22 June – Geology Walk in the McHarg Ranges
Posted on 14 June, 2013 by Connecting Country
Have you ever wondered what a “metamorphic aureole” might be? Or where ancient lava flows started and stopped? Or where rivers have cut through some rocks, but have met with more resistance with others? And why this is relevant to today’s inhabitants of the landscape?
On Saturday 22nd June, Dr Neville Rosengren, formerly Senior Lecturer in Earth Sciences at La Trobe University, is going to explain the local landscape in terms of geology and landform, first in a talk at the Baynton Hall and then on a walk on the McHarg Range nearby. This event is being organized by Baynton Sidonia Landcare group.
A view of the McHarg Ranges, which lie on the Eastern egde of the Mt Alexander Shire, between Glenhope and Baynton.
The aureole is a rim of “cooked” rock that stands up in a ring around the granitic rock of the Cobaw. The cooking that the rock received has made it more able to resist the weather, so that the surrounding rock has worn away, leaving the aureole standing up, clearly visible in the landscape. Further complexity has been added when creeks have cut through but then been filled up with lava flows and in many cases, worn away again by further water action.
Trying to interpret the landscape from a book or on one’s own can be a frustrating business. But looking at it with Dr Rosengren, a very knowledgeable, patient and enthusiastic teacher, the vast, complex story is revealed. The landscape, including the metamorphic aureole, from the viewpoint on the McHarg Range is awe-inspiring and piecing together the story of how it developed is fascinating. As is discussing its impact on those of us living in the landscape today.
After the walk on the McHarg Range, there is an “extra” for those participants who are still hungry for further geological sights and explanations, with a short four-wheel drive descent to a viewpoint where the basalt rocks meet the sedimentary.
All are welcome to the talk at the Baynton Hall which starts at 11 am. A free BBQ lunch is provided and then there will be a car-pool to the McHarg Range site.
Unfortunately, the site has able bodied access only; there is about a 500 metre reasonably steep climb to the viewing site. No wheeled access is permitted, so everyone must be able to walk up and down.
The Seminar is organized by Baynton Sidonia Landcare group and is free, but booking is essential by contacting Clare on 54 234 152 or clare@knco.net.
Baynton Sidonia Landcare group’s forthcoming spring seminar series includes a session on reptiles in September, a walk around some local indigenous revegetation and regenerating properties in October and a bird-spotting walk in November.
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