very large petrified conifer, wood slice from Madagascar, Araucaria

A very large polished petrified conifer wood slab from Madagascar, from the prehistoric genus Araucaria. 96 cm in length in a cross-sectional geometry that makes the tree's original growth history legible.

Madagascar provides petrified wood from Jurassic and Cretaceous sediments, approximately 150-100 million years old. The trunks of the Araucaria genus were preserved in fluvial deposits under anoxic conditions, then transformed into quartz through permineralization.

The annual rings and wood fiber structures are clearly visible in the cross-section. Each ring documents one year of tree growth during the Mesozoic Era, a paleontological teaching plate in stone.

The reddish-brown color bands are caused by iron oxides that were washed into the wood pores from the surrounding sediments during mineralization. Madagascar material typically shows warmer colors than North American material.

A paleontological collector's item of museum dimensions.