Due anni e mezzo di lavoro e finalmente ieri è uscito il mio ultimo articolo su carsismo e speleogenesi nelle quarziti, una sintesi globale sulle conoscenze attuali su Earth Science Reviews.
Per gli esploratori: l’articolo è corredato di un catalogo su tutte le grotte e zone di quarzite con potenziale esplorativo conosciute al mondo, divise per continente.
Se volete ispirazione per future spedizioni!
L’articolo è dedicato a Robert Wray, uno dei maggiori esperti al mondo di questo tipo di forme e grotte, prematuramente scomparso questa primavera.
http://www.sciencedirect.com/science/article/pii/S0012825217300235
Abstract
Quartz is considered one of the less soluble minerals of the Earth’s crust, and thus hardly affected by chemical weathering. Despite this, for more than forty years, it is clear that the formation of caves and peculiar solutional weathering dominated landforms in quartz-rich lithologies is common and shares several similarities to the well-known karstic ones in carbonate rocks. In the last thirty years great strides have been made in furthering our knowledge of the distribution of these forms around the world, and the geochemical processes involved. These studies have clearly shown that solutional weathering is a fundamental process, acting through intergranular dissolution of quartz increasing the rock porosity and decreasing the rock strength to erosion. This process has been described in the concepts of ‘arenization’ and ‘phantomization’ and the widespread evidences of the fundamental role of quartz solution in landform genesis has even developed to the extent of several geomorphologists reassessing the definition of the term ‘karst’, and its application to these peculiar lithologies. Nonetheless the process is complicated by several factors, related both to environmental conditions (water chemistry and availability) as well as to the compositional and textural characters of the lithology (presence of clays, iron hydroxides, carbonate cement, etc.). All these aspects have to be taken carefully in consideration in order to understand if solution is a dominant or accessory process in the landscape evolution. In this review the state of knowledge on the relevant chemical processes, weathering mechanisms, and speleogenesisk involved in the surface and underground karstification, and clear examples of quartz solution and solutional landforms from different world locations, are outlined and discussed.