Comments on: Whats that in my shale? http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/ A blog about geology, geoscience, paleontology and related topics Thu, 03 Dec 2009 15:34:18 +0000 http://wordpress.org/?v=1.5.1-alpha by: Valentin http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-174 Sat, 26 Jul 2008 15:18:24 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-174 Looks like metamorphic to me. Mainly because: 1) I've seen such minerals in metamorphic shales :) 2) They don't have any particular orientation. To have such an high concentration of fossils of one kind, a process such as selective transport of water (based on the weight of these "clasts") is often invoqued, as for bone beds. BUT, oil shales forms under really calm waters, below wave action, because you would have had an oygenated ocean/basin floor otherwise, which is in contradiction with the fact they are source rocks I'm sure it's not pyrite. I would agree with some posters on andalousite/staurotide. However, these minerals are formed from pellitic sediments (so concordant with a shale origin, with high alumina content) BUT under moderately high to high degrees of metamorphism, and at this degree, the rock should bear a nice schistosity :p A super high resolution of some of these would be helpful :) Looks like metamorphic to me.

Mainly because:
1) I’ve seen such minerals in metamorphic shales :)
2) They don’t have any particular orientation. To have such an high concentration of fossils of one kind, a process such as selective transport of water (based on the weight of these “clasts”) is often invoqued, as for bone beds. BUT, oil shales forms under really calm waters, below wave action, because you would have had an oygenated ocean/basin floor otherwise, which is in contradiction with the fact they are source rocks

I’m sure it’s not pyrite. I would agree with some posters on andalousite/staurotide. However, these minerals are formed from pellitic sediments (so concordant with a shale origin, with high alumina content) BUT under moderately high to high degrees of metamorphism, and at this degree, the rock should bear a nice schistosity :p

A super high resolution of some of these would be helpful :)

]]> by: bjorn http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-172 Sat, 26 Jul 2008 01:44:40 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-172 I have tried to say that perhaps 80% and not a white, yellow överlevnadsvärld (conclusions and democracy, etc.). In order to survive (democracy = most choose the truest, most överlevnadsflexibla = solutions that have the breadth and width of the tip but above all - more artistic). As a matter Tex replace coal in us (Germanium) Plants and planter to replace, and make photosynthesis more efficient (only percent today to 25%) Local democracy Toquevilles analysis (best social sciences through and in all times) Local democracy and a sufficient number of wins and voted for Italy-USA-England one part Otherwise, we go over (our leaders are capable sas is not this) Just as Tolkiens world = kind of democracy Experts (knowledge = implemntera and make on the basis of a policy). See paradigm which today replaced (and the judgement then made some wrong with that thinking). See, all senior experts (Cambridge) judgement is as firm in thinking, etc. (and believe theories be right). Empirical and darwinism therein (choose above simply so you can manipulate a world - so it is doing and stand up for generations and centuries) Tex da Vinci world paint a picture and get it designed (like trees) and stimulants that integrate the interface ml of our world and the states (perception). Technical solutions that are most important And ordinary people who say the truth = do this for överlevnadsvärdet (democracy) And we are going into space (also överlevnadsvärde 2.0) Egenintresset = so strong force Turn on a sufficient number who actively take responsibility I have tried to say that perhaps 80% and not a white, yellow överlevnadsvärld (conclusions and democracy, etc.).
In order to survive (democracy = most choose the truest, most överlevnadsflexibla = solutions that have the breadth and width of the tip but above all - more artistic).
As a matter
Tex replace coal in us (Germanium)
Plants and planter to replace, and make photosynthesis more efficient (only percent today to 25%)

Local democracy
Toquevilles analysis (best social sciences through and in all times)
Local democracy and a sufficient number of wins and voted for

Italy-USA-England one part

Otherwise, we go over (our leaders are capable sas is not this)
Just as Tolkiens world = kind of democracy
Experts (knowledge = implemntera and make on the basis of a policy). See paradigm which today replaced (and the judgement then made some wrong with that thinking).
See, all senior experts (Cambridge) judgement is as firm in thinking, etc. (and believe theories be right). Empirical and darwinism therein (choose above simply so you can manipulate a world - so it is doing and stand up for generations and centuries)
Tex da Vinci world paint a picture and get it designed (like trees) and stimulants that integrate the interface ml of our world and the states (perception).

Technical solutions that are most important

And ordinary people who say the truth = do this for överlevnadsvärdet (democracy)

And we are going into space (also överlevnadsvärde 2.0)

Egenintresset = so strong force
Turn on a sufficient number who actively take responsibility

]]> by: Silver Fox http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-171 Thu, 24 Jul 2008 13:12:50 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-171 I was thinking that besides porphyroblasts of some kind, that if those minerals are metallic shiny like pyrite, they would have to be marcasite. There is a little bit of iron-oxide in weathered-out spots on the right side of the rock. Otherwise they look more like something like kyanite or staurolite or some amphibole like tremolite or actinolite to me. I'm not sure that gypsum is usually shaped like that. They do cross the way kyanite or staurolite would. (Could you have two rock types? In your beach photo, the ones with little crystals look slightly darker.) Sometimes, for rock and mineral guessing, if you upload a larger picture, then when we click on it, we can see it closer and in more detail. I was thinking that besides porphyroblasts of some kind, that if those minerals are metallic shiny like pyrite, they would have to be marcasite. There is a little bit of iron-oxide in weathered-out spots on the right side of the rock.

Otherwise they look more like something like kyanite or staurolite or some amphibole like tremolite or actinolite to me. I’m not sure that gypsum is usually shaped like that. They do cross the way kyanite or staurolite would. (Could you have two rock types? In your beach photo, the ones with little crystals look slightly darker.)

Sometimes, for rock and mineral guessing, if you upload a larger picture, then when we click on it, we can see it closer and in more detail.

]]> by: Antimonite http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-169 Tue, 22 Jul 2008 19:01:22 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-169 Mel: Ah, thanks for your answer. That makes sence. Mel: Ah, thanks for your answer. That makes sence.

]]> by: Mel http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-168 Tue, 22 Jul 2008 17:40:32 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-168 If it were pyrite, I would expect to see more square features in your sample. Even though it can for blobs like in the picture you showed, it still has square crystal faces in the blob. And, if it were "all" weathered out, I would still expect to see some rust (oxidized iron) remaining behind. I don't have the mineralogy book in front of me, but I would guess those are gypsum/anhydrite crystals. It could be something else, but gypsum can for small blades and larger blobs, occur in shale, and leave open cavities if dissolved during burial (and later hydrocarbon maturation). That's my best guess so far. If it were pyrite, I would expect to see more square features in your sample. Even though it can for blobs like in the picture you showed, it still has square crystal faces in the blob. And, if it were “all” weathered out, I would still expect to see some rust (oxidized iron) remaining behind.
I don’t have the mineralogy book in front of me, but I would guess those are gypsum/anhydrite crystals. It could be something else, but gypsum can for small blades and larger blobs, occur in shale, and leave open cavities if dissolved during burial (and later hydrocarbon maturation). That’s my best guess so far.

]]> by: Antimonite http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-167 Tue, 22 Jul 2008 16:00:03 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-167 Thanks for the comments everyone. I took the photo out in the bright sun, it might have affected the picture and make it look more schist than I think it is. I picked it up from the beach, wich was covered by oil shale. Picture of the beach: http://antimonite.blogsome.com/wp-admin/images/simrislund5.jpg Im 95% its oil shale since the area is full of it otherwise and known for it, covering the cambrian quartzites of the region. Its deep solid black brittle and almost a little bit oily to the touch and sight. And in some other pieces I picked up there where obvious fossils (brachiopods) wich I never heard of being found in . So if its not possible to find in oil shale, then its not it I guess. It looks like something grown and I also remeber fining other pieces of shale there on the beach which hade much larger pieces of these bright granules inside of them, but they where much more irregular in shape. On googling the net I found this picture of a oil shale with pyrite. I know that my picture above doesnt show it, but the crystal looks just the same up close, only smaller. http://www.humboldt.edu/~natmus/lifeThroughTime/PreCam.web/PyrShale7.JPG Thanks for the comments everyone. I took the photo out in the bright sun, it might have affected the picture and make it look more schist than I think it is. I picked it up from the beach, wich was covered by oil shale.
Picture of the beach:
http://antimonite.blogsome.com/wp-admin/images/simrislund5.jpg

Im 95% its oil shale since the area is full of it otherwise and known for it, covering the cambrian quartzites of the region. Its deep solid black brittle and almost a little bit oily to the touch and sight. And in some other pieces I picked up there where obvious fossils (brachiopods) wich I never heard of being found in .

So if its not possible to find in oil shale, then its not it I guess. It looks like something grown and I also remeber fining other pieces of shale there on the beach which hade much larger pieces of these bright granules inside of them, but they where much more irregular in shape.

On googling the net I found this picture of a oil shale with pyrite. I know that my picture above doesnt show it, but the crystal looks just the same up close, only smaller. http://www.humboldt.edu/~natmus/lifeThroughTime/PreCam.web/PyrShale7.JPG

]]> by: BrianR http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-166 Tue, 22 Jul 2008 14:34:59 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-166 My first impression before reading the comments was that they weren't fossils ... I'm not sure what mineral though. Staurolite could be a good guess. If they are fossils, their shape and size is similar to some Permian fusulinids. My first impression before reading the comments was that they weren’t fossils … I’m not sure what mineral though. Staurolite could be a good guess. If they are fossils, their shape and size is similar to some Permian fusulinids.

]]> by: Ron Schott http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-165 Tue, 22 Jul 2008 13:31:10 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-165 I second Kim's assessment. Looks a little more phyllitic/schistose to me. And I too suspect those are porphyroblasts rather than fossils. Andalusite makes a lot of sense, or possibly staurolite? Aaah, the joys of doing "float" geology in a glaciated terrain! I second Kim’s assessment. Looks a little more phyllitic/schistose to me. And I too suspect those are porphyroblasts rather than fossils. Andalusite makes a lot of sense, or possibly staurolite?

Aaah, the joys of doing “float” geology in a glaciated terrain!

]]> by: Kim http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-164 Tue, 22 Jul 2008 12:52:33 +0100 http://antimonite.blogsome.com/2008/07/22/whats-that-in-my-shale/#comment-164 Is that still shale? It looks pretty shiny... and those things look like andalusite to me. Is that still shale? It looks pretty shiny… and those things look like andalusite to me.

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