The geodiverse landscapes of the Saminatal, the Galinatal and the northwestern Gamptal (Vorarlberg and Liechtenstein) A cross border inventory based on geomorphological mapping

A study was carried out to fulfill requirements for the establishment of an IUCN 1b Category protected area in the Saminatal and Galinatal, specifically to close knowledge gaps in the domains of geology and geomorphology. Complying with the request, our study focused on capturing the geomorphological diversity of the area within the framework of the main characteristics of the bedrock and with special attention to Quaternary valley fills. Using a GIS geodatabase consisting of a LiDAR-derived digital elevation model (DEM), land surface parameter (LSP) maps derived from the DEM, digital geomorphological and geological maps and digital airphotos, we have generated an area-covering geomorphological map with a legend consisting of a three-tiered nested hierarchy, which was developed and applied in previous work in areas adjacent to the study area in Vorarlberg. As a routine element of the work flow, the geoconservation potential of the classes of the Tier 3 map level, i.e. the level with the finest geomorphological detail, was assessed.
Whereas the bedrock of the study area consists largely of dolomites of the Hauptdolomite Formation—with the notable exception of the Gamptal, where gypsum beds of the Raibler Schichten formation exert a strong control on the landscape development—the geomorphology of the area is very diverse: glacial-erosional and accumulational, fluvial-erosion and accumulational, mass-movement degradational and accumulational, periglacial-accumulational, and sulphate-karst features have been observed and mapped.
During the culmination of the last glaciation, the entire area was covered by glaciers—only the highest peaks possible protruding as nunataks above the ice. The glacial valleys and cirques of the high regions, however, have been—and still are—subject to severe fluvial and mass movement degradation and the concurrent production of large amounts of scree once the deglaciation started. Moraines, glaciofluvial landforms, and relict rock glaciers are preserved on the floor of these valleys and cirques as witnesses of the transitional period from the cold climate of the last ice age to today’s warm climate.
The lower, deeper segments of the Saminatal and Galinatal contain the remnants of thick sections of fluvial, lacustrine, glacial and slope sediments. These fills document the changing environmental conditions from the onset of the glaciation through the culmination and to the end of the glaciation. The key controlling factor was the interaction of the large Ill Glacier, which penetrated the lower sections of tributary valleys, and the small local glaciers, such as the Samina glacier.
Regarding the geoconservation potential, nine of the twenty-three mapped Tier 3 geomorphological classes rank as highly valuable, i.e. they are potential geoconservation sites. Linked to glacial, fluvial, periglacial and sulphate-karst processes, these morphogenetic domains contain information critical for a thorough understanding of the landscape evolution. The valley fills of the Saminatal and Galinatal are exposed in slopes created by fluvial erosion and mass movements, or underlie terraces. As such they are not captured by the geomorphological mapping and are, hence, not part of the standard assessment of geoconservation potential. Nevertheless they are scientifically very important. Based on the occurrence of potential geoconservation sites, eight areas are described in detail: Galinatal, Northwestern Gamptal, Wurmtal, Garsellaalp, Plankner Garselli, Säslitobel, Triesenberger Garselli and the Samina river valley. Notably in Liechtenstein, the high-altitude areas are isolated and poorly accessible, contributing to a undisturbed near-natural state. The findings of this study align well with research on geodiversity and climate-driven landscape development in Vorarlberg, Liechtenstein, and southern Germany. The study area is a rich archive of scientific evidence on past climate conditions and hosts a variety of potential geoconservation sites. In addition, the high intensity of fluvial and mass-movement processes creates a rugged topography, characteristic of postglacial landscape development of a mountainous area.