 From 85,000 to around 15,000 years ago, the present Gulf St Vincent was a deep river valley to the west while the nearest site of exposed Quartzite was likely near the coast, which during that time lay some to the south.It has been suggested that a debri slope may have stretched far into the gulf, covering the local Quartzite which had likely eroded out only after the present coastline was established around 6,000 years ago.The finds include a number of very well made Quartzite tools of the type in use when Adelaide was settled.