STALACTITES
& STALAGMITES & COLUMNS
The general term for all
syn- & post-cave formation mineral deposits is speleothem.
Between 200 and 300 different minerals have been reported to occur in various
speleothems around the world. The most common speleothem minerals are
calcite (CaCO3), aragonite (CaCO3), and gypsum (CaSO4·2H2O).
Calcitic speleothem is often given the rock name travertine.
Relatively few speleothems are actively growing in Carlsbad Caverns in modern
times, due to the present dry climate. Available chronologic data has
indicated that most of Carlsbad’s speleothems formed during the Middle and
Early Pleistocene.
Stalactites & stalagmites
are the most commonly encountered speleothem types. They form by dripping
water, and are thus varieties of dripstone. Slowly dripping water
results in large/long stalactites hanging from cave ceilings. Rapidly
dripping water results in large/tall stalagmites projecting upward from cave
floors. Stalactites usually have a hollow central canal through which
water passes. Stalagmites are solid masses.
The physical form of
stalactites & stalagmites varies from nicely conical to irregularly conical
to cylindrical. Narrow, cylindrical stalactites are called soda straws.
If stalactites & stalagmites become physically fused, a column is
formed.
How does dripstone
form? Typically not by evaporation, as is commonly supposed.
Water dripping from cave ceilings is slightly acidic and contains dissolved
ions originating from the partial dissolution of overlying bedrock (typically
limestone). When water emerges from a cave roof, it loses carbon dioxide
gas (CO2), loses acidity, and dissolved ions precipitate
(crystallize) out. The crystals are usually CaCO3.
STALACTITES
All stalactites shown below
are composed of travertine.
Stalactites (dripstone), near Crystal
Spring Dome, eastern side of the Big Room, Carlsbad Caverns, New Mexico, USA.
Stalactites (dripstone), near Rock of
Ages, eastern side of the Big Room, Carlsbad Caverns.
Stalactites (dripstone) (looking upward
at ceiling), Fairyland, western side of the Big Room, Carlsbad Caverns.
Stalactites (dripstone) (looking upward
at ceiling), Fairyland, western side of the Big Room, Carlsbad Caverns.
Stalactites (dripstone), Fairyland,
western side of the Big Room, Carlsbad Caverns.
Stalactites (dripstone), Papoose Room,
King’s Palace Trail, Carlsbad Caverns.
Broken stalactites - naturally broken
stalactites lithified in travertine; near Crystal Spring Dome, eastern side of
the Big Room, Carlsbad Caverns.
STALAGMITES
All stalagmites &
flowstone coverings shown below are composed of travertine.
Stalactite-stalagmite pair (dripstone), near the
Chinese Theater, near northern end of the Big Room, Carlsbad Caverns, New
Mexico, USA.
Stalagmite (dripstone), northwestern
portion of the Big Room, Carlsbad Caverns.
Stalagmite (dripstone), northwestern
portion of the Big Room, Carlsbad Caverns.
Twin Domes - two extremely large stalagmites
in the Hall of Giants area, Big Room, Carlsbad Caverns. They consist of
dripstone (axial portions) and flowstone (flanking portions). The taller
of the two Twin Domes reaches almost 60' above the level of the walking trail.
Stalagmites (dripstone with flanks
covered in flowstone), northwestern portion of the Big Room, Carlsbad Caverns.
Stalagmite (dripstone with flanks
covered in flowstone), a little north of Crystal Spring Dome, eastern side of
the Big Room, Carlsbad Caverns.
Breast of Venus (northwestern wall of the
southern end of the Big Room, Carlsbad Caverns) - mammiform stalagmite
(dripstone), formed by rapidly dripping water. Less rapidly dripping
water results in relatively narrow & tall stalagmites. Very rapidly
dripping water results in relatively wide & low stalagmites.
Stalagmites (dripstone), near Rock of
Ages, eastern side of the Big Room, Carlsbad Caverns.
COLUMNS
All columns & flowstone
coverings shown below are composed of travertine.
Column (dripstone with lower
flanks covered in flowstone), northwestern portion of the Big Room, Carlsbad
Caverns.
Giant Dome (on the right; Hall of
Giants area, Big Room, Carlsbad Caverns) - an extremely large column reaching
62 feet above the level of the walking trail. The column consists of
dripstone in its axial portions and flowstone in the flanking areas. The
two large stalagmites on the left are the Twin Domes.
Column (dripstone), Queen’s
Chamber, King’s Palace Trail, Carlsbad Caverns.
Columns & composite
columns
(dripstone), northwestern portion of the Big Room, Carlsbad Caverns.
Composite column (dripstone), Fairyland, Big
Room, Carlsbad Caverns.
Column (dripstone), Chinese
Theater, Big Room, Carlsbad Caverns.