A keyed classification of natural geodiversity for land management and nature conservation purposes

Abstract

Application of the geosciences to land management and nature conservation is retarded by lack of a systematic classification encompassing the entirety of geodiversity. The system suggested here attempts to draw together the many existing sub-disciplinary geoscientific schemes into an overarching framework, whilst allowing their continued use for detailed differentiation of rocks, landforms and soils. It is essentially genetic and based upon reasonable inference of formative process rather than description of material, form or age. It recognises six fundamental classes according to the scale and physico-chemical conditions prevailing during the substantive creation of any aspect of geodiversity. Those classes are: (1) biogenic forms and palaeobiota, (2) offshore sedimentary, (3) non-volcanic igneous, (4) chemical, (5) tectonic and (6) surficial. Within the hierarchy classes are subdivided into themes and then types, for example class igneous, theme intrusive, type felsic or class surficial, theme glacial and cryogenic, type depositional. Twenty-five themes are suggested, encompassing 81 types. A systematic key to type level classification is provided. A fourth level of classification termed element allows more descriptive interface with the multitude of established geoscientific conventions. Geological age provides a fundamental modifier and distinction between active geomorphic process and a record of similar events progressively more lithified with age. The classification is intended principally to assist the identification of a comprehensive and representative geoconservation estate and to facilitate comparison of like objects for significance assessment. The considerable geodiversity of the Australian island state of Tasmania is tabulated by way of example.