Simpson Desert Coral
Submitted: Wednesday, Nov 29, 2006 at 11:58
ThreadID:
39885
Views:
3965
Replies:
10
FollowUps:
9
This Thread has been Archived
Ando79
Sorry if this has been asked before, but on a trip though
the desert this year I noticed some coral like fragments exposed on the surface of some sand dunes, usually locally abundant. Does anyone know what they are? They look for all money like broken up pieces of coral.
Reply By: Dave198 - Wednesday, Nov 29, 2006 at 12:12
Wednesday, Nov 29, 2006 at 12:12
I can't speak with any authority Ando as I haven't been there, but I would suspect maybe pieces of gypsum crystals.
Gypsum is reasonably common in sandy environments. The crystals can be clear or many other colours.
Near where I live we can find them varying from nearly clear, through to nearly white and through to the deep red of the surrounding sand.
They take all sorts of forms.
Do a google on gypsum and see if you recognise any of the shapes.
Dave
AnswerID:
207523
Follow Up By: Ando79 - Wednesday, Nov 29, 2006 at 13:09
Wednesday, Nov 29, 2006 at 13:09
Yeah you're probably right. It doesn't look like the gypsum we put on fields up here to help break up the clay, but it could be another form.
FollowupID:
467451
Follow Up By: Dave198 - Wednesday, Nov 29, 2006 at 13:41
Wednesday, Nov 29, 2006 at 13:41
The ceilings and interior walls (gyprock) of most houses are gypsum as
well, but that is just another form.
FollowupID:
467460
Follow Up By: Member - Davoe (Nullagine) - Wednesday, Nov 29, 2006 at 17:11
Wednesday, Nov 29, 2006 at 17:11
yet another form is Gypssum dunes you find around saltlakes - very finre powder with no bottom if you drive on a bare gypsom dune dont expect to get out reeeel soon
FollowupID:
467497
Reply By: Member - Stephen L (SA) - Wednesday, Nov 29, 2006 at 13:19
Wednesday, Nov 29, 2006 at 13:19
Hi Ando79,
What part of
the desert did you see these formations. Was this in the area near the Knolls? or on one of the many salt clay pans?
In the Knolls area there is a lot of gypsum in the area, being white in colour, being either exposed or just under the surface of the sand. The only other area very similar to that of the Knolls that we have come across is an area approx 150kms north of the Knolls and
well out of the way for the normal
Simpson Desert Trip. When you pick up a large lump, of say 8" diameter, it will crumble in your hands.
Stephen
AnswerID:
207538
Follow Up By: Ando79 - Wednesday, Nov 29, 2006 at 14:00
Wednesday, Nov 29, 2006 at 14:00
On the French Line, after the
rig road turn off and towards
Birdsville, before you get to Poepells corner from memory.
It's definately calcium carbonate as I just dropped it into conc HCL and it gave off CO2.
FollowupID:
467465
Reply By: Member - Andrew W (SA) - Wednesday, Nov 29, 2006 at 17:53
Wednesday, Nov 29, 2006 at 17:53
I think it is the gypcrete idea ... plants grow through this highly salty environment and the moist setting of the roots draws water and salts which dry out and set like concrete.
The hot wind blows the plant to extinction, roots dry up and wither to nothing but the surrounding concrete like dry salt stays.
The wind blows some more and the sand blows away leaving these coral-like, stallegmite thingamees.
I don't think it is a pre-history thing ... I think they are largely modern.
They crunch under your feet and make for quite an interesting landscape. Perhaps i'll put up a shot two.
I have seen them in coastal areas too, as
well as
Great Victoria Desert, Mungo as was mentioned by someone else, Nullabor and Simpson.
The kids picked the biggest one to bring
home (I'm sure this was technically illegal) from
Twilight Cove general vacinity, but they fell to bits on the Anne Beadell.
Cheers
Andrew.
AnswerID:
207586