Weathering: cyclical or continuous? An Australian perspective

Abstract

A study of the age distribution of existing weathering profiles and related ferruginous products on the Australian continent was undertaken using information from published and unpublished sources. The age distribution of existing weathering profiles follows an increasing trend towards the present, which can be approximately represented by an exponential curve. This corresponds to similar trends relating to most other geological entities on earth and can be correlated with the process of recycling, that is, destruction over time and rebirth, possibly in another form. In accordance with general theory and past assumptions, a possible increase in weathering was observed at the beginning of the Tertiary, although this was much less significant than previous studies claimed. There is now reasonable evidence to suggest that such deviations from long-term trends may have occurred as a consequence of increases in the potential for preservation rather than as a direct result of climate influence, despite the well-known effect that precipitation has on weathering. A broad range of dates from Permian to the present, within a consortium of recognised dating techniques, supports the contention that weathering in Australia has been relatively continuous and did not occur as distinct episodes.