| National
Significance |
Most
boxwork of any known cave, most complex 3D rectilinear maze cave (network
maze), fourth longest cave in the world, one of the most diverse mineralogical
and speleothem assemblages and one of the largest barometric wind
caves in the United States. |
|
| Rock
Formation |
Madison
(deposited during the Mississippian, 340-330 million years ago - locally
called Pahasapa limestone), 275-325 feet (84-99 m) thick in the park. |
| Dip
of Madison Formation |
Beds
dip 4-5.5° to S 50° E. |
| Strike
of Cave |
The
cave strikes at N 52° E. |
| Cave
Boundaries |
Cave
is within a 1.1 by 1.3 mile rectangle (370.4 ha) on the surface. |
| Length
of Surveyed Cave |
121.25
miles (195.13
kilometers). |
| Deepest
Point Surveyed |
The
Lakes are 654 feet (199.3 m) below the highest point in the cave. |
| Maximum
Relief at One Point |
~250
feet (76.2 m) through multiple levels near the south end of Half Mile
Hall. |
| Elevations |
Natural
Entrance 4084 feet (1244.8 m) , Elevator Building 4059 feet (1237.2
m), Garden of Eden level 3940 feet (1200.9 m), Assembly Room level
3863 feet (1177.4 m). |
| Paleokarst |
Original
caves and sinkholes (karst) developed in Mississippian times (320-310
million years ago) in a fresh/salt water mixing zone. Filled
with Minnelusa sediments (red sand, silt, clay, and fragments of limestone,
sandstone or chert) during Pennsylvanian times (310 million years
ago). Deepest penetration seen in the cave is the upper-middle
level at the Beauty Parlor, ~150 feet (46 m) of vertical relief. |
| Major
Cave Development |
Probably
during Paleocene-Eocene times (40-50 million years ago), definitely
after Laramide uplift of Black Hills (60-70 million years ago). Cave
developed along gypsum deposits and paleokarst zones. |
| Upper
Level of Cave |
80-130
feet (24.3-39.6 m) thick. It is near the chert layer and is
characterized by smooth rounded walls and ceilings and domes, boxwork
is rare, paleofill common, corrosion residue and fossils common. |
| Middle
Level of Cave |
100-120
feet (30.4-36.5 m) thick and divided into three sublevels. It
is below the chert layers and is characterized by boxwork, wide and
irregular passages, frostwork, and bedded limestone. Upper middle
has nodules of chert, poor boxwork, crumbly bedrock, zebra rock, spar-filled
vugs, and fossils. The middle has very well developed boxwork,
lots of moonmilk, chert is rare, and low wide passages. Lower
middle has a <¼ inch (6 mm) coating on everything with hard hollow
floors. |
| Lower
Level Cave |
65-100
feet (19.8-30.4 m) thick. Characterized by canyon or fissure
passages with thick coatings on everything, also with false floors
and large vugs. |
| Cave
Sediment Dating |
0.9-2
million years based on paleomagnetic dating in a 30 foot section of
loose, bedded sediments exposed at Selenite Avenue. |
| Draining
of Cave |
Water
stagnant from 40 million to 0.5 million years ago. Cave started
draining as a backwater around 470,000 years before present (based
on crust dating). Drained down to Boxwork Chimney 250,000 years
ago, draining at a rate of 1.3 feet (.4 m)/1000 years. Began
draining from base of Boxwork Chimney by 155,000±18,000 years ago.
Lakes were 60 feet above current level 1,500 years ago (based on calcite
raft dating). |
| Water
Flow into Walk-in Entrance |
1-2
feet (.3-.6 m) deep from a May 19, 1982 rainfall event. It ponded
at the low spot between the North Room and the first transformer. |
| Presence
of Water |
11%
of survey stations have some form of water nearby, mostly under surface
drainages. |
| Running
Water |
What
the Hell Pool started running in 1996 and Rebel River, both in the
Lakes section. |
| Large
Lakes |
Phantom
(McDonald's Wind River?), and Windy City Lake (Calcite, Transition,
Jim-Bob's Plunge and Lovely Little Lake have merged with the rising
water table and Windy City Lake to form one large lake). |
| Elevation
of Lakes |
3630
feet (1106.4 m). |
| Losing
Streams in Park |
Beaver
and Highland Creek average a combined loss of 2,514,240 gallons (9,554,112
liters) per day. |
| Lake
pH and Temperature |
pH
if 7.7-8.35, while temperature is 56.7-57.2° F (13.7-14.0° C). |
| Cave
Lake Water |
Local
artesian water that has cooled and degassed in the cave. Saturated
in terms of calcite. |
| Dye
Traces |
Various
traces ranged from 6 hours (south end of parking lots to Minnehaha
Falls), to 2 months (picnic ground to Minnehaha Falls), to 1½ years
(south end of parking lot to Assembly Room), to a long trace of 4½
years (gully SW of parking lot to Pop Secret). |
| Types
of Cave Minerals |
Calcite,
aragonite, hydromagnesite, gypsum, selentie, magnesite, quartz, manganese
oxides, hematite, geothite, huntite, mirabalite, romanichite, ice. |
| Cave
Sediment (Minerals/Rocks) |
Quartz,
calcite, mica, feldspar, tourmaline, hematite, gypsum, hornblende,
quartzite, arsenic, illite, kaolinite chlorite, Deadwood siltstone,
Minnelusa shale, precambrian schist. |
| Flowstone/Dripstone
Distribution |
5%
of survey stations have flowstone or dripstone near them. Of these,
83% are in the upper level. |
| Wall
Crusts |
Subaqueous
deposits 2-3 cm thick in lower levels. Deposited as waters receded. |
| Unusual
Formations |
Boxwork,
helictite bushes, quartz rinds, logomites, hydromagnesite ballons,
dogtooth and nailhead spar, quartz, christmas trees, button popcorn,
sawtooth flowstone, gypsum luster, flowers, starbursts, and hair and
conulites. |
| Biggest
Earthquakes Heard |
January
27, 1990 - 3.9 Richter scale, heard but not felt in the cave, 10 second
rumble. August 6, 1999 - 3.0 Richter scale, heard for 3-5 seconds
but not felt in the cave, rolling thunder-like sound. |
| Cave
Volume of Surveyed Passage |
39,110,000
ft³ (1,107,467 m³)(based on a average passage size, 2% of Conn's total
volume estimate). |
| Volume
of All Cave |
Herb
Conn estimated total cave volume of 2 billion ft³ (55 million m³)
based on airflow. |
| Barometric
Winds |
>75
mph (120 kph) is highest recorded measurement at Walk-In Entrance
before revolving door was installed. The highest recorded measurement
at the Natural Entance was 25 mph (40 kph). North Room 0.28-1.75
mph (.5-2.8 kph) (March-August 1985). |
| Air
Exchange |
Average
of 1,000,000 ft³ (28317 m³) of air from cave exchanged with the surface
each hour. |
| Effects
of Air Exchange |
Warm
summer air cools and water condenses on walls. Cool, dry winter
air warms up and evaporates water. When the cave is expelling,
16.1 gallons (73.2 liters) of water is lost per hour out the natural
entrance. |
| Temperature |
53°
F (11.7° C). Varied 12° F from entrance to Post Office before
revolving door. Mean annual surface temperature is 47° F (8.3°
C) for the area. It is theorized that the cave is heated from
below by geothermal gradient. |
| Radon |
0.23
working levels, average between May and August. Varies between
0.27 and 0.34 between October and November. |
| Faunal
Remains |
Bison,
elk, frog, woodrat and bat from Chamber of Lost Souls - undated remains.
Bat and woodrat bones found scattered around the cave. |
| Biota
(near entrances) |
Bats,
bushy-tail woodrats, deer mice, tiger salamanders, frogs, rattlesnake,
bullsnake, milksnake, earthworms, camel crickets, beetles, spiders,
ant lions, flies, springtails, nematodes, mites, microbes, fungi (12
genera), protozoa and bacteria. |
| Dark
Zone Cave Biota (near trails) |
Nematodes,
springtails, mites, microbes, bacteria and fungi. |
| Dark
Zone Cave Biota (far from trails) |
Springtails,
mites, protozoa, bacteria, and fungi. |
| Bat
Species |
Myotis
ciliolabrium (small-footed myotis), Eptesicus fucus (big brown);
Myotis volan (long-legged),
Myotis lucifugus (little brown),
Myotis subulatus (small-footed), Myotis thysanodes (fringed-from
Coyote Cave), Corynorhinus townsendii (Townsend's big-eared). |
| Cave
Adapted Species |
Springtails
(collembolas, Arrhopalites caecus and Onchopodura curveseta). |
