First of all/Warning!

Even the caves are publicity available, there is always the danger of cave ins, rock falls, getting lost and, during rainy weather, slippy ground. You enter the caves at your own risk. If you feel unsafe, there are severals guides who know the caves and can guide you.

On top, there are severals animals living in the caves, so always remember: You are a guest in their home, don't distrub them. It is not neccesary to enter the caves for the EarthCache, but we recommend it. Especially Cave No 1.

When you want to explore the tube, remember wearing footwear and a flashlight.

Lava tubes in Roche Noires

Mauritius belongs to the Mascarene Islands and have been created by vulcanic activity, about 8 million years ago. You can find indication of vulcanic activity almost everywhere and in a lot of different ways. There are many spot on this island, where you can find lava tubes. But in Roche Noires, there is a well preserved tube, which is easy accessible. 

Lava tubes are a special kind of caves. A cave is an naturally spawn hole, formed during a geological process. If humans are involved during the formation, as in living caves, it's not labeled as a cave anymore. You can differentiate caves by many categories, the most common ist the difference between secondary and primary caves. Primary caves develop at the same time as the surrounding rock while sencodary caves develop later, for example during erosion, tectonics or corrosion.

This EarthCache is about the formation of lava tubes, which is a typically indication of vulcanic activities. They can be found on several places in the world, but need some special conditions to develop. The most known and longest tube is located in Hawaii and is more than 65 kilometer long. And this tube is also very young- the age is about 300-500 years. The lava tubes in Mauritius are older, the vulcanic activity is extinct about 20.000-100.000 years ago. There are only sleeping vulcanos left.

Lava tubes can be found anywhere in the world, but they can not develop during any volcanic eruption. The formation relate on the viscosity and the inclination. They often form at eruptions at shield volcanos. For a better understanding of the markings of lava tubes, let's take a closer look on the formation of lava tubes. At the following, you can see a schematic drwaing of the forming of lava tubes. In the blue cube, you can see the profile of the lava flow.

Logging requirements

Your tasks at the main coordinate

1. At the coordinates you'll find a memorial stone. Over the way, stairs are leading to the entrance of a cave. Count the steps from the top to the bottom. (The cave opposide of the memorial stone is ment, not all the steps to Cave No 1)

2. Is a lava tube a primary or secondary cave?

Your task at the entrance to cave #1

3. Lava tubes can't develop everywhere, often near shield volcanos. What do you think, what are the requirements (viscosity [thin and fast flowing or tough and slow flowing?] and the inclination [steep gradient or flat terrain?]) for the formation? Think about, why do they often develop near shield volcanos?

You can log the cache right after you sent us the answer, prefered as mail. Of course we looking forward to see a lot of photos of you, but this is optional.