Mount Barker Summit rises steeply from the surrounding low hills to an altitude of 516.6 metres (1695 feet) above sea level. The Summit is located within the Scotts Hill Environmental Association (3.2.8) of the Mount Lofty Block (Laut et al, 1977), which is characterised by steep strike ridges on metasediments.
The reserve encompasses most of the long north-south ridge of the mountain. To the south of the reserve the ridge line extends to link Little Mount/Twin Peak (480 metres above sea level) on the adjoining property to the south west. The ridge line falls away abruptly to both the west (to 405 metres at the entrance from Williams Road) and the east (405 metres on the lower slopes of the eastern boundary).
The north-south tending ridge which forms Mount Barker Summit has resulted from differential weathering between the hard Mount Barker Quartzite and the adjacent, less resistant, phyllites and grey wackes. The Mount Barker Quartzite is one of the southernmost equivalents of the extensive ABC Quartzite which makes up a large proportion of the peaks and ridges of the Flinders Ranges.
On the eastern side of the mountain there is a north-south fault line known as the Nairne Fault, marking the boundary between the Lower Cambrian Kanmantoo Group to the east and the Upper Precambrian Marino Group to the west.
The Nairne Fault has been clearly exposed within the adjacent Emerald Quarry. It is the only known exposure of the fault and is the only locality other than the south coast of the Fleurieu Peninsula where the Kanmantoo Group and older rocks are seen in actual contact. The exposure within Emerald Quarry has been recorded as a geological monument
Questions:
Please email me the answers and do not put them in your log entry.
Q1. What evidence do you see of metamorphism?
Q2. Describe the eastern formation? Why do you think it is this shape?
Q3. Do you see any evidence of metamorphosed siltstones and limy siltstones?
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