Campbell's Hole Volcanic Dyke 4
Posted by: 
3l diesel
S 34° 43.535 E 150° 50.705
56H E 302689 N 6155273
A volcanic dyke emerges in a line in a tidal rock platform and finishes in a large crevice where ocean waves show considerable force.
Waymark Code: WMBBBE
Location: New South Wales, Australia
Date Posted: 04/29/2011
Views: 12
This dyke forms the fourth point of interest in Earthcache "Campbell’s Hole Volcanic Dykes" GC311VW looking at the dykes in this area.
This dyke forms the most obvious example of its type in this area with the extrusion of magma from a fissure standing proud of the surrounding rock platform. To advance northwards on this rock platform involves a short scramble over this dyke.
The dyke surfaces from the cliffline, and it should be noted that there are two dykes emerging from the cliff, but only one continues across the rock platform. The one continuing across the rock platform finishes at a crevice that is subject to ocean wave action and very quickly becomes about 7m deep. Significantly, this crevice is guarded on either side by two rock outcrops of the Budgong Sandstone type prevalent here which stand nearly two metres higher than the surrounding flat rock platform.
Close to the cliff where the two dykes emerge, there the sandstone appears to have been drawn upwards as if the dyke at formation was applying significant heat to the surrounding rock and it has moved in a plastic manner before cementing on cooling.
This writer will conjecture that magma rising through a plastic sandstone similarly caused the two guarding outcrops which eventually held their position, whilst hot magma oozed away leaving the crevice. The crevice is not directly in line with the dyke, however the nearby Dyke 5 also takes a number of changes in direction - somewhat in contrast to the other waymarked examples in this area, and so a change of dyke direction here is a possibility.
The writer welcomes alternate viewpoints.
Waymark is confirmed to be publicly accessible: yes
Parking Coordinates: N 34° 43.704 W 150° 50.256
Access fee (In local currency): .00
Requires a high clearance vehicle to visit.: no
Requires 4x4 vehicle to visit.: no
Public Transport available: no
Website reference: [Web Link]
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Visit Instructions:
No specific requirements, just have fun visiting the waymark.