Cova de Can Marçà [Earthcache]

Attention:
To log this earthcache you have to join a guided tour.
It will take approximately 40 minutes and costs 7€ for children and 11€ for adults.
The tour takes place from May to October (10.00am – 5.30pm every 30 minutes) and from November to April (11.00am – 5.30pm every 45 minutes).

The stalactite cave Can Marçà: An extraordinary place in the north of Ibiza.
I discovered this admirable place during my summer holidays.
The cave is located in Port de San Miguel. From here you have a beautiful view on the bay and on the opposite islands Murada and Ferradura.



History:
The history of this cave is very various although the development is not really known. 70 million years ago, during the Cretaceous period, calcium carbonate (a.k.a. chalk), iron oxide, magnesium and loam sedimented in the shallow and warm water. In the course of time thoseelements got formed by geotectonic and 2 million years ago (during the Quaternary Period) this cave evolved. For geological circumstances, this is a very early time period, which means this cave is still very "young".
Because of the process of becoming a glacier, a.k.a. karst, almost everything is fossilized. Most of the adits and galleries are undamaged and because of drops, beautiful stalactites, stalacmites and pillars developed.
In early times of the present human history, the cave was used by smugglers to hide their goods. They got access to the cave through a small entrance which was 8-10 meters above the sea. Today, you can still see the painted marks of the emergency exits which the smugglers used when they had to escape.
In the 70s the Belgian speleologist Jean Pierre Van Den Abeele discovered this special geological landmark. With the help of the citizens he tried to find the entrances and exits in the rocky cliffs in order to start getting access to the cave later on. In addition to that he tried to retrace the development of the cave. For that reason he reconstructed the old watercourses ant waterfalls. Today you can still have a look at those. Jean Pierre Van Den Abeele was able to determine the age of the cave with the help of fossilized plants.
Also some fossilized bones of an unknown rodent were found. To categorize this small animal, it was given to a natural historic museum. It was an enrichment for the prehistoric fauna of the old Mediterranean area.
Since the 80s the cave is open and can be visited.

The cave today:
Nowadays people can visit the stalactite cave and look at the beautiful dripstone formations and fossils. But because the climate is really dry, the cave has to be humidified so that the dripstones don’t dry up and become porose.
But not only can the dripstones be visited, furthermore there are magnificent gleaming sinter basins and big galleries.
The total area of the cave adds up to 8,500 m² although not everything can be visited.



General advice:
Because this cave is so special, please pay attention, that you only take picture without any flashes. Also very important is that you don’t touch anything. It is easily damaging the dripstones when they get touched several times a day.

What you need to log this Earthcache:
To log this earthcache you need to take part in the tour and answer the following questions. The first question can be answered with the help of this cache description. The second and third question will be answered by the tour guide. If he is not talking about it, you should ask him.

• What kind of cave is the Can Marçà (read the text below)?
• How broad was the entrance of the smugglers and which colors did they use to mark the emergency exits?
• Why is the water gleaming in the sinter basins

It is not allowed anymore to demand a photo when you want to log. However, I would be delighted, if you would upload a photo of yourself in your log.

Please send your answers including you OC/GC-nickname in the subject to "covadecanmarca [at] gmail.com".
You are instant allowed to log. If your answers are wrong, I'll speak up if necessary with you.
Logs without PRIOR mail to this address will be deleted without any comment!

Background informations for answering the questions:
Primary and secondary caves

• Primary caves: Those caves are formed at the same time as the surrounding rock. Basically it is all about lava caves which come into existence when gases are locked in the solidified lava. Most of the time those caves get opened by a coincidence. Also lava caves which are longer than a few kilometers exist. Those lava canals are formed because the surface solidified and the lava below the surface continued flowing until the eruption came to an end. You can find such caves in Hawaii, Iceland and the Canary Island.
• Secondary caves: Those caves developed later than their surrounding rock. This category of caves evolved from corrosion (chemical decomposition), erosion (mechanical decomposition), tectonics (movements of the lithosphere) or a combination of all those influences. Secondary caves can be found in rocks, which are water soluble as for example different types of limestone.

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