Territory Stories

Report on the lands of the Ord River catchment, Northern Territory



Report on the lands of the Ord River catchment, Northern Territory

Other title

by J. M. Aldrick, D. F. Howe and C. R. Dunlop.


Aldrick, J. M.; Howe, D. F. (David F.); Dunlop, C. R. (Clyde Robert)


E-Publications; E-Books; PublicationNT; 78/24




Made available via the Publications (Legal Deposit) Act 2004 (NT).


Date:1978; Bibliographhy: p. 103.




Land use -- Northern Territory -- Ord River Region

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Animal Industry & Agriculture Branch, Dept. of the Northern Territory

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109 p.,[23] p. of plates : ill., maps ; 29 cm.

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Check within Publication or with content Publisher.

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III GEOMORPHOLOGY By J.M. Aldrick The area can be usefully divided into a number of geomorphological provinces, each characterized by a different set of landscape - forming processes. The provinces are shown in Figure 2. Each province is composed of a characteristic set of land systems, although some land systems are common to more than one province. The provinces are quite distinct, but they are not necessarily continuously uniform areas. For example province 3, Volcanic Areas Exposed After Removal of Headleys Limestone, contains land systems that merge into province 4, Volcanic Hills and Plains. Also areas of provinces 7, Proterozoic Sedimentary Exposures, and 8, Southern Lateritic Plateaux, tend to occur in discrete but discontinuous areas, especially near their margins. Figure 2 is therefore a simplification, drawn to provide an understanding of major regional differences within the area. 1. The Hardman Basin Land systems have not been delineated for the has been done previously. (Robinson 1971). 2. Areas of Headleys Limestone The dissection and erosion of this formation have been controlled by two main factors. Firstly the beds dip gently (5) towards the west with a low escarpment on the eastern side, and drainage has been induced to flow westwards. Parallel drainage channels have developed on the areas draining to the west. Secondly, strong joint cracking and removal of limestone from the cracks by solution has led to weak karst formations in the flatter areas of the rock. Generally this is not evident at the surface but some sink-holes do occur. The karst formations, mainly solution cavities, can be clearly seen on the east of the formation where backwearing of the escarpment and erosion have exposed the rock below. Removal of rapid process. of the junction boulders fallen adjacent to the the limestone by solution has been a relatively Very few outliers of limestone occur to the east with the volcanics. Detritus of limestone from the cliffs has only survived immediately cliffs. The materials underlying the Headleys limestone are soft and easily erodible, (see notes on province 3) and consequently the escarpment is being maintained and is retreating towards the weste - 9