Info from solving WOGE #262 - The Mallee
Feb. 1st, 2011 02:24 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
reynardoWOGE 262 looked awfully familiar. The trees, the dryness, the dunes - and it didn't take long to pinpoint the actual spot. I can't post all of this to Felix's blog, so I'm putting it here.
The picture Felix used was at 142° 3'39.35"E 34°58'46.24"S, right in the middle of some rather lovely dunes. It's about 20km north of Walpeup and 30km NW of Ouyen.
Wikipedia on the Mallee.
Things about the origins of the Mallee that you've always wanted to know.
Excellent resource on the Mallee.
The Mallee region consists of a vast plain where there are superficial undulations. Elevations vary in the south of the region from 100 to 120 metres above sea level, falling to between 50 to 70 metres in the centre and north. The major drainage pattern is the Murray River system along the northern boundary. There are occasional creeks such as the Tyrell, Lambert, Yarriambiack and Outlet Creeks that are usually dry. They terminate in the central part of the region in basins containing salt and gypsum.
Four main landforms have been recognised in the region: dunes, jumbled dunes, ridges and hummocks. Other landforms such as lunettes and copi islands occur to a more limited extent. These superficial undulations are all of aeolian origin.
The Birchip area lies within the Murray Basin - a large sedimentary basin that evolved as a result of subsidence at the beginning of the Tertiary period (approximately 65 million years ago). As global sea levels rose in the middle Tertiary period, this basin became flooded by the sea to form the ‘Murravian Gulf’. This gulf covered most of what is known today as the Wimmera and Mallee regions and extended into New South Wales as well.
The uppermost Tertiary sediments are referred to as Parilla Sandstone and this was deposited as the Murravian Gulf receded in the late Tertiary period (approximately 5 million years ago). The sea retreated in a number of stages, which has resulted in numerous coastal ridges forming. These are obvious today in many areas of the Wimmera and Mallee as NNW/SSE trending sandstone ridges and rises. As the sea retreated it left behind a sandy coastal plain over much of the area.
Much of the Tertiary sandstone was covered by aeolian (wind), alluvial (stream) and lacustrine (lake) deposits during the Quaternary period (from 1.6 million years ago). In the Quaternary period there were several major climatic oscillations with phases of global glaciation. In drier climatic periods, Parilla Sandstone was eroded and 'reworked' into quartz rich (siliceous) sand dunes. These white to yellow coloured sand dunes are common in the Big Desert, Little Desert and Sunset Country regions. In the Birchip region, the Parilla Sandstone material has largely been covered by Quaternary deposits of windblown sands, silts and calcareous clays. These deposits are referred to as the Woorinen Formation and occur as elongated east-west trending dunes (e.g. Site MP28) and as thin sheets of sediments. Sites MP22, MP26, ORZC11 and ORZC12 have alkaline soils derived from Woorinen Formation deposits that overlie part of an earlier acidic soil formed on Parilla Sandstone material.
In more recent geological times, sediments have been deposited by drainage systems related to present day streams. An example occurs around Birchip and has been termed the Tyrell Creek Land System by Rowan and Downes (1963).
Landform map here.
The area is used for wheat growing. Another introduced species is the Alien Dinosaur Egg, also known as the Paddy Melon. When the Afghan camel drivers brought their camels to Australia in the 1880s, they also brought their saddles, which were stuffed with the fibres from the melons. The fibres also contained seeds, so when the saddles split with wear, the seeds landed on the ground and like most of our introduced pests, they went for it.
Myself, I was going to use Mount Wycheproof as a WOGE one of these days. It's the smallest registered mountain, at 148m above sea level, or 43 metres above the plain. Yes, I've climbed it. It's also the world's only source of Wycheproofite. Lord only knows what you'd use it for.
The picture Felix used was at 142° 3'39.35"E 34°58'46.24"S, right in the middle of some rather lovely dunes. It's about 20km north of Walpeup and 30km NW of Ouyen.
Wikipedia on the Mallee.
Things about the origins of the Mallee that you've always wanted to know.
Excellent resource on the Mallee.
The Mallee region consists of a vast plain where there are superficial undulations. Elevations vary in the south of the region from 100 to 120 metres above sea level, falling to between 50 to 70 metres in the centre and north. The major drainage pattern is the Murray River system along the northern boundary. There are occasional creeks such as the Tyrell, Lambert, Yarriambiack and Outlet Creeks that are usually dry. They terminate in the central part of the region in basins containing salt and gypsum.
Four main landforms have been recognised in the region: dunes, jumbled dunes, ridges and hummocks. Other landforms such as lunettes and copi islands occur to a more limited extent. These superficial undulations are all of aeolian origin.
The Birchip area lies within the Murray Basin - a large sedimentary basin that evolved as a result of subsidence at the beginning of the Tertiary period (approximately 65 million years ago). As global sea levels rose in the middle Tertiary period, this basin became flooded by the sea to form the ‘Murravian Gulf’. This gulf covered most of what is known today as the Wimmera and Mallee regions and extended into New South Wales as well.
The uppermost Tertiary sediments are referred to as Parilla Sandstone and this was deposited as the Murravian Gulf receded in the late Tertiary period (approximately 5 million years ago). The sea retreated in a number of stages, which has resulted in numerous coastal ridges forming. These are obvious today in many areas of the Wimmera and Mallee as NNW/SSE trending sandstone ridges and rises. As the sea retreated it left behind a sandy coastal plain over much of the area.
Much of the Tertiary sandstone was covered by aeolian (wind), alluvial (stream) and lacustrine (lake) deposits during the Quaternary period (from 1.6 million years ago). In the Quaternary period there were several major climatic oscillations with phases of global glaciation. In drier climatic periods, Parilla Sandstone was eroded and 'reworked' into quartz rich (siliceous) sand dunes. These white to yellow coloured sand dunes are common in the Big Desert, Little Desert and Sunset Country regions. In the Birchip region, the Parilla Sandstone material has largely been covered by Quaternary deposits of windblown sands, silts and calcareous clays. These deposits are referred to as the Woorinen Formation and occur as elongated east-west trending dunes (e.g. Site MP28) and as thin sheets of sediments. Sites MP22, MP26, ORZC11 and ORZC12 have alkaline soils derived from Woorinen Formation deposits that overlie part of an earlier acidic soil formed on Parilla Sandstone material.
In more recent geological times, sediments have been deposited by drainage systems related to present day streams. An example occurs around Birchip and has been termed the Tyrell Creek Land System by Rowan and Downes (1963).
Landform map here.
The area is used for wheat growing. Another introduced species is the Alien Dinosaur Egg, also known as the Paddy Melon. When the Afghan camel drivers brought their camels to Australia in the 1880s, they also brought their saddles, which were stuffed with the fibres from the melons. The fibres also contained seeds, so when the saddles split with wear, the seeds landed on the ground and like most of our introduced pests, they went for it.
Myself, I was going to use Mount Wycheproof as a WOGE one of these days. It's the smallest registered mountain, at 148m above sea level, or 43 metres above the plain. Yes, I've climbed it. It's also the world's only source of Wycheproofite. Lord only knows what you'd use it for.
