Bacchus Marsh Council Trench Geological Reserve (Triassic Park)
This small reserve located to the north of Bacchus Marsh holds an important key to understanding the past. In a small quarry, unusual sedimentary rocks are exposed providing a window into Victoria's distant geological history. In Triassic Park you?ll see a piece of Victoria's only Triassic Age rocks (250 million years old). Formations from a time when dinosaurs roamed.
A brief history
Once a small test quarry, this site is now known to contain the only Triassic age (about 205 to 250 million years ago) sedimentary rocks in Victoria.
Rare plant fossils from the site were identified as Triassic in age by eminent palaeontologist Frederick McCoy in 1892. He determined that the sediments were deposited about 210 million years ago in an ancient river bed. Later investigations have confirmed this early work.
During the Triassic period dinosaurs and early mammals evolved. The climate was warmer than today, after a long cold period in the Permian when ice sheets and glaciers covered much of Australia. The remains of the Permian glaciers can be seen throughout the Bacchus Marsh area as vast deposits of grey or white glacial rocks, including those at Werribee and Lerderclerg gorges and nearby at Bald Hill, but little is known of the Triassic landscape.
The derivation of the name 'Council Trench' is uncertain. The site was referred to as the 'trench in the Council Paddock' in 1927. The term 'Council Trench' first appeared in studies of the site in 1937.
Set aside as a quarry in 1873, the land is now reserved for its natural values including the Triassic sedimentary rocks and as a rare small refuge for native plants and animals.
Plants and animals
The eucalypt and wattle woodland is an important remnant of native vegetation in the largely cleared landscape of the Pentland Hills.
Conservation of natural values including indigenous vegetation is an important management objective for the committee that maintains the reserve. This also includes the range of native grasses found within the southern part of the site, and on the rock exposures.
Flora
The reserve is host to an important vegetation community that is rare throughout the Midlands region known as a Rocky Chenopod Woodland. The yellow gums and wattles are characteristic of the overstorey of this type of vegetation which grows on infertile soils and may appear stunted from a lack of nutrients.
The ground level plants consist of saltbush, flax lily and native grass such as wallaby and kangaroo grass.
The south-east portion of the reserve contains remnants of Grassy Woodland with exotic grasses.
Lystrosaurus a Triassic sheep-sized plant-eating mammal-like reptile with prominent canine teeth could well have grazed at Triassic Park.
Things to do and see
Take in the view of Bacchus Marsh and the Pentland Hills from the highest point or trace the Triassic sandstones and conglomerates along the trench or cut, and into the side of the hill.
Watch birds of prey soar on thermals over the Korkuperrimul Creek valley and Pentland Hills where once pterosaurs may have flown. Explore the woodlands where superb fairy wrens forage, but millions of years ago strange reptiles like the Lystrosaurus came to eat and drink.
From the highest point at the north east corner of the reserve, views over Bacchus Marsh and the Pentland Hills can be obtained. The incision of Korkuperrimul Creek can be traced to the west with cliffs exposing light coloured Permian glacial sandstones, brown-yellow Tertiary iron-strained sandstones and conglomerates and dark coloured Tertiary Older Volcanics basalts.
How to get there
Triassic Park is located about 2 km north of Bacchus Marsh.
From Melbourne, approach the site via the Western Freeway, then exit the freeway at the first Bacchus Marsh exit and stay on Main Road, pass through the township continuing until the freeway overpass is crossed to Condons Lane, then turn right at Tramway Lane.
From Ballarat simply exit the freeway at the first Bacchus Marsh ramp and turn left along Condons Lane, then right at Tramway Lane.
The entrance gate os about 100m along Tramway Lane.
Caring for the Area
Please help us to conserve this special area.
Collection of plants or wildflowers is prohibited.
Do not remove rocks from the site. The site is used by university students for teaching purposes and it is important to protect the outcropping rocks to study in the future.
Location
Tramway Lane, Darley 3340 Map
Web Links
→ www.mln.org.au/friends-groups/bacchus-marsh-council-trench-triassic-park
