**1. Introduction**

In this study, the karst of the horsts of the Bakony Region belonging to horst types of different development is described. Horsts belonging to different types have different elevations, expansions and coveredness (the expansion and quality of the cover), degrees and methods of its exposure, environments and positions as compared to karstwater level, bedrock morphologies and the presence of the aquifuge that is intercalated into the bedrock. Therefore, the reason for the different karstification of horst types is found in one (or even several) of the above factors and thus, the karstification of the horsts is traced back to such properties. The karstifications of the horst types differ from each other to a larger and smaller degree, which can also be interpreted by the consideration of the above-mentioned factors.

Modern karst research focuses on the detailed study (hydrology, geomorphology) of different karst areas [1–6]. This will be followed in the case of the description of the karst of the Bakony Region. The flow systems of the karst of the Bakony Region are classified based on the work of Klimchouk [7] and Goldscheider et al. [8], its karst features and their characteristics are described considering the work of Sweeting [9], White [10], Waltham et al. [11], Ford and Williams [12], Gutierrez [13] and Veress [14].

Basic features of karsts are features that can be found nearly on all karst types, but in different densities. The karst features are the following: karren, dolines and uvalas (they may have different varieties on different karst types), ponors with blind valleys, poljes, concretions, karstic gorges, inselberg karst and subsurface karst features [11]. Their common characteristic feature is that they develop by dissolution (caves are partly formed by erosion) and, with the exception of gorges and some karren features, surface features are closed.

Karren may develop on bare surfaces (rillenkarren, rinnenkarren, grikes) or below the soil (kamenitza, grike, rootkarren). Some of them may develop on both bare surfaces and soil-covered surfaces, or on karst covered with sediment too. Among dolines, solution dolines (mainly drawdown dolines) are distinguished, which are widespread on soilcovered karst. Caprock dolines are formed on the caprock, on consolidated rock, while

**Citation:** Veress, M. Horst-Controlled Karstification in the Bakony Region (Hungary). *Land* **2023**, *12*, 682. https://doi.org/10.3390/ land12030682

Academic Editor: Xiaoyong Bai

Received: 17 February 2023 Revised: 7 March 2023 Accepted: 10 March 2023 Published: 14 March 2023

**Copyright:** © 2023 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

the several varieties of subsidence dolines develop on permeable, unconsolidated rock. Collapse dolines develop by collapse processes. Poljes are large features with independent hydrography (with springs, surface streams and ponors). Concretions are accumulation features that develop at karst springs and in the channels of streams. Ponors are formed along rock boundaries where the water of the streams from non-karstic areas flows into the karst. Inselberg karst is a complex landform assemblage and is constituted by residuals (inselbergs) of various shapes that developed by dissolution.

There are caves that develop by dissolution (spring caves, shafts), while others are of both dissolution and erosion origin (inflow cave, through cave, spring cave).

Among karst types, evaporate karsts and carbonate karsts are distinguished. Carbonate karsts include temperate karsts, tropical karsts, glaciokarsts, mixed allogenic-autogenic karsts and covered karsts. Their features are partly different. On temperate karsts, solution dolines are specific, while on mixed autogenic–allogenic karsts, there are ponors with blind valleys, on glaciokarsts, karren and shafts, on covered karsts, caprock dolines and subsidence dolines, on tropical karsts, inselberg karst, and on Mediterranean karst and tropical karsts, poljes are common.

A variety of temperate karsts have a horst structure, such as the Bakony Region. Since this karst is constituted by horsts of different structures and development, there occur features that are characteristic of covered karst, partly of soil-covered karst and of mixed allogenic–autogenic karst. However, it has to be noted that some features as epigenetic-antecedent gorges and cave-ins related to them are particularly specific to the Bakony Region.
