Bükk Plateau: A Karst Landscape

Abstract

The Bukk Mountains are among those with the most intricate geological structure and marked topographical contrasts in Hungary. They comprise the Big and Little Plateaus, the Bukkalja foothills and the northern foreland (Bukkhat). The unique rock sequence with highly variable hydrogeological properties suffered moderate regional metamorphosis and heavy folding over an extensive area during the Variscan and Alpine Orogenies. The accumulation of carbonates, which are affected by intensive karstification, began in the Carboniferous and lasted until the Middle Jurassic. The Big Plateau has an undulating surface of low rounded mounds and enclosed shallow valleys with landforms like doline fields in poljes, doline rows with ponors aligned along valleys and major individual ponors. Underground avens, chimneys and caves are found in large numbers, constituting a quarter of all caves in Hungary. The northern edge of the plateau is dissected by valleys with deep gorges. Along the marked southern margin, bastion-like limestone cliffs, called “The Rocks”, form a prominent edge rising from the foreland of limestone and volcanic zones. Karst landforms (karren fields, opened caves) are also typical of “The Rocks”.