Research - Mr Walker's Caves Project -
Tijou Reef Western Lagoon Wall Caves
During October 1995 I had the opportunity to dive in the lagoon
at the southern end of Tijou Reef for the first time since 1973
when we 'found' this 40m deep lagoon. As I was about to begin my
ascent from my dive I noticed a small slot between the talus
slope sand and vertical wall at about 32m on the western side of
the lagoon. Upon investigation I found an entrance to a cave
which extended several metres into the reef and laterally for at
least five to six metres.
Over the previous 22 years of GBR experience I, along with many
others, always had the fantasy of discovering a cave which may
have remains - indicating Aboriginal occupation during periods
of low sea stands.
After discussing the cave location and lagoon morphology with
Prof Peter Davies a leading reef geologist it was likely that:
had been subjected to at least two periods of inundation
the reef to
the seaward side appeared to be Pleistocene age
i.e. more than 120000 years old, but this needs confirmation
been Aboriginal activity in this area as they moved south
into Australia through this area which was dry from about
17000 to about 10000 thousand years ago
be possibly the only site on the GBR where such a site
remained somewhat intact
discussed the cave with Dr Peter Veth (Archaeology and
Anthropology JCUNQ) and he was similarly excited about such a
prospect for an underwater cave with the incredibly unlikely
chance of indications of Aboriginal occupation.
As a result of
this interest I planned a return to the site and gained a permit
from the GBRMPA to undertake mapping and photography of the
site. In November 1996, February 1997 and April 2003 I had the
opportunity to dive the site again.
I was also
assisted in these dives by many individuals and as a result the
whole western wall has now been looked at, albeit briefly. The
caves extend almost from the southern end to about ¾ northwards.
They vary from 7m deep, 20m along the wall and up to 7m high
through to a simple concavity in the wall - classic wave cut
notches into a reef front during a low sea stand. On the floor
of the enclosed caves there is sediment.
are - what is the age of the reefal material around the caves
and does the sediment overlay terrestrial sediments laid down
during the low sea stand period when the reef was dry 17-10,000
UPDATE Feb 05:
As part of a 90 minute commercial TV documentary being done by
Ushuaia Nature from TFN1 France I was able to spend three days
coring in the base of Mr Walker's caves.
In addition to the coring we were able to survey the entire
western wall of the lagoon and GPS fix each of the best caves
for future reference/research.
We cored the base of the cave that offered the best promise in
terms of highly protected sediments. We got sediment to 3m and
it kept going! This is a bit of a problem as that depth of
sediment was totally unexpected. The two cores resulting from
the work will be taken to the UNE in Armidale for analysis.
Results will be posted here as they come to hand. It is hoped
that ultimately we may find an interface between marine and
terrestrial sediments - those laid down during the last
The cave system is named after Terry Walker a friend and great
reefie who died at sea in the Gulf of Carpentaria doing what he
loved - running around in small boats researching islands and
birds. I miss him.
Dating from UNE shows sediments to be 3000 years old between
2-3m depth. Now that I am an Adjunct at James Cook University I
am developing more links within the research community to
continue the work from this base. We will be seeking grant funds
from various sources.