A good core sample, she says, tells you 'everything you need to know about the history and geography and inhabitants and social conditions of the area, in wonderfully concise form'.

And here are three sets of independently issued certificates that confirm that the core sample you can see on the picture contains really quite impressive quantities of gold.

It has been fairly well chronicled by core sample data and turned into graphic form (see article).

In 1999 a new core sample was taken.

In 1927, a sulphur-rich core sample was retrieved from the caprock and the production of sulphur began.