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词条 Natural Bridge Caverns
释义

  1. History

  2. Further exploration

     Recent exploration 

  3. Passages renamed

  4. Wildlife

     White nose syndrome 

  5. Natural Bridge Caverns Sinkhole Site

  6. Gallery

  7. See also

  8. References

  9. External links

{{Infobox Protected area
| name = Natural Bridge Caverns
| iucn_category =
| photo = Natural_Bridge_Caverns_Logo.jpg
| location = Comal County, Texas, United States
| nearest_city = San Antonio
| coordinates = {{coord|29|41|31.16|N|98|20|34.26|W|format=dms|display=inline,title}}
| established = July 3, 1964
(Discovered in March 1960)
| visitation_num =
| visitation_year =
| governing_body =
| embedded1 = {{designation list | embed = yes
| designation1 = NNL
| designation1_date = 1971
|website=https://naturalbridgecaverns.com}}

The Natural Bridge Caverns are the largest known commercial caverns in the U.S. state of Texas. The name[1] is derived from the 60 ft natural limestone slab bridge that spans the amphitheater setting of the cavern's entrance. The span was left suspended when a sinkhole collapsed below it.

The caverns are located near the city of San Antonio, Texas in the Texas Hill Country next to the Natural Bridge Wildlife Ranch, a drive-through wildlife safari park. The caverns feature several unique speleothems and other geological formations. The temperature inside the cave is 21 degrees Celsius (70°F)[2] year-round and the humidity rate is a constant 99 percent. The deepest part of the public tour is 180 feet below the surface, although undeveloped areas of the cavern reach depths of 230 feet.

The caverns are still slowly developing. Due to the porosity of the limestone, rainwater travels downwards through the layers of rock, where it dissolves out calcite, a weak mineral that makes up all of the speleothems at Natural Bridge Caverns. After exiting the limestone, water enters the caverns where it flows and drips constantly throughout, causing the formations to retain a waxy luster that can be seen in few caverns.

History

The caverns were discovered on March 27, 1960, by students Orion Knox Jr., Preston Knodell Jr., Al Brandt and Joe Cantu[3] from St. Mary's University[4] in nearby San Antonio. On their fourth trip into the caverns, the men discovered/explored just over a mile of passage. Subsequent explorations revealed 2 miles associated with what became known as the "North Cavern."

After discovery, Orion Knox Jr. assisted the landowners in obtaining information and suggestions for development. Mrs. Clara Wuest[5] (the landowner), wanted to show the world the cave under her property. Orion approached both the National Park Service and the Texas Park System. While both entities agreed that the cavern was substantial and merited development, both groups told the landowners that funds did not exist for their respective groups to undergo such an endeavor.

Mrs. Wuest then decided that she would fund development.[5] Orion dropped out of school to assist. He also approached Jack Burch who had just finished work on developing the Caverns of Sonora near Sonora, Texas. Jack agreed to help and development began early in 1963. Mrs. Wuest remarried Harry Heidemann, a retired Texas Highway Patrolman in the early 1960s. Together, they started work on developing the cavern. The full-time development crew included Mrs. Wuest-Heidemann, Mr. Heidemann, Jack Burch, Orion Knox, and Reggie Wuest (Mrs. Wuest-Heidemann's son).[3] Development on the cavern began in 1963 and work on lights and trails continued until opening day, July 3, 1964.[6] The cavern has been opened ever since and is still owned and operated by family members. Natural Bridge Caverns became a registered United States National Natural Landmark in 1971.[7]

During excavation of the entrance trail, a human tooth, arrowheads, and spearheads dating from 5,000 BC were found. Also, just inside the entrance, a jawbone and femur from an extinct species of black bear were discovered. This leads many to believe that uppermost areas of the cavern were used as a shelter by early peoples and animals at some point. An archaeological dig was recently done under the natural bridge. Archaeologists recovered arrow heads and other tools which further indicate the presence of early peoples at some point in history.

Further exploration

In 1967, speculation on a southern extent to the North Cavern was confirmed when test drilling indicated the presence of a large void approximately 90 feet beneath the surface. A camera was sent down the narrow shaft and photographs revealed a large chamber filled with formations. This original shaft was reamed out to 22 inches and three men were lowered into the ground. They discovered a large breakdown chamber and numerous formations. The first three men to enter this room were Jack Burch, Reggie Wuest, and Myles Kuykendall. By combining the first two letters of each man's first name, they arrived at JAREMY, and thus this newly discovered room was called the Jaremy[8] Room.

Further investigation near the bottom of the Jaremy Room revealed a strong likelihood that another passage existed beyond a pile of rocks and boulders. In 1968 the drillers were once again brought out to the property and another exploratory shaft was sunk into the ground.[3] This shaft also penetrated a large void approximately 150 feet below ground. As before, the initial shaft was enlarged and people dropped down into the unknown. Explorations revealed another half-mile of cavern extending to the south. This then became known as the South Cavern.

Recent exploration

Exploration continues to date.[9] During the summer of 2005, several hundred feet were added to the current surveyed length of the cave. It is believed that as much as another mile could be added to the survey by just mapping the known passages which have not yet been surveyed. Additional unexplored leads exist in sections of the Discovery Passages (North Cavern).

Passages renamed

In 2008, the Caverns' owners changed the names for the passages.[3] The "North Cavern" was changed to "Discovery Passages," and the "South Cavern" was changed to "Hidden Passages." According to the land owners, the change in names better reflects the discovery and exploration history of the cavern and removes some confusion for guests.

Development for new tours continues.

Wildlife

There is recent evidence of bats residing in Natural Bridge Caverns including roosting areas and accumulation of bat guano. Bracken Cave, near Natural Bridge Caverns is home to one of two large bat colonies in Texas. The bats that inhabit Bracken Cave are a small species called Mexican free-tailed bats. Bats control the insect population, help to pollinate plants, and are a food source for other animals, making them a valuable part of the ecosystem. The cave was the focus of a 2013 episode of the syndicated anthology television series, Texas Country Reporter, hosted by Bob Phillips.[10]

White nose syndrome

Recently it has come to the attention of conservationists that there is a disease called white nose syndrome affecting bats in North America. Little is known about the disease however it is having devastating effects on at least six species of bats. Natural Bridge Caverns has partnered with Bat Conservation International in an effort to combat the disease. Together they raise money for research and also attempt to raise awareness about WNS.

Natural Bridge Caverns Sinkhole Site

{{Infobox NRHP
| name = Natural Bridge Caverns Sinkhole Site
| nrhp_type =
| location = {{Address restricted}}, Natural Bridge Caverns, Texas
| added = October 29, 2004
| area = less than one acre
| refnum = 04001202[11]
}}

Located on the property is the Natural Bridge Caverns Sinkhole Site, an archeological site listed on the National Register of Historic Places. The location of the site is not publicly disclosed in order to preserve artifacts in their context for ongoing research.

Gallery

See also

{{Portal|NRHP|Texas}}
  • National Register of Historic Places listings in Comal County, Texas
  • List of National Natural Landmarks in Texas

References

1. ^{{cite book | last = Cooke | first =Paul | title =Natural Wonders of Texas | publisher =Country Roads Press | year =1995 |page=175 | isbn = 978-1-56626-109-8}}
2. ^{{cite journal |last1=Sharpe |first1=Patricia |last2=Thompson |first2=Helen |year=1985 |title=Around the State |journal=Texas Monthly |publisher=Texas Monthly |volume= |issue=August 1985 |pages=22 |url= |doi= }}
3. ^{{cite book | last = Pittman | first =Blair | last2=Abernethy | first2=Frances Edward | title =Texas Caves | publisher =TAMU Press | year =2000 |pages=65–77 | isbn = 978-0-89096-899-4}}
4. ^{{Cite web | title=Natural Bridge Caverns Discovery | publisher=Texas Historical Marker | url=http://www.9key.com/markers/marker_detail.asp?atlas_number=5091003552 | accessdate=11 May 2010 | deadurl=yes | archiveurl=https://web.archive.org/web/20110313000300/http://www.9key.com/markers/marker_detail.asp?atlas_number=5091003552 | archivedate=13 March 2011 | df= }}
5. ^{{Cite news |title=50 years since discovery of largest-known caverns in Texas |author=George, Patrick J |date=23 March 2010 |newspaper=Statesman |url=http://www.statesman.com/news/local/50-years-since-discovery-of-largest-known-caverns-425529.html?printArticle=y |accessdate=11 May 2010 |archive-url=https://web.archive.org/web/20110607062146/http://www.statesman.com/news/local/50-years-since-discovery-of-largest-known-caverns-425529.html?printArticle=y |archive-date=2011-06-07 |dead-url=yes |df= }} Statesman
6. ^{{Handbook of Texas | name=Natural Bridge Caverns| id=rqn01| retrieved=11 May 2010}} Texas State Historical Association
7. ^{{Cite web|url=https://www.nps.gov/subjects/nnlandmarks/site.htm?Site=NABR-TX|title=National Natural Landmarks - National Natural Landmarks (U.S. National Park Service)|website=www.nps.gov|language=en|access-date=2019-03-30|quote="Year designated: 1971"}}
8. ^{{Cite web |title=Jaremy Room | publisher=Show Caves | url=http://www.showcaves.com/english/usa/showcaves/NaturalBridgeTX.html | accessdate=11 May 2010}}
9. ^{{Cite news |title=50 years of Natural Bridge Caverns |author=Weilbacher, Eric J |date=27 March 2010 |newspaper=The Herald-Zeitung |url=http://herald-zeitung.com/story.lasso?ewcd=46cd78773ecd5351 |accessdate=11 May 2010 }}{{dead link|date=February 2018 |bot=InternetArchiveBot |fix-attempted=yes }} The Herald-Zeitung
10. ^{{cite web|url=http://www.naturalbridgecaverns.com/(S(2wlp3cibtcnuiw45bfxdvp2x))/whiteNoseSyndrome.aspx|title=Natural Bridge Caverns is going bat for the bats|publisher=naturalbridgecaverns.com|accessdate=July 19, 203|archive-url=https://web.archive.org/web/20101126082050/http://www.naturalbridgecaverns.com/whiteNoseSyndrome.aspx|archive-date=2010-11-26|dead-url=yes|df=}}
11. ^{{NRISref|version=2010a}}

External links

{{commons category|Natural Bridge Caverns}}
  • Natural Bridge Caverns official website
  • {{Handbook of Texas|id=rqn01|name=Natural Bridge Caverns}}
{{National Natural Landmarks in Texas}}{{NRHP in Texas}}{{Comal County, Texas}}

8 : Caves of Texas|Natural arches of Texas|Landforms of Comal County, Texas|National Natural Landmarks in Texas|Show caves in the United States|Tourist attractions in San Antonio|Tourist attractions in Comal County, Texas|Texas Hill Country

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