CRCLEME

Cooperative Research Centre for OPEN FILE Landscape Environments and Mineral Exploration REPORT SERIES

GEOMORPHOLOGY AND SURFACE MATERIALS: ROBINVALE TO BOUNDARY BEND

J. Clarke, V. Wong, C. Pain, H. Apps, D. Gibson, J. Luckman and K. Lawrie

CRC LEME OPEN FILE REPORT 244

December 2008

CRCLEME (CRC LEME Restricted Report 259R, 2007 2nd Impression 2008)

CRC LEME is an unincorporated joint venture between CSIRO-Exploration & Mining, and Land & Water, The Australian National University, Curtin University of Technology, University of Adelaide, Geoscience Australia, Primary Industries and Resources SA, NSW Department of Primary Industries and Minerals Council of Australia, established and supported under the Australian Government’s Cooperative Research Centres Program. CRCLEME

Cooperative Research Centre for Landscape Environments and Mineral Exploration

GEOMORPHOLOGY AND SURFACE MATERIALS: ROBINVALE TO BOUNDARY BEND

J. Clarke, V. Wong, C. Pain, H. Apps, D. Gibson, J. Luckman and K. Lawrie

CRC LEME OPEN FILE REPORT 244

December 2008

(CRC LEME Restricted Report 259R, 2007 2nd Impression 2008)

CRC LEME 2007

CRC LEME is an unincorporated joint venture between CSIRO-Exploration & Mining, and Land & Water, The Australian National University, Curtin University of Technology, University of Adelaide, Geoscience Australia, Primary Industries and Resources SA, NSW Department of Primary Industries and Minerals Council of Australia.

Headquarters: CRC LEME c/o CSIRO Exploration and Mining, PO Box 1130, Bentley WA 6102, Australia

This report (CRC LEME Open File Report 244) is a reprinting of CRC LEME Restricted Report 259R, first issued in 2007 as part of the CRC LEME/Geoscience Australia River Murray Corridor (South Australian Border To Gunbower) Victorian AEM Mapping Project.

Electronic copies of the publication in PDF format can be downloaded from the CRC LEME website: http://crcleme.org.au/Pubs/OFRSindex.html. Information on this or other LEME publications can be obtained from http://crcleme.org.au. Hard copies will be retained in the Australian National Library, the J. S. Battye Library of West Australian History, and the CSIRO Library at the Australian Resources Research Centre, Kensington, Western Australia.

Reference: Clarke, J., Wong, V., Gibson, D., Apps, H., Luckman, J., Pain C., and Lawrie, K. 2007. Geomorphology and Surface Materials: Robinvale to Boundary Bend. CRC LEME Restricted Report 259R, 61 pp. (Reissued as Open File Report 244, CRC LEME, Perth, 2008).

Keywords: 1. Regolith materials 2. Geomorphology - Victoria 3. Salinity 4. River Murray

ISSN 1329-4768 ISBN 978 0 643 09671 4

Address and affiliation of Author:

J. Clarke, V. Wong, C. Pain, H. Apps, D. Gibson, J. Luckman and K. Lawrie Geoscience Australia PO Box 378 CANBERRA ACT 2601

Published by: CRC LEME c/o CSIRO Exploration and Mining PO Box 1130, Bentley, Western Australia 6102.

Disclaimer The user accepts all risks and responsibility for losses, damages, costs and other consequences resulting directly or indirectly from using any information or material contained in this report. To the maximum permitted by law, CRC LEME excludes all liability to any person arising directly or indirectly from using any information or material contained in this report.

© This report is Copyright of the Cooperative Research Centre for Landscape Environments and Mineral Exploration 2007, which resides with its Core Participants: CSIRO Exploration and Mining and Land and Water, the Australian National University, Curtin University of Technology, the University of Adelaide, Geoscience Australia, Primary Industries and Resources South Australia, New South Wales Department of Primary Industries and Mineral Council of Australia.

Apart from any fair dealing for the purposes of private study, research, criticism or review, as permitted under Copyright Act, no part may be reproduced or reused by any process whatsoever, without prior written approval from the Core Participants mentioned above. EXECUTIVE SUMMARY

Over the past 15 years more than 40 airborne electromagnetic (AEM) surveys have been acquired for groundwater and salinity mapping and natural resource management in Australia. Most of these have been in floodplain or other low relief landscapes. Several projects have successfully demonstrated how AEM surveys can be used to underpin a wide range of salinity management strategies, and a review of salinity mapping methods in the Australian context by Spies and Woodgate in 2004 recommended that AEM systems were the most appropriate for mapping salinity in Australia’s landscapes.

In early 2007, an airborne electromagnetic (AEM) survey was acquired along a 450 km reach of the River Murray Corridor (RMC) in SE Australia. This aim of this survey, carried out under the auspices of the Australian Government’s Community Stream Sampling and Salinity Mapping Project (CSSSMP), and managed by the Bureau of Rural Sciences (BRS), is to provide information vital for addressing salinity, land management and groundwater resource issues. The study area stretches from the South Australian border eastwards to Gunbower in Victoria. A total of 24,000 line km of AEM data were acquired. The survey area encompasses iconic wetland areas, national and state forest parks, and areas of irrigation and dryland farming.

Within the RMC project area key land management questions include (1) what is the impact of irrigation on the floodplain, river and groundwater system?; (2) what is the distribution of saline groundwaters where these have the potential to impact on the floodplain and river?; (3) where are the salt stores in the unsaturated zone within the floodplain?; (4) what is the potential for salt mobilisation during Living Murray inundation actions and natural flood events; (5) what are the drivers for floodplain health with respect to groundwater processes?; (6) is there leakage from salt disposal infrastructure?; and (7) what is the extent of losing and gaining effects along different reaches of the river system?

To address many of these questions, maps of the distribution of salt stores, saline and fresh groundwater and the hydraulic properties of soil and regolith materials in the shallow sub- surface are required. These are required to provide a 3-D understanding of how salt stores and saline groundwaters connect to the surface waterways and land surface. Sub-surface interpretations in the survey areas are hampered by a low density of useful borehole data in the floodplain in particular, and by a paucity of soil and landscape surface mapping at appropriate scales throughout the project area. New maps of surface materials, and a new geomorphic understanding of the RMC project area is required to constrain the interpretation of the AEM surveys, and address the land management questions.

This report documents the results of new surface materials mapping in the Robinvale to Boundary Bend survey area, and the methodology used to produce the maps.

This area lies on the downthrown side of the Tyrrell fault, and the floodplain is no longer being incised by the Murray River. The floodplain itself is still inset into the Mallee landscape, although the height of the inset valley sides are lower than downstream. Colluvial deposits mantle the sides and the Blanchetown Clay which makes up the sides is now exposed.

The Murrumbidgee joins the Murray in this stretch of the river. No obvious change in the morphology of the floodplain and inset valley fill has been observed.

The valley fill, as is the case downstream, consists of a Quaternary terrace unit mantled by thick silt and clay, and the modern floodplain. The floodplain is a scroll plain, with three generations of scroll maps and meanders. The youngest scroll bars of active meander loops

iii are composed of sand. Progressively older scroll bars and mantled and smoothed by every increasing thicknesses of silt and clay.

Ken Lawrie Project Leader

iv ABBREVIATIONS

ACRES Australian Centre for Remote Sensing AEM Airborne Electromagnetics ASTER Advanced Spaceborne Thermal Emission and Reflection Radiometer BC Blanchetown Clay BRS Bureau of Rural Sciences CF Coonambidgal Formation CMA Catchment Management Authority CRC LEME Cooperative Research Centre for Landscape Environments and Mineral Exploration DEM Digital elevation model GA Geoscience Australia GMW Goulbourn-Murray Water LIDAR Light Detection and Ranging MDBC Murray-Darling Basin Commission MS Monoman Sands PS Parilla Sands RGB Red, Green, Blue RMC River Murray Corridor RMG River Murray Gorge SF Shepparton Formation SPOT Satellite Pour l'Observation de la Terre STRM Shuttle Radar Terrain Mission VNIR Very near infrared radiation WF Woorinen Formation XRD X Ray Diffraction XRF X Ray Fluorescence

v CONTENTS

1 INTRODUCTION ...... 1 2 PREVIOUS STUDIES ...... 1 3 LAND MANAGEMENT QUESTIONS ...... 2 4 Methodology...... 4 4.1 Data Availability and Quality ...... 4 4.1.1. Satellite imagery...... 4 4.1.2 Digital Elevation Models...... 4 4.1.3 Gamma-ray data...... 5 4.2 Image Processing ...... 5 4.3 Fieldwork ...... 6 5 RESULTS...... 6 5.1 Regolith Landform Units ...... 6 5.1.1 Uplands...... 8 5.1.2 Alluvial terrace ...... 8 5.1.3 Floodplain...... 8 5.2 Vegetation ...... 10 5.1.4 Uplands...... 10 5.1.5 Terrace ...... 10 5.1.6 Floodplain...... 10 6 ANALYTICAL DATA...... 12 6.1 Granulometry ...... 13 6.1.1 Methodology...... 13 6.1.2 Results ...... 13 6.2 EC and pH...... 14 6.2.1 Methodology...... 14 6.2.2 Results ...... 14 6.3 XRF geochemistry ...... 16 6.3.1 Methodology...... 16 6.3.2 Results ...... 16 6.4 XRD mineralogy...... 17 6.4.1 Methodology...... 17 6.4.2 Results ...... 17 7 IMPLICATIONS ...... 17 7.1 Constrained inversion and interpretation of AEM data ...... 17 7.2 Hydrogeological issues ...... 17 7.3 Relevance to land management questions...... 18 REFERENCES...... 19 APPENDIX 1. ASTER data and interpretation...... 21 APPENDIX 2. SPOT data and interpretation...... 23 APPENDIX 3. DEM data and interpretation...... 25 APPENDIX 4. Gamma-Ray Imagery...... 27 APPENDIX 5. Surface Materials ...... 28 APPENDIX 6. Site descriptions...... 29 APPENDIX 7: Analytical Results...... 41 Appendix 7.1. Robinvale-Boundary Bend Soil EC and pH data ...... 41 Appendix 7.2. Robinvale-Boundary Bend Laser Grainsize...... 42 Appendix 7.3. Robinvale-Boundary Bend XRF ...... 43 Appendix 7.4. Robinvale-Boundary Bend XRD...... 45

vi LIST OF FIGURES

Figure 1. The Robinvale – Boundary Bend study area...... 1 Figure 2. Conceptual model (cross-section) and geophysical targets in the Robinvale – Boundary Bend area ...... 3 Figure 3. Preliminary schematic hydrogeological cross-section representing the Robinvale – Boundary Bend reach of the Murray River Floodplain upstream of the Tyrell Fault...... 3 Figure 4. DEM coverage in the Robinvale-Boundary bend reach of the RMC survey...... 5 Figure 5. Perspective labelled view of LIDAR DEM approx 10km west of Boundary Bend... 7 Figure 6. Diagrammatic representation of relationships between geomorphic and stratigraphic units...... 7 Figure 7. Vertical view showing uplands, the alluvial terrace, and three generations of meander belts...... 8 Figure 8. Complex alluvial architecture between three generations of floodplain meander belts incised into intermediate flood sediments of the terrace...... 9 Figure 9. LIDAR DEM showing different degrees of meander belt scroll bar degradation in floodplain units of different ages...... 10 Figure 10. Terrace vegetation and materials...... 11 Figure 11. Modern floodplain (left) with well developed river red gum forest and scroll bars. Intermediate floodplain (left) with black box woodland and salt bush understorey...... 11 Figure 12. Oldest floodplain (left) with black box and Lignum-saltbush savannah (Gadsdens Bend, south of Robinvale). Boundary Bend, looking down from terrace across Murray River at youngest meander belt unit. (right)...... 11 Figure 13. Location of soil sample sites in the Robinvale-Boundary Bend area...... 13 Figure 14. Sand and clay percentage from each geomorphic unit...... 14 Figure 15. Mean pH profiles from each geomorphic unit. Note: horizontal bars indicate the standard error of the mean...... 15 Figure 16. Mean EC profiles from each geomorphic unit. Note: horizontal bars indicate the standard error of the mean...... 15

LIST OF TABLES

Table 1. Associations between regolith landform units, vegetation and surface materials ..... 12 Table 2. Range of EC and pH values for different geomorphic units in the Robinvale- Boundary Bend study area...... 14 Table 3. Selected XRF analyses...... 16

vii 1 INTRODUCTION

This report covers the preliminary interpretation of the geomorphology of the River Murray Corridor between Robinvale and just north of Wakool Junction (Figure 1). The name of the survey is thus a misnomer, as the area terminates a considerable distance east of Boundary Bend, which lies a little more than half way along the described area. As described in the Liparoo–Robinvale report (Clarke et al. 2007a) but to a lesser degree, this reach of the River Murray Gorge is narrow, and hence, many geomorphic features are more constrained than further downstream.

Figure 1. The Robinvale – Boundary Bend study area. The main objective of the studies reported here is to provide information for constrained inversion of AEM data as a first step in interpreting those data to provide answers to land use questions posed by catchment management authorities (CMAs) for the area. The studies also provide a materials framework within which to assess the value of the airborne electromagnetic (AEM) data for the land use questions that have been posed by CMAs in the area.

2 PREVIOUS STUDIES

There has been a paucity of studies undertaken on the Murray Floodplain. Those which have been undertaken relate largely to the geology and its evolution in the region, and soils and pedogenesis (Brown and Stephenson 1991; Gill 1973; Macumber 1977; Hills 1975). However, a number of studies have been undertaken in the Riverine Plain of Victoria and NSW, and extrapolated to the Murray floodplain region due to similarities in their evolutionary histories (Bowler and Harford 1966; Butler et al. 1973; Pels 1966). More recently, studies have focused on the ecological or vegetation health (Jolly et al. 1993; Thoms et al. 1999) of the native vegetation. Few studies have linked the geology and physical geography to vegetation, and hence questions of land management, with the study by Rowan and Downes (1963) being a notable exception. This is particularly important given that the

1 floodplain of the Murray River in this region acts as an interface between the river and the regional groundwater systems, with the potential to mobilise large stores of salt under altered hydrological regimes.

This area predominantly falls into the Lindsay Island Land System, with small pockets of the Boigbeat land system (Rowan and Downes 1963). The soils of the Murray Basin are closely related to the underlying Quaternary geology. Grey and brown soils of the Riverine Plain and solonised brown soils of the Mallee region are dominant. The grey and brown soils overlie mainly the fluvial Shepparton and Coonambidgal Formations, while the solonised brown soils overlie a variety of aeolian units including the Woorinen Formation (Brown and Stephenson 1991).

Previous studies (Gill 1973, Kotsonis et al. 1999) have identified terraces in the region. These have been identified as either Shepparton or Rufus Formation, the two terms being equivalent (Brown and Stephenson 1991).

Thoms et al. (1999) recognise that the present day channels and rivers in this region are inset within older channel systems, and are therefore associated with relict floodplain surfaces that contain numerous palaeo-channels and oxbow lakes. Kotsonis et al. (1999) have identified three terraces in the Hattah Lakes region of the Murray River, located in the Nangiloc- Colignan reach of this study.

While the Riverine Plain, on which many of these studies have been based, consists of thick lacustrine and fluviatile sediments deposited mainly in the late Tertiary and Quaternary, the Mallee is a semi-arid region with extensive aeolian deposits often overlying either the Pliocene Loxton Parilla Sands (west of the Tyrell Fault at Robinvale) or the Pleistocene Blanchetown Clay east of the Tyrell Fault. These aeolian deposits occur in the form of two types of dunes in the Mallee. The first is a regular series of linear dunes with an east-west trend mostly stabilised by vegetation which generally have calcareous B horizons and buried palaeosols. The material of which the east-west dunes are composed is a pale to dark reddish- brown calcareous sand with some clay fraction of the Woorinen Formation (Hills 1975). The second type of dune is a complex set of parabolic and transverse dunes which are found outside of the study area.

The Murrumbidgee River joins the Murray River in this reach, forming an ancestral floodplain that is 10 km wide characterised by terraces, abandoned channels, ancestral river meanders and irregular sand dunes (Currey and Dole 1977), similar to those landforms observed downstream. This area, where the Murrumbidgee and Murray Rivers meet, has been described as a vast inland sea during flooding events, often with lengthy inundation periods (Baker and Wright 1977).

3 LAND MANAGEMENT QUESTIONS

There are concerns that existing and potentially new irrigation development could have deleterious impacts on ecological assets such as the Murray River floodplain and its adjacent wetlands. Therefore, key stakeholders, GMW and Mallee CMA, want to identify high and low impact irrigation zones in order to develop a strategy for targeted trading of water to minimise adverse environmental impacts. Identification of major salt influxes to the river and possible interception zones is also desired. In addition, there is an identified need to gain a more detailed understanding of the floodplain characteristics, including flush zones and salt stores, in order to inform management of environmental flows and revegetation strategies.

2 Four land management questions have been identified for this area (Lawrie 2006). They are:

1. Where is salt likely to be mobilised within floodplain? Answering this question involves identifying high conductivity areas within the floodplain (target 1 in Figure 2).

2. What is the influence of irrigation on salt mobilisation and groundwater? Answering this question involves identifying the groundwater mound under irrigation areas (target 2 in Figure 2). Salt likely to be mobilized by irrigation is identified as target 2a in Figure 2. There is the issue of establishing a baseline distribution of high conductivity areas?

3. Can the AEM confirm groundwater flow away from river? Answering this question involves identifying flush zones near the river (target 3 in Figure 2). To confirm flow away from river it is necessary to map the presence or absence of clays, the connectivity of sands and clays in the Murray Gorge sediments, and presence of flush zones, recharge zones and salt stores. Targets that represent elements of this are 1, 3, 3a and 4 in Figure 2.

4. What salinity is associated with leakage from Lake Powell and Carpol, and can AEM help to understand the hydrogeology under these lakes? On Figure 2, target 4 depicts lateral and vertical leakage from the lake.

Reid (2007) provides a schematic hydrological section that shows the distribution and some of the characteristics of stratigraphic units in the area (Figure 3).

The relationships between AEM targets shown in Figure 2, the stratigraphy shown in Figure 3 and the surface geomorphology are discussed below.

Figure 2. Conceptual model (cross-section) and geophysical targets in the Robinvale – Boundary Bend area: WF = Woorinen Formation, CF = Coonambidgal Formation, MS = Monoman Sands, SF = Shepparton Formation, BC = Blanchetown Clay

Figure 3. Preliminary schematic hydrogeological cross-section representing the Robinvale – Boundary Bend reach of the Murray River Floodplain upstream of the Tyrell Fault.

3 4 METHODOLOGY

The primary objective of this study is to define the distribution and character of surface and near-surface materials in the study area. However, mapping the distribution directly is not possible given time and data constraints, as the data required to reliably detect surface material composition are not available and intensive field work is required for verification. Geomorphology can be used as a surrogate and predict the surface materials present. This is a specialised application of the more general principles underpinning regolith landform mapping (Pain et al. 2001). We therefore used LIDAR data to define geomorphic units within the survey area. These units were then characterised using other digital data, listed below, and verified with field checking. Where LIDAR was not available, other available data were used to compile the maps. Polygon definition was based on one set of criteria only where multiple datasets were used to ensure consistency in mapping methods. This procedure provides a reliable definition of the distribution of surface materials within the time available.

4.1 Data Availability and Quality

4.1.1. Satellite imagery The primary satellite images used to compile surface polygons were those from ASTER and SPOT. LANDSAT images were used for comparison and infill, but were not normally interpreted as SPOT and ASTER coverage was generally adequate for the project area. ASTER was used to map total surface variability (including soil mineralogy, moisture and vegetation; Appendix 1), while SPOT was used to compile vegetation maps (Appendix 2).

Most of the Robinvale-Boundary Bend survey area was covered by two ASTER scenes, with the exception of a strip approximately 4 km wide. These scenes, dated 16 April 2001 and 05 March 2001, were the only scenes available and acquired from ACRES in GA. The ASTER scenes were displayed as a composite RGB images using the visible and near infrared radiation (VNIR) bands 3, 2 and 1. Three pan-sharpened pseudo natural colour SPOT scenes with 2.5 m resolution and dated 24 April 2005, 09 May 2005 and 30 December 2004 were also acquired from GA. Bands 3, 2 and 1 were displayed in a composite RGB image. The Landsat-7 ETM ortho-corrected image with 30m resolution was acquired on the 04 Feb 2002.

4.1.2 Digital Elevation Models High resolution airborne LIDAR digital elevation model (DEM) coverage was available for part of the area (Figure 4). The LIDAR data were supplied by MDBC in ArcGRID format with 170 2 km x 2 km tiles at 1 m resolution within the Robinvale-Boundary Ben boundary. The tiles were mosaiced together in ArcInfo and resampled to 2 m to reduce file size.

The Shuttle Radar Terrain Model (SRTM) DEM was used as the base where other, higher resolution DEM data were not available. The SRTM DEM was used as supplementary data only, as the spatial and vertical resolution are too low and the noise level too high at a scale of 1:25 000.

The LIDAR DEM was used for interpretation where it was available. The lower resolution DEMs, supported by ASTER and gamma-ray data, were used to extrapolate the distribution of units defined on the LIDAR DEM, guided by experience gained elsewhere in the River Murray Gorge. The final compilation is shown in Appendix 3.

4

Figure 4. DEM coverage in the Robinvale-Boundary bend reach of the RMC survey.

4.1.3 Gamma-ray data Images of ternary gamma-ray data, displayed showing the potassium channel as red, the uranium channel as blue and the thorium channel as green (Appendix 4), were used to supplement geomorphic mapping of areas with poor LIDAR coverage. This is effective because the materials of the terrace formed by the Rufus Formation (Gill 1973) are distinct from those of the active floodplain on ternary gamma-ray images. The floodplains are almost white in the ternary gamma-ray imagery, indicating strong signals in all three channels. The Rufus Formation on the terrace is generally reddish, indicating a dominant potassium signal. The exception is where the aeolian sands on the terrace are relatively thick, these zones are black, because of low signals in all three channels. The distribution of this distinct material can be used as a proxy for mapping the terrace when LIDAR data, were not available allowing for distinction of the terrace from the floodplain.

4.2 Image Processing The ASTER level 1B scenes were supplied by ACRES in .hdf format, corrected for crosstalk, which is caused by signal leakage from band 4 into adjacent bands 5 and 9, and imported into ERMapper. Importing was carried out in three steps with bands of similar resolution ie. the VNIR bands 1-3 at 1 5m resolution, SWIR (shortwave infrared radiation) bands 5 – 9 at 30 m resolution and TIR (thermal infrared radiation) bands 10 – 14 at 90 m resolution. All bands were rotated and corrected for dark pixels and radiance calibration, which included rescaling of digital values to observed top of atmosphere radiance values. The resultant ERMapper datasets were displayed as composite RGB images.

SPOT 5 images were processed by Geoimage Pty Ltd for NSW Department of Infrastructure Planning and Natural Resources and supplied by GA. Processed LANDSAT 7 data was supplied following ACRES Quality Assessment.

5 The ASTER, SPOT and LIDAR images were printed at a scale of 1:25,000 and interpreted by mapping unit boundaries onto a registered stable transparent overlay with mapping pens. The interpreted line work was digitally scanned and the polygons attributed. The finished images were then printed for verification.

4.3 Fieldwork A field trip was undertaken from 16th-20th May for ground validation. Mapped units were validated by field inspection and samples were collected from soil pits to determine the nature of the materials in the mapped geomorphic units. Field inspection showed that 95% of the mapped units were correctly interpreted during mapping. The soil pits provided qualitative data on the soil profiles to a depth of 30 cm in each unit.

A total of 12 soil pits were dug, all located on road reserves or adjacent to public access tracks. Shallow pits 30 cm deep were dug adjacent to roads in the Robinvale to Boundary Bend area and sampled at 0-10, 10-20, 20-30 cm intervals. These pits provided information of the near-surface stratigraphy and characteristics of the regolith materials and also provided information on the soil structure of the site. These samples will be analysed for mineralogy using X-Ray Diffraction (XRD), for grain size using laser granulometry, and for chemistry using X-Ray Fluorescence (XRF). The site and the pits were photo-documented and the soil profiles and samples described in the field. The holes were filled in on completion. Results of the field tests and descriptions are contained in Appendix 6.

5 RESULTS

5.1 Regolith Landform Units The River Murray Gorge (the Murray River Gorge of Twidale et al. 1978) contains several mappable geomorphic units (Figure 5) and their accompanying sediments (Figure 6) (Appendix 3, 5). Geomorphic differentiation of Gorge fill into terrace and floodplain deposits coincide well with the distinct airborne gamma-ray patterns which show terrace units (Rufus Formation) to be rich in muscovite and therefore comparatively higher in K than in Th or U, whereas the floodplain units (Coonambidgal Formation) show an equally strong signal in all three radioelements. The quartz sand dune-covered uplands showed a very low signature in all three radiogenic elements. Examples of the different geomorphic units are given in Figure 5, Figure 7, Figure 8 and Figure 9.

6 Uplands with dunes Intermediate floodplain

Salt lake or clay pan

Dune

Modern Intermediate floodplain floodplain Intermediate floodplain Dune N

Figure 5. Perspective labelled view of LIDAR DEM approx 10km west of Boundary Bend. 20 x vertical exaggeration.

Figure 6. Diagrammatic representation of relationships between geomorphic and stratigraphic units.

7 5.1.1 Uplands The uplands have sandy regolith, slightly more clayey in the swales, developed on the dunes of the Woorinen Formation. Soils are well-drained and sandy to sandy loams, with moderate amounts of carbonate in the older dunes. These areas are generally cleared for cropping.

Youngest Dune on floodplain floodplain

Alluvial terrace

Uplands

Figure 7. Vertical view showing uplands, the alluvial terrace, and three generations of meander belts. Small source bordering dune present on intermediate meander belt unit.

5.1.2 Alluvial terrace This unit consists of clay and fine sandy alluvium of the Rufus Formation (Gill 1973), which is a western correlative of the Shepparton Formation. It has a discontinuous cover of sand dunes (~Woorinen Formation) and is approximately 60,000 years old (Rogers and Gatehouse 1990). The terrace is mostly flat, with local reddish sand dunes and sand sheets. Where there is no sand the surface of the terrace consists of light to dark olive brown clay loams. Most soils are slightly to moderately saline. Loamy sands of relict dunes locally overlie the floodplain clays.

5.1.3 Floodplain The floodplain is formed on sediments on the Coonambidgal Formation (Butler 1958), and consists of three discrete meander belts with well developed scroll bars (Appendix 3). These units correlate well with vegetation densities and soil types, described in more detail below.

The oldest floodplain meander belt has a degraded scroll bar morphology. This unit is characterised by very dark greyish brown light to medium clay drapes over degraded scroll bars with a relief of about 2 m. There are thin (>2 m in height) source bordering dunes of grey sand. In the Robinvale – Boundary Bend reach of the Murray River, the oldest floodplain units are only present downstream of the confluence of the Murrumbidgee and Murray rivers.

The intermediate floodplain meander belt has rounded morphology, where scroll bars are not as distinct as on the modern floodplain in the LIDAR DEM. Olive-brown clay drapes over lower relief (~1 m) scroll bars are found in this unit. Source-bordering dunes also occur on this unit.

The modern floodplain consists of meander belts and high relief (2 m) scroll bars with crisp morphology and little or no clay draped over the surface. The scroll bars are distinct in the LIDAR DEM. Sediments consist largely of yellowish brown sands. Each set of scroll bars

8 have distinct upstream and downstream morphologies. The upstream portions are higher and have smoothed tops and sand-infilled swales. The downstream portions are slightly lower and show well developed swale and bar morphologies.

Alluvial terrace

Oldest floodplain meander belt Alluvial terrace

Oldest floodplain Dune meander belt

Intermediate floodplain meander belt

Figure 8. Complex alluvial architecture between three generations of floodplain meander belts incised into intermediate flood sediments of the terrace. Location is immediately east of Robinvale. The main Murray River channel sustains active flow and consists of a typical migrating meandering channel. Abandoned channels of the Murray River consist of broad oxbow billabongs lined with clay.

Most soils on the floodplain are slightly to moderately saline. Loamy sands of relict dunes locally overlay the floodplain clays. Clays within the floodplain are typically smectitic and sodic. They are highly dispersive and form an impermeable seal after modest rain. Minor variations in floodplain elevation can significantly affect soil development. Scroll bars found on the oldest and intermediate floodplain units (Coonambidgal Formation) exhibit more profile development with heavier textures and are highly structured in swales compared to the corresponding crest. Due to the formation of a surface seal, water infiltration is limited to the upper layer of the soil profile, leading to surface ponding after rainfall prior to loss through evaporation. While in the field in the Lindsay-Wallpolla reach of the river (Clarke et al. 2007b) in January 2007 we (JC and VW) experienced a 50-150 mm rainfall event and observed only 10-30 cm of moisture penetration afterwards in similar floodplain materials to those observed in the Robinvale to Boundary bend reach of the river. A previous study in the nearby Loddon Plains region noted that increasing salinity was linked to decreasing grain size due to the influence of more dynamic Quaternary stream systems, while saturation of clays near the water table causes swelling which seals flow paths and prevents lateral flow of water (Macumber 1968).

9 Intermediate floodplain meander belt Dune

Billabong

Youngest floodplain meander belt

Intermediate floodplain meander belt Intermediate floodplain meander belt

Figure 9. LIDAR DEM showing different degrees of meander belt scroll bar degradation in floodplain units of different ages. Image is of location ~10 km east of Robinvale.

5.2 Vegetation The distribution of different vegetation units and their relative health are critical for the identification of land management issues, soil types, and provides an indication as to the effectiveness of management strategies. SPOT, LANDSAT and ASTER satellite imagery were proven to be effective in mapping the distribution of these associations. Vegetation units were described according to the structural units established in Specht (1981), as shown in Appendix 2. In the Robinvale – Boundary Bend region, the following associations were observed on the equivalent geomorphic units. The regolith landform units correlate well with vegetation densities and surface materials, shown in Table 1.

5.1.4 Uplands Uplands are covered by E-W trending sand dunes and have extensively cleared for agriculture and horticulture. The remaining native vegetation is predominantly a saltbush (Atriplex sp.) shrubland with isolated Eucalyptus spp. trees.

5.1.5 Terrace In this reach, vegetation found on the terrace unit is predominantly a low open woodland of Black Box (E. largiflorens) with an understorey of Saltbush (Atriplex sp; Figure 10). The dominant vegetation found on this unit is different to that found in the Lindsay-Wallpolla reach most likely due to slight increases in rainfall towards the east.

5.1.6 Floodplain Vegetation on the modern floodplain consists of River Red Gum (E. camaldulensis) open forest (Figure 11). The intermediate floodplain has Black Box (E. largiflorens) woodland or low open woodland (Figure 10), while the oldest floodplain has Black Box (E. largiflorens) low open woodland with Saltbush (Atriplex sp.)-Lignum (Muehlenbeckia florulenta) understorey (Figure 12).

10 River Red Gum low open woodland or woodland occurs along most water courses, with Black Box woodland along smaller, drier courses.

Figure 10. Terrace vegetation and materials. Uncleared terrace (left), cleared terrace (right).

Figure 11. Modern floodplain (left) with well developed river red gum forest and scroll bars. Intermediate floodplain (left) with black box woodland and salt bush understorey.

Figure 12. Oldest floodplain (left) with black box and Lignum-saltbush savannah (Gadsdens Bend, south of Robinvale). Boundary Bend, looking down from terrace across Murray River at youngest meander belt unit. (right).

11 Table 1. Associations between regolith landform units, vegetation and surface materials

Regolith Landform Vegetation Surface Material Unit Uplands (U) Native vegetation primarily Sandy regolith, slightly more cleared for cropping, grazing clayey in the swales, developed on or irrgation the dunes of the Woorinen Formation Alluvial terrace (Ta) Black Box (E. largiflorens) Local red sand dunes and sand low open woodland with sheets, elsewhere the surface of the Saltbush (Atriplex sp.) terrace consists of olive brown clay understorey; occasional Black loams of the Rufus Formation Box savannah Oldest floodplain scroll Black Box (E. largiflorens) Very dark greyish brown light to bars (Fm3) low open woodland with medium clay drapes over degraded Saltbush (Atriplex sp.)-Lignum scroll bars of the Coonambidgal (Muehlenbeckia florulenta) Formation understorey Intermediate floodplain Black Box (E. largiflorens) Olive brown clay drapes over lower scroll bars (Fm2) woodland or low open relief scroll bars of the woodland Coonambidgal Formation Modern floodplain River Red Gum (E. Yellowish brown sands with little scroll bars (Fm1) camaldensis) open forest or no clay of the Coonambidgal Formation

6 ANALYTICAL DATA

Samples from the Robinvale-Boundary Bend section of the survey were collected during the period of May 16th-20th. The soil pit descriptions are contained in Appendix 6 and the full analytical results in Appendix 7. There locations are shown in Figure 13.

12

Figure 13. Location of soil sample sites in the Robinvale-Boundary Bend area.

6.1 Granulometry

6.1.1 Methodology The grainsize was determined using a Malvern Instruments Mastersizer 2000 instrument. The laser diffraction instrument consists of three parts, a laser source (He-Ne gas or diodes emitter), detectors, and sample chamber that allows suspended particles to recirculate in front of the laser beam. The Mie theory (Rawle, 2001) was used to solve the equations for interaction of light with matter and calculates the volume of the particle. This technique calculates the % volume of a range of particle sizes (0.05 – 2000 μm), and the results are grouped according to the Wentworth scale. To standardise with other analytical data, SI units (μm) were reported instead of Phi units.

6.1.2 Results Samples from each site had fairly similar distributions, indicating that within the sampled depth range there were only minor differences in grainsize distribution. Some surface samples were less sandy than those at depth, indicating more abundant silt and clay at the surface. This is interpreted to be from the draping of older land surfaces by fine-grained material deposited by flood waters.

As observed at Lindsay-Wallpolla and Liparoo-Robinvale, the youngest meander plain units were predominantly silty sands to sandy silts. Older units were clayey silts and silty clays, indicating that the coarser meander units had been draped by overbank fines.

Particle size analysis showed a general trend of fining with distance from the main river channel within the Murray River Trench (Figure 14). Soils were generally sandier on the Fm1 unit and more clay-rich on the Fm2 and Terrace units unit.

13 60 Fm1 Fm2 50 T 40

30 Sand (%) Sand 20

10

0 0 102030405060 Clay (%)

Figure 14. Sand and clay percentage from each geomorphic unit

6.2 EC and pH

6.2.1 Methodology Measuring salinity and pH in soil was carried out using the 1:5 method. With this method, 10ml of distilled water was placed in a measuring container and small soil particles added until the volume of the contents of the container increased by 5ml to bring the volume to 15ml. additional water is then added to bring the total volume to 30ml. the sample is shaken intermittently for five minutes and allowing it to settle for five minutes. EC and pH probes are dipped into the solution and readings taken.

6.2.2 Results The measured EC values ranged between 0.081 and 2.256 dS/m, with the majority (all but seven) falling below 1.0 dS/m. There is no obvious trend between conductivity and geomorphic unit. The relatively high conductivities (>1.0) are found in units Fm1 and T.

Table 2. Range of EC and pH values for different geomorphic units in the Robinvale-Boundary Bend study area.

Geomorphic Unit pH (1:5) EC1:5 (dS/m)

Fm1 4.22-6.4 0.081-1.27

Fm2 5.91-6.9 0.129-0.219

T 6.51-9.13 0.177-2.256

Measured pH values range between 4.22 and 9.043, with the majority of the samples being acidic. There is a clear trend between increasing age of geomorphic unit and increasing pH. The youngest geomorphic units are almost entirely acidic, including almost all examples of unit Fm1, levees of the Murray River above Wakool Junction and abandoned or anastomosing channels. The smooth floodplain unit above Wakool Junction shows a wide range of values

14 from acid to alkaline. Soils from the terrace unit are near neutral to alkaline. Comparison between EC, pH, and geomorphic unit, are made in Table 2. pH and EC profiles are shown in Figure 15 and Figure 16, respectively. pH was lowest in the Fm1 unit, however, there were insufficient replicates to determine trends in pH in the Fm2 and T units. Similarly, however, there were insufficient replicates to determine trends in EC in the Fm2 and T units. The Fm1 unit was non-saline at the surface (EC1:5 < 0.4 dS/m) and increased in EC with depth ( Figure 16).

pH1:5 3456789 0

0.05

0.1 Fm1 0.15 Fm2 T

Depth (m) Depth 0.2

0.25

0.3

Figure 15. Mean pH profiles from each geomorphic unit. Note: horizontal bars indicate the standard error of the mean; Fm2 and T profiles do not have error bars due to insufficient replicates.

EC1:5 (dS/m) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0

0.05 Fm1

0.1 Fm2 T 0.15

Depth (m) 0.2

0.25

0.3

Figure 16. Mean EC profiles from each geomorphic unit. Note: horizontal bars indicate the standard error of the mean; Fm2 and T profiles do not have error bars due to insufficient replicates.

15 6.3 XRF geochemistry

6.3.1 Methodology The samples were pulverized using a tungsten carbide mill and the elements were analyzed by XRF. For major element determination (SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, P2O5, and S), samples were prepared as fused discs following the method of Norrish and Hutton (1964), with the exception that the flux used consisted of 12 parts lithium tetraborate to 22 parts lithium metaborate. The glass discs were analyzed on a PW2400 wavelength dispersive X-ray fluorescence (XRF) spectrometer. The 35 trace elements were determined on pressed powder samples using a SPECTRO X-Lab energy dispersive XRF spectrometer. The powders were also measured on a PW1400 wavelength dispersive XRF spectrometer for Sc, V and Cr, using methods described in Chappell (1991) and Norrish and Chappell (1967). Tungsten and Co were probably added to the samples during the milling process, and hence these elements have not been reported. The major elements and minor element values are shown as % and ppm respectively.

The percentage of volatile materials in the samples was determined using a LECO RC-412 multiphase carbon and water analyzer. Nitrogen was used as the carrier gas for combustion and the furnace control system allows the temperature of the furnace to be stepped and subjected to ramping (from 90 to 1040 oC). Water and carbon dioxide released from the minerals during combustion are detected by means of infrared absorption cells (IR-cells) and the results are then calculated as CO2 and H2O respectively.

Table 3. Selected XRF analyses.

Geomorphi Depth Al2O CaO Cl Fe2O3 K2O Na2 S SiO2 Th (%) U (%) c unit (m) 3 (%) (%) (%) (%) (%) O (%) (%) (%) 11.88 0.435 0.634 3.542 2.175 0.42 0.37 70.45 0.0240 0.0082 0.00-0.10 9 6 2 0 0 3 12.04 0.340 0.323 3.552 2.229 0.45 0.21 73.55 0.0222 0.0071 Fm1 0.10-0.20 1 4 7 7 5 4 11.61 0.343 0.236 3.433 2.208 0.46 0.17 74.76 0.0236 0.0083 0.20-.030 8 9 8 3 3 8 14.13 0.687 0.154 4.728 2.432 0.35 0.22 66.28 0.0290 0.0052 0.00-0.10 5 4 9 7 0 5 15.18 0.756 0.195 5.152 2.482 0.36 0.16 65.93 0.0270 0.0063 Fm2 0.10-0.20 5 6 2 6 0 5 15.33 0.826 0.187 5.280 2.441 0.35 0.14 64.38 0.0365 0.0086 0.20-.030 1 2 7 2 0 5 11.30 1.476 0.147 3.828 2.188 0.34 0.20 71.70 0.0250 0.0071 0.00-0.10 6 1 9 1 0 5 11.53 3.797 0.566 3.942 2.103 0.43 0.21 66.14 0.0520 0.0075 T 0.10-0.20 2 4 9 8 0 0 12.49 3.879 1.728 4.368 2.173 0.59 0.30 65.14 0.0225 0.0061 0.20-.030 6 1 6 8 0 5 Note: Fm1 depths show mean concentrations; Fm2 and T show concentrations from one profile

6.3.2 Results The primary purpose of the XRF analyses was to obtain measurements of the abundances of K, Th, and U, should detailed interpretation of the gamma-ray radiometric data be required. Beyond this, only a limited number of comparisons of elemental abundances were made

16 because of time limitations. Major elements correlated reasonably well with what can be predicted from the main minerals present. The XRF results reflect the high quartz content of the soils with high SiO2 concentrations across all geomorphic units and depths (Table 3. Selected XRF analyses..

6.4 XRD mineralogy

6.4.1 Methodology Samples were analysed using both semi-quantitative XRD and qualitative PIMA methods. Samples for XRD were scanned on a Siemens D500 Diffractometer, from 2° to 70° 2θ, in 1° increments, 2 seconds per degree, using a Cu anode X-ray tube. Minerals were identified using Bruker Diffracplus and Siroquant V3 was used to quantify minerals. The samples are characterised by simple scans, containing predominant Quartz peaks with accessory mica (probably Muscovite), feldspar and clay (probably Kaolin). Specific feldspars have been identified according to best-fit of peaks. Further petrological work would be required to conclusively identify feldspars.

6.4.2 Results XRD shows that the samples all contain quartz, muscovite, and microcline. Kaolinite and albite are present in almost all. These results are consistent with the samples being composed of two sediment types, a slightly feldspathic micaceous quartz sand and kaolinitic quartz silt with very fine-grained detrital muscovite, forming a sand of sub-arkosic composition. These are consistent with sediment derived from largely unweathered rocks in the eastern highlands. Some contribution from the reworking of unweathered Loxton-Parilla sands is possible, as these too contain muscovite. Further work on clay separates may provide useful data on sources and regional distribution of clay types (c.f. Gingele and De Deckker 2004) but is beyond the scope of the present study.

7 IMPLICATIONS

7.1 Constrained inversion and interpretation of AEM data For preliminary AEM constrained inversions the survey area fill should be divided into three units:

• The Uplands outside the River Murray Gorge

• The terrace lithologies inside the Gorge (Rufus Formation)

• The modern floodplain inset into the Rufus Formation (Coonambidgal Formation).

From interpretation of the AEM data inverted into a conductivity structure of the ground it may be possible to differentiate the floodplain into smaller units that correspond to the meanders belts identified in LIDAR interpretation.

7.2 Hydrogeological issues Reid (2007) should be consulted for details on the hydrogeology. However, the following observations add to that work from a geomorphic point of view.

The geomorphological interpretation of the data suggests that river flow may be strongly compartmentalised along river by different aged floodplain units in a hierarchical fashion.

17 The River Murray Gorge is cut into older Murray Basin units (in this reach the Blanchetown Clay, which is, however covered by dunes and slope deposits) and filled by a number of discrete stratigraphic units. The Rufus Formation forms a high level terrace of older alluvial sediments. The Coonambidgal Formation is inset within the Rufus Formation (Gill 1973) and is shown in cross sections by Rogers and Gatehouse (1990). The modern, intermediate and oldest meander belt units are morphological subdivisions of the Coonambidgal Formation.

The different relative ages noted above are likely to indicate different regolith properties with different flow characteristics. There is likely to be good connectivity in a down valley direction, within similar morphological and sedimentary units. On the other hand there may be poor cross-valley interconnection between different morphological and sedimentary units. From these observations we can predict a number of recharge characteristics.

All but the youngest floodplain sediments are sealed by dispersive clays, and therefore there will be little or no recharge on older floodplain and terrace units. On the other hand, active channels have sandy bottoms, but once flow stops they become clay lined, so there is no recharge via abandoned channels. Cracking clays are of limited extent, and occur only in abandoned channels. There is limited bypassing of surface clays early in heavy rainfall events through these cracks. Sand dunes on the uplands are areas of localised high infiltration, and there is local perching of water within the sand and on top of underlying Blanchetown Clay.

Zones of healthy vegetation that show as red in colour on ASTER images are widest on modern floodplain where the scroll bars consist of exposed sand. This suggests extensive flushing of saline water from runoff, infiltration, and through flowing river waters. The healthy zone is much narrower in abandoned or inset channels, indicating less flushing, possibly due to isolation of channel water from surrounding floodplain materials by the clay seal on the channel bed.

7.3 Relevance to land management questions Where is salt likely to be mobilised within floodplain?

Not answerable by within the data contained in the geomorphology report.

What is the influence of irrigation on salt mobilisation and groundwater?

Not answerable by the data contained in the geomorphology report.

Can the AEM confirm groundwater flow away from river?

Not answerable by within the data contained in the geomorphology report.

What salinity is associated with leakage from Lake Powell and Carpol, and can AEM help to understand the hydrogeology under these lakes?

Not answerable by the data contained in the geomorphology report. Ground truthing on the salinity of the near surface sediments may assist in answering this question which will otherwise depend on AEM data and their interpretation.

18 REFERENCES

Baker, B.W. and Wright, G.L. 1977. The Murray Valley: its hydrologic regime and the effects of water development on the river. Proceedings of the Royal Society of Victoria 90, 103-110.

Bowler, J. M, and Harford L. B. 1966. Quaternary tectonics and the evolution of the Riverine Plain near Echuca, Victoria. Journal of the Geological Society of Australia 13, 339- 354.

Brown, C.M. and Stephenson, A.E. 1991. Geology of the Murray Basin, southeastern Australia. BMR Bulletin 235, 430pp.

Butler, B. E. 1958. Depositional systems of the riverine plain of south-eastern Australia in relation to soils. Commonwealth Scientific and Industrial Research Organisation, Soil Publication 10, 35pp.

Butler, B. E., Blackburn, G., Bowler, J. M., Lawrence, C. R., Newell, J. W., Pels, S. 1973. A Geomorphic Map of the Riverine Plain of South-eastern Australia. Australian National University Press, Canberra.

Chappell, B.W. 1991. Trace element analysis of rocks by X-ray spectrometry. Advances in X- Ray Analysis 34, 263-276.

Clarke, J. Pain, C., Wong, V., Apps, H., Gibson, D., Luckman, J., and Lawrie, K., 2007a. Geomorphology and Surface Materials: Liparoo to Robinvale. CRC LEME Restricted Report 258R.

Clarke, J. Wong, V., Pain, C., Apps, H., Gibson, D., Luckman, J., and Lawrie, K., 2007. Geomorphology and Surface Materials: Lindsay to Wallpolla. CRC LEME Restricted Report 261R.

Currey, D.T. and Dole, D.J. 1977. River Murray flood flow patterns and geomorphic tracts. Proceedings of the Royal Society of Victoria 90, 67-77.

Gill, E.D. 1973. Geology and geomorphology of the Murray River region between Mildura and Renmark, Australia. Memoirs of the National Museum of Victoria 34, 1-97.

Gingele, F.X. and De Deckker, P. 2004. Fingerprinting Australia's rivers with clay minerals and the application for the marine record of climate change. Australian Journal of Earth Sciences 51(3), 339-348.

Hills, E. S. 1975 Physiography of Victoria: an introduction to geomorphology. Whitcombe and Tombs, Australia).

Jolly, I. D., Walker, G.R., and Thorburn, P. J. 1993. Salt accumulation in semi-arid floodplain soils with implications for forest health. Journal of Hydrology 150, 589-614.

Kotsonis, A, Cameron, K. J., Bowler, J. M., Joyce, E. B. 1999 Geomorphology of the Hattah Lakes Region on the River Murray, southeastern Australia: A record of late Quaternary climate change. Proceedings of the Royal Society of Victoria 111, 27-42.

Lawrie, K. 2006. Report by technical working group chair on proposed River Murray corridor (South Australian border to Gunbower) Victorian AEM mapping project. CRC LEME Restricted Report 265R, 29pp.

19 Macumber, P.G. 1968. Interrelationship between physiography, hydrology, sedimentation, and salinization of the Loddon River Plains, Australia. Journal of Hydrology 7, 39-57.

Macumber, P.G. 1977. Evolution of the Murray River during the Tertiary period: evidence from northern Victoria. Proceedings of the Royal Society of Victoria 90, 43-52.

Norrish, K. and Chappell, B. W. 1967. X-ray fluorescence spectrography. In Zussman, J. (ed.) Physical methods in determinative mineralogy. Academic Press, London.

Norrish and Hutton 1969. 1969. An accurate X-ray spectrographic method for the analysis of a wide range of geological samples. Geochimica et Ccosmochica. Acta 33 431-453.

Pain, C.F., Craig, M.A., Gibson, D.L. and Wilford, J.R. 2001. Regolith-landform mapping: an Australian approach In P.T. Bobrowsky (Editor). Geoenvironmental Mapping, Method, Theory and Practice A.A. Balkema, Swets and Zeitlinger Publishers, The Netherlands, 29-56.

Pels, S. 1966. Late quaternary chronology of the riverine plain of southeastern Australia. Journal of the Geological Society of Australia 13, 27-40.

Rawle, A.F. 2003. Method development for particle size measurement by laser diffraction. Particulates Systems Analysis Conference (2003), Harrogate, UK

Reid, M. 2007. Hydrogeological Review of the Victorian Side of the Murray River Floodplain Site (Gunbower Island to Lindsay Wallpolla). CRC LEME Restricted Report 257R, 71pp.

Rogers, P.A. and Gatehouse, C.G. 1990. Late Quaternary stratigraphy of the Roonka archaeological sites. Quarterly Geological Notes - Geological Survey of South Australia, 113, 6-14.

Rowan, J. N. and Downes, R.G. 1963. A study of the land in north-western Victoria. (Soil Conservation Authority: Victoria).

Specht, R. L. 1981. Foliage projective cover and standing biomass. In Gillison, A.N. and Anderson, D.J . (eds), Vegetation classification in Australia, CSIRO & ANU: Canberra, 10-21.

Thoms, M.C, Ogden, R.W., and Reid, M.A. 1999. Establishing the condition of lowland floodplain rivers: a palaeo-ecological approach. Freshwater Biology 41, 407-423.

Twidale, C.R., Lindsay, J.M., and Bourne, J.A. 1978. Age and origin of the Murray River and gorge in South Australia. Proceedings of the Royal Society of Victoria, 90, 27-42.

20 APPENDIX 1. ASTER DATA AND INTERPRETATION

21 Surface properties map interpreted from ASTER data

22 APPENDIX 2. SPOT DATA AND INTERPRETATION

23 Vegetation map interpreted from SPOT data

24 APPENDIX 3. DEM DATA AND INTERPRETATION

25 Landforms interpreted from DEM data

26 APPENDIX 4. GAMMA-RAY IMAGERY

27 APPENDIX 5. SURFACE MATERIALS

28 APPENDIX 6. SITE DESCRIPTIONS

Site 107

Knights bend

Coordinates

0664789E 6169706N

Location description

Terrace Unit

Site description

Flat, cleared pasture, minor signs of disturbance; brick fragments, drain line to east, dyke to north. Original vegetation likely to be a low open woodland of Black Box with saltbush understorey.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-10 5YR 3/3 8.5 Loamy sand Platy Fine and coarse roots present

10-20 10YR 4/4 9.5-10 Sandy loam Sub-angular Fine and coarse roots blocky present

20-30 10YR 4/6 with 9.5-10 Sandy loam Sub-angular Fine and coarse roots minor mottling blocky present

29 Site 108

Knights bend

Coordinates

0665115E 6169984N

Location description

Fm2 (intermediate floodplain meander belt), south side of bend cutoff.

Site description

Black box low open woodland with occasional River Red Gums, lower stratum of juvenile Eucalypts and grassy understorey.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-10 7.5 YR 2.5/2 5.5 Clay loam Sub-angular Cryptogamic crust and blocky thin layer of litter and occasional carbonate nodules on surface; fine and coarse roots present

10-20 5Y 2.5/1 7.5 Light clay Angular Diffuse boundary at 10 blocky cm; carbonate and manganese nodules present; fine and coarse roots present

20-30 5Y 2.5/1 8 Medium clay Angular Carbonate and blocky manganese nodules present; fine and coarse roots present

30 Site 109

Small, low amplitude meander to east of Walsh’s bend.

Coordinates

0668193E 6168053N

Location description

Terrace

Site description

Low open woodland of Black Box with occasional River Red Gum and understorey of Saltbush.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-10 10YR 3/3 6 Sandy clay Sub-angular Cryptogamic crust and blocky occasional carbonate nodules on surface; fine and coarse roots present

10-20 10YR 3/2 6.5 Sandy clay Angular Fine and coarse roots blocky present

20-30 2.5Y 3/2 8 Light clay Angular Manganese nodules blocky present; fine and coarse roots present

31 Site 110

Small low amplitude meander to east of Walsh’s bend

Coordinates

0668638E 6167686N

Location description

Fm1 (youngest floodplain meander belt), spill over bar

Site description

Open forest of mixed River Red Gums and Black Box, understorey of lignum, saltbush and grass.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-6 10YR 3/2 5.5 Sandy loam Sub-angular Thin layer of litter on blocky surface; dark A horizon; fine and coarse roots present

6-10 10YR 5/4 mottled 6 Loamy sand Sub-angular Fine and coarse roots with 10YR 4/6 blocky present (approx 10% mottles)

10-20 10YR 4/3 6.5 Loamy sand Sub-angular Fine and coarse roots blocky present

20-30 10YR 3/2 mottled 6.5 Sandy clay Sub-angular Distinct boundary at 20 with 10YR 5/4 blocky cm; fine and coarse (approx. 20 % roots present mottles)

32 Site 111

Small low amplitude meander to east of Walsh’s bend

Coordinates

0668617E 6167741N

Location description

Fm1, spill over swale

Site description

Open forest of mixed River Red Gums and Black Box, understorey of lignum, saltbush and grass.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-6 10YR 5/3 5.5 Loamy sand Sub-angular Layer of litter on blocky surface of approx. 2 cm; slightly darker layer; fine and coarse roots present

6-10 10YR 6/3 with 5 Loamy sand Sub-angular Fine and coarse roots minor mottling blocky present

10-20 2.5Y 3/3 mottled 5 Sandy clay Angular Diffuse layering at 15 with 10 YR 5/8 blocky cm; fine and coarse (approx. 25% roots present mottles)

20-30 2.5Y 3/1 with 6 Light clay Angular Fine and coarse roots minor mottling blocky present

33 Site 112

Small low amplitude meander to east of Walsh’s bend

Coordinates

0668019E 6168445N

Location description

Fm1, trailing bar

Site description

Open forest of River Red Gums with occasional Black Box trees and grassy understorey.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-4 7.5 YR 3/2 7 Loam Sub-angular Layer of litter on blocky surface of approx. 3 cm; darker A horizon high in organic material; fine and coarse roots present

4-10 10YR 4/2 mottled 4.5 Clay loam Sub-angular Fine and coarse roots with 10 YR 4/6 blocky present (approx. 25% mottles)

10-20 10YR 4/3 mottled 4.5 Light clay Sub-angular Fine and coarse roots with 10YR 4/6 blocky present (approx. 10 % mottles)

20-30 10YR 4/2 mottled 4.5 Medium clay Angular Fine and coarse roots with 7.5YR 4/6 blocky present (approx. 10% mottles)

34 Site 113

Small low amplitude meander to east of Walsh’s bend

Coordinates

0668026E 6168459N

Location description

Fm1, trailing bar

Site description

Open forest of River Red Gums with occasional Black Box trees and grassy understorey.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-5 7.5YR 2.5/1 7 Sandy loam Sub-angular Surface layer of litter of blocky approx. 3 cm; darker layer with organic material mixed in; Fine and coarse roots present

5-10 10YR 5/3 mottled 4.5 Clay loam Sub-angular Fine and coarse roots with 10YR 5/8 blocky present (approx. 25% mottles)

10-20 10YR 5/3 mottled 4.5 Clay loam Sub-angular Fine and coarse roots with 10YR 5/8 blocky present (approx. 25% mottles)

20-30 10YR 4/3 mottled 4.5 Medium clay Angular Fine and coarse roots with 5YR 5/8 blocky present (approx. 50% mottles)

35 Site 114

Walshs bend

Coordinates

0668026E 6168459N

Location description

Fm1, spill over bar

Site description

Open forest of River Red Gums with grassy understorey. Some site disturbance by campers.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-5 7.5 YR 3/2 7 Loamy sand Sub-angular Surface layer of litter of blocky approx. 2 cm; layer high in organic material; fine and coarse roots present

5-10 10YR 4/3 5.5 Loamy sand Sub-angular Fine and coarse roots blocky present

10-20 10YR 5/3 mottled 4.5 Sandy loam Sub-angular Fine and coarse roots with 10YR 5/8 blocky present (approx. 25 % mottles)

20-30 10YR 4/3 mottled 4.5 Sandy loam Sub-angular Fine and coarse roots with 7.5 YR 5/8 blocky present (approx. 40% mottles)

36 Site 115

Walsh’s bend

Coordinates

0667168E 6169710N

Location description

Fm1 Spill over swale

Site description

About 10 m from previous site, River Red Gum woodland with abundant litter. Some site disturbance by campers.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-5 10YR 3/4 7.5 Loamy sand Sub-angular Thick layer of surface blocky litter of approx. 5 cm; fine and coarse roots present

5-10 10YR 4/3 mottled 5 Loamy sand Sub-angular Fine and coarse roots with 7.5 YR 4/6 blocky present (approx. 25 % mottles)

10-20 10YR 4/4 mottled 4.5 Sandy loam Sub-angular Fine and coarse roots with 7.5 YR blocky present (approx. 10% mottles)

20-30 10YR 4/3 mottled 4.5 Clay loam Angular Fine and coarse roots with 7.5YR 5/8 blocky present (approx. 10% mottles)

37 Site 116

Walsh’s bend

Coordinates

0666856E 6169437N

Location description

Fm1 trailing bar

Site description

Well developed scroll bar-swale relief; River Red Gum open forest with grassy understorey

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-6 10YR 3/2 6 Clay loam Sub-angular Thin layer of surface blocky litter; fine and coarse roots present

6-10 10YR 4/3 mottled 5 Clay loam Sub-angular Fine and coarse roots with 10YR 5/8 blocky present (approx. 10% mottles)

10-20 10YR 4/3 mottled 4.5 Clay loam Sub-angular Fine and coarse roots with 7.5YR 5/8 blocky present (approx. 20 % mottles)

20-30 10YR 4/3 mottled 4.5 Light clay Sub-angular Fine and coarse roots with 7.5 YR 5/8 blocky present (approx. 20% mottles)

38 Site 117

Walsh’s bend

Coordinates

0666862E 6169405N

Location description

Fm1, trailing swale

Site description

Swale to scroll bar at site 116. Well developed scroll bar-swale relief, River Red Gum open forest with grassy understorey

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-6 10YR 3/3 6 Loam Sub-angular Fine and coarse roots blocky present

6-10 10YR 4/3 5 Sandy loam Sub-angular Fine and coarse roots blocky present

10-20 10YR 4/3 mottled 4.5 Light clay Sub-angular Fine and coarse roots with 5YR 4/6 blocky present (approx. 40% mottles)

20-30 10YR 4/2 mottled 4.5 Medium clay Angular Fine and coarse roots with 5YR 4/6 blocky present (approx. 40% mottles)

39 Site 118

Walsh’s bend

Coordinates

0667031E 6168407N

Location description

Narrow strip of Fm2 between terrace and Fm1

Site description

Black Box low open woodland with saltbush and grass understorey, microbiotic crust.

Soil Profile

Depth Munsell Colour Field pH Field Texture Structure Comments (cm)

0-10 10YR3/2 6 Clay loam Sub-angular Thin layer of litter on blocky surface; fine and coarse roots present

10-20 10YR 3/1 7 Light clay Sub-angular Fine and coarse roots blocky present; manganese nodules present

20-30 10YR 3/1 7.5 Medium clay Angular Fine and coarse roots blocky present

40 APPENDIX 7: ANALYTICAL RESULTS

Appendix 7.1. Robinvale-Boundary Bend Soil EC and pH data Moisture Site Geomorphic Top Base EC1:5 Easting Northing Zone Sample ID Sample No. pH (1:5) Content No. unit Depth (m) Depth (m) (dS/m) (%) 107 664789 6169706 54 T 0 0.1 2007735026001 1937002 7.58 0.167 14.5 107 664789 6169706 54 T 0.1 0.2 2007735026002 1937003 9.04 0.227 15.7 107 664789 6169706 54 T 0.2 0.3 2007735026003 1937004 9.13 0.565 15.5 108 665115 6169984 54 Fm2 0.2 0.3 2007735027003 1937007 6.9 0.139 17.1 108 665115 6169984 54 Fm2 0.1 0.2 2007735027002 1937006 6.76 0.154 29.8 108 665115 6169984 54 Fm2 0 0.1 2007735027001 1937005 6.57 0.219 17.1 109 668193 6168053 54 T 0 0.1 2007735028001 1937008 6.53 0.177 17.1 109 668193 6168053 54 T 0.1 0.2 2007735028002 1937009 6.51 0.938 17.0 109 668193 6168053 54 T 0.2 0.3 2007735028003 1937010 6.57 2.250 17.3 110 668638 6167686 54 Fm1 0.1 0.2 2007735029002 1937012 6.4 0.081 11.3 110 668638 6167686 54 Fm1 0.2 0.3 2007735029003 1937013 6.38 0.090 12.6 110 668638 6167686 54 Fm1 0 0.1 2007735029001 1937011 6.33 0.155 15.0 111 668617 6167741 54 Fm1 0.2 0.3 2007735030003 1937016 5.45 0.187 13.1 111 668617 6167741 54 Fm1 0.1 0.2 2007735030002 1937015 5.13 0.202 11.9 111 668617 6167741 54 Fm1 0 0.1 2007735030001 1937014 4.79 0.381 11.1 112 668019 6168445 54 Fm1 0.1 0.2 2007735031002 1937018 4.58 0.310 19.4 112 668019 6168445 54 Fm1 0.2 0.3 2007735031003 1937019 4.65 0.330 20.3 112 668019 6168445 54 Fm1 0 0.1 2007735031001 1937017 4.22 0.911 18.1 113 668026 6168459 54 Fm1 0.2 0.3 2007735032003 1937022 5 0.131 17.0 113 668026 6168459 54 Fm1 0.1 0.2 2007735032002 1937021 4.79 0.145 15.8 113 668026 6168459 54 Fm1 0 0.1 2007735032001 1937020 4.63 0.280 12.9 114 668026 6168459 54 Fm1 0.2 0.3 2007735033003 1937025 4.66 0.136 12.2 114 668026 6168459 54 Fm1 0.1 0.2 2007735033002 1937024 4.26 0.240 12.7 114 668026 6168459 54 Fm1 0 0.1 2007735033001 1937023 4.32 0.433 25.1 115 667168 6169710 54 Fm1 0.2 0.3 2007735034003 1937028 4.31 0.407 17.7 115 667168 6169710 54 Fm1 0.1 0.2 2007735034002 1937027 4.32 0.623 14.5 115 667168 6169710 54 Fm1 0 0.1 2007735034001 1937026 4.27 1.270 11.5 116 666856 6169437 54 Fm1 0.2 0.3 2007735035003 1937031 4.48 0.400 16.0 116 666856 6169437 54 Fm1 0.1 0.2 2007735035002 1937030 4.46 0.655 17.6 116 666856 6169437 54 Fm1 0 0.1 2007735035001 1937029 4.95 0.909 22.2 117 666862 6169405 54 Fm1 0.2 0.3 2007735036003 1937034 5 0.131 11.2 117 666862 6169405 54 Fm1 0.1 0.2 2007735036002 1937033 4.94 0.178 17.3 117 666862 6169405 54 Fm1 0 0.1 2007735036001 1937032 4.54 0.251 17.2 118 667031 6168407 54 Fm2 0.1 0.2 2007335037002 1937036 6.28 0.159 17.1 118 667031 6168407 54 Fm2 0.2 0.3 2007735037003 1937037 6.53 0.176 17.2 118 667031 6168407 54 Fm2 0 0.1 2007735037001 1937035 5.91 0.207 18.1

41 Appendix 7.2. Robinvale-Boundary Bend Laser Grainsize Top Base % Sand Geomorphic % Clay % Silt (3.9- Site No. Easting Northing Zone Depth Depth Sample No. Sample ID (62.5- unit (<3.9um) 62.5um) (m) (m) 2000um) 110 668638 6167686 54 Fm1 0 0.1 1937011 2007735029001 16.042068 31.707594 52.250337 clayey silt sand 110 668638 6167686 54 Fm1 0.1 0.2 1937012 2007735029002 16.212569 28.105415 55.682016 clayey silt sand 110 668638 6167686 54 Fm1 0.2 0.3 1937013 2007735029003 18.530354 41.968149 39.501498 clayey sandy silt 111 668617 6167741 54 Fm1 0 0.1 1937014 2007735030001 20.608031 41.625375 37.766594 clayey sandy silt 111 668617 6167741 54 Fm1 0.1 0.2 1937015 2007735030002 23.878522 44.043449 32.078029 clayey sandy silt 111 668617 6167741 54 Fm1 0.2 0.3 1937016 2007735030003 28.494312 46.732169 24.773519 sandy clayey silt 112 668019 6168445 54 Fm1 0 0.1 1937017 2007735031001 31.22127 64.699767 4.078964 clayey silt 112 668019 6168445 54 Fm1 0.1 0.2 1937018 2007735031002 29.399773 68.130167 2.47006 clayey silt 112 668019 6168445 54 Fm1 0.2 0.3 1937019 2007735031003 27.28018 68.43868 4.28114 clayey silt 113 668026 6168459 54 Fm1 0 0.1 1937020 2007735032001 31.266619 63.493523 5.239858 clayey silt 113 668026 6168459 54 Fm1 0.1 0.2 1937021 2007735032002 29.605814 65.616339 4.777847 clayey silt 113 668026 6168459 54 Fm1 0.2 0.3 1937022 2007735032003 25.839831 61.66646 12.493709 sandy clayey silt 114 668026 6168459 54 Fm1 0 0.1 1937023 2007735033001 20.833935 49.283201 29.882864 clayey sandy silt 114 668026 6168459 54 Fm1 0.1 0.2 1937024 2007735033002 17.062698 41.547848 41.389454 clayey sandy silt 114 668026 6168459 54 Fm1 0.2 0.3 1937025 2007735033003 12.035328 37.040299 50.924373 clayey silty sand 115 667168 6169710 54 Fm1 0 0.1 1937026 2007735034001 23.740278 55.559001 20.700721 sandy clayey silt 115 667168 6169710 54 Fm1 0.1 0.2 1937027 2007735034002 21.589425 56.744043 21.666532 clayey sandy silt 115 667168 6169710 54 Fm1 0.2 0.3 1937028 2007735034003 19.886298 55.625928 24.487775 clayey sandy silt 116 666856 6169437 54 Fm1 0 0.1 1937029 2007735035001 25.306697 60.974477 13.718826 sandy clayey silt 116 666856 6169437 54 Fm1 0.1 0.2 1937030 2007735035002 19.735112 63.453307 16.811581 sandy clayey silt 116 666856 6169437 54 Fm1 0.2 0.3 1937031 2007735035003 19.61836 59.902975 20.478666 clayey sandy silt 117 666862 6169405 54 Fm1 0 0.1 1937032 2007735036001 26.700117 63.090789 10.209094 sandy clayey silt 117 666862 6169405 54 Fm1 0.1 0.2 1937033 2007735036002 29.764771 65.551374 4.683855 clayey silt 117 666862 6169405 54 Fm1 0.2 0.3 1937034 2007735036003 24.210439 64.209378 11.580183 sandy clayey silt 108 665115 6169984 54 Fm2 0.1 0.2 1937006 2007735027002 20.80787 38.86516 40.326969 clayey silty sand 108 665115 6169984 54 Fm2 0.2 0.3 1937007 2007735027003 37.959742 33.179711 28.860547 sandy silty clay 118 667031 6168407 54 Fm2 0 0.1 1937035 2007735037001 33.451115 55.909902 10.638983 sandy clayey silt 118 667031 6168407 54 Fm2 0.1 0.2 1937036 2007335037002 39.184562 52.384532 8.430906 clayey silt 118 667031 6168407 54 Fm2 0.2 0.3 1937037 2007735037003 44.362282 47.726094 7.911624 clayey silt 108 665115 6169984 54 Fm2 0 0.1 1937005 2007735027001 42.188486 49.470038 8.341476 clayey silt 107 664789 6169706 54 T 0 0.1 1937002 2007735026001 53.236425 44.831983 1.931592 silty clay 107 664789 6169706 54 T 0.1 0.2 1937003 2007735026002 44.957577 53.061284 1.981139 clayey silt 107 664789 6169706 54 T 0.2 0.3 1937004 2007735026003 29.155832 61.332998 9.51117 clayey silt 109 668193 6168053 54 T 0 0.1 1937008 2007735028001 45.352064 29.468111 25.179825 sandy silty clay 109 668193 6168053 54 T 0.1 0.2 1937009 2007735028002 45.080019 31.01074 23.90924 sandy silty clay 109 668193 6168053 54 T 0.2 0.3 1937010 2007735028003 51.385937 41.857549 6.756514 silty clay

42 Appendix 7.3. Robinvale-Boundary Bend XRF Top MLOI Geomorphic Base Al2O3 As Ba CaO Ce Cl Co Cr Cu F Fe2O3T K2O La MgO MnO Mo Na2O Site No. Easting Northing Zone Depth SampleID Calculate unit Depth (m) % ppm ppm % ppm ppm ppm ppm ppm ppm % % ppm % % ppm % (m) % 107 664789 6169706 54 T 0 0.1 1937002 5 7.4 284 2.46 57 74 11 60 22 1716 4.014 2.215 24 1.373 7.158 0.103 2 0.164 107 664789 6169706 54 T 0.1 0.2 1937003 10.255 6.8 337 7.115 59 100 10 62 28 1752 3.721 2.021 23 1.825 11.678 0.082 0.219 107 664789 6169706 54 T 0.2 0.3 1937004 10.677 10.6 433 7.197 59 460 8 59 24 1878 3.895 2.044 30 2.053 10.582 0.086 0.345 108 665115 6169984 54 Fm2 0 0.1 1937005 15.23 7 472 0.761 89 159 16 80 18 1852 5.261 2.474 44 1.133 9.288 0.148 0.309 108 665115 6169984 54 Fm2 0.1 0.2 1937006 15.938 6.7 540 0.866 95 193 17 77 21 1884 5.467 2.541 51 1.244 8.534 0.162 0.318 108 665115 6169984 54 Fm2 0.2 0.3 1937007 15.896 7.6 523 0.984 88 195 15 77 23 1647 5.427 2.525 42 1.266 9.461 0.132 0.328 109 668193 6168053 54 T 0 0.1 1937008 11.705 5.8 440 0.492 101 219 10 59 13 1713 3.641 2.16 59 0.844 6.479 0.167 2 0.517 109 668193 6168053 54 T 0.1 0.2 1937009 12.809 6.6 404 0.478 97 1031 13 73 19 1590 4.162 2.184 43 0.978 7.142 0.181 0.648 109 668193 6168053 54 T 0.2 0.3 1937010 14.315 7.6 405 0.56 74 2996 16 85 18 1870 4.84 2.301 31 1.267 6.012 0.167 0.837 110 668638 6167686 54 Fm1 0 0.1 1937011 8.196 4.1 358 0.463 53 94 7 51 8 1855 2.58 1.881 23 0.502 6.141 0.052 5 0.356 110 668638 6167686 54 Fm1 0.1 0.2 1937012 8.058 6.8 390 0.333 53 63 4 46 7 1706 2.438 1.891 36 0.451 3.415 0.038 2 0.346 110 668638 6167686 54 Fm1 0.2 0.3 1937013 8.848 7.4 401 0.431 67 88 7 60 6 2021 2.797 1.934 29 0.547 4.641 0.061 5 0.383 111 668617 6167741 54 Fm1 0 0.1 1937014 10.865 6.8 376 0.349 71 328 6 68 74 1965 3.082 2.125 37 0.653 5.186 0.027 4 0.452 111 668617 6167741 54 Fm1 0.1 0.2 1937015 11.938 8.9 386 0.365 85 197 9 66 18 1932 3.918 2.197 39 0.73 5.456 0.029 6 0.471 111 668617 6167741 54 Fm1 0.2 0.3 1937016 12.086 6.5 456 0.364 77 167 10 77 14 1971 3.671 2.199 39 0.747 5.184 0.046 5 0.476 112 668019 6168445 54 Fm1 0 0.1 1937017 14.369 8.7 475 0.381 88 1217 11 89 15 1999 4.403 2.359 43 0.961 7.701 0.062 4 0.426 112 668019 6168445 54 Fm1 0.1 0.2 1937018 13.198 9.2 443 0.333 94 350 11 76 20 1838 4.121 2.275 46 0.83 6.274 0.052 2 0.436 112 668019 6168445 54 Fm1 0.2 0.3 1937019 13.077 8.8 438 0.332 89 331 11 75 18 1777 4.031 2.267 43 0.789 6.582 0.063 0.418 113 668026 6168459 54 Fm1 0 0.1 1937020 14.035 10 460 0.425 75 155 13 78 15 1863 4.224 2.346 42 0.886 10.949 0.075 0.36 113 668026 6168459 54 Fm1 0.1 0.2 1937021 15.167 7.7 402 0.343 82 125 13 90 14 1819 4.524 2.436 47 0.95 7.928 0.061 0.35 113 668026 6168459 54 Fm1 0.2 0.3 1937022 14.675 8.7 492 0.345 88 81 12 76 27 2040 4.546 2.419 43 0.924 6.443 0.066 0.373 114 668026 6168459 54 Fm1 0 0.1 1937023 10.96 3.8 396 0.388 86 461 7 81 128 1982 3.038 2.178 38 0.646 7.694 0.041 0.495 114 668026 6168459 54 Fm1 0.1 0.2 1937024 10.697 6.1 455 0.332 79 213 6 64 18 2059 2.879 2.209 41 0.592 4.699 0.023 3 0.532 114 668026 6168459 54 Fm1 0.2 0.3 1937025 8.836 8.2 389 0.325 70 138 3 63 6 1935 2.289 2.114 32 0.445 3.485 0.021 5 0.575 115 667168 6169710 54 Fm1 0 0.1 1937026 11.675 7.5 406 0.49 92 1643 10 72 11 1884 3.451 2.145 55 0.786 10.793 0.059 6 0.507 115 667168 6169710 54 Fm1 0.1 0.2 1937027 11.652 8.6 466 0.352 94 699 6 67 10 1872 3.213 2.207 55 0.707 7.77 0.034 3 0.529 115 667168 6169710 54 Fm1 0.2 0.3 1937028 11.401 6.7 445 0.323 75 498 6 74 9 1975 3.12 2.222 37 0.673 5.302 0.027 3 0.539 116 666856 6169437 54 Fm1 0 0.1 1937029 11.877 6 451 0.596 97 986 11 68 10 2210 3.737 2.103 49 0.83 13.851 0.103 4 0.413 116 666856 6169437 54 Fm1 0.1 0.2 1937030 11.005 7.9 404 0.315 85 806 9 72 12 2039 3.135 2.169 48 0.661 4.053 0.032 7 0.568 116 666856 6169437 54 Fm1 0.2 0.3 1937031 10.324 8.3 411 0.291 83 495 5 69 10 1937 2.961 2.132 40 0.587 4.163 0.016 0.571 117 666862 6169405 54 Fm1 0 0.1 1937032 13.131 4.9 488 0.388 81 187 10 75 12 1968 3.824 2.263 41 0.808 9.747 0.05 3 0.397 117 666862 6169405 54 Fm1 0.1 0.2 1937033 14.612 8.1 476 0.345 91 127 9 79 13 2017 4.186 2.445 51 0.902 7.162 0.051 0.399 117 666862 6169405 54 Fm1 0.2 0.3 1937034 13.696 9 451 0.329 93 89 10 84 16 2252 4.046 2.375 38 0.831 6.07 0.044 0.42 118 667031 6168407 54 Fm2 0 0.1 1937035 13.04 6.9 501 0.612 82 148 13 69 19 1953 4.194 2.389 51 0.913 8.473 0.14 1 0.399 118 667031 6168407 54 Fm2 0.1 0.2 1937036 14.431 6.2 562 0.645 89 197 18 79 16 2068 4.836 2.422 43 1.07 6.419 0.202 3 0.414 118 667031 6168407 54 Fm2 0.2 0.3 1937037 14.765 10.3 502 0.667 82 178 18 77 14 1762 5.132 2.357 45 1.116 8.15 0.17 0.375

43 Appendix 7.3. Robinvale-Boundary Bend XRF (Contd)

Top Base Site Geomorphic Nb Nd Ni P2O5 Pb Rb S Sc SiO2 Sr Th TiO2 U V Y Zn Easting Northing Zone Depth Depth SampleID W ppm Zr ppm No. unit ppm ppm ppm % ppm ppm ppm ppm % ppm ppm % ppm ppm ppm ppm (m) (m) 107 664789 6169706 54 T 0 0.1 1937002 12 30 21 0.075 29 105.6 230 8 70.65 96.4 16 0.561 5.7 49 5 28 75 284 107 664789 6169706 54 T 0.1 0.2 1937003 14 26 39 0.067 34 108.8 248 3 62.16 197 54 0.514 9.2 60 12 22 56 234 107 664789 6169706 54 T 0.2 0.3 1937004 12 27 27 0.067 21 105.3 340 4 62.11 216 21 0.537 6 64 3 27 56 219 108 665115 6169984 54 Fm2 0 0.1 1937005 19 36 28 0.143 30 177.5 215 22 64.04 86.7 31 0.837 2.9 83 8 38 85 252 108 665115 6169984 54 Fm2 0.1 0.2 1937006 20 38 29 0.089 27 199.3 154 19 63.61 93.7 40 0.84 9 93 14 36 91 234 108 665115 6169984 54 Fm2 0.2 0.3 1937007 18 40 23 0.076 25 194.2 164 17 62.71 100 31 0.833 4.9 87 2 37 85 226 109 668193 6168053 54 T 0 0.1 1937008 20 36 13 0.066 33 141.2 187 11 72.75 79.4 34 0.808 8.6 61 11 45 58 396 109 668193 6168053 54 T 0.1 0.2 1937009 21 45 20 0.053 34 152.5 189 11 70.14 78.8 50 0.789 5.8 67 7 42 67 360 109 668193 6168053 54 T 0.2 0.3 1937010 21 38 36 0.053 26 157.5 271 15 68.18 86.4 24 0.798 6.3 78 9 41 76 307 110 668638 6167686 54 Fm1 0 0.1 1937011 13 34 9 0.066 31 102.4 211 78.94 59.4 21 0.485 6.1 47 9 30 36 357 110 668638 6167686 54 Fm1 0.1 0.2 1937012 15 20 4 0.055 29 105.7 139 8 82.19 53.4 35 0.475 8.6 45 14 28 31 326 110 668638 6167686 54 Fm1 0.2 0.3 1937013 15 26 13 0.068 21 113.1 158 11 79.36 60.2 18 0.572 7.4 47 2 36 44 419 111 668617 6167741 54 Fm1 0 0.1 1937014 15 27 17 0.066 23 122.6 289 2 76.16 59 13 0.636 6.8 61 11 34 52 363 111 668617 6167741 54 Fm1 0.1 0.2 1937015 14 38 24 0.086 21 135.8 202 11 73.75 59.7 8 0.683 77 22 37 57 361 111 668617 6167741 54 Fm1 0.2 0.3 1937016 14 30 16 0.07 25 134.8 168 10 74.08 61.9 11 0.698 5.2 73 9 38 59 354 112 668019 6168445 54 Fm1 0 0.1 1937017 18 39 18 0.09 25 154.9 291 19 67.88 66.9 18 0.869 5.1 82 10 40 72 306 112 668019 6168445 54 Fm1 0.1 0.2 1937018 21 42 13 0.082 31 151.2 210 11 71.15 62.8 19 0.857 9.7 80 4 42 63 331 112 668019 6168445 54 Fm1 0.2 0.3 1937019 21 38 11 0.069 27 153.8 202 15 71.14 63.5 28 0.846 12.1 86 7 41 61 324 113 668026 6168459 54 Fm1 0 0.1 1937020 16 31 18 0.099 25 156.6 447 13 65.37 68.9 28 0.827 11.6 81 18 38 72 309 113 668026 6168459 54 Fm1 0.1 0.2 1937021 19 27 11 0.083 32 165.1 226 20 66.92 65.8 27 0.872 9 95 2 40 77 281 113 668026 6168459 54 Fm1 0.2 0.3 1937022 19 43 14 0.085 29 163.3 183 13 68.85 65.2 26 0.884 7.9 93 6 42 72 301 114 668026 6168459 54 Fm1 0 0.1 1937023 17 38 15 0.077 35 128.9 287 19 73.36 64.2 30 0.686 11.2 69 5 38 49 419 114 668026 6168459 54 Fm1 0.1 0.2 1937024 19 31 11 0.068 31 127.4 199 7 76.9 61.7 30 0.669 9.4 59 15 37 46 440 114 668026 6168459 54 Fm1 0.2 0.3 1937025 16 29 1 0.056 19 113.2 136 4 80.94 60.9 21 0.559 7.4 44 7 37 34 475 115 667168 6169710 54 Fm1 0 0.1 1937026 18 32 13 0.107 27 134.7 538 18 68.7 69.2 23 0.731 7.2 70 10 36 59 403 115 667168 6169710 54 Fm1 0.1 0.2 1937027 18 41 3 0.074 25 137.8 323 15 72.27 64 28 0.747 8.6 64 40 55 409 115 667168 6169710 54 Fm1 0.2 0.3 1937028 20 28 11 0.064 27 137.1 240 7 75.17 62.9 29 0.732 8.8 66 37 50 413 116 666856 6169437 54 Fm1 0 0.1 1937029 17 40 12 0.104 33 140 491 14 65.11 78.9 31 0.753 9.9 70 13 37 59 343 116 666856 6169437 54 Fm1 0.1 0.2 1937030 17 33 15 0.069 23 130.9 190 11 76.74 63.1 4 0.795 3.7 62 9 44 50 435 116 666856 6169437 54 Fm1 0.2 0.3 1937031 20 34 0.057 23 132 145 12 77.74 62.1 28 0.749 10.6 62 4 38 44 482 117 666862 6169405 54 Fm1 0 0.1 1937032 18 42 12 0.089 37 149.6 424 19 68.08 67.3 28 0.802 7.9 75 8 40 68 364 117 666862 6169405 54 Fm1 0.1 0.2 1937033 18 39 16 0.073 29 165.1 249 21 68.54 67.3 27 0.89 8.1 88 9 41 71 307 117 666862 6169405 54 Fm1 0.2 0.3 1937034 20 43 12 0.072 26 161.3 194 13 70.83 63.7 28 0.878 7.6 84 9 41 66 329 118 667031 6168407 54 Fm2 0 0.1 1937035 19 30 18 0.101 35 155 242 20 68.54 83.1 27 0.811 7.6 75 3 41 70 302 118 667031 6168407 54 Fm2 0.1 0.2 1937036 17 33 23 0.063 35 168.5 169 13 68.26 87.3 14 0.824 3.7 85 9 42 74 294 118 667031 6168407 54 Fm2 0.2 0.3 1937037 19 32 24 0.056 31 173.9 129 9 66.05 86.6 42 0.789 12.4 89 7 38 73 278

44 Appendix 7.4. Robinvale-Boundary Bend XRD

Site Sample Minerals Weight Site Sample Minerals Weight Sample Minerals Weight Depth Depth Site No. Depth No. # Identified % No. # Identified % # Identified %

101 0-10 1936984 Quartz 65 103 10-20 1936991 Quartz 74.3 105 10-20 1936997 Quartz 66.1 Halloysite 20 Kaolin 11.5 Kaolin 14.3 Muscovite 7.5 Albite 6.8 Muscovite 10.4 Albite 7.1 Muscovite 4.5 Albite 8.1 Microcline 0.4 Microcline 2.9 Microcline 1.1 100 100 100

101 10-20 1936985 Quartz 78.6 103 20-30 1936992 Quartz 75.7 105 20-30 1936998 Quartz 63.3 Albite 9.8 Kaolin 9.5 Kaolin 16.6 Muscovite 7.3 Albite 6.6 Muscovite 13.1 Microcline 4.3 Muscovite 6.2 Albite 5.7 100 Microcline 2 Microcline 1.4 100 100.1 101 20-30 1936986 Quartz 79.9 Albite 8.9 104 0-10 1936993 Quartz 79.4 106 0-10 1936999 Quartz 64.9 Muscovite 7.2 Albite 6.9 Kaolin 15.6 Microcline 4 Kaolin 6.3 Muscovite 11.1 Albite (low) 100 Muscovite 3.7 accurate 6.3 Microcline 3.6 Microcline, inter 2 102 0-10 1936987 Quartz 57.3 99.9 99.9 Kaolin 20.9 Muscovite 15.3 104 10-20 1936994 Quartz 75.4 106 10-20 1937000 Quartz 66 Microcline 6.5 Kaolin 10.7 Kaolin 13.2 100 Albite 7 Muscovite 11.6 Muscovite 3.7 Albite 6.3 102 10-20 1936988 Quartz 59.2 Microcline 3.1 Microcline 2.9 Kaolin 19.5 99.9 100 Muscovite 13.4 Albite 6.6 104 20-30 1936995 Quartz 74.6 106 20-30 1937001 Quartz 66.8 Microcline 1.4 Kaolin 10.5 Kaolin 11.5 100.1 Albite 7.8 Muscovite 10.5 Muscovite 5 Albite 7.2 103 0-10 1936990 Quartz 73.1 Microcline 2.1 Microcline 4 Kaolin 11.4 100 100 Albite 6.8 Muscovite 5.4 105 0-10 1936996 Quartz 68.8 1937002 Quartz 61.9 Microcline 3.3 Kaolin 12.1 107 0-10 Kaolin 15.3 100 Muscovite 10.9 Microcline 8.7 Albite 7.4 Muscovite 8.7 Microcline 0.7 Calcite 3.3 99.9 Albite 2.1 100

45

Site Sample Minerals Weight Site Sample Minerals Weight Sample Minerals Weight Depth Depth Site No. Depth No. # Identified % No. # Identified % # Identified % 107 10-20 1937003 Quartz 49.9 109 10-20 1937009 Quartz 54 111 10-20 1937015 Quartz 62 Kaolin 18.7 Kaolin 20.3 Kaolin 17.9 Calcite 16.3 Muscovite 12.6 Muscovite 10.7 Muscovite 9.4 Microcline 8.1 Microcline 4.8 Microcline 4.4 Albite 5 Albite 4.6 Albite 1.3 100 100 100 109 20-30 1937010 Quartz 60.2 111 20-30 1937016 Quartz 61.9 1937004 Quartz 46.4 Muscovite 18.2 Kaolin 18 107 20-30 Kaolin 18.4 Kaolin 11.9 Muscovite 10.7 Calcite 17.2 Albite 7.2 Albite 4.8 Microcline 8.3 Microcline 2.5 Microcline 4.6 Muscovite 8 100 100 Albite 1.7 100 110 0-10 1937011 Quartz 72.7 112 0-10 1937017 Quartz 52.9 Kaolin 12.6 Kaolin 22.1 108 0-10 1937005 Quartz 58.8 Microcline 5.4 Muscovite 17.2 Muscovite 20.9 Albite 5 Albite 3.9 Kaolin 13.3 Muscovite 4.3 Microcline 3.9 Albite 3.8 100 100 Microcline 3.2 100 110 10-20 1937012 Quartz 73.4 112 10-20 1937018 Quartz 58.3 Kaolin 13 Kaolin 18.4 108 10-20 1937006 Quartz 43.1 Microcline 5.1 Muscovite 14 Kaolin 30 Albite 5 Albite 5.5 Muscovite 17.4 Muscovite 3.6 Microcline 3.7 Microcline 5.3 100.1 99.9 Albite 4.2 100 110 20-30 1937013 Quartz 71.7 112 20-30 1937019 Quartz 57 Kaolin 12.7 Kaolin 20.6 108 20-30 1937007 Quartz 42.7 Microcline 5.5 Muscovite 13.5 Kaolin 26.4 Muscovite 5.4 Albite 4.9 Muscovite 20.1 Albite 4.6 Microcline 4 Microcline 7.1 99.9 100 Albite 3.7 100 111 0-10 1937014 Quartz 66.8 113 0-10 1937020 Quartz 62.8 Kaolin 15.2 Muscovite 15.6 109 0-10 1937008 Quartz 61.5 Muscovite 7.8 Kaolin 9.4 Kaolin 18.9 Microcline 5.2 Microcline 6.3 Muscovite 9.7 Albite 4.9 Albite 6 Albite 5.4 99.9 100.1 Microcline 4.5 100

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Site Sample Minerals Weight Site Sample Minerals Weight Sample Minerals Weight Depth Depth Site No. Depth No. # Identified % No. # Identified % # Identified % 113 10-20 1937021 Quartz 58.2 115 10-20 1937027 Quartz 69 117 10-20 1937033 Quartz 59.8 Muscovite 17.9 Kaolin 13.4 Muscovite 18.1 Kaolin 10.5 Muscovite 11.3 Kaolin 9.9 Microcline 7.4 Albite 4.4 Microcline 6.8 Albite 6 Microcline 1.9 Albite 5.5 100 100 100.1

113 20-30 1937022 Quartz 64.4 115 20-30 1937028 Quartz 72.1 117 20-30 1937034 Quartz 58.9 Muscovite 17.6 Muscovite 14.9 Kaolin 15.9 Kaolin 8.8 Microcline 5.6 Muscovite 14.3 Microcline 5.7 Albite 7.5 Microcline 5.5 Albite 3.5 100.1 Albite 5.4 100 100 116 0-10 1937029 Quartz 60.6 114 0-10 1937023 Quartz 65.3 Kaolin 15 118 0-10 1937035 Quartz 58.1 Kaolin 11.2 Muscovite 12.7 Muscovite 16.1 Muscovite 10.6 Albite 6.5 Kaolin 13.7 Albite 6.6 Microcline 5.3 Microcline 6.5 Microcline 6.2 100.1 Albite 5.6 99.9 100 116 10-20 1937030 Quartz 63.2 114 10-20 1937024 Quartz 65.9 Muscovite 12.3 118 10-20 1937036 Quartz 56.4 Kaolin 11.4 Kaolin 10.8 Muscovite 19 Muscovite 9.9 Microcline 7.5 Kaolin 11.7 Albite 6.5 Albite 6.2 Microcline 8.1 Microcline 6.3 100 Albite 4.8 100 100 116 20-30 1937031 Quartz 66.3 118 20-30 1937037 Quartz 48.9 114 20-30 1937025 Quartz 72.7 Kaolin 10.9 Kaolin 23.5 Kaolin 8.6 Muscovite 9.5 Muscovite 18 Muscovite 6.8 Microcline 6.8 Microcline 6 Albite 6.2 Albite 6.5 Albite 3.6 Microcline 5.7 100 100 100 117 0-10 1937032 Quartz 60.2 115 0-10 1937026 Quartz 63 Kaolin 15.5 Kaolin 14.7 Muscovite 14.8 Muscovite 12.5 Microcline 5.1 Albite 5.1 Albite 4.4 Microcline 4.8 100 100.1

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