Quick Facts
- Discovered and explored by G Rankin in 1823
- Opened for public inspection in 1870
- Illuminated with electricity in 1932
- Length: 155 mtrs
- Max height: 22 mtrs
Come on a prehistoric adventure and explore the popular Cathedral Cave. Formed over millions of years, the Cathedral Cave contains arguably the world's largest stalagmite - they're the one's that go up. This inspiring limestone structure reaches a staggering 15 metres in height - that's as tall as a three-story building!
Most of the world's caves occur in limestone. The limestone at the Wellington Caves was created from the deposition of the skeletal remains of marine creatures in the ocean floor, over eons. Eventually, the sea floors were shifted above sea level by the pressures of earth movements - the limestone deposits was once under many kilometres under the ocean.
Upon rising above sea level, the limestone became subject to water erosion. Rainwater seeps through the cracks and joints in the rock. The water from creeks also adds to the underground erosion. As rain falls, it picks up carbon dioxide from the atmosphere, and from the ground. This forms a weak acid (carbonic acid) which causes the continuous breakdown of the limestone rock along the cracks and joints where the water enters. Over many thousands of years passages are worn out within the limestone and these fill with air. On occasions, parts of the ceiling of some tunnels will collapse forming caverns. In broad terms, the Cathedral Cave was formed this way.
Stalactites and Stalagmites
Without doubt, these are the most popular and best known decoratinons in a limestone cave. Stalactites grow down from the ceiling of a cave while stalagmites grow up from the floor. Stalactites are formed from the slow seepage of water throughout the tiny cracks in the limestone, which allows calcium carbonate soloution to form in a drip on the cave ceiling. The particles of calcium carbonate then solidify on the ceiling. This solidified soloution is called calcite. The process continues over thousands of years, slowly forming a stalactite.
Stalagmites are created by faster seepages of calcium carbonate soloution which drip off the ceiling and onto the floor. As each drop solidifies, so the decoration is slowly built up. Stalactites and stalagmites do not grow at the same rate. The rate of seepage can vary widely even within one cave. Therefore, sometimes you will view great stalagmites built up with little or no stalactite decoration above them. The reverse is also often seen.
Just how slow do they grow?
Well, on a very rough average, a stalactite might grow about one cubic centimetre in every hundred years!
Regular guided tours are taken through the Cathedral Cave. Experienced guides will take you through the cave and explain all the interesting phenomenan.