I through M

I THROUGH M:

• Igneous rock – these are formed with magma from a volcano and cooled, compressing with intrusions of other things.

• Interlocking rock – this is a rock where grains of minerals or crystals form a mosaic due to their interlocking nature.

• Intrusions – these are areas of igneous rocks that have cooled and later crystallized when magma is cooling deep under the earth.

• Invertebrates – these are animals without any backbone, such as insects, shellfish, and worms.

• Joints – these are cracks you see in rocks due to the release of pressure from erosion above the rock that decrease the weight on them, or shrinkage of rocks.

Most joints are vertical.

• Lahar – a mudflow formed from the combination of water and volcanic ash. This can damage large areas of land and homes.

• Landslide – any mass movement of rocks and earth down some type of slope.

Mudflows, rock falls, and landslips are all types of landslides. A Landslip is similar but often involves clay that slips on an already-defined surface.

• Lava – this is molten basalt rock that has escaped from a volcano. Magma is not the same thing as lava.

• Limestone – this is sedimentary rock made mostly of calcium carbonate and formed when marine animals with shells die.

• Lithosphere – this is the main outer layer of the earth containing the top part of the mantle and the earth's crust.

• Longshore drift – this is movement of any type of sediment due to wave action near a shoreline.

• Magma – this is the molten rock containing mostly dissolved gases from a volcano that resides beneath the surface of the earth.

• Marble – this is a type of metamorphic rock that is made out of limestone.

• Medium-grained – this is a rock where the grains in it are of any type and are between microscopic and pea-sized in nature.

• Metamorphic rock – a rock type where the rock was once one type but was reshaped later due to any combination of heat and pressure.

• Metamorphic areole – any area around an intrusion where hot magma managed to heat and then alter the surrounding rocks.

• Metamorphism – the process altering a rock from one form to another through heat, pressure, or both.

• Mineral – any natural compound that crystallizes with a regular structure.

• Mica – a type of mineral that is flaky and shiny. You will see it in schist, gneiss, and granite mainly.

• Moraine – this is rocky material that is carried in a glacier and gets dumped in a spot wherever the glacier has retreated and melted.

• Mudstone – soft rock actually made of fine clay that is compressed later. This is also known as shale.