Limestone weathering in Eastern Australia. Part 1: Erosion rates

Abstract

A traversing microerosion meter (MEM) was used to measure the rates of surface weathering of limestones in southeastern Australia. There were two groups of MEM sites installed in 1978/9. The aim of the experimental design for the first type, the 13 sites at Cooleman Plain and Yarrangobilly Caves, was to obtain erosion rates for limestones of similar lithology exposed under comparable climate conditions. The sites were positioned to measure erosion over a range of microsolutional forms and with exposure to differing forms of erosion, i.e. subaerial, subsoil and instream. The second set, at Ginninderra close to Canberra, consists of nine limestone slabs of differing lithology, collected from different locations but exposed under identical climatic conditions. The number of individual measurement points at each MEM site varied from 24 to 68.There were major differences in erosion rates between subaerial bedrock and instream sites at Yarrangobilly and Cooleman Plain, but no evidence of differential erosion across the micro-forms. There were differences in the weathering rate for bedrock sites, due to climatic differences, and between the limestone lithologies exposed at Ginninderra. The average rate of erosion for the subaerial bedrock sites at Cooleman Plain and Yarrangobilly over the 13 years was 0.01 3 mm a-' and at Ginninderra 0.006 mm a-' . At some of the sites microflora (lichens and mosses) caused problems for field measurement.The weathering processes that contribute to the surface lowering are discussed in the accompanying paper by Moses et al.

Palaeohydrogeological control of palaeokarst macro-porosity genesis during a major sea-level lowstand: Danian of the Urbasa–Andia plateau, Navarra, North Spain

“…Despite this later erosion, the absence of residual relief and large epikarst features such as sinkholes and pit caves indicates that during the exposure the karst surface was rather flat and that little thickness of the upper Danian rocks was eliminated by dissolution. This is typical of karst terrains in arid or semi-arid climates, where surface dissolution is limited due to low precipitation, high evaporation rates and sparse vegetation cover (Choquette and James, 1988;Tucker and Wright, 1990;Smith et al, 1995).…”

Using in situ Chlorine-36 cosmonuclide to recover past earthquake histories on limestone normal fault scarps: a reappraisal of methodology and interpretations

“…Cucchi et al 1995;Smith et al 1995;Furlani et al 2009), while those rates are generally not constrained for longer time spans. In the absence of well-documented denudation rates, we present in Fig.…”

Hydraulic Parameters and Morphometric Variables Interactions in Bedrock Channel

“…Miller (1991), Wohl et al (1994), Seidl et al (1996), Righter (1997), Seidl (1997, 1998), Wohl andIkeda (1998), Wohl (2000), Wohl andMerritt (2001), wohl andAchyuthan (2002) contributed valuable work on knick points. Erosion rates in natural bedrock channels have been measured by Foley (1980), Smith et al (1995), Righter (1997), Hancock et al (1998), Tinkler and Parish (1998), Whipple et al (2000b), Wohl and Achyuthan (2002), Kale and Joshi (2004), Reusser et al (2004).…”