Hypogenic Speleogenesis within Seven Rivers Evaporites: Coffee Cave, Eddy County, New Mexico

Coffee Cave, located in the lower Pecos region of southeastern New Mexico, illustrates processes of hypogenic speleogenesis in the middle Permian Seven Rivers Formation. Coffee Cave is a rectilinear gypsum maze cave with at least four stratigraphically-distinct horizons of development. Morphological features throughout the cave provide unequivocal evidence of hypogenic ascending speleogenesis in a confined aquifer system driven by mixed (forced and free) convection. Morphologic features in individual cave levels include a complete suite that defines original rising flow paths, ranging from inlets for hypogenic fluids (feeders) through transitional forms (rising wall channels) to ceiling half-tube flow features and fluid outlets (cupolas and exposed overlying beds). Passage morphology does not support origins based on epigenic processes and lateral development, although the presence of fine-grained sediments in the cave suggests minimal overprinting by backflooding. Feeder distributions show a lateral shift in ascending fluids, with decreasing dissolutional development in upper levels. It is likely that additional hypogenic karst phenomena are present in the vicinity of Coffee Cave because regional hydrologic conditions are optimum for confined speleogenesis, with artesian discharge still active in the region

The Pecos River Hypogene Speleogenetic Province: a Basin-Scale Karst Paradigm for Eastern New Mexico and West Texas, USA

Since the mid-Tertiary, lateral migration and entrenchment of the Pecos River Valley in eastern New Mexico and west Texas, USA, has significantly influenced regional groundwater flow paths, providing a focus for ascending flow in multi-storey artesian systems and a powerful potentiometric driving force for hypogene speleogenesis. Individual occurrences of hypogene karst phenomena associated with the central Pecos River Valley are widespread throughout the greater Delaware Basin region, including development in a wide range of Permian carbonate and evaporate fades. Hypogene occurrences are well-documented as far north as Santa Rosa, New Mexico and as far south as Lake Amistad, Texas. Throughout the northern shelf, intrastratal dissolution and brecciation of the San Andres formation is widespread as a result of eastward migration of the Pecos River. Proximal to the current river, hypogene dissolution in interbedded carbonate/evaporite facies of the Seven Rivers Formation has produced three-dimensional network caves and vertical collapse structures. In the carbonate reeffacies of the Guadalupe Mountains, complex three dimensional caves are common, as well as stepped terraces associated with eastward migration of thePecos River. Although these caves have been attributed to sulfuric acid dissolution, they are the result of hypogene speleogenesis in which solutional aggressivity was increased by the addition of both thermal and sulfuric-acid components. Within the interior of the Delaware Basin, hypogene karst in basin-filling evaporite facies of the Castile and Salado Formations is widespread, including development of large solution subsidence troughs associated with the lateral migration of the Pecos River. On the far eastern margin of the Delaware Basin, at the southeastern tip of the Central Basin Platform, persistent down cutting of the Pecos River Valley contributed to the development of hypogene karst within the Yates Petroleum Field, providing cavernous reservoir porosity for the largest individual oil field known within the Permian Basin region. Immediately below the confluence of the Pecos River and the Rio Grande, the large first order magnitude spring, Goodenough Spring, flows from a deep phreatic cave under extreme artesian conditions, even as 45 meters of pressure head has been added over the spring from Amistad Reservoir

Karst relief of the Mali me Gropa Massif, central Albania

The mid-al ti tude moun tain mas sif of Mali me Gropa is lo cated in the cen tral part of Al ba nia, rises to an al ti tude of 1500–1800 m a.s.l., is com posed mostly of Me so zoic lime stone, and is char ac ter ized by ex ten sive sur face karst de vel op ment. The karst re lief is dom i nated by “doline” mor phol ogy in clud ing “po lyg o nal” karst. De tailed geomorphological anal y sis of the west ern part of the Mali me Gropa mas sif (so-called West ern Mas sif) by means of GIS meth ods is used to de ter mine and ex plain the morphometric and mor pho log i cal di ver sity of the area’s to pog ra phy. Based on a ho mo ge ne ity cri te rion, a num ber of geomorphological units with spe cific kinds of karst re lief have been dis tin guished within the mas sif. The dif fer ences in karst sculp ture con cern the size (di am e ter) of dolines and de pres sions, their depth, shape and sym me try, ori en ta tion, den sity of oc cur rence and spa tial pat tern, which pro vide the ba sis for dis tin guish ing geomorphological units. The spa tial dif fer en ti a tion of the karst re lief is ex plained by the in flu ence of fac tors which are evo lu tion ary (geo log i cal and geomorphological evo lu tion of the mas sif), hypsometric (al ti tude dif fer ence of ter rains) and geomorphologic-struc tural (in cli na tion of the slopes and lay -ers). The rel a tively poor ex pres sion of open karst con duits (i.e. caves and ver ti cal shafts) on the sur face of the mas sif may re -sult from the rel a tive im ma tu rity of the epikarst zone, the wide spread oc cur rence of re sid ual cover on the pla teau, and the ac cu mu la tion of large amounts of clay ma te rial in dolines and de pres sions. De tailed hydrogeological stud ies show, how ever, high karst per me abil ity and dom i nance of con duit flow. Con sid er ing the high geomorphological land scape and eco log i cal value of the area, it should be granted the sta tus of a na ture re serve or na tional park. Geomorphological and karstological re -search within the mas sif should be con tin ued as it rep re sents a type of karst found also in other parts of Al ba nia. This type of karst area is of great eco nomic (ground wa ter re serves) and nat u ral pro tec tion (en vi ron men tal) im por tance

Speleogenesis in gysum

Satisfactory explanation of the origin and development of caves (speleogenesis) is a core problem of karst studies. Karst evolves as a circulation system, organised and interconnected through a conduit structure. Such a system may include superficial inputs and outputs, expressed as or related to karst landforms. However, there may be no such components if the system is represented entirely by conduits as in the case with deep-seated intrastratal karst. The main differences between speleogenesis in gypsum and in carbonate rocks lie in the chemistry and kinetics of their dissolution, in some of the lithological or structural peculiarities of the respective rocks and formations, and in their hydrogeological characteristics. The present chapter considers how these factors influence cave origin and development

Discrimination of the Hranice Karst waters (Czech Republic) based on the archival data

This chapter discusses the notion of hypogene karst, reviews its diversity and further develops the hydrogeological approach to classifying hypogene karst and its settings. Since an understanding of hypogene karst requires much deeper and broader hydrogeological and geodynamic context as compared to more familiar epigene karst, this chapter provides an overview of basic concepts about fluid dynamics and hydrodynamic zoning of the upper crust and about the influence of the mantle processes on crustal fluids. The relationships of hypogene karstification with metasomatism and other processes of fluid-induced transformations of rocks are examined. It is argued that the phenomena of the so-called ghost-rock karstification (commonly attributed to epigene settings) and cavernous decay (commonly attributed to external weathering) are manifestations of hypogene karstification and related alteration of rocks around conduits. Genetic categorization and discrimination of characteristic settings of hypogene karst are based on consideration of driving forces and conditions for fluid circulation and ascending flow in the upper crust in the context of tectonic/geodynamic positions and history of regions. Development and distribution of hypogene karst of the artesian type in gravitational flow systems of cratons are governed by the basin’s configuration, topography and hydrostratigraphy. Hypogene karst of the endogenous type is governed by the geodynamic regimes and intimately related to cross-formational fluid-conducting systems. Hypogene karst is a significant component of fluid-induced lithogenesis and plays an important role in the porosity and permeability development in many sedimentary rocks and some metamorphic rocks