NM: EDDY CO.: BIG MANHOLE CAVE, JUST N OF CARLSBAD CAVERN N.P. BOUNDARY; NW1/4 SW1/4 SE1/4 SEC 22, T24S, R24E, 4200'
Entrance to Big Manhole Cave. Photograph by Lauri Bartlema.
General Description.—North of Carlsbad Caverns National Park boundary and less than 4,000 ft from Lecheguilla Cave. Small opening near top center of large chamber; 52-ft drop to floor, where chamber ca. 100 ft in diameter. Floor slopes to near ceiling on one side (collapse feature), otherwise fairly flat.
Comments.—Cavers during Spring 1989 have been digging near one wall at the lowest area of the "flat" floor, having reached about 19-22 ft in clay. Have encountered bones from ca. 14 - 19 feet. Packed in Ziplock bags. Some charcoal associated. Jim Goodbar (Carlsbad BLM) brought the bones to Harris on 15 June 1989. Material to be curated at the Laboratory for Environmental Biology, Centennial Museum.
26 Mar 1993: Visited yesterday by myself and Lauri Lear Bartlema, accompanied by Jim Goodbar et al. Bones mentioned above from the so-called Clay Shaft, also sampled extensively by Safford. Small bones and snails visible. Two other tests had been made by spelunkers: on talus (quickly abandoned) and the Breakdown Shaft. Extensive tunneling from bottom of Clay Shaft, including into dry, fairly non-cemented area (survey point F4-C) where trove of mustelid skulls, etc., came from.
26 Mar 1995: Back from one week of excavation at Big Manhole Cave (18-25 Mar 1995). From information garnered from various people who have worked in Big Manhole Cave, appears the silts and clays began to accumulate following the flowstone cap deposition. That is, that stoping and collapse and deposition of some material occurred, then covered by flowstone. When the flowstone sealed, then silt, etc., trapped by the flowstone and began to build up to the present depth. The mustelid trove noted above is below the flowstone and thus greater than 24,900 and presumably than 30,000 BP. Excavation this past week limited to a pit in presumed Holocene silts above flowstone, reaching a maximum depth of 1.5 m.
Age.—Pleistocene (based on presence of horse); Holocene in pit excavated by Bartlema and Harris.
Publications.—Bartlema 2001; Harris 1993c.
Pleistocene Fauna.—
AVES
Last Update: 4 September 1998.