The Karst Paradigm: Changes, Trends and Perspectives

Abstract

UDC 551.435.8 Alexander Klimchouk: The karst paradigm: changes, trends and perspectives The paper examines representative definitions of karst (21), and discusses some concepts that influenced the modern understanding of the phenomenon. Several trends are discussed that took karst science beyond the limits of the traditional paradigm of karst. Dramatic progress in studies of speleogenesis plays the most significant role in changes taking place in the general understanding of karst. Also important is an adoption of the broad perspective to karst evolution which goes beyond the contemporary geomorphologic epoch and encompasses the entire life of a geological formation. Speleogenesis is viewed as a dynamic hydrogeological process of self-organization of the permeability structure in soluble rocks, a mechanism of the specific evolution of the groundwater flow system. The result is that these systems acquire a new, "karstic", quality and more complex organization. Since almost all essential attributes of karst owe their origin to speleogenesis, the latter is considered as the primary mechanism of the formation of karst. Two fundamental types of speleogenesis, hypogene and epigene, differentiate mainly due to distinct hydrodynamic characteristics of the respective groundwater flow systems: (1) of layered aquifer systems and fracture-vein flow systems of varying depths and degrees of confinement, and (2) of hydrodynamically open, near-surface unconfined systems. Accordingly, two major genetic types of karst are distinguished: hypogene and epigene. They differ in many characteristics, notably in relationships with the surface, hydrogeological behaviour, groundwater quality, and the areas of practical importance and approaches to solving karst-related issues. Although views on essential attributes of karst have been clearly changing, this was not reflected in definitions of the notion which are in broad use in the earth-science literature. A refined approach is suggested to the notion of karst in which it is viewed as a groundwater (fluid) flow system of a specific kind, which has acquired its peculiar properties in the course of speleogenesis. Keywords: karst, definition of karst, speleogenesis, karst geosystem, karst evolution. IzvlečekUDK 551.435.8 Alexander Klimchouk: Kraška paradigma: spremembe, tre ndi in perspektive Dokument obravnava reprezentativne definicije krasa (21) in obravnava nekatere koncepte, ki so vplivali na sodobno razumevanje tega pojava. Razpravlja o več trendih, ki so popeljali krasoslovje preko meja tradicionalne paradigme krasa. Dramatični napredek v speleogenetskih raziskavah je igral najpomembnejšo vlogo pri spremembah, ki so se zgodile pri splošnem razumevanju krasa. Prav tako je za razvoj krasoslovja pomembno sprejetje široke perspektive, ki presega sodobno geomorfološko epoho in zajema celoten geološki razvoj. Speleogeneza je predstavljena kot dinamični hidrogeološki proces samoorganizacije stopnje prepustnosti posameznih struktur v topnih kamninah, to je kot mehanizem specifičnega ...

Sequence stratigraphy, seismic stratigraphy, and seismic structures of the lower intermediate confining unit and most of the Floridan aquifer system, Broward County, Florida

“…karst "A fluid flow system (geohydrodynamic system) with a permeability structure evolved as a consequence of dissolutional enlargement of initial preferential flow pathways, dominated by interconnected voids and conduits, and organized to facilitate the circulation of fluid in the downgradient direction due to the positive feedback between flow and conduit growth" (Klimchouk, 2015). marl A lithology consisting of 35 to 65 percent carbonate and 65 to 35 percent clay (Pettijohn, 1957, p. 410;Flügel, 2004 …”

Seismic Characterization of Hypogenic Karst Systems Associated with Deep Hydrothermal Fluids in the Middle-Lower Ordovician Yingshan Formation of the Shunnan Area, Tarim Basin, NW China

“…As noted in Klimchouk [7], epigene karstification occurs in the nearsurface conditions and is directly linked with recharge from the immediately overlying or adjacent surface. The individual string-beads-like seismic reflection has been interpreted as the evidences of "epigenic karst system" in the Tarim Basin in the published papers, which is always linked with the terms "unconformities, weathering crusts, exposure, etc."…”

“…Hypogenic karst is a genic type of karst, regardless of the lithologies in which it develops [6,7]. Speleogenesis is often considered as the primary mechanism of the formation of karst because almost all essential attributes of karst owe their origin to speleogenesis [7].…”

“…Speleogenesis is often considered as the primary mechanism of the formation of karst because almost all essential attributes of karst owe their origin to speleogenesis [7]. Two fundamental types of speleogenesis, hypogene and epigene, are differentiated mainly by the distinct hydrodynamic characteristics of the respective groundwater flow systems: (1) stratiform confined aquifer systems or across-formational fracture-vein flow systems, of varying depths and degrees of confinement, and (2) hydrodynamically open, near-surface unconfined systems [7].…”

“…Speleogenesis is often considered as the primary mechanism of the formation of karst because almost all essential attributes of karst owe their origin to speleogenesis [7]. Two fundamental types of speleogenesis, hypogene and epigene, are differentiated mainly by the distinct hydrodynamic characteristics of the respective groundwater flow systems: (1) stratiform confined aquifer systems or across-formational fracture-vein flow systems, of varying depths and degrees of confinement, and (2) hydrodynamically open, near-surface unconfined systems [7]. Accordingly, the principal difference between hypogenic and epigenic karst systems lies in the modes (confined versus unconfined) and principal vectors (ascending versus descending) of fluid circulation and in the source of recharge to a given unit (recharge from depth versus recharge from the overlying or immediately adjacent surface) [6,7].…”