Microscale Geology and Micropalaeontology of the Becher Point Cuspate Foreland, Australia: Significant Geoheritage Values at the Smallest Scale—A Model for Identifying Similar Features in Geosites and Geoparks

Geological features of heritage significance can range from the largest scale (montane and drainage basin) to microscale. The smallest scale of geoheritage include globally significant features such as the Archaean zircon crystals from Jack Hills, Australia (the oldest crystals on Earth), snowball garnets from Sweden (illustrating kinematic rotation under metamorphism and shear), and microbiota in Precambrian rocks. It also can include regionally significant microscale features that provide insights into the more local history of the Earth, hydrology, hydrochemistry, climate, and vegetation. The Becher Point Cuspate Foreland, a Holocene accretionary sandy deposit in south-western Australia, is recognised as an internationally significant area for its geomorphology, stratigraphy, wetlands, and record of climate history. Of specific importance are the wetlands that occur in the inter-ridge swales of the beach ridges. The wetlands record in their sediments a history of climate, vegetation, hydrology, and hydrochemistry, staged over a 4,500 year interval in the oldest wetlands, and over an interval of <1,000 years in the youngest wetlands. Whilst Becher Point has been recognised as Internationally significant as a Ramsar site for its macroscopic features, its importance as a site of geoheritage significance continues to the smallest scale in that its microscale geology (calcrete, carbonate grain dissolution) and micropalaeontology (pollen, calcified charophyte fructifications, and other microbiota) provide important (metaphoric) “letters of the alphabet” that can be used to read the history of the sedimentary and climate record of the region. This area provides an excellent example of how the pollen and charophyte fructifications and other microscale geological features function as important markers and signatures within the Holocene history of the beach ridge plain and wetlands and, as such, represent significant geoheritage values at the smallest scale.