First Fossil hunt- a few questions! (pics)

rccaulfield

Spent a few hours tippin away last week and although i found Notta i really enjoyed it! Anyway i'm a total amatuer and was hoping there might be a few brains i could pick in this forum about rock type etc. If you can answer even one question i'd be greatful! I'm told the rock in the area is of Ordovician age.
Sorry pics aren't great-cameraphone!


1-First off headed into this cave and found what looks like a iron band formation, this right?




2-I spent most of my time tipping away on loose small overhanging rocks from this type of rock. Is this limestone or at least sedimentary or was i barking up the wrong tree?


3-Is this limestone thats been altered? -is it a potential site for fossils?



4-What type of rock is that?



5-Again any id on this layered rock?



6- Found the same type of rock again later in the day with this soft maybe shale type black flakey rock inbetween the layers. I'm pointing to it with the chisel. Is it a potential site for fossils?

Coriolanus

I have no idea, but I do now all of a sudden have a burning need to know the answer to these questions. Here's to hoping someone is along to help!

Wibbs

FWIW Looks sedimentary to me alright R. Might be carboniferous limestones and shale more than Ordovician, but hard to tell from photos. Carboniferous limestone tends to be full of fossils though.

My suggestion would be leave the chisel and hammer at home. Look at loose stones eroded out from the main body of rock. Around the shale layer in number 6 would be my first place to look. The fossils will erode out of that layer faster as it's softer.

Looking at the eroded stones will be much easier and you're much more likely to find fossils that way. It will help you get your eye in too. And that's a biggie. Once you get your eye in you start to find more and more. IMHO trying to extract fossils from in situ rock should be your very last resort. I'd go so far as to say don't even try. Unless you're really really careful(and lucky) you won't find any and if you do, you're very likely to destroy it/them in the process(Oh I speak from experience there ). On the legality front I'm not even sure it's OK to attack the living rock.

Rubecula

rccaulfield wrote: »

Spent a few hours tippin away last week and although i found Notta i really enjoyed it! Anyway i'm a total amatuer and was hoping there might be a few brains i could pick in this forum about rock type etc. If you can answer even one question i'd be greatful! I'm told the rock in the area is of Ordovician age.
Sorry pics aren't great-cameraphone!


1-First off headed into this cave and found what looks like a iron band formation, this right?



Looks like a possibility of iron there.



2-I spent most of my time tipping away on loose small overhanging rocks from this type of rock. Is this limestone or at least sedimentary or was i barking up the wrong tree?

Certainly seems to look like limestone ( a good source for fossils in some places)


3-Is this limestone thats been altered? -is it a potential site for fossils?

Appears to resemble limestone. Possibly deformed by geo forces. Not too sure to be honest.



4-What type of rock is that?

Looks like weathered slate to me



5-Again any id on this layered rock?

Again Slate or a hard shale



6- Found the same type of rock again later in the day with this soft maybe shale type black flakey rock inbetween the layers. I'm pointing to it with the chisel. Is it a potential site for fossils?

It is sedimentary? then if it is not pre cambrian in age (which I doubt) then it has the possibility of having fossils.

Hope that helps.

rccaulfield

Rubecula wrote: »

Hope that helps.

It did Thanks!

Wibbs wrote: »

FWIW Looks sedimentary to me alright R. Might be carboniferous limestones and shale more than Ordovician, but hard to tell from photos. Carboniferous limestone tends to be full of fossils though.

My suggestion would be leave the chisel and hammer at home. Look at loose stones eroded out from the main body of rock. Around the shale layer in number 6 would be my first place to look. The fossils will erode out of that layer faster as it's softer.

Looking at the eroded stones will be much easier and you're much more likely to find fossils that way. It will help you get your eye in too. And that's a biggie. Once you get your eye in you start to find more and more. IMHO trying to extract fossils from in situ rock should be your very last resort. I'd go so far as to say don't even try. Unless you're really really careful(and lucky) you won't find any and if you do, you're very likely to destroy it/them in the process(Oh I speak from experience there ). On the legality front I'm not even sure it's OK to attack the living rock.

Yea, i looked over the whole site before using a chisel but there was nothing to be seen so tipped away a little bit. Hoping no one minds me while im there but i'm well out of public view in that area. What do you mean get my eye in exactly? Cheers.

Wibbs

Get practiced in finding fossils basically. The more practice the more success kinda thing. Maybe go to an area with carboniferous limestone. Very fossil rich in most cases so easier to find and practice on.

rccaulfield

Wibbs wrote: »

Get practiced in finding fossils basically. The more practice the more success kinda thing. Maybe go to an area with carboniferous limestone. Very fossil rich in most cases so easier to find and practice on.

Will do, i've a geological map i downloaderd from Fingalcoco in north county Dublin but can't see many sites near me of that epoch? Anyone know different from experience?

Rodger_Muir

I think that might be a rich siltstone in your second picture.Possibly with quartz nodules. Anyone else wanna wade in on that one.

Patrick Stillman and George Sevastopulo have written a excellent guide to the geology of the North East. Which you can pick up cheaply second hand from Amazon
https://www.amazon.co.uk/Leinster-Classic-Geology-Europe-Stillman/dp/1903544130/ref=sr_1_1?ie=UTF8&qid=1316472806&sr=8-1

It covers the North Dublin coastline in some detail and gives descriptions of the fossil types you can expect to find. Along with a detailed overview of the geological history of the area.

I also cant recommend Patrick Wyse Jacksons Introducing Palaeontology enough. It comes in very handy when trying to identify what you've found.

Rodger_Muir

I've just taken another look at your pictures

1b: as above, silt stone, with nodules. Possibly quartz

2: Definatly sedimentry, with out looking at a fresh surface its hard to say exactly what rock type it is

3: I cant really tell what Im looking at, and what do you mean by altered. Deformation, metamorphism???

4: From the way its wheatered I'm guessing a type of mudstone.

5; They look like sedimenty beds to me

6: If its shale or mudstone yes. But if there is a cleave in it. Unless the clevage and bed line up all you going to find are axial cross sections. So basically white circles.

Hope that helps