Latitude -30.402861, Longitude 152.343024
Located in the New England Region of NSW, nearest town Armidale
Source: National Parks and Wildlife Service Plan of Management
Source: Field Geology of NSW Branagan & Packham
Ebor Falls at an elevation of 1290 metres and with a drop of 120m (Mather 1993) is one of the best known and frequently visited waterfalls in the Guy Fawkes National Park. The falls comprise two drops known as, the Upper Ebor Falls and the Lower Ebor Falls which are separated by 600m. There are two lookouts to view the falls and both falls can be seen from the lower falls lookout. The falls are interesting from a geological viewpoint as they are formed where columnar jointing has occurred in the basalt.
The basalts are a part of an extensive occurrence of mafic lavas (rock that is rich in magnesium and iron) that extend north east to Dorrigo and which were derived from the central vent east of Point Lookout. Flows average about 50m thick, but are up to 300m thick. Note the variation in thickness of the basalt at the lower and upper falls. (Branagan & Packham) There are four distinct basalt flows visible at Upper Ebor Falls and the cut-back effect of the falls is clearly evident here. Large dislodged blocks lie on the second terrace and rocks are weathering through access points provided by the columnar jointing.
Stroll down the path to the Lower Falls where you will notice two distinct zones of columnar jointing in the cliff on the far side of the falls.
Careful observation will reveal large vertical pillars on the lower section and small jointing at an angle directly above the vertical columns. These irregular fractured columns are called entablature. 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. Entablature is probably the result of cooling caused by fresh lava being covered by water. The flow of basalt probably damned a river, when the river returned the water seeped down the cracks in the cooling lava and caused rapid cooling from the surface downward. The division of colonnade and entablature is the result of slow cooling from the base upward and rapid cooling from the top downward.
There are picnic tables and toilets available near the car park at the falls. Access to Ebor falls can be gained via Waterfall Way from Armidale (78km) and from Bellingen (75km).