The EC is easy accessed and both waypoints are at locations where easy and spacious off road parking is available. The road is steep and caution should be taken with small children present. That being said, the initial impression is of the immense layered sandstone structures and the effects time and weather have had on them, this is known as Spheroidal weathering. The second feature is the 50m deep roadside cut at WP 01 which reveals the true layered structure of the area.
Spheroidal weathering is a form of chemical weathering that affects jointed bedrock and results in the formation of concentric or spherical layers of highly decayed rock within weathered bedrock that is known as saprolite. When saprolite is exposed by physical erosion, these concentric layers peel (spall) off as concentric shells much like the layers of a peeled onion. Within saprolite, spheroidal weathering often creates rounded boulders, known as corestones or woolsack, of relatively un-weathered rock. Spheroidal weathering is also called onion skin weathering, concentric weathering, spherical weathering, or woolsack weathering.
Definitions of the boundaries and what comprises the Sydney basin vary significantly. The Australian Government classifies the basin as an interim Australian bioregion consisting of 3,629,597 hectares (8,968,930 acres).
According to NSW Primary Industries, the basin extends through approximately 350 kilometres (220 mi) of coastline from Newcastle in the north to Durras Lake (near Batemans Bay) in the south. From Durras Lake the western boundary continues in a line through Lithgow to around Ulan (near Mudgee). To the north the boundary extends 120 kilometres (75 mi) along the Liverpool Range to a point 80 kilometres (50 mi) north of Muswellbrook, and then runs 200 kilometres (120 mi) back to the coast at Newcastle.
To the east the basin continues to the edge of the continental shelf.The total area of the basin is approximately 44,000 square kilometres (17,000 sq mi) onshore plus 5,000 square kilometres (1,900 sq mi) offshore.The centre of the basin is located around 30 kilometres (19 mi) west of the Sydney central business district at Fairfield.
The Sydney Basin consists of Permian and Triassic sedimentary rocks. It is named for the city of Sydney which is centered 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 centers of Newcastle and Wollongong,
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.
1. At WP 01 Please describe what effect the weather has had on the exposed rocks and how they appear.
2. At WP 02 Note the exposed layers:
a. Are they horizontal or vertical?
b. Are there more that 10 layers visible?
C. Some of the layers separated by a thin black band, what do you think could have caused this distinct colouration?