Hello,

Fossil trees at Box Head were first reported in 2003, with a photo of them
which was taken by Andrew Taylor published by Tasman Walker in that year.
The photo has also been widely used in a creationist leaflet letterboxed in
the Gosford area and elsewhere.

Recently the site was visited by a locally organised excursion .. which had
been a long time coming (getting organised, with NPWS help to open locked
gate etc). It is found that the vertical objects in sandstone are not
trees but rather some curious vertical pipelike iron oxide concretions.
There are probably very many of them present. Box Head is a fair hike to
get to (unless one had a motorbike or something, and the track in is
accessible to some vehicles but rough and with a locked gate part way along
it) and it thus seems to have been very rarely visited by geologists.

At the moment I don't know of anything comparable to there vertical
concretions from anywhere else in the world.

Photos and description are under "GOSFORD" at:

http://www.lachlanhunter.deadsetfreestuff.com/JB/geo-sitesG-I.htm

Also there (under GOSFORD) is consideration of a concretions horizon which
occurs high in the Hawkesbury Sandstone. I suspect that this continues
over to the southern side of Broken Bay and also west as far as Maroota.

These concretions are not very substantial internally and 'outcrop' often
as circles or small partially weathered out "cup marks" on the sandstone
outcrops .. and have been thought to be human (Aboriginal) engravings by
some persons interested in rock art engravings .. So because there are very
many of them, one idea had developed that they may represent stars, and
hence that patterns of them could record Aboriginal cosmology etc. ... but
no chance of that if they are concretions.

Information on any other known concretion occurrences in Hawkebury
Sandstone, or indeed any quarry sites or fossil sites or interest features
not yet in the ongoing "directory", would be appreciated .. since most
things/sites are presumably not yet in it (yet the number that are is
increasing).

I've also gotten recently a little info about Bowral fossil fish from
someone who works with someone whose brother works or worked at Bowral
brickpit. The account goes that one person told another, from whom I
learned it, that "some years ago, South Australian Museum staff went for a
dig at the bottom of the quarry. Some hours later they arrived at his
office, breathless, carrying a fish fossil which they declared would be on
display at the Adelaide Museum". This is said to have happened years ago.
I'm following up to try and confirm this. From the railway cutting nearby
(approach to Mt Gibraltar tunnel) fish and a fragmentary labryrinthodont
were recovered long ago. When I worked at the Mining Museum I think they
too had quite bit of material from Bowral but I don't know if that was from
the railway line exposures or from the quarry. The source is either the
Mittagong Formation or basal Ashfield Shale.

Cheers,



John Byrnes