Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: neilep on 03/09/2008 12:36:04

Title: Why Are There No Fossills In Marble ?
Post by: neilep on 03/09/2008 12:36:04
Dear Marbleologists,

See this rather fetching palette of Marble cosmopolitan goodness and variety ?


 [ Invalid Attachment ]

nice eh ?  being delivered Tuesday !

I am informed that ewe rarely find fossils in Marble !

Why's that then ?...can't some ancient creatures be arsed to die within it ? Or is there an even more rational and logical answer !
( hard to imagine but I'll entertain your opinions !)


Thanks



Neil
Officer In Charge Of Asking About Marble
xxxxxxxxxxxxxx
Title: Why Are There No Fossills In Marble ?
Post by: blakestyger on 03/09/2008 13:41:19
There are fossils but only tiny bits. Limestone is sedimentary so those creatures that could be arsed to die in it will be readily found. Marble is metamorphic, formed when the sedimentary limestone is naturally heated and under pressure during rock formation and the calcium carbonate grains recrystallise, the fossil fragments, originally in the limestone, are there but damaged and tiny.

A good reason for not seeing them would be that a fossil visible in a piece of marble used for decorative stonework would be seen as a flaw and likely to be rejected.

The purest marbles (required by sculptors) come from the tops of deposits such as at Carrara in Italy - the stone used by Michelangelo for his David.
Title: Why Are There No Fossills In Marble ?
Post by: Bass on 03/09/2008 16:49:17
Never found any fossils in my marbles either [???] [???]

 [ Invalid Attachment ]


must have lost my marbles, can't seem to find them anywhere
Title: Why Are There No Fossills In Marble ?
Post by: LeeE on 03/09/2008 18:45:17
Have a look at:

http://en.wikipedia.org/wiki/Marble#Origins (http://en.wikipedia.org/wiki/Marble#Origins)
Title: Why Are There No Fossills In Marble ?
Post by: neilep on 03/09/2008 21:13:40
There are fossils but only tiny bits. Limestone is sedimentary so those creatures that could be arsed to die in it will be readily found. Marble is metamorphic, formed when the sedimentary limestone is naturally heated and under pressure during rock formation and the calcium carbonate grains recrystallise, the fossil fragments, originally in the limestone, are there but damaged and tiny.

A good reason for not seeing them would be that a fossil visible in a piece of marble used for decorative stonework would be seen as a flaw and likely to be rejected.

The purest marbles (required by sculptors) come from the tops of deposits such as at Carrara in Italy - the stone used by Michelangelo for his David.


Thank you very much blakestyger ....so, it's the nature of marbles' formation that does not allow large fossils to exist !..I see !...fantastic !....(I mean the information is fantastic !)

Many Thanks
Title: Why Are There No Fossills In Marble ?
Post by: neilep on 03/09/2008 21:16:49
Have a look at:

http://en.wikipedia.org/wiki/Marble#Origins (http://en.wikipedia.org/wiki/Marble#Origins)


Wicked !!

As quoted from Wiki !


Quote
Marble is a metamorphic rock resulting from regional or rarely contact metamorphism of sedimentary carbonate rocks, either limestone or dolostone, or metamorphism of older marble. This metamorphic process causes a complete recrystallization of the original rock into an interlocking mosaic of calcite, aragonite and/or dolomite crystals. The temperatures and pressures necessary to form marble usually destroy any fossils and sedimentary textures present in the original rock."

Gosh ewe guys know your stuff !

Thanks LeeE
Title: Why Are There No Fossills In Marble ?
Post by: neilep on 03/09/2008 21:17:46
Never found any fossils in my marbles either [???] [???]

 [ Invalid Attachment ]


must have lost my marbles, can't seem to find them anywhere


There they are.. *sheepy points to screen*.....inside your computer monitor !!
Title: Why Are There No Fossills In Marble ?
Post by: JimBob on 04/09/2008 01:16:12
Also, peeps, marble is not colored - or coloured (for you backwards individuals.) Greens, purples and blues are not found in nature. Red ones are occasionally found because of high iron staining or iron in the original limestone. Greys, whits, tans are the most common. Traverine turned into marble can be a wide range of colors because of the different chemicals that can be deposited in the mineral springs that form travertine but is VERY rare.
Title: Why Are There No Fossills In Marble ?
Post by: susanshirleyjamaica on 11/09/2008 17:30:22
I beg your pardon... the true English (used in Jamaica) spelling is coloured, also favour, flavour,etc.  It is the upstarts in America who are backwards.  No offence meant... I was an American once myself... and was unaware of proper spelling, speech inflections and everyday manners until I was transplanted here 33 years ago!

Here in Jamaica a thing called "Hellshire Marble" is widely used for flooring... including in our old house in Kingston.  It is chock full of fossils but of course it is not a true marble. Those fossil holes are filled in with fine grout but we left ours in all their pitted glory!  It is dense limestone not completely morphed to marble.  It comes in beige, green, and a most beautiful pink.