Mount Saddleback facts for kids

Mount Saddleback is the tallest mountain in the Darling Range in Western Australia. It stands 593 meters (about 1,946 feet) high. This mountain is located in the eastern part of the Darling Range. It is about 20 kilometers (12 miles) south of Boddington. It is also about 40 kilometers (25 miles) west of Williams.

What Makes Mount Saddleback Special?

Mount Saddleback is not just a tall mountain. It is also an important place for mining. A special rock called bauxite is found here. Bauxite is used to make aluminum.

Mining Bauxite at Mount Saddleback

Bauxite is dug up from the sides of Mount Saddleback. This rock is then sent to a place called Worsley Alumina. At Worsley Alumina, the bauxite is processed. This processing turns the bauxite into alumina. Alumina is then used to make aluminum metal. The Worsley Alumina plant has been working since 1984.

How Mount Saddleback Was Formed

The entire Darling Range, including Mount Saddleback, was created by a huge crack in the Earth. This crack is called the Darling Fault. It is about 1,000 kilometers (620 miles) long. This fault has been moving for a very long time.

The last big movement happened 135 million years ago. This was when Australia began to break away from a supercontinent. This ancient supercontinent was called Gondwana. The steep edge of the Darling Range, called the Darling Scarp, formed around 570 million years ago. The rocks here are very old, about 3,700 million years old. Most of these rocks are granite. Mount Saddleback sits on the eastern side of this fault. It is part of the Darling Plateau.

The Rocks and Soil of Mount Saddleback

The main rock under Mount Saddleback is granite. Sometimes, even older rocks from the Archaean time are found. These are also a type of granite. The very top layer of the mountain is a hard, iron-rich cap. This cap is about 6 meters (20 feet) thick. It contains a lot of iron, along with quartz sand.

Below this hard cap, there is a layer rich in aluminum oxide. This layer has a clay-rich bottom. It is usually about 5.5 meters (18 feet) deep. In some places, it can be up to 20 meters (66 feet) deep. Underneath this, there is a transition zone. This zone is mostly made of kaolin clays. Finally, below all these layers, you find the weathered bedrock.

Bauxite Reserves in the Area

The soil above the bedrock contains a good amount of bauxite. About 25% to 30% of the soil is bauxite. This bauxite is found in irregular, lens-shaped deposits. The largest deposit of bauxite holds about 20 million tonnes (44 billion pounds) of bauxite. This covers an area of 600 hectares (about 1,480 acres). There are also many smaller deposits. The total amount of bauxite estimated in the mining area is about 400 million tonnes (880 billion pounds). This shows how important Mount Saddleback is for mining.