01690 720214

Columnar Jointing

Carlo Forte (April)



Here is a good example of columnar jointing on the ridge of Crib y Ddysgl.
The rock on the top of the ridge is an upper rhyolitic tuff formation.
The regular hexagonal patterns to the columns and the formations occur due to stress lava cools. The lava contracts as it cools, forming cracks. Once the crack develops it continues to grow. The growth is perpendicular to the surface of the flow.
The division of the colonnades is the result of slow cooling from the base upward and rapid cooling from the top downward.






Got A Date Available - Need An Adventure To Match?

Find out what's going on at the National Mountain Sports Centre between any date range on this handy new search page



Latest News

ENVIRONMENT SYMPOSIUM FOR MOUNTAIN LEADERS

Environment Symposium For Mountain LeadersThe 2017 Plas y Brenin Environment Symposium for Mountain Leaders and Mountaineering Instructors wil....



NEW AUTUMN FAST TRACK INSTRUCTOR SCHEME OPTION ADDED

New Autumn Fast Track Instructor Scheme Option AddedWe've added another option to our Fast Track Instructor Scheme. Until now, the course has always run....



FAST TRACK INSTRUCTOR SCHEME
OPEN DAYS

Fast Track Instructor Scheme<br/>Open DaysJoin us for a free information day on May 1st and find out how the Fast Track Instructor Scheme can ....



NEW MOUNTAIN BIKE COURSES LAUNCHED

New Mountain Bike Courses LaunchedCheck out our new range of mountain bike courses designed to help you improve your skills fast.....



EQUIPMENT HIRE

Equipment HireOur equipment stores is packed with carefully chosen, well maintained technical gear. Provided we ....



What's On In Our bar?

Our friendly and lively bar is open to the public. From talks and lectures to film nights and live music, there's always something going on. Find out what's coming up next here



Adventure Sport
Summer Camps (Age 12-17)

Summmer Camps For Young People Aged 12-17Young climbers, mountaineers, paddlers and mtb riders aged 12-17. Develop your outdoor skills with our top coaches on one of our residential summer camps.


Enhanced Learning Credits

Enhanced Learning CreditsThe Enhanced Learning Credit Administration Service offers funding for armed forces personnel. Plas y Brenin is able to accept ELCAS funding for a few specific non residential courses.




Weather Forecast, Tides and Surf Conditions

Find out what the weather's doing in North Wales over the next five days.



Review your holiday or course here

Review Your Course
Help us by reviewing your holiday or course here


Adventure Map


Working alongside UCLan
to educate
outdoor professionals

University Of Central LancashireFind out how we are working with one of the country's top universities to develop lasting careers in the outdoors.