Radioactive dating performed
The next image (below left) is of charred fossil wood; and beside that is intact fossil wood (Note biro gives size perspective).The bottom two images are of basalt with holes from former gas bubbles (left) and visible fossil tree roots in siltstone.Pieces of the basalt samples from the outcrop and the drill core were also sent to analytical laboratories, for major, minor, and trace element analyses to establish the character of these rocks, but mainly for radioactive ‘dating’ analyses.Potassium-argon (K-Ar) ‘dating’ was performed on the two outcrop samples by the AMDEL laboratory in Adelaide (Australia), while one of the two outcrop samples and two drill core samples, one being in contact with the fossil wood, were ‘dated’ by Geochron Laboratories. When subsequently questioned regarding the limits of the analytical method for the radiocarbon and any possibility of contamination, staff at both laboratories (Ph. scientists) were readily insistent that the results, with one exception, C results (last column in Table 1), consistent with the carbon being organic carbon from wood, and indicating no possibility of contamination.When miners were sinking a ventilation shaft for the new Crinum Coal Mine in Central Queensland in 1993 (see map below) they unearthed a rare find.After digging through the thin surface sands and clays, followed by basalt, 21 metres (almost 69 feet) down they found pieces of wood entombed in the bottom basalt flow.
However, an exploratory hole had been drilled close to where the shaft was eventually dug.
In the relevant drill core, at the bottom of the lowermost basalt flow, pieces of fossil wood still containing organic carbon were present encased in the basalt, right at the boundary of the basalt flow with the siltstone below.
This drill core was subsequently sent to us once permission was granted by the mining company.
So how could these tree trunks have survived being engulfed by molten lava?
At approximately four metres (13 feet) thick, the basalt flow is relatively thin, Since the tree trunks were engulfed at the bottom of the flow, cooling may have been immediate, with any water present in the wood aiding extremely rapid encapsulation and thus preservation.