It has been cold recently in Luxembourg, like, really cold. I’m talking way down into negative double figures. Take our garden pond, for example. Poor fish.
But when the weather gets this cold, something beautiful happens in Luxembourg: a “tufa” spring in the Mullerthal goes all, well… frozen.
We put on as many layers as we possibly could and ventured into the forest to check out this bizarre winter phenomenon:
From our parking spot, a raised wooden trail leading to the spring serves the dual purpose of preserving the forest floor from erosion and delighting any children off on an adventure. Down this fairy-tale path, it’s only a few hundred metres to the “Kalktuffquelle”… and it truly is a sight to behold:
How was this frozen fantasy created? Although it may look like Queen Elsa has paid a visit to Luxembourg, there is, of course, a more scientific rationale. You see, immediately above this “waterfall”, calcium-rich water rises up from the ground. Upon making contact with the air, this water loses some of its carbon dioxide, making it more alkaline (plants and algae living in the water also get rid of carbon dioxide through photosynthesis). This abrupt loss of acidity means that the calcium carbonate in the water can no longer remain in soluble form; it turns into a sediment, creating those weird shapes of soft, puffy tufa. And since the spring is on the side of a valley, the water tumbles softly down through this porous landscape to a glittering turquoise pool below.
When it remains extremely cold for several days on end, this constant dripping of water turns into magnificent ice columns, and the splashing of the drops in the pool below creates curiously-shaped formations, crystals and textures of ice.
This phenomenon doesn’t happen very often, so make sure you don’t miss it if you’re in Luxembourg during the next big freeze.
Where to find the Kalktuffquelle:
It’s in the east of Luxembourg, just off the road “CR 121” (Junglinster to Grundhof), roughly half-way between the hamlets of Blumenthal and Mullerthal. Parking available nearby (see map).
By foot, it is directly on the hiking trail “Mullerthal Trail 3“.
(Map sources: www.geoportail.lu)
Daisy the bus visited the Kalktuffquelle in March 2018. Winter tyres are a wonderful thing.
(c) 2018 Jonathan Orr