Open conduit modeling of cave stream floods can yield useful information about water velocities and shear stresses, which can in turn be used to estimate sediment transport capabilities. All such calculations require roughness coefficients for estimating energy losses and a priori knowledge of either discharge or flow depths to set model boundary conditions. However, the difficulties associated with observing in-cave floods generally preclude measuring discharge; roughness coefficients must be assumed based on channel properties. To overcome these challenges, we monitored stream flow depths in Fullers Cave, Greenbrier County, West Virginia using pressure transducers, and simultaneously measured stage and discharge in a karst window immediately upstream of the cave. Five pressure transducers were deployed opportunistically along a 93-meter-long reach in a 10+ meter high canyon averaging 1.5 to 3 meters wide. Stage-discharge relationships were determined for the karst window using an electromagnetic flow meter for floods with peak discharges of 1.66 m3 s-1 or less. The collected data was used to obtain the empirical Manning’s n roughness values, head losses, and energy gradients. Calculated floodwater velocities are comparable to values obtained from scallops on passage walls. Major energy losses were observed where breakdown partially occludes the passage. At peak flow, Manning n values average 0.053 for reaches typified as cobble-floored canyons, but n was 0.069 in the breakdown reach. Roughness values declined exponentially with increasing discharge, but friction slopes calculated using head losses show more complex relationships with discharge. Notably, n values back calculated using bed gradients differ from those calculated using measured head losses by as little as 12%, so the use of bed gradients in roughness estimations will generally yield reasonable approximations of flow conditions. Fullers Cave experiences significantly larger open conduit floods than we observed, so additional work is needed to estimate roughness coefficients for higher discharges. Our empirical roughness coefficients can be applied to similar cave passages in other caves and contexts, including modeling slot canyon-like channels, and our methods demonstrate a technique for measuring hard to obtain data. The addition of data for open conduit conduits significantly expands the range of environments that can be modeled using empirical data beyond pipe-full caves. Applications include studying flooding, sediment transport, and bedrock erosion process. All of these topics will be addressed in Fullers in the future.

Scallops are extremely valuable indicators of past water flows in caves because they often record events that cannot be safely witnessed nor measured. Qualitatively, the inverse relationship between their lengths and formative water velocities is useful for determining how flow changes along a cave passage, but they are most valuable because they can be used to directly estimate actual water velocities and discharges. We explore the effects of sample size, measurement choices, and other methods commonly applied to the use of cave scallops in estimating cave stream velocities and discharges. We measured 100 scallops on a cave wall and find them to be log-normally distributed. We used Monte Carlo simulations to sub-sample the 100 scallops for sample sizes of 10 to 30. As expected, smaller sample sizes yield widely varying means with precision increasing slowly with sample size. A sample size of 30 results in greater than 50% of simulated means falling within one standard deviation of the mean for all 100 scallops. This is also true of sample sizes as small as 20, so we recommend a minimum of 20 to 30 scallop measurements in the field. The formulas we use to estimate water velocities and discharges explicitly use the Sauter mean of scallop lengths, but some authors use the arithmetic mean. We simulated the use of both the Sauter and arithmetic means and find that the latter yields substantially larger velocities and discharges. We recommend use of the Sauter mean because that is consistent with the original formulations and the arithmetic mean may cause significant overestimation of velocity and discharge.

A completely new (sub)type of calcite stalactite, similar to a soda straw but showing an external square shape, has been recently observed within Dry Cave, West Virginia, USA. Though rare speleothems with one or more planar sides (triangular to hexagonal cross sections) have been described in the past, this is the first reported example of a subaerial stalactite-like speleothem with a rhombic parallelepiped structure. More than a dozen examples were observed in the cave. The suggested genetic mechanisms allowing the atypical growth of a parallelepiped seem to be controlled by several boundary conditions that normally preclude their development. Constrained by the specifics of calcite crystallization in descending vadose waters and the morphology of collected (already broken) samples, we hypothesize that an initial very low supersaturation within the feeding tube, together with relatively fast dripping, causes the growth of a normal monocrystalline calcite soda straw with the C axis coincident with the tubular axis and circular cross sections. Calcite precipitation on the outside of the soda straw is possible only if there is a water film flowing on the straw’s external surface. Normally, this external flow will cause the rapid transformation of a tubular straw into a typical, polycrystalline conical stalactite. But in this case, the external feeding film is minimally supersaturated or even absent, which slows epitaxial growth over the pre-existing monocrystalline structure of the soda straw and suppresses radial (polycrystalline) growth of calcite crystals. This induces, in stationary conditions, transformation of the straw into parallel, twinned calcite crystals stacked to form a pyramidal stalactite with rhombic cross sections and an overall tapering angle of <2°. In the most extreme cases, the soda straws are gradually transformed into a seemingly square monocrystalline parallelepiped. The necessary boundary conditions involve a non-stationary distribution of always scarce supersaturated/undersaturated flow over the soda straw, alternating with periods of simple saturation. The controlling factor for the development of conical, pyramidal, and parallelepiped stalactites seems to be the tapering angle. This just outlined genetic mechanism is speculative and should be experimentally tested. Finally, in the few collected samples of the square straws, this shape is often masked by another development step, which probably became active when they were already broken. This final stage was characterized by a sudden increase in supersaturation of epitaxial water, which induced the deposition of a thin layer of polycrystalline calcite that masks, at least partially, the monocrystalline structure of the speleothem.

A cave monitoring program of three caves in southeastern West Virginia, USA, was undertaken from September 2011 to December 2013. Culverson Creek Cave, Buckeye Creek Cave, and Lost World Caverns were continuously monitored for temperature and relative humidity, revealing a highly-stable environment year-round. The caves were visited approximately every three months during the study period, when discrete CO2 measurements were taken, revealing a seasonal ventilation cycle characteristic of temperate-region caves. Dripwaters from 12 sampling stations were collected throughout the first year, from which the isotopic results show the relationship between cave dripwaters and meteoric precipitation. Two sampling periods, those of March 2012 and October 2012, were distinctly different than most of the other isotope values that fell on, or very near, the Global Meteoric Water Line (GMWL). The March 2012 dripwater isotopes were very negative, resulting from several days of heavy meteoric precipitation preceding the collection time that likely pushed water through the vadose zone that had accumulated in the previous winter months. The October 2012 samples displayed a positive linear trend, falling to the right of the GMWL, indicating that those samples were comprised of waters with evaporative loss. Drip frequency loggers placed above the cave allow a direct comparison between surface precipitation and six cave drip-frequency loggers, placed strategically throughout the study caves. These frequency data help to characterize the drips, where one was shown to be highly responsive and underwent flow-switching. Two are shown to have a seasonal-response and three demonstrated no response, characteristic of slow seepage flow. Stalagmites formed as a result of the latter are generally regarded as the most suitable for long-term paleoclimate studies. Monitoring programs performed prior to stalagmite collection for paleoclimate reconstructions could aid in the selection of suitable samples, thereby preserving priceless cave formations, as well as aiding in the interpretation of geochemical proxy variations in speleothem calcite.

The nature and controls of orbital-scale climate variability in North America (NA) are subjects of ongoing debates. On the basis of previous cave records from Southwestern United States, two mutually incompatible hypotheses have been proposed. One links NA orbital-scale climate variability to Northern Hemisphere (NH) summer insolation forcing in a manner analogous to low-latitude monsoon systems, while the other suggests that it is not causally tied to either changes in global ice-volumes or NH summer insolation. Here we report new cave oxygen isotope (delta O-18) records from Buckeye Creek Cave (BCC), West Virginia, east central North America, covering most of the past three glacial-interglacial periods (similar to 335 to 45 kyr ago). The BCC delta O-18 record exhibits a strong precession-band cycle, which is in-phase with changes in global ice-volumes (i.e., sea level), sea surface temperatures in the NE Gulf of Mexico and is consistent with the results from published cave records from Nevada and Devils Hole. As with global ice-volume, the BCC records lag summer insolation at 65 degrees N by similar to 5000 yr, which stands in contrast with records of low-latitude monsoon variability in South America and Asia, which are in phase and out-of-phase with changes in summer insolation and sea level, respectively. Provided the degree of lag to summer insolation provides a measure of competing forcing from global ice-volume and summer insolation, our data suggest that NA orbital-scale climate variability is dominantly driven by ice-volume forcing. In addition, the sea surface temperatures in the NE Gulf of Mexico and changes in northern high-latitude cryosphere may be also important in explaining the unusually low delta O-18 values at times of the intermediate ice-volume periods in BCC and other NA cave records. (C) 2019 Elsevier B.V. All rights reserved.

A cave monitoring program of three caves in southeastern West Virginia, USA, was undertaken from September 2011 to December 2013.Culverson Creek Cave, Buckeye Creek Cave, and Lost World Caverns were continuously monitored for temperature and relative humidity, revealing a highly-stable environment year-round.The caves were visited approximately every three months during the study period, when discrete CO 2 measurements were taken, revealing a seasonal ventilation cycle characteristic of temperate-region caves.Dripwaters from 12 sampling stations were collected throughout the first year, from which the isotopic results show the relationship between cave dripwaters and meteoric precipitation.Two sampling periods, those of March 2012 and October 2012, were distinctly different than most of the other isotope values that fell on, or very near, the Global Meteoric Water Line (GMWL).The March 2012 dripwater isotopes were very negative, resulting from several days of heavy meteoric precipitation preceding the collection time that likely pushed water through the vadose zone that had accumulated in the previous winter months.The October 2012 samples displayed a positive linear trend, falling to the right of the GMWL, indicating that those samples were comprised of waters with evaporative loss.Drip frequency loggers placed above the cave allow a direct comparison between surface precipitation and six cave drip-frequency loggers, placed strategically throughout the study caves.These frequency data help to characterize the drips, where one was shown to be highly responsive and underwent flow-switching.Two are shown to have a seasonal-response and three demonstrated no response, characteristic of slow seepage flow.Stalagmites formed as a result of the latter are generally regarded as the most suitable for long-term paleoclimate studies.Monitoring programs performed prior to stalagmite collection for paleoclimate reconstructions could aid in the selection of suitable samples, thereby preserving priceless cave formations, as well as aiding in the interpretation of geochemical proxy variations in speleothem calcite.

Rock-inhabiting fungi were isolated for rock walls in Golubinka and Medova Buža littoral anchialine caves in Croatia and tested for their halotolerance. Isolates were identified as Cladosporium psychrotolerans, C. delicatulum, Mucor circinelloides, Rhizopus stolonifer, Aureobasidium pullulans var. pullulans, and Talaromyces diversus. Of them, T. diversus appears most resistant to cosmotropic (NaCl) and chaotropic (KCl) salts. It was also the most common species isolated from rock walls. Despite the negative influence of salinity on acid production, we propose that some fungal strains can be recognized as active agents in carbonate dissolution and as good competitors on rocks in saline environments. Anchialine caves can be a refugium for unique halotolerant fungi.

The Buckeye Creek watershed is a 14 km2 enclosed basin of which 12 km2 drains through Buckeye Creek Cave to lower Spring Creek. The 1.6-km long stream passage is generally 6+ meters wide and 3+ meters high with the primary restrictions being the Gray Canyon near the entrance and partially flooded sewer passages near cave’s downstream terminus. The passages below Turner Avenue are large trunks that are connected to the present stream passage by collapse features and solutional passages that may be remnant phreatic loops. Buckeye Creek grades to Spring Creek and the modern cave stream generally follows strike. The highest passages in Buckeye Creek Cave are at least 788,000 years old based on magnetic reversals found in cave sediments. Buckeye Creek Cave is being enlarged by corrosion, but abrasion and quarrying also play important roles. The abrasion is accomplished by sediment transported during floods. Three stalagmites were used to study local climates over the past 7,000 years. The most detailed time series record multiple dry periods lasting centuries. The “droughts” coincided with Bond Events, which were episodic periods of enhanced ice-rafting in the North Atlantic Ocean believed to have been triggered by protracted cooling.

Surface channel incision rates are of broad geomorphological interest because they set the boundary conditions for landscape change by affecting changes in local relief and hillslope angles. We report groundwater table lowering rates associated with subsurface Buckeye Creek and the surface channel of Spring Creek in southeastern West Virginia, USA. The mountainous watersheds have drainage areas of 14 km2 and 171 km2, respectively. The lowering rates are derived from U/Th-dating of stalagmites and the paleomagnetostratigraphy of clastic sediments in Buckeye Creek Cave. The oldest stalagmites have a minimum age of 0.54 Ma and we use a minimum age of 0.778 Ma for clastic cave sediments deposited during a period of reversed magnetic polarity. The water table at Buckeye Creek has lowered at a rate of ≤40 m Ma-1. Based on the relative elevations of Buckeye and Spring creeks, the water table at Spring Creek has lowered at a rate of ≤47 m Ma-1. These values are consistent with previously published rates obtained from caves in the region, although those rates were reported as surface channel incision rates, based on the assumption local groundwaters drained to the surface channel of interest. However, the rates we report are almost certainly not simple bedrock incision rates because of autogenic processes within the cave and surrounding, well-developed fluviokarst. Caveats aside, incision rates of ≤47 m Ma-1 now appear typical of landscapes of the Appalachian Mountains and Plateau.

Speleothems are important paleoclimate archives. Researchers typically compile measurements of stable isotopic ratios dated using high precision U-Th radiometric techniques to reconstruct regional and global climate. Magnetic material incorporated within speleothems can provide an independent means of connecting large-scale climatic changes with their impact on more localized processes in soils overlying cave systems. Under certain environmental conditions, pedogenic processes can produce magnetite nanoparticles. Enhancement of pedogenic magnetite in soil profiles depends strongly on local precipitation. Pedogenic magnetite can be subsequently transferred via drip-waters into underlying cave-systems and incorporated into speleothems as they grow. Here, we employ high-resolution magnetic methods to analyze a well-dated stalagmite from Buckeye Creek Cave, West Virginia (USA), and find that changes in magnetite concentration follow both changes in stable isotopes measured in the same stalagmite and global climate proxies. We interpret the changes in magnetite concentration as reflecting variations in local pedogenic processes, controlled by changes in regional precipitation. This record demonstrates how magnetic measurements on speleothems can constrain interpretations of speleothem climate proxies.

Long-term, high-resolution stalagmite carbon and oxygen isotope records from eastern North America (ENA) provide a midlatitude history of relative changes in moisture availability and climate states during the last interglacial and glacial inception (127.7 to 41.6 ka before present). The West Virginia carbon record shows low-amplitude variability at orbital time scales, superimposed on a long-term asymmetric pattern similar to global sea level changes. Relative moisture availability peaked at similar to 114 ka, and following a brief dry interval at similar to 96 ka, moisture availability gradually decreased. The almost linear change in moisture availability over ENA may reflect gradual changes in midlatitude zonal circulation as the polar cell and Laurentide Ice Sheet expanded or decreased. In contrast, our oxygen record is precession modulated and in phase with spring insolation, perhaps due to changes in precipitation seasonality. The separate pacings by eccentricity (carbon) and precession (oxygen) expose an underlying complexity that will be a challenge to explain.

A 100-year flood on the Cheat River in January 1996 left sandy deposits less than 0.5 in below high-water marks indicated by flotsam and erosional trim lines. This relatively close match suggests slackwater deposits in Appalachian canyons have good potential as paleostage indicators that may allow regional flood records to be extended back several centuries. The accuracy of the stage record varies with landscape position; deposits in caves and on sheltered terrace surfaces are closer to high-water marks than deposits at tributary mouths, floodplain obstructions, or recesses along channel margins. The good match between slack-water deposits and high-water marks from the 3350 m(3)/s 1996 flood contrasts markedly with the poor match found after an extraordinary (>500 year) 5380 m(3)/s flood in November 1985. The 1985 flood stage was so much higher than floodplain and terrace surfaces that it lapped upon steep colluvial slopes, well above minor fluvial landforms favorable to deposition. Accordingly, depositional evidence of moderate paleofloods in Appalachian canyons may have greater preservation potential than evidence of extreme floods. All slackwater deposits in humid climates are vulnerable to post-flood modification, including those formed in caves. Those in canyon reaches are particularly vulnerable in the face of the construction and maintenance of transportation corridors. Reconstruction of long-term Appalachian flood chronologies based on slackwater deposits will require careful planning, detailed air-photo interpretation, and substantial fieldwork, including more studies documenting the relationships between high-water marks and stage indicators left by other floods on other rivers in the region.

We compare micro-charcoal abundances in laminated cave-stream sediments to the presences of Native Americans and later settlers in the same watershed. Samples were obtained from a core taken from a 2.5 m high point bar located 1 km inside of Buckeye Creek Cave, West Virginia. Thirty-three subsamples were treated with hydrogen peroxide to bleach or whiten non-charcoal organic matter. In the absence of opaque mineral grains, this technique creates a large visual contrast between dark charcoal grains and other substances. The subsamples were photographed using a microscope-mounted camera, and pixels darker than 99/255 (grayscale) were used to calculate charcoal concentrations. The record spans the last 6,000 years, and four of the five highest charcoal concentrations are from the last 2,000 years. The highest concentration is from AD 1093, and the second-highest concentration is from the nineteenth century. Post-Colonial settlers began making extensive use of the watershed sometime in the eighteenth century and may, therefore, be responsible for the second-highest charcoal concentration. However, archaeologists independently concluded that Native Americans made peak use of the watershed between AD 1000 and 1200, which coincides with the highest charcoal concentration in the record. Native Americans are known to have extensively used fire, so there is good circumstantial evidence tying high concentrations in the last 2,000 years to human activities. Our method is suitable for use elsewhere, and we present a detailed statistical analysis of our data as a guide toward interpreting charcoal concentrations in karst and non-karst deposits.