Wondering if there is any professional paleontologists or geologists here.
Found some unusual rocks on an old gazetted road out in the bush today,while at work.
They are quite light,and different to fossilized wood,one looks like it might be a neck bone from a creature many moons ago,the smaller ones feel very very light.I have enclosed images of larger one.Taken with Canon EF-S 60 mm macro lens (always take a selection of lenses to work).The inner part looks like 'spider web' structure-never seen rocks like them.There was nothing else like them in area,but I am going to look again.
Anyhow,thought these maybe of general interest,and hopefully someone might tell us more about them.
That is not osseous (bone) IMHO. That looks like a few things, impossible to tell from the photos. Possibilities:
1. limestone as suggested
2. weathered pumice / aerated liquified rock
3. molten aluminium (seen similar lumps from old aircraft burnt wrecks)
Limestone is reasonably dense/heavy, but pumice and aluminium are lightweight.
Definitely not a vertebrate fossil - it looks like either a bit of syngentic karstification (localised mineralisation of the near surface soil due to CaCO3 rich groundwater movement), or as the other poster has already said, heavily weathered limestone. Would also add - definitely not volcanic either, so not pumice.
Qualifications - undergrad in geology from QUT, so I know the rocks of the region, and postgrad in geophysics from UQ, Uni of Utah and UWA. But it is still pretty hard to tell from the pictures exactly what it is. Nothing beats knocking off a corner to see a fresh bit, and giving it a lick.
cheers,
Andrew.
Definitely not a vertebrate fossil - it looks like either a bit of syngentic karstification (localised mineralisation of the near surface soil due to CaCO3 rich groundwater movement), or as the other poster has already said, heavily weathered limestone. Would also add - definitely not volcanic either, so not pumice.
Qualifications - undergrad in geology from QUT, so I know the rocks of the region, and postgrad in geophysics from UQ, Uni of Utah and UWA. But it is still pretty hard to tell from the pictures exactly what it is. Nothing beats knocking off a corner to see a fresh bit, and giving it a lick.
cheers,
Andrew.
Thanks Andrew and @Heuy for your helpful and informed replies.Might try and do a test with vinegar,if I get time
I'm also only an undergrad-trained non-geologist but I do work amongst real geologists. However, without a bit more detail I doubt they can help. A few things that could help:
a bit more detail about the location
if it was on/near an old road, is it local rock or was it brought in as part of the road building
a photo of a fresh face, with some sort of scale (eg coin, tape measure)
Being very very light argues for either a volcanic rock that contained significant amounts of gas or maybe a plutonic rock where crystals of a reactive mineral have weathered out from a less reactive mass. I suppose limestone or soil carbonate are possible but the weathering doesn't look right to me. Perhaps the best match I've found in a quick search is a trachyte, which do occur is SE Qld.
Get back to us with more info; these little mysteries are always fun.
Hydrochloric acid is what is used to test for limestone, I doubt vinegar will produce much in the way of bubbles. And having specialised in petrography of igneous and metamorphic rocks for a few years I am very confident it is neither of those. The easiest way to recognise a trachyte are the white rectangular plagioclase crystals - I can't see anything remotely resembling those in the pictures. The texture of the veins is purely a secondary mineralisation process.
Still - anyone else here who's brother's lawn is mowed by a guy who lives in the same street as a guy who knew a geologist's sister is just as entitled to an opinion. It's hard to know for sure without holding it - but it ain't a trachyte!
Cheers,
Andrew.
Ha - another shiny-bum fizzy drink
When was the last time you looked at a rock Mario. Now the world will see that two geos = three interpretations!
How's it going in the seismic world over there?
Ciao,
Andrew.
Quote:
Originally Posted by cybereye
I think I fit your requirements - I majored in Geology at UNSW and did some Palaeontology at Macquarie Uni - so I'll throw in my 2 cents worth...
Split the bugger with a hammer so we can see a fresh(er) surface...
Ha - another shiny-bum fizzy drink
When was the last time you looked at a rock Mario. Now the world will see that two geos = three interpretations!
How's it going in the seismic world over there?
Ciao,
Andrew.
Andrew,
1998, I think, when I was mapping allochthonous limestone blocks near the Broken River, inland from Charters Towers!
Seismic world's going quite well - I'm heading your way for the Good Oil conference early next month in Freo then to Auckland at the end of the month for the NZ Petroleum Summit. Yep, it's all going well...
1998, I think, when I was mapping allochthonous limestone blocks near the Broken River, inland from Charters Towers!
Seismic world's going quite well - I'm heading your way for the Good Oil conference early next month in Freo then to Auckland at the end of the month for the NZ Petroleum Summit. Yep, it's all going well...
Cheers,
Mario
PS 1 Geo = many interpretations!
That must have been one of Simon Lang's field trips? I was in the first class he ever took as a lecturer! Seem to remember poring over a whole bunch of his thin sections from there.
To the original poster, have a look at these things in Nambung national park.
That must have been one of Simon Lang's field trips? I was in the first class he ever took as a lecturer! Seem to remember poring over a whole bunch of his thin sections from there.
To the original poster, have a look at these things in Nambung national park.
Günther Bischoff too? It's all about the 'foramINifers'...
I don't remember Gunther - apparently he retired from teaching at Macquarie Uni in 1997 and I was there in 1998 as an external student. From a bio I've found Gunther died in 1999.
Really? That's sad. I last met him when I was doing Honours in 1995 - I needed to use HF to prepare some palynological samples, and he was the goto man for that treatment! He ran a good 2nd year course at MU that I took in 1992, and all the students noted his obsession with conodonts and forams!
for your helpful and informed replies.Might try and do a test with vinegar,if I get time
