comparing the recent basaltic soils of parts of nsw with deeply weathered soils of western australia
TRANSCRIPT
![Page 1: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/1.jpg)
Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of
Western Australia
![Page 2: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/2.jpg)
Australian soils tend to be:
• Old• Salty• clayey - except in the west of the continent
where they tend to be sandy• Acidic• nutritionally and organically impoverished• structurally challenging
![Page 3: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/3.jpg)
Basaltic soils of East Coast• Pockets of recently formed
basaltic soils exist in parts the East Coast of Australia.
• Recent volcanic activity -oldest extinct volcano found in Northern Queensland 33 mil yrs oldn Youngest in Victoria 10 mil yrs old (Australia moved over hotspot)
• Eg Mt Warning Tweed Coast is a remnant of a volcano that spewed lava around 20 million years ago.
![Page 4: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/4.jpg)
![Page 5: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/5.jpg)
Australian plate is moving North at around 7cm per yr
![Page 6: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/6.jpg)
Basaltic Soil
• Parent rock basalt (mafic)
• Fine textured• Deep red/ chocolate
colour• High in nutrients (high
level of calcium phosphate which acts like fertilizer)
• Very fertile
![Page 7: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/7.jpg)
Deeply weathered laterite soils of Western Australia
• Parent rock generally granite (felsic)
• Laterite (soil residue composed of secondary iron oxides)
• Coarse texture• Old (long time of weathering,
leaching)• Nutrient poor• Colour red (due to oxidation of
iron)• Rich in Aluminium and Iron
![Page 8: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/8.jpg)
![Page 9: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/9.jpg)
• Australian soils have been subject to extensive degradation due to such practices as; overgrazing, over cultivation, tree clearing, and irrigation.
• A continuous cover of vegetation on the soil results in the most stable situation. However this is not possible for many land uses, particularly those in the agricultural sector.
• Major forms of degradation:wind and water erosionreduced fertility because of nutrient loss physical
breakdown of soil structure soil acidificationsalinisation
![Page 10: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/10.jpg)
Soil ErosionIs the movement of particles Of soil, surface sediments and rocks by the action of water, glaciers, winds, waves and so on
![Page 11: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/11.jpg)
Wind erosion
![Page 12: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/12.jpg)
Sheet erosion• Removal of uniform layer of soil over a wide area.
Usually caused by rainfall (rain drop splash)• Removes the top soil layer (bulk of nutrients)
![Page 13: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/13.jpg)
Rill Erosion• Numerous small channels
![Page 14: Comparing the recent basaltic soils of parts of NSW with deeply weathered soils of Western Australia](https://reader035.vdocuments.us/reader035/viewer/2022062516/56649e0d5503460f94af7634/html5/thumbnails/14.jpg)
Gully ErosionRemoval of soil by a concentrated flow Of water with a sufficient velocity to cutLarge channels