Are “Collapse Dolines” Formed Only by Collapse?

UDC: 551.435.84(497.4) France [u{ter{i~: Are “collapse dolines” formed only by collapse? The paper concerns collapse dolines, which appear to be one of the best-defined surface karst phenomena. Despite this appearance, one may find quite different views in the literature, and some the aspects of their morphogenesis have been overlooked completely. Among these aspects the most obvious is the question of the ongoing development of the closed depression. After the perpendicular walls have disappeared, the slopes are reshaped only by pocket weathering, and denudation penetrates deep below the former level of the preexisting cave floor. Dolines at this stage of development have been termed phantom collapse dolines. Five of the most common collapse doline types found in Slovenia are considered in terms of general systems theory, leading to a conclusion that cave roof collapse remains the crucial event in a collapse doline’s development. However, the collapse event itself may be relatively subdued in terms of the volume of free fallen mass involved.