KARST GEOMORPHOLOGY AND SPELEOLOGY, 1963-2003

Karst geomorphology is concerned with surface landforms and epikarst. It lacks a guiding concept more complex than recognition of the dominance of rock dissolution because attempts to fit landforms into simple deterministic models of cyclic or climatic kind have foundered on controlling effects of lithology and geologic structure. Microbiogeomorphology is an exciting new area of investigation. Three broad genetic categories of dissolutional caves are now recognized: (i) coastal mixing zone caves in young carbonates; (ii) roughly dendritic caves where there is unconfined circulation of meteoric waters; (iii) deep dissolution with confined and/or ascending waters. Numbers, lengths and depths of explored caves have increased enormously. Computer modelling has focussed on aquifer and cave evolution. Ab initio models of unconfined aquifers converge on solutions obtained with earlier hardware models. A posteriori modelling from spring hydrographs, etc. is successfully adopted by karst specialists but too often ignored by others. Dating and paleo-environmental reconstruction using calcite and aragonite speleothems is advancing rapidly. U-series methods now date to 600 ka B.P. U/Pb dating of calcites, Al/Be dating of quartz sands and pebbles in caves have great potential in karst and paleokarst study. O and C isotopic paleo indicators in speleothems enhance oceanic and ice core isotopic records of the Ice Ages. Analysis of annual and other depositional banding in speleothems (principally by variations of luminescence intensity) is an exploding field.