Understanding the ongoing speleogenic processes that produce sinkholes and control the vital drinking water supplies of Florida and much else of the world is necessary research. This article （and the associated poste...Understanding the ongoing speleogenic processes that produce sinkholes and control the vital drinking water supplies of Florida and much else of the world is necessary research. This article （and the associated poster presentation） discusses theoretical processes that may act in addition to mass dissolution kinetics in producing voids, conduits and caves in autogenic karst landforms. Possible theoretical factors that affect these speleogenic processes are： microscopic mixing corrosion （low constant flow, low constant flow against current, temperature-induced mixing corrosion, and pressure-induced mixing corrosion in karst matrix）, random dissolution models, simulation of gravity-induced microscopic breakdown, and storm surge effects. Finally, a theoretical model is discussed that unifies these various microscopic processes into a macro-scale process, called internal pressure sculpting. Computer models were designed to illustrate these theoretical processes： Non-calibrated computer models simulating each process discussed in this paper are presented for illustration, as well as the preliminary results of calibrated models depicting random dissolution, mechanical breakdown, and storm surge effects. The theoretical processes discussed and simulated may have major effects on cave morphology. Computer simulations appear to accurately portray the shape and form of some cave features with dissolutional morphologies. Theoretical discussion concludes with a general discussion of possible improvements to the presented models as well as the ability to generalize theoretical processes to hypogenic, halogenic, and autogenic speleogenesis.展开更多
Yunnan is famous for its attractive karst landscapes especially shilins, fengcong and fenglin. The development of caves beneath the shilins in the vicinity of Lunan is closely connected with the formation of shilins. ...Yunnan is famous for its attractive karst landscapes especially shilins, fengcong and fenglin. The development of caves beneath the shilins in the vicinity of Lunan is closely connected with the formation of shilins. Most of the waters percolating through shilins run through the caves beneath them and are responsible for their formation. The study of cave speleogenesis deepens knowledge about both the development of shilins and karst structure. In the vicinity of the Lunan Shilin, speleological, morphological and structural geological studies of four karst caves have been accomplished. At Puzhehei, Qiubei, which is characterised by numerous fenglin, fengcong and caves, speleological and morphological studies have been performed. Cave sediments for paleomagnetic analyses have been taken from all studied areas (samples CH 1-9). Karst caves in SE Yunnan are probably much older than the age of the cave sediments (<780,000 years B.P.). The studied areas are located in the vicinity of the Xiaojiang fault (N-S direction I and the Red River fault (NW-SE direction). The general directions of both active faults are assumed to influence the direction of the most frequent fissures as well as the cave passages near the Lunan Shilin. The Xiaojiang fault more strongly influences cave passage orientation, while the more distant Red River fault most strongly influences fissure orientation.展开更多
The Baiyun cave is a 380 m long karst cave in the Naigu Shilin, situated 70 km southeast of Kunming, Yunnan Province, China. The prevailing orientations of the cave passages are N110°–120°E and N0°-10&...The Baiyun cave is a 380 m long karst cave in the Naigu Shilin, situated 70 km southeast of Kunming, Yunnan Province, China. The prevailing orientations of the cave passages are N110°–120°E and N0°-10°W and those of the fissures in the cave are N30°–40°W and N20°–30°W. The cave is developed in the thick-bedded Lower Permian Qixia Formation. The cave has an active water flow and is currently at the near water-table stage. There are large amounts of different infills of cave sediments. The cave shows different stages of paragenesis. The palaeomagnetic analysis of cave sediments shows that their ages are younger than 780 ka B.P. (the Brunhes Chron). The upper part of the sampled profile belongs to the reverse Blake event (112.3–117.9 ka B.P.). The formation of the Baiyun cave is directly connected with the development of the Naigu Shilin. The formation of karst underground and surface features depends on the regional tectonic deformation and the Cenozoic extension of the study area.展开更多
Cave levels, passages found at similar elevations and formed during the same constant stream base level event, reveal information about paleoclimates and karst geomorphology. The investigation presented here examines ...Cave levels, passages found at similar elevations and formed during the same constant stream base level event, reveal information about paleoclimates and karst geomorphology. The investigation presented here examines how Stream Power Index (SPI) relates to cave levels. The study area, Carter Caves State Resort Park (CCSRP), is a fluviokarst system in northeastern Kentucky containing multiple cave levels. SPI determines the erosive power overland flow based on the assumption that flow accumulation and slope are proportional to potential for sediment entrainment. Part of this digital terrain analysis requires the creation of a flow accumulation raster from a digital elevation model (DEM). In creating the flow accumulation raster, one has the option to fill depressions (also considered errors) within the DEM. Filling these depressions, or “sinks,” creates a well-connected stream network;however it also removes possible sinkholes from the DEM. This paper also investigates the effects a filled and an unfilled DEM have on SPI and what each reveals about erosion potential in the area. The data shows that low elevations within the filled DEM maintain a high SPI value when compared to the unfilled DEM. The filled DEM also created a stream network similar to reality. The unfilled DEM demonstrated similar SPI results between all levels, indicating a well-connected karst system. In order to truly understand the mechanics of this system, a combination of these two DEMs is required.展开更多
文摘Understanding the ongoing speleogenic processes that produce sinkholes and control the vital drinking water supplies of Florida and much else of the world is necessary research. This article （and the associated poster presentation） discusses theoretical processes that may act in addition to mass dissolution kinetics in producing voids, conduits and caves in autogenic karst landforms. Possible theoretical factors that affect these speleogenic processes are： microscopic mixing corrosion （low constant flow, low constant flow against current, temperature-induced mixing corrosion, and pressure-induced mixing corrosion in karst matrix）, random dissolution models, simulation of gravity-induced microscopic breakdown, and storm surge effects. Finally, a theoretical model is discussed that unifies these various microscopic processes into a macro-scale process, called internal pressure sculpting. Computer models were designed to illustrate these theoretical processes： Non-calibrated computer models simulating each process discussed in this paper are presented for illustration, as well as the preliminary results of calibrated models depicting random dissolution, mechanical breakdown, and storm surge effects. The theoretical processes discussed and simulated may have major effects on cave morphology. Computer simulations appear to accurately portray the shape and form of some cave features with dissolutional morphologies. Theoretical discussion concludes with a general discussion of possible improvements to the presented models as well as the ability to generalize theoretical processes to hypogenic, halogenic, and autogenic speleogenesis.
文摘Yunnan is famous for its attractive karst landscapes especially shilins, fengcong and fenglin. The development of caves beneath the shilins in the vicinity of Lunan is closely connected with the formation of shilins. Most of the waters percolating through shilins run through the caves beneath them and are responsible for their formation. The study of cave speleogenesis deepens knowledge about both the development of shilins and karst structure. In the vicinity of the Lunan Shilin, speleological, morphological and structural geological studies of four karst caves have been accomplished. At Puzhehei, Qiubei, which is characterised by numerous fenglin, fengcong and caves, speleological and morphological studies have been performed. Cave sediments for paleomagnetic analyses have been taken from all studied areas (samples CH 1-9). Karst caves in SE Yunnan are probably much older than the age of the cave sediments (<780,000 years B.P.). The studied areas are located in the vicinity of the Xiaojiang fault (N-S direction I and the Red River fault (NW-SE direction). The general directions of both active faults are assumed to influence the direction of the most frequent fissures as well as the cave passages near the Lunan Shilin. The Xiaojiang fault more strongly influences cave passage orientation, while the more distant Red River fault most strongly influences fissure orientation.
文摘The Baiyun cave is a 380 m long karst cave in the Naigu Shilin, situated 70 km southeast of Kunming, Yunnan Province, China. The prevailing orientations of the cave passages are N110°–120°E and N0°-10°W and those of the fissures in the cave are N30°–40°W and N20°–30°W. The cave is developed in the thick-bedded Lower Permian Qixia Formation. The cave has an active water flow and is currently at the near water-table stage. There are large amounts of different infills of cave sediments. The cave shows different stages of paragenesis. The palaeomagnetic analysis of cave sediments shows that their ages are younger than 780 ka B.P. (the Brunhes Chron). The upper part of the sampled profile belongs to the reverse Blake event (112.3–117.9 ka B.P.). The formation of the Baiyun cave is directly connected with the development of the Naigu Shilin. The formation of karst underground and surface features depends on the regional tectonic deformation and the Cenozoic extension of the study area.
文摘Cave levels, passages found at similar elevations and formed during the same constant stream base level event, reveal information about paleoclimates and karst geomorphology. The investigation presented here examines how Stream Power Index (SPI) relates to cave levels. The study area, Carter Caves State Resort Park (CCSRP), is a fluviokarst system in northeastern Kentucky containing multiple cave levels. SPI determines the erosive power overland flow based on the assumption that flow accumulation and slope are proportional to potential for sediment entrainment. Part of this digital terrain analysis requires the creation of a flow accumulation raster from a digital elevation model (DEM). In creating the flow accumulation raster, one has the option to fill depressions (also considered errors) within the DEM. Filling these depressions, or “sinks,” creates a well-connected stream network;however it also removes possible sinkholes from the DEM. This paper also investigates the effects a filled and an unfilled DEM have on SPI and what each reveals about erosion potential in the area. The data shows that low elevations within the filled DEM maintain a high SPI value when compared to the unfilled DEM. The filled DEM also created a stream network similar to reality. The unfilled DEM demonstrated similar SPI results between all levels, indicating a well-connected karst system. In order to truly understand the mechanics of this system, a combination of these two DEMs is required.
