Fun Fact. The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface. The below image shows the intrusive igneous rock: (Image to be added soon) So, we studied the two types of igneous rocks viz: Intrusive igneous rocks and Extrusive igneous rocks with their formation. Define Intrusive igneous rock. Batholiths. An inappropriate or unwelcome addition. These are igneous rocks that are formed by the solidification of hot magma deep inside the earth’s crust. Intrusive igneous rocks crystallize below Earth's surface, and the slow cooling that occurs there allows large crystals to form. 2. Intrusive rocks are characterized by large crystal sizes, i.e., their visual appearance shows individual crystals interlocked together to form the rock mass. As the magma cools down slowly the rock is coarse-grained and the mineral grains can be identified easily with naked eye. Examples of intrusive igneous rocks are: diabase, diorite, gabbro, granite, pegmatite, and peridotite. Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. Intrusive Rock is a kind of igneous rock which is formed when magma slowly cools and solidifies beneath the earth's surface. What are Intrusive Rocks? Intrusive igneous rocks are generally formed from magma that cools and solidifies within the Earth's crust and is surrounded by pre-existing rock. All magma develops underground, in the lower crust or upper mantle, because of the intense heat there.. Igneous rocks can have many different compositions, depending on the magma they cool from. Definition - What does Intrusive Rock mean? Intrusive and extrusive are two types of these igneous rocks. Intrusive rocks which are also known as plutonic rocks are those that have solidified below ground; the word "Plutonic" comes from Pluto, the Greek god of the underworld. When magma cools and solidifies in these spaces, Intrusive or plutonic igneous rocks are formed deep beneath the Earth’s surface. Common intrusive rock structures: #1 Laccolith, #2 & #4 Dikes, #3 Batholith, #4 Sill, #6 Volcanic neck or pipe, and #7 Lopolith. n. 1. Intrusive Rocks Definition In geology, intrusive rocks are the type of igneous rocks that form and crystallize under the Earth’s ground surfaces, within other geologic formations. Batholiths are the largest intrusive bodies Batholiths are the largest intrusive bodies in the crust of the Earth. In fact, intrusive rocks form by the process of magma shooting through a pre-existing sedimentary, igneous or metamorphic rock. Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals. These large bodies of intrusive rocks can cover thousands of square kilometers of land. Intrusive features like stocks, laccoliths, sills, and dikes are formed. Igneous rocks are divided into two groups, intrusive or extrusive, depending upon where the molten rock solidifies. Intrusive Rocks Igneous rocks which form by the crystallization of magma at a depth within the Earth are called intrusive rocks. Intrusive igneous rock synonyms, Intrusive igneous rock pronunciation, Intrusive igneous rock translation, English dictionary definition of Intrusive igneous rock. It is the difference between intrusive and extrusive rocks that creates confusion in the minds of students. For instance, a pegmatite dyke or a batholith. It is fascinating to note that igneous rocks were the first to be formed and are also known as ‘primary rocks’. If the conduits are emptied after an eruption, they can collapse in the formation of a caldera, or remain as lava tubes and caves. Igneous rocks (from the Latin word for fire) form when hot, molten rock crystallizes and solidifies. The intrusive igneous rocks that forms below the surface of the earth are termed as plutonic and are coarse grained whereas the intrusive igneous rock formed near the surface is known as subvolcanic and are medium grained. The act of intruding or the condition of being intruded on. Intrusive igneous rocks are formed from magma that cools and solidifies within the crust of a planet, surrounded by way of pre-present rock (called us of a rock); the magma cools slowly and, as a result, these rocks are coarse-grained.