Search results for "igneous rocks"

  • Igneous rock types

    Igneous rocks can be divided up into four groups, based on how they were formed and what they are made of.

  • Igneous rocks

    Igneous rocks are formed when magma cools and solidifies. They are classified by using grain size, silica content, and/or silica saturation. View some examples of igneous rocks from the Australian Museum's Mineralogy Collection.

  • Classification of igneous rocks

    Igneous rocks are formed when magma cools and solidifies. They are classified by using grain size, silica content, and/or silica saturation. Other methods of classification include the International Union of Geological Sciences (IUGS) scheme and the Total Alkalis vs Silica scheme.

  • Museum in a box - rocks

     

  • Igneous intrusions

    Molten magma can invade the Earth's upper layers and then solidify as igneous intrusions.

  • Museum in a Box - Rocks

    Museum in a Box® is available for set three week loan periods and can be sent to any educational institution across Australia.

  • Museum in a Box - Rock

     

  • Igneous Rocks, Central Plateau in The Lake Country of Tasmania

     

  • Magma

    Magma is hot molten mobile rock. Igneous rocks form when magma cools and solidifies. Magmas come out of active volcanoes as lavas. The most abundant magma is a melt of silicate composition and this can carry suspended crystals and gases which bubble out in air.

  • Radioactive dating

    Radioactive dating is a method of dating rocks and minerals using radioactive isotopes. This method is useful for igneous and metamorphic rocks, which cannot be dated by the stratigraphic correlation method used for sedimentary rocks.

  • Metamorphic rocks

    Metamorphic rocks are pre-existing rocks whose mineralogy and/or texture has been changed by processes within the Earth. Metamorphic rocks form because of changes in temperature and depth of burial within the Earth without actual melting. This means that the changes that affect these rocks occur in the solid state.

  • Metamorphic processes

    Metamorphism is an internal process of the Earth and occurs as a result of changes in temperature and/or pressure. This is because most minerals are only stable at particular temperatures and pressures, so changes in these result in the formation of new minerals which are stable at the new temperatures and pressures.

  • Geology Trail - Stage 4-5 Teacher Notes

    Students complete three self-guided activities using both the Albert Chapman Mineral Collection and the Planet of Minerals exhibitions. These activities are designed to expose students to the vast number and variety of rocks and minerals that exist and to increase their awareness and wonderment of nature. Students will learn about the colour of minerals, the three types of rocks – igneous, sedimentary and metamorphic and Australia’s geological wealth.

  • Geology Trail - Stages 4-5

    Students investigate rocks and minerals in this self-guided activity.

  • Sedimentary processes

    Sediments are formed by the breakdown (both physical and chemical) of pre-existing rocks, which may be of igneous, metamorphic or sedimentary origin.