Rankin Island Project

During an expedition with Aurora Expeditions in 2003 we had the opportunity to visit a series of ephemeral pools on Rankin Island. An aerial photo we had showed these pools as beautiful blue splashes of colour in the usual harsh Kimberley landscape.

Upon arrival we found an incredible scene of rock beach and hillside ridges looking extremely symmetrical and no water.

In an attempt to discover and photograph as much as possible we spread out and all ran to agreed locations. One scout found a cave which has signs of human habitation in the past and as we approached it we were struck with an amazing 75cm high man-made ridge of stones on the top of one beach ridge.

The stone construction ran almost from the mouth of the cave for about 75m along the top of the ridge, made a loop about 10x15m and nearby were a series of 'pools'. All this was very reminiscent of Aboriginal fish trap construction except for one very strange feature - it was 2m above sea level!

Prof Peter Flood (UNE) has shown that there have been several higher sea stands over the last 5000 years. 2m higher 5000 years ago, 1.5m higher 3000 years ago and 80cm higher about 800 years ago.

So is this an old, 5000 years old, fish trap? Or is it a ceremonial stone site? Or is it something else?
Working with the traditional owners, the WA Museum (Dr Moya Smith), Aurora Expeditions and the University of New England (Prof Peter Flood) we have gained a permit to visit the site and collect several specimens, if we can find any, for dating.

We need to ensure that no damage is done to any aspect of the area and a 3m croc we saw there keeps us well behaved! In addition we will map the site and photograph it again to provide researchers with better tools to assess it. This will lead to appropriate understanding and management of the area.

In December 2004 at a meeting during the Australian Arhcaeology Association Conference at the University of New England with Dr Peter Veth, AIATSIS, Dr Sue OÇonnor, ANU, Prof Peter Flood and myself it was decided that there was no point in trying to get any further dates on the corals from the wall - the 4565 years (+ or - 40 years) indicates that the wall could be that old, or whoever built it used a piece of coral that old.
As a result a small paper is in preparation and will be published later in the year.

Dr Moya Smith - Anthropologist
Western Australian Museum - WAM

Professor Peter Flood - Dean of the Sciences - geologist
University of New England - UNE

Greg Mortimer
Aurora Expeditions - AE

With thanks to:

Mike Cusack - mapping and spotting stone 'tool pools' - Aurora Expeditions
Chris Done - cave sediment probing and mapping - Aurora Expeditions
Coral Princess Cruises - staff and equipment support
Aurora Expeditions and Australian Geographic passengers - general observations, mapping and collection support.


During an Aurora Expeditions 'expeditionary stop' to Rankin Island in 2003 to investigate pools shown in a photograph by Damon Smith a large site of human constructed stone walls and 'pools' in the loose beach ridge rocks about 2m above present sea-level was found. Adjacent to this worked material is a small cave with possible evidence of human occupation.

As a result of this initial investigation a proposal was put to the WAM, UNE and AE to support a more intensive examination of the site and a collection of organic material from the walls, more photography, mapping and general examination of the site.

Due to the efforts of Dr Moya Smith permission was obtained from the traditional owners to undertake the proposed second investigatory visits and collection of material and data in June 2004.

Preparations were made and the AE expeditions into the area on board Coral Princess were undertaken on Thursday 10 June and Friday 25 June 2004 with the possible visits again in later July for some more specimen collection only.



1. Collect organic material from within or below the human
constructed walls for dating to assess the age of the material and indicate what earliest age the walls were constructed.
2. Collect organic material from the beach-rock strike for
3. Map the site.
4. Probe the sediments of the cave floor to assess
suitability for excavation.


Photography - Nikon Coolpix 5000 (5 megapixel) and 8700 (8 megapixel) digital cameras on Fine settings and broom handle marked into 10cm sections as a scale.

Mapping - Garmin 12 channel and Garmin Gekko GPSs, 10m tape measure, pencils and paper.

Sediment probing - 1m 9mm threaded bar, small ball pean hammer and notepad and pen.

Organic material collection - zip-lock bags and marking pen.


Organic Material Collection


Two coral specimens were taken from within the human constructed wall on the inside (away from the seaward edge) and two from the seaward side of the wall. The latter two were not integrated into the wall and could conceivably have been washed in by extreme seas or similar events and were later
discarded. All specimens were photographed in situ prior to removal.

Beach rock

As the beach rock was well below present high tide mark it was initially decided not to collect from it. On the second visit two specimens were taken from its upper and lower limits.

As the beach rock was well below present high tide mark it was initially decided not to collect from it. On the second visit two specimens were taken from its upper and lower limits.


A map of GPS coordinates taken on each of the wall points, cave and stone tools location is attached. In addition four walk tracks around much of the site and 26 waypoints were collected on 25 June as shown on the attached aerial photos of the site. The raw data is stored on the attached CD in NMEA format 10 June and Garmin format 25 June.

Aerial view of primary site showing approximate waypoints and track positions.

Cave Sediment Probes

The floor and size of the cave were measured and photographed with a series of probes on a rough grid pattern being driven gently into the sediment. Each probe depth was measured and its location plotted on a 'mud map' of the cave floor. The maximum depth achieved was 26cm with an average of about 18cm.

Chris Done gently taps the probe into the cave floor for sediment depth assessment

The floor of the cave was fine powder littered with small slab-like ceiling material and some water worn rocks. The aspect of the cave is southerly with the floor level appearing to be 0.5-1m below the top of the stone beach ridge with the wall.


On June 10 256 and 62 images were taken of the site, cave, tools and source rocks, 'tool pools', surrounds and any interesting features and are on the attached CD. Some of these were then stitched together into panoramas which are also on the CD. Also on the CD are the images from the 2003 visit to the site.

General Observations

Whilst undertaking the mapping Mike Cusack spotted a stone axe in the base of one of the 'pool' areas and this discovery led to many stone axes, spear points, source rocks and chipped flakes being found in most of the 'pools'. Some of this material was GPS plotted and photographed. All material was left where it was found.

These 'tool pool' areas were found to be on much of the tops of the walls and lower areas near the walls throughout the whole of the island areas visited as seen on the aerial photos showing the tracks and waypoints.

As much of the site was covered in Stinking Passionfruit Vine (Passiflora
foetida) it was difficult to assess the extent of the tool pool areas. A quick assessment indicates that all the level areas had tool pools present and with worked material in them.

In addition it was found that there appeared to be 'mines' about a metre deep into the rocks at the eastern end of the wall beach wall. These may have been for tools source rocks or to dig out yam roots or similar.

Several small 'midden' sites were also observed.

There were also found the marks on the rocks indicating that a helicopter has recently landed on the site.



1. Accurate mapping of the site be undertaken.

2. An anthropologist assess the site and excavate the cave sediments.

3. A survey of the remainder of the island be undertaken to assess its archaeological values and conservation status.

4. That included in any planning of an extensive survey will be the need for a cleaning of the site of the Stinking Passionfruit vine by fire or weed killer and fire.

5. Appropriate interpretation and management of the site be undertaken to ensure its survival.

6. That an immediate placement of some site usagerestriction be implemented to ensure the site can be controlled and damage to it minimized. This would also include permitted entry by those meeting the site management requirements.






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