page_title: The Gurdies, Victoria
section_title: Prehistoric Period
hierarchical_section_title: The Gurdies, Victoria / History / Prehistoric Period
caption_attribution_description: English: Sand and Gravel Quarry located in The Gurdies, Victoria, Australia
context_page_description: The Gurdies is a village located in Bass Coast Shire in Victoria, Australia.
context_section_description: Important because much of "The Gurdies" lies in the Victorian Department of Primary Industries, Melbourne supply area Extractive areas of interest (2003) with many quarries operating in the area supplying Melbourne's Sharp sand
  In the late Jurassic and early Cretaceous periods (160 - 96 million years ago), Australia and Antarctica began to separate. As they moved apart, a large basin (or ‘rift valley’) was formed by subsidence. This basin was then slowly filled by up to 3 000 metres of sediments (sandstones and mudstones) which were deposited by rivers and lakes. Accumulated swamp material would later be compacted to form coal seams in the Wonthaggi area. During this period, the vegetation was dominated by conifers and ferns, and dinosaurs roamed the earth. From the middle Cretaceous period, Australia had moved further away from Antarctica. The stresses caused by this separation resulted in significant folding, faulting and uplifting of the earlier Cretaceous sediments. The uplift resulted in the development of the Otway and Strzelecki Ranges.
  Victoria experienced a warm and wet tropical type climate throughout much of the Tertiary period and temperate rainforest was widespread over much of the state. During the Tertiary period, (from approximately 65 million years ago) Australia continued to drift away from Antarctica (at rates of up to 6 cm per year). Three interconnected marine basins (Otway, Gippsland and Bass) formed along the southern edge of Victoria’s continental plate and significant marine sediments were laid down in shallow seas. Some parts of these basins now lie onshore but most are to be found beneath Bass Strait where commercial oil and gas reserves have been found within these sediments. During the Tertiary period, significant earth movements occurred along fault lines. Subsidence between fault lines resulted in the formation of the Port Phillip and Westernport sunklands. Port Phillip and Westernport Bays were formed within these sunklands as sea levels rose. The sea level fluctuated significantly during Tertiary times.
  Following the uplift of the South-Eastern highlands in the late Tertiary period (approximately 5 million years ago), extensive river systems developed over dry land areas. These rivers formed deep channels which were filled with coarse gravels. Some of these have been preserved as river terraces along present day streams. As the uplands became eroded away, the rivers draining them became reduced in size. These slower flowing streams then deposited only finer grained sediments. These Tertiary sediments covered much of the Silurian sediments but have since been largely covered by more recent Quaternary deposits.
  The eastern margin of the Koo-Wee-Rup Plain is marked by an abrupt rise trending northeast-southwest. This rise extends from west of Drouin towards the coast at Grantville and forms the western margin of the elevated block-faulted terrain of the South Gippsland Hills. The principal control of relief is the Heath Hill Fault which is of late Pliocene or early Pleistocene age.
caption: The Gurdies" Nature Conservation Reserve Quarry
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