From the Land Down Under - Caves
[continued from previous page] Over the past few years, Deanna has managed a Southern Nevada Public Land Management Act project; Mine Gates, Inc. was contracted to complete 20 cave assessments. The Act allows the BLM to sell land in Clark County and use the revenue for projects in a wide variety of categories (learn more at http://www.blm.gov/pgdata/detail/htnf/home/?cid=nv/en/snplma.html).
The cave contractor identified cultural, biological, geological and paleontological resources in completing those cave assessments. Along the way, Mine Gates, Inc., discovered and mapped 36 additional caves and identified 60 leads for future exploration.
"Cave and Karst (landscapes characterized by caves, sinkholes, sinking streams and underground drainage) resources are important because they support critical groundwater systems," explained Deanna. "These groundwater systems supply drinking water to communities, provide habitat for rare biological communities, offer recreation for people who enjoy exploring the underground world, and furnish a natural setting for scientific study and environmental education," stated Deanna.
Caves also preserve the remains of our prehistoric and historic past, as well as contain data relevant to significant geologic events, climate change, and much more.
And just what is new lurking underground that we didn't know about a year ago in Nevada? “We actually found three caves with an undescribed troglobitic flatworm, two undescribed troglobitic millipedes, and a possible new species of troglobitic pscopteran and sabaconid harvestman," said Deanna.
Say what? "Exactly what they sound like, cave species of flatworms - troglobitic just means these live entirely in the dark parts of caves," said Deanna.
"One cave also contains possible world-class examples of a rare cave formations, called speleothems, including folia, hydromagnesite balloons, and radial anthrodites," said Deanna.
Folia are found on ceilings and walls, develop as water lowers, depositing more calcite underneath, creating a flat surface (photo 1 of 5 in photo gallery). It’s also possible that carbon dioxide is trapped in the ribs of the flat surface and invites calcite deposits on the cave ceilings and walls.
Hydromagnesite balloons are rare, resemble small gas-filled balloons, and are usually made of hydormagnesite (photo 3 of 5 in photo gallery). The balloons probably form when solutions under pressure seep into a cave through cracks or out of porous walls of limestone. If the solutions combine with moonmilk, a highly plastic material, the material may expand like a balloon. The thin moonwalk coating, which forms the cast, may crack or dry out, exposing the underlying hydromagnesite balloon.
Anthodites are composed of long needle-like crystals, arranged in clusters, which radiate outward from a common base (photo 2 of 5 in photo gallery). The needles may be quill-like or feathery. Most anthodites are made of the mineral aragonite. Chemistry buffs may be interested that aragonite is a variety of calcium carbonate, such as caco3, although some are composed of gypsum, which is CaSO4·2H2O.
[Access Photo Gallery]
In addition to the rare cave formations and the flatworms, plenty of paleontological resources were discovered during the cave assessment project.
“Paleontology is the study of life forms existing in prehistoric or geologic times, and is represented by plants, animals, or other organisms’ fossils,” said Eric Stever. Paleontological resources in the cave assessments revealed vertebrate fossils of bat, deer mouse, pika, weasel, birds, marmot, rabbit, wolf, chipmunk, mountain sheep, and a shrew.
Dr. Timothy Heaton, University of South Dakota, PhD in Paleontology, collected these fossils and is still working on confirming their types of species. “Our caves’ relatively constant temperatures and humidity’s help preserve organic materials, and are often valuable sources for fossils,” explained Eric.
Eric was also excited about a few cultural and geological discoveries and within the caves. “We found a culturally modified stairway that led up to a small alcove,” said Eric.
He determined the four stairs took advantage of naturally occurring footholds in the cave, but were expanded and deepened either through extensive use or through chipping of the rock. Given the central location of the alcove within the cave, and the visibility from the entrance, it is assumed this stairway served some ceremonial purpose. Two flat rectangular quartzite rocks were also found within the cave, one at the base of the modified stairs. These do not contain visible pigment, show little wear, and are not incised in any way. It is also assumed they are related to the ceremonial use of the cave. All artifacts were left as they were found.
“This may not sound important initially, but a second cave was found to contain a corncob,” said Eric Stever. “This cave was excavated extensively in the 1970s, but did not continue into the less accessible portions of the cave,” he explained.
“The corncob was likely brought there by packrats; however, Fremont villagers in the valley to the east were known to grown corn and to cache excess crops in rock shelters and other protected places,” continued Eric. “Further investigation is warranted to determine the age of the corn, and if the cave represents a granary for the Native Americans,” said Eric.
Protecting these caves and their priceless resources isn’t an easy task. “Some of the threats include population growth, increased water demands, the continuing spread of white-nose syndrome, a fatal disease for bats, and increased mineral exploration,” said Jose Noriega, Ely District Ranger. “It is now even more important to raise awareness about the value of cave and karst resources and the need for active management,” said Noriega.
The white nose syndrome is named for the fuzzy fungus that grows on the bats' nose, mouth, and wings as they hibernate. It has killed more than 5.5 million bats in the United States and Canada since it was first detected in New York in 2006, according to the U.S. Fish & Wildlife Service. It has since spread to at least 21 Eastern states, and fortunately has not affected bats in the Western states. Bats are believed to be the primary vector for the fungus.
Three of the most common bats found on the Humboldt-Toiyabe are: Townsend’s big-eared bat (Corynorhinus townsendii), the Little brown bat (Myotis lucifugus), and the Big free-tailed bat (Nyctinomops macrotis). Learn more by about a great Nevada bat conservation plan by visiting the following website at http://heritage.nv.gov/node/170.
One way to increase awareness about caves and karst systems is through exciting education adventures. BatsLIVE was created for just this purpose by 30 federal, state, and local agencies, educational institutions, and non-governmental organizations in 2012.
This free learning program for 4-to-8 graders and their teachers includes live webinars, free education resources to use to bring bat and cave conservation to life in the classroom, and a live webcast from Bracken Cave (summer home to the largest colony of bats in the world, 20 million from March to October, outside the city of San Antonio in southern Texas). Learn more about this unique classroom opportunity by visiting http://batslive.pwnet.org/.
The Humboldt-Toiyabe National Forest (HTNF) has 32 “significant caves” that were nominated in 1994,plus many others yet to be nominated under The Federal Cave Resource Protection Act of 1988.
Six Ranger Districts on the Forest have known caves: Austin, Tonopah, Mountain City, Ruby Mountains, Ely, and the Spring Mountains National Recreation Area.
Ely, Spring Mountains, and Ruby Mountains have the highest concentrations of caves.
Number of caves existing on National Forests and National Grasslands: 2,200. Those caves cover roughly 205,335 square miles.
Number of bat species in Nevada: 23
Want to know where the caves are? Contact your local National Forest office’s Cave Manager or your local caving group (called grottos). Local grottos for the Humboldt-Toiyabe National Forest include: Southern Nevada Grotto, Northern Nevada Grotto, Silver Sage Grotto (southern Idaho) and Mother Lode Grotto (California). The Federal Cave Resource Protection Act doesn’t allow federal agencies to provide cave locations and names to the public.