
TY  - JOUR
A1  - Osborne, R.A.L. 
A1  - Zwingmann, H. 
A1  - Pogson, R. 
A1  - Colchester, D.M. 
T1  - Illite dates from the World?s oldest caves
JF  - ASEG Extended Abstracts
JO  - ASEG Extended Abstracts
Y1  - 2006
VL  - 2006
IS  - 1
SP  - 1
EP  - 4
KW  - 
UR  - https://doi.org/10.1071/ASEG2006AB128 
N2  - K-Ar dating of illitic clays at Jenolan Caves has given the first direct evidence for the great antiquity of eastern Australian caves. It shows that sections of the caves formed in the Visean, before 340 Ma, making them the World?s oldest dated accessible caves by more than 240 Ma. Early Devonian (394 Ma) volcaniclastic palaeokarst was also identified. Permian and Triassic dates for some <0.4 mm fractions indicate growth of acicular illite during burial below the Sydney Basin. As well as raising problems about landform persistence, these dates set a new minimum age for folding in the eastern Lachlan Fold Belt. The most recent ``Kanimblan' folding must have occurred prior to 340 Ma. 
ER  -

