Dansk:

Et jordfaldshul, også kendt som en sink, rystes hul, swallow hole, swallet, doline eller cenote, er en naturlig depression eller hul i jordens overflade skyldes karst processer — kemiske opløsningen af karbonat rocksor suffosion processer for eksempel i sandsten. Doliner kan variere i størrelse fra 1 til 600 meter (3.3 til 2.000 ft) både i diameter og dybde, og varierer i form fra jord-foret skåle til fundament-kanter kløfter.

Doliner kan være dannet gradvist eller pludseligt, og findes på verdensplan. Et Sink hul er dannet af en underjordisk sammenbrud. Jordfalds huller kommer særlig, hvor kalk undergrunden indeholder, og hvordan konserverede er skyllet væk ved vand, eller hvor der er eller har været minedrift.

Jordfalds huller kan også dannes ved en istid, i indlejrede moræne dannelse isblok i er smeltet væk. Det øverste lag af tumbling ned i hulrummet når de ikke længere kan stå til pres . Dannelse mekanisme Doliner kan erobre overflade dræning fra kører eller stående vand, men kan også danne i høj og tør lokationer.

Mekanismerne i dannelse indebærer naturlige processer af erosion eller gradvis fjernelse af lidt opløselig fundament (f.eks. kalksten) ved percolating vand, sammenbruddet i en grotte tag, eller en sænkning af watertable. Doliner danner ofte gennem processen med suffosion. Således, for eksempel, kan grundvand opløses karbonat cement holde sandsten partikler sammen og derefter foretage væk de slappe partikler, gradvist danner et tomrum.

Doliner er fælles hvor rock under jordoverfladen er kalksten eller andre karbonat klipper, salt senge eller klipper, der kan naturligvis være opløst ved udsendelse grundvand. Som rock opløser, udvikle mellemrum og huler under jorden. Disse doliner kan være dramatiske, fordi den overflade jord normalt forbliver intakte, indtil der ikke er tilstrækkelig støtte. Derefter kan en pludselige sammenbrud af jord overflade forekomme.

Doliner også formular fra menneskelig aktivitet, såsom den sjældne men stadig lejlighedsvis sammenbrud opgivet miner.

Spørgsmål til besvarelse til owners GC-account::

1. Hvor bred er jordfalshul

2. Hvor former seg denne jordfalhul

3. Omkring 1620 levede en man, den huserede flere steder langs Hostebro Viborg landsvej. Hvor heder han ?

4. Du må gerne tage et billed og uploade sammen med din log (optional).

Du behøver ikke at vente på svar for at logge cachen, du bliver kontaktet hvis dine svar ikke er rigtige.

English:

The landscape in Denmark is largely a result of a modeling process that took place at the end of the Ice Age about 10,000 years ago. At that time, a huge ice cap covered most of the country. As the temperatures rose, the glacier gradually melted. But during the melting period, the glacier stood still for a while in the middle of Jutland. In the southwestern parts of Jutland, the soil is sandy due to deposits from the large meltwater rivers that flowed out from the glacier. The resulting landscape is quite flat.

A Sink hole is formed by an underground collapse. Jordfalds holes coming in particular, where lime subsoil contains, and how preserved is washed away by water, or where there are or mining have been. Jordfalds holes can also be formed by a ice age , in nested moraine formation isblok in has melted away. The top layer of the tumbling down in cavities when they can no longer stand up to pressure
A sinkhole, also known as a sink, shake hole, swallow hole, swallet, doline or cenote, is a natural depression or hole in the Earth's surface caused by karst processes — the chemical dissolution of carbonate rocksor suffosion processes for example in sandstone. Sinkholes may vary in size from 1 to 600 meters (3.3 to 2,000 ft) both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may be formed gradually or suddenly, and are found worldwide.

Sinkholes may capture surface drainage from running or standing water, but may also form in high and dry locations.
The mechanisms of formation involve natural processes of erosion or gradual removal of slightly soluble bedrock (such as limestone) by percolating water, the collapse of a cave roof, or a lowering of the watertable. Sinkholes often form through the process of suffosion. Thus, for example, groundwater may dissolve the carbonate cement holding the sandstone particles together and then carry away the lax particles, gradually forming a void.

Sinkholes are common where the rock below the land surface is limestone or other carbonate rocks, salt beds , or rocks that can naturally be dissolved by circulating ground water. As the rock dissolves, spaces and caverns develop underground. These sinkholes can be dramatic because the surface land usually stays intact until there is not enough support. Then, a sudden collapse of the land surface can occur.
Sinkholes also form from human activity, such as the rare but still occasional collapse of abandoned mines.

Sources: Wikipedia, Infoboard

To log the Earthcache, please answer the following questions by mail to the owners GC-account:

1. Estimate the diameter of the hole

2. What was the reason forming this sinkhole ?

3. By the year 1620, there was a man passing often this hole. What was his name ?

4. Take a photo of you / your GPSr at the hole (optional)

You do not have to wait for replies to log the cache, you will be contacted if your answers are incorrect!

Happy Hunting