>From an archaeology mail list:
Jewel Cave NM Celebrates Centennial On February 7, 1908, President Theodore Roosevelt signed a proclamation that established Jewel Cave NM under the authority of the 1906 Antiquities Act. The monument was established to protect the small, but extraordinarily beautiful cave, which is known for the jewel-like calcite crystals that line the cave walls. Jewel Cave has the most extensive known collection of different types of calcite crystals. The most abundant formations are called dogtooth spar and nail-head spar. Helictites twist and turn as though they were formed in a chamber without gravity. Another formation, called popcorn, grows in small knobby clusters. Veins of calcite deposited in a crisscross pattern are called boxwork. Frostwork, needle-like formations of calcite or aragonite, is as delicate as blown glass. Some formations are translucent, formed of pure calcite. Other crystals contain additional minerals and appear yellow, red, or opaque white. Individual crystals range in size from a grain of rice to a goose egg. When Jewel Cave NM was proclaimed in 1908, less than half a mile of cave had been discovered. Currently, Jewel Cave is the second longest cave in the world, with a current length of over 141 miles. Exploration continues to reveal the hidden miles of passages beneath the Black Hills, South Dakota. Beginning in the 1950s, explorers Herb and Jan Conn mapped over 62 miles of cave passages. Jewel Cave NM will celebrate its centennial through a series of events, programs, and exhibits that will highlight the theme "Generations of Discovery.�? The centennial celebration will formally begin on February 9, 2008, in the visitor center of the monument with a special program to commemorate the anniversary. Honored guests and former cave explorers Herb and Jan Conn will present a program on their 21 years of exploration as they mapped over 60 miles of cave passages, beginning in 1959. The caving parties led by this husband-and-wife team made 708 trips into the cave and logged 6,000 hours of exploring and mapping. A new generation of cavers has continued to push the known boundaries of Jewel Cave, but the mystery of its magnitude remains. As the Conns once said, âWe are still just standing on the threshold.�? Other special guests will join the Conns for this celebration, which will kick off a series of monthly programs focusing on a variety of topics related to the past, present, and future of Jewel Cave. For more information about Jewel Cave go to www.nps.gov/jeca/index.htm (From contributions by Eric Peterson on www.howstuffworks.com/) --------------------------------------------------------------------- Visit our website: http://texascavers.com To unsubscribe, e-mail: texascavers-unsubscr...@texascavers.com For additional commands, e-mail: texascavers-h...@texascavers.com