×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

rock identification

rock identification

rock identification

(OP)
Hi all!

I have a rock sample that needed be to identify.

The rock is large in size, approximately 200-400kg with pores and fossil which can be seen by naked eyes.

Attached along are an overview of the rock and the microscopic view of the rock and the fossil observed.

I need to know what type of rock is this and whether can it be found in France?

Thank you.

[img http://files.engineering.com/getfile.aspx?folder=e... http://files.engineering.com/getfile.aspx?folder=b... http://files.engineering.com/getfile.aspx?folder=4... http://files.engineering.com/getfile.aspx?folder=b...]

RE: rock identification

Probably some type of limestone or other carbonate rock.
Try dropping dilute Hydrochloric acid on it to see if it "fizzes" to confirm carbonate content. I'm sure it could be found in France.

RE: rock identification

agree with moe.....further, it looks more like the texture of a sandstone, but is obviously calcareous...likely from a shallow formation.

RE: rock identification

the crystals in the vugs seem to show some secondary mineralization - likely from mineralizing fluids coursing their way through discontinuities. The dusty surface seems to suggest a carbonate rock, i.e., limestone or dolostone. The acid-test will help. Not sure about the presence of sand. Maybe it's there? Usually though limestone is deposited in an quiet water environment and sandstone is deposited in a shoreline environment.

It's hard to see if the crystals in the vugs are calcite or quartz. I mean I could tell with the naked eye.

So, with what I know, I'd just call it a limestone. If you knew the source of the rock, you could check geologic publications and learn the formation name. That may help too?

When in doubt, call it, "Leaverite." Leave 'er right there!

f-d

¡papá gordo ain’t no madre flaca!

RE: rock identification

There is a web site forum called "GeologyRocks". It would appear to me you can get your question answered there.

RE: rock identification

Don't you sort of have to reverse your question?

"We found this rock in so-and-so province in France. Can it be found elsewhere in France? " *<)

RE: rock identification

(OP)
Dear all,

Thanks for your opinion.

I have tested it with diluted HCl and also done a SG test. Meanwhile, I have also sent a piece of the rock to a local geology lab for analyse. It is said that the rock sample is a compact limestone (fossiliferous) with various type of fossils seen include gastropods, bivalve and radiolaria/foraminifera. Consider as an organogenetic sedimentary rock.

Another geologist agrees that the rock is a type of fossiliferous limestone but the physical appearance is not a common in Malaysia but have seen a similar rock in UK that also extent to France and other Europe countries. May I know does anyone can recommend a geology laboratory in France?

RE: rock identification

Anteagroup (see their website, activity : "infrastructures", then select "carrières" (quarries) or "Géotechnique".

RE: rock identification

I don't know if this rock can be found in France but I have about a dozen rocks of that type and size on my front lawn in northeast Pennsylvania. You're welcome to take them.

RE: rock identification

(OP)
Thank you so much BigHarvey..smile

You are funny, bridgebuster..tongue

RE: rock identification

autoThanks alchemistjr, but the offer still stands. There's about one ton; just bring your truck.

RE: rock identification

I'm curious. Why are you posting a geology-related question that seemingly has nothing to do with engineering on a geotechnical-engineering thread? And why do you want to know if the rock could be from France? If you're doing engineering work based on information you get from this sample, you of course must know where it came from.

If this relates to a problem that has to do with engineering, with a bit more information, we can probably help you out. If you need geology information, this is not the best place to post your question.

RE: rock identification

AW, ebernozen. Geology, geotechics, it all in the ground. He got help.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources