The Great Victoria Desert is characterized by red-brown sand with a low organic content. This type of soil is known as red-brown desert soil, which is typical of arid and semi-arid environments. Here's a breakdown:

* Sand: The desert is mostly covered in sand dunes and plains, with the sand being primarily composed of quartz.

* Red-brown color: This coloration comes from iron oxides, which are abundant in the region due to the hot, dry climate.

* Low organic content: The harsh conditions, including low rainfall and high evaporation, make it difficult for vegetation to thrive. This means there's very little decaying plant material to contribute organic matter to the soil.

In addition to red-brown desert soil, other soil types found in the Great Victoria Desert include:

* Calcareous soils: These soils are rich in calcium carbonate, often found in areas with low rainfall.

* Saline soils: These soils are high in salts, found in areas where water evaporates and leaves behind dissolved minerals.

Overall, the Great Victoria Desert is a harsh environment with poor soil quality. The limited water availability and low nutrient content make it challenging for plants to grow.