Lunettes
Lunettes are sandy dunes that form on the Leeward bank of a lake and take thousands of years to form. Because they only form on a particular edge of a lake, they generally appear in large crescent moon shapes, which is the base of their name (Twidale & Campbell. 2005).
Although there has been much research into the formation of lunettes, a definitive theory has yet to be developed. In brief the most recent theories for their development involve westerly winds carrying the sand particles to the basin edge by saltation (particle transport by fluids). Vegetation then traps the sand, building them into sandy dunes and eventually forming into lunettes (Monroe. 2011). Another possible theory is that they are formed by overflowing lakes, where sediment and water erode the surface, creating a mound on top of the ground (Rutherford & Kenyon, 2005).
Lunettes are just a small part of the the development of a landscape but play an important part nonetheless. The following video is an interpretation of the development of the Willandra Lakes over 45,000 years, including the slow development of the lunette that that can still be seen there today (Parks NSW, 2014). Although the video is based on a different location, similar ideas could be applied to the history and formations present on the Murray River.
Although there has been much research into the formation of lunettes, a definitive theory has yet to be developed. In brief the most recent theories for their development involve westerly winds carrying the sand particles to the basin edge by saltation (particle transport by fluids). Vegetation then traps the sand, building them into sandy dunes and eventually forming into lunettes (Monroe. 2011). Another possible theory is that they are formed by overflowing lakes, where sediment and water erode the surface, creating a mound on top of the ground (Rutherford & Kenyon, 2005).
Lunettes are just a small part of the the development of a landscape but play an important part nonetheless. The following video is an interpretation of the development of the Willandra Lakes over 45,000 years, including the slow development of the lunette that that can still be seen there today (Parks NSW, 2014). Although the video is based on a different location, similar ideas could be applied to the history and formations present on the Murray River.