The area is made up of the Southern end of the Sydney Sandstone Basin and the visbly steep cliffs provide a dramatic vista. The water drops about 60m over a cliff of Nowra Sandstone, at which point Tianjara Creek changes its name to Yarramunmun Creek. The Park is open to the public year round
The Sydney Basin consists of Permian and Triassic sedimentary rocks. It is named for the city of Sydney which is centred within it and stretches from Newcastle in the north to Batemans Bay in the south, and west to the Great Dividing Range. The basin is also home to the major centres of Newcastle and Wollongong, and contains economically significant reserves of coal. Sydney’s famous harbour and the sculptured cliffs of the Blue Mountains are signature formations of relatively hard upper strata of sandstone. The basin contains the UNESCO World Heritage-listed Greater Blue Mountains Area.
The area is defined by the presence of the Tianjara Mesa. Amongst the landmarks of the Shoalhaven district is the Tianjara group of mesas. They lie about 5 miles south of the Braidwood road, near Tianjara Falls. Their flat surfaces, bounded by cliffs and steep slopes make them obvious from all directions, but particularly from the north. They are easily visible from Bundanoon, Saddleback, and Durras Mountain.A mesa is formed when the weaker horizontal rocks around a big formation start to erode and fall away, leaving stronger rocks standing in a flat-topped hill.
Extensive outliers of the Berry Formation cap the coastal hills south from Tianjara Falls to the Little Forest Plateau. This is uninhabited country, used as a military practice area and out of bounds from time to time. The sediments of the Berry Formation are rather coarser than those further north. The presence of the mesas may be due to the peculiar resistance of the strata in this area. Some geographers have suggested that they may be relics of a former land surface, uplifted and largely removed before the more recent uplift which has been responsible for such features as Tianjara Falls and the Ettrema Gorge.
Photos are encouraged
1. At the Carpark the information sign can confirm the following:
a. What archaic human activity/impact can be seen along the river
b. What feature of the rock at the base of the waterfall would have an advantage for the activity described?
2. At the viewing platform
a. You can walk from here to the head of the waterfall using the formed track. At the head of the falls a number of large potholes will be visible. how do you think these function with the waterfall?
b. What is the definition of a Mesa?
Please submit your answers as soon as you can. It's ok to post prior, I will check your findings and respond if there are issues. Feel free to add a photo of yourself at the site if you want too. Group visits are encouraged. I hope you enjoy the experience, this is a very special area.