Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: CanopicJar on 01/11/2010 00:34:50

Title: Hello & Please identify this rock
Post by: CanopicJar on 01/11/2010 00:34:50
I found this rock on vacation and had to bring it back with me!  What is it?

Thanks,

Travis

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_0524.JPG&hash=420dc64b90fc4ce1c444268ee660b6bf)

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_0525.JPG&hash=579fa0fad9cf4eb9e6efb5c92a87999a)

Title: Hello & Please identify this rock
Post by: RD on 01/11/2010 01:40:30
Possibly grey outer layer is "vesicular basalt (http://www.pitt.edu/~cejones/GeoImages/2IgneousRocks/IgneousTextures/7VesicularAmygdaloidal.html)"  [?]
the holes (vesicles) are caused by gas bubbles when the basalt was molten.

The basalt has coated another type rock so is a "basaltic intrusion"  [?]

[ [?] these are uneducated guesses, but may be of help]
Title: Hello & Please identify this rock
Post by: Bass on 01/11/2010 15:38:47
My guess is some sort of concretion in limestone?  Can you scratch the outer rind with a knife?
Title: Hello & Please identify this rock
Post by: CanopicJar on 01/11/2010 17:42:41
It does not seem to scratch with a flat blade from my multi-tool.

Here are some additional shots.

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_1223a.JPG&hash=ad24108a82963b5967b6900e8958b311)

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_1224a.JPG&hash=22fa3b6e9e244b454b839d1dabe1818e)

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_1225a.JPG&hash=6d6b92915122440d75cfb59a39deeedb)

FYI, this rock was found on the Slate Islands, which were apparently created from a meteor impact.  It is also home to the world's largest shatter cone:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_8201.JPG&hash=d7b1f0fd92272c8e0c78294b9ba38be5)

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_8202.JPG&hash=a1fa2627167cd40381c61ad97bd639cc)

and...

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_8139.JPG&hash=9fa05dd7b137b28eed1136f3e4b73d02)

Travis
Title: Hello & Please identify this rock
Post by: RD on 01/11/2010 18:46:58
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.fuse.net%2FCanopicJar%2FIMG_1223a.JPG&hash=ad24108a82963b5967b6900e8958b311)

This bulls-eye mark may have been made by a limpet (http://www.theseashore.org.uk/theseashore/Resources%20for%20seashoreweb/Images%20for%20New%20Pages/Limpets%20&%20scars.jpg).
Title: Hello & Please identify this rock
Post by: Bass on 02/11/2010 00:26:48
In that case, I suspect the rock may be psuedotachylite (interior is an impact breccia clast).

Nice photos, by the way.
Title: Hello & Please identify this rock
Post by: RD on 02/11/2010 00:52:52
Bigger vesicles in cross section...

 [ Invalid Attachment ]

http://mountainbeltway.wordpress.com/2010/04/09/holey-basalt/
Title: Hello & Please identify this rock
Post by: CanopicJar on 02/11/2010 01:18:10
Thanks for the help!  The trip to the Slate Islands was an amazing trip.  Every time you turned a corner on the beach, you ran into different types of rocks.