Burleigh Head is a land form created by a basalt lava flow from the now long extinct Mt Warning/Tweed Volcano Shield Volcano. The formation of the headland occurred between 23 and 25 million years ago when the enormous Tweed volcano to the southwest was active.
The headland was created by a large basalt lava flow from the volcano – one of many that flowed down through eroded valleys in the ancient sedimentary rock.
Cooling and contraction of the lava then formed six-sided columns of basalt sitting on top of the underlying sedimentary rock. Over the millions of years since, wave action and rain seepage has attacked and eroded the sedimentary base rock causing the basaltic columns to tumble and fall, as evidenced by the boulder strewn foreshore.
This process continues today and periodically walkways within the national park need to be closed for public safety because of the unstable nature of the headland.
This Earthcache
This earthcache will take you to a few spots on the headland where you can witness this interesting geological phenomena. At each spot, you will need to perform a task, as listed below. You must not leave the paved tracks for any of these tasks.
1. At the published coordinates you will need to examine the sign and answer the following question: How many metres does the headland rise above Burleigh Beach?
2. At WP2 (S 28 05.457 E 153 27.484), measure the diameter of the large column laying down on the uphill side of the track here?
3. At WP3 (S 28 05.507 E 153 27.477), optionally take a photo of yourself and/or your GPSr in front of the boulders located beside the track here. Upload this photo with your online log.
4. At WP4 (S 28 05.512 E 153 27.513), you must describe what has happened to the columns on the uphill side of the track here in as much detail as possible.
The answers to the above questions must be sent to the cache owner, and the photo uploaded with your online log. No email with answers and your online log may be deleted.
You can log this cache straight away after you have emailed your answers to the cache owner, no need to wait for confirmation. Please include the name of this earthcache in the email - you'd be surprised how many people forget. Also, when contacting us with answers, if you want a reply, please include your email address. Any problems with your answers we'll be in touch.
We hope you enjoy this earthcache at this beautiful location on the Gold Coast. Happy earthcaching!
lat&long junkie and Mrs Lat&Long Junkie