Black Cliffs
Approximately 600 million years ago sand and silt were deposited in the sea. 100 million years later Black Cliff was formed from massive movements in the earth, which in turn caused folding. This changed the landscape and turned it into mountain ranges.
Approximately 600 million years ago sand and silt were deposited in the sea. 100 million years later Black Cliff was formed from massive movements in the earth, which in turn caused folding. This changed the landscape and turned it into mountain ranges.
Sugar Loaf
Sugar Loaf gets its name for its resemblance to hard refined sugar. The shape of Sugar Loaf is a result of wind and rain erosion acting on the soft glacial sediment over the past few thousand years. Southern Australia was covered by an ice cap around 280 million years ago and when it melted around 10 million years later the red and white layers of sediment that form Sugar Loaf were deposited. The red layer is made up of sand and clay that contain dropstones. The white sand makes up most of Sugar Loaf and the clay and boulders that lay around the base of the Sugar Loaf fell from the ice while it was traveling across the lake. At the top of Sugar Loaf is a thin layer of brown alluvial clay, placed there around 2 million years ago.
Sugar Loaf gets its name for its resemblance to hard refined sugar. The shape of Sugar Loaf is a result of wind and rain erosion acting on the soft glacial sediment over the past few thousand years. Southern Australia was covered by an ice cap around 280 million years ago and when it melted around 10 million years later the red and white layers of sediment that form Sugar Loaf were deposited. The red layer is made up of sand and clay that contain dropstones. The white sand makes up most of Sugar Loaf and the clay and boulders that lay around the base of the Sugar Loaf fell from the ice while it was traveling across the lake. At the top of Sugar Loaf is a thin layer of brown alluvial clay, placed there around 2 million years ago.
Chatter Marks
Chatter marks are a series of wedge shaped groves in the rocks surface, formed by rock fragments carried in the
base of glaciers. The marks are commonly at right angles to the direction of the ice movement and are crescent in shape. The evidence of chatter marks and polishing on Black cliff indicate that the ice sheet moved in a north west direction.
Chatter marks are a series of wedge shaped groves in the rocks surface, formed by rock fragments carried in the
base of glaciers. The marks are commonly at right angles to the direction of the ice movement and are crescent in shape. The evidence of chatter marks and polishing on Black cliff indicate that the ice sheet moved in a north west direction.
Slickensides
SSlickensides are parallel groves or scratches on the surface of a rock, which create a striated effect. They are can be formed from the action of moving ice (glacial slickenside) or as a result of friction between moving rocks along a fault line.
SSlickensides are parallel groves or scratches on the surface of a rock, which create a striated effect. They are can be formed from the action of moving ice (glacial slickenside) or as a result of friction between moving rocks along a fault line.
Layers of Rock
Hallett cove has many great examples of rock layers. Sedimentary rocks are formed when sediments are deposited into bodies of water or on Earths surface. After many years the sediments are hardened by weight and pressure. This process, by which the sediment is transformed into Sedimentary rock is called 'lithification'. Around 75% of the surfaces exposed on Earth's continents and land is sedimentary rocks or sediments. The rocks and landforms at Hallett Cove Conservation Park are records of a succession of of separate periods over millions of years and have evolved through a process of deposition, burial, uplift, weathering and erosion.
Hallett cove has many great examples of rock layers. Sedimentary rocks are formed when sediments are deposited into bodies of water or on Earths surface. After many years the sediments are hardened by weight and pressure. This process, by which the sediment is transformed into Sedimentary rock is called 'lithification'. Around 75% of the surfaces exposed on Earth's continents and land is sedimentary rocks or sediments. The rocks and landforms at Hallett Cove Conservation Park are records of a succession of of separate periods over millions of years and have evolved through a process of deposition, burial, uplift, weathering and erosion.
Fossils
In the Pliocene Era approximately 4 million years ago, a warm shallow sea covered part of the land of what is now the Gulf of St Vincent. Fossils from the marine life that exsisted at that time (eg. the many chambered Foraminifera and Shellfish) are found in the Hallett Cove Sandstone.
In the Pliocene Era approximately 4 million years ago, a warm shallow sea covered part of the land of what is now the Gulf of St Vincent. Fossils from the marine life that exsisted at that time (eg. the many chambered Foraminifera and Shellfish) are found in the Hallett Cove Sandstone.
Glacial History
Around 280 million years ago two thirds of Australia was covered in an ice cap. At this time Australia was also a part of the super-continent called Gondwana. There is evidence of this glacier throughout Hallett Cove.
Around 280 million years ago two thirds of Australia was covered in an ice cap. At this time Australia was also a part of the super-continent called Gondwana. There is evidence of this glacier throughout Hallett Cove.