[meteorite-list] OT: Rock type

From: Bjorn Sorheim <astrogeo_at_meteoritecentral.com>
Date: Tue, 06 Aug 2013 23:22:17 +0200
Message-ID: <6.2.1.2.2.20130806232014.03d15e38_at_pop.online.no>

Thanks for sending me your reflections on this image.
I got quite a variety of rock types suggested.
So this seems difficult without more information.

Here are the types you suggested:
-Basalt
-Pillow lava(basalt), with a degree of metamorphosis
-Quartzite
-Gneiss, with banded texture
-Limestone schist or Serpentinite (latter from gabbro or peridotite)
-Shale
-Shale with concretions

The rock layers in the first image have a band of white marble (10-15 cm)
overlain by a
layer of dark grey clay containing much lime (about 50 cm), seemingly only
little
metamorphosed. While the layers over and under seems much folded - if that is
what they are - these two layers are fairly straight. A lot of mostly
whitish stones are
visible in them. Seems a bit strange that the layers should be so straight
while the
layers under and above are undulating so much.
An explanation could be that the undulating layers are felsic lava. Does
this seem likely from
what you see in the 3 images? And do the white stones suggest any clues?

Two images of the layers:
tinyurl.com/l4aqx83
tinyurl.com/k6lzfh7

Bj?rn





> From: Bjorn Sorheim [astrogeo at online.no]

> List,
> Sorry this is off topic.
> This has nothing to do with meteorites.
>
> But I'm trying with some interest to determine which rock type is in the
> picture on the link.
> I need an 'international' answer, so this list could do the trick, I hope.
> So if you have any idea about earthly rock types, I would like to hear your
> opinion.
> You don't have to be a geologist to do it. If you have seen a similar rock
> type, what
> would you term this rock type in the image?
> Since this is off topic might be best to mail me off list.
> Considered mailing this to sci.geo.geology but too there is just too
much spam.
>
> The link: tinyurl.com/rollingstx
>
> All the best,
> Bj?rn S?rheim
>
Received on Tue 06 Aug 2013 05:22:17 PM PDT