list. Alan

RICHARD GOSNELL said...

One needs to know the scale of the Shap Fell granite picture. It could be anything from a microscpoe shot up to several feet's worth.

Regards, Rigard Gosnell