Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: adam15 on 10/01/2015 15:54:25

Title: Few questions about rocks
Post by: adam15 on 10/01/2015 15:54:25

Hi all. I was collecting fossils in the Menlough quarry few kilometres north from Galway in west Ireland. Fosils are from early carboniferous. I found there is few kinds of rocks. My first question is about their id.

First type of rock is fine grained and soft. Big stone after few hits with hammer cracks to uneven slabs. Shells of brachiopods which are main fossil in this rock are very nice preserved and easy to prep.
http://www.fotosik.pl/pokaz_obrazek/ce1dc4a7701d0d1f.html

Second type of rock which is the most common in the quarry is very hard grey-black. It's very hard to hammer. Most of fossils in this rock are colonial corals and large productids.
http://www.fotosik.pl/pokaz_obrazek/b74ba680f2f8afa3.html

Third type is easy to hammer but not so easy like the first one. Grains are coarse. Main fossils smaller species of brachiopods.
http://www.fotosik.pl/pokaz_obrazek/829ea422c6cd0f6f.html

Second question is, where in this formation is a place of those rocks. which of them are the oldest and youngest.
http://www.fotosik.pl/pokaz_obrazek/7ee3dae73e1e99ba.html

There is more kinds of rocks in the quarry without fossils ,probably volcanic.
I will appreciate any help. Adam

Title: Re: Few questions about rocks
Post by: adam15 on 14/01/2015 08:50:59

Hi.I found that rock from the first pic could be mudstone shale.