Peanut wood is a silicified (petrified) wood, generally of a black colour with numerous borings, which were made by a marine wood-boring bivalve or clam, called Teredo.
This petrified wood was named peanut wood by the first people who found it, because they presumably thought that the light coloured areas resembled peanuts.These light coloured areas are what used to be boreholes in the original wood. Before the wood was petrified, it was washed into the ocean as driftwood. It was then attacked by the Teredos (another name for these little clams is shipworm).They bore a small tunnel into the wood and eventually the entire piece can be riddled with boreholes. When the wood became waterlogged, it then sank to the bottom of the ocean and settled into the mud.The boreholes then filled with the light coloured radiolarian sediment. Some time later, petrification began.
The wood is of several varieties, the main ones being Araucaria which is a conifer and podocarp.It is found along the edges of the Kennedy Ranges about 100 miles inland from the coastaltown of Carnarvon, Western Australia. The geological formation that it occurs in is called Windalia Radiolarite.The age is Cretaceous.....which makes it around 120 million years old.
The following photos give an idea of the sort of terrain that the peanut wood is found in.