2.9. Geology and Soils
The Upper Murrumbidgee occurs on the central and southern parts of the Lachlan Fold Belt and contains many rock types of vary ages. Sedimentary, igneous, volcanic and metamorphic rocks are all present. The diverse geology of the region is reflected in its soils. Many sedimentary soils are shallow and of poor quality, and so often retain their tree cover. Granitic soils tend to be deeper, more fertile and retain water more effectively, but are often more erodible. Volcanic soils (such as those found in the Yass River subcatchment and to the south of Cooma) are fertile but stony. Colluvial and alluvial soils also occur. The latter occupy only a small part of the catchment, but can be highly fertile.
References and Resources
• For more information, see CAP (1998), sections 6.1.9 and 6.1.10.