Symbol: Bi
Geology - Tertiary period sediments (sandstones).
Landform - Gently undulating rises. The original late Tertiary land surface is now weakly dissected and the present landscape is gently undulating rises to gently undulating plains with slopes generally less than 3%.
Soils - Most of the surface soils are dark brownish grey to dark greyish brown sandy loams to clay loams overlying a bleached similarly textured zone generally containing iron oxide nodules (ironstone gravel) just above the clay. This clay occurs abruptly between about 300 mm to 500 mm and is a mottled yellowish brown, light grey and red-brown medium clay or sandy clay. Clays or sandy clays continue until the weakly cemented rock is encountered. On the rises this may be within 1 m of the surface. These soils can generally be regarded as Chromosols using the new Australian Soil Classification system (Isbell 1996). Site GP 22 is an example of this soil type.
![]() | Figure 13. Road cutting near Clyde showing a typical soil (Bittern sandy loam) formed on Tertiary sandstone (referred to as 'Baxter Sandstone' on geological maps). Note the presence of a bleached subsurface (A2) horizon and accumulation of 'ironstone' nodules at the A/B horizon boundary. |
![]() | 0 - 150 mm. Dark brownish grey sandy* loam to clay loam. Clear transition to: 150 - 400 mm. Pale brownish grey fine sandy loam to clay loam. Ironstone gravel concretions above the clay. Abrupt transition to: 400 mm continuing. Mottled yellowish brown and grey with red-brown medium clay generally becoming sandier with depth. Mottled red-brown, yellow-brown and grey soft sandstone generally occurs before 1.5 m on the low rises. * The soil profile may contain some coarse sand. |