Rocks PDF

You ROCK My World!!!  You are expected to: ✓ identify the three types of rocks; ✓ classify rocks as to igneous, sedimentary and metamorphic rocks; and ✓ appreciate the importance of rocks in our daily life.  Rocks Rock is a naturally occurring, solid aggregate or colle...

You ROCK My World!!!  You are expected to: ✓ identify the three types of rocks; ✓ classify rocks as to igneous, sedimentary and metamorphic rocks; and ✓ appreciate the importance of rocks in our daily life.  Rocks Rock is a naturally occurring, solid aggregate or collection of one or more minerals or mineral-like substances, formed through the action of various processes such as heat, pressure, aggregation, and compaction and transformation of its mineral components. ❖ Petrology is the scientific study of rocks. ❖ Petrologist classified rocks based on how they were formed. CLASSIFICATION OF ROCKS IGNEOUS SEDIMENTARY METAMOPHIC 1. - formed from hardening and crystallization of magma or molten material that originates deep within the Earth. TWO TYPES OF IGNEOUS ROCKS TWO TYPES OF IGNEOUS ROCKS Extrusive/Volcanic rock - Intrusive/Plutonic - It forms when magma cools slowly beneath the makes its way to Earth’s Earth surface and are surface as lava and then created by magma. The cools. The crystals are intrusive igneous rocks very small (fine-grained) have very large crystals since the cooling process (coarse grained). is fast. EXTRUSIVE or VOLCANIC ROCKS INTRUSIVE or PLUTONIC ROCKS INTRUSIVE or PLUTONIC ROCKS Igneous rocks are classified based on 1. Composition- it refers to rock’s mineral and chemical make-up. Felsic – igneous rocks that are light in colors; feldspar and silicates Mafic – dark-colored igneous rocks made up of magnesium, calcium and iron Intermediate – refers to igneous rocks between mafic and felsic composition. Ultramafic – denotes igneous rocks that composed chiefly of mafic minerals. 2. Texture - overall appearance of a rock based on the size, shape, and arrangement of interlocking mineral crystals. Aphanitic – fine-grained rocks with crystals seen by aid of microscope. Phaneritic - coarse-grained rocks Porphyritic – presence of large crystals (called phenocrysts) embedded within a matrix of much smaller crystals. Glassy - a rock that looks like colored glass with no visible mineral crystal Pyroclastic- results from explosive fragmentation of volcanic material  provide information about surface conditions that existed in the Earth’s past. ❑ Particles of sand, shells, pebbles, and other fragments of materials called sediments, accumulate in layers and over long period of time harden into rocks. ❑ Compaction-due to increase of pressure of layered sediments it bind together to form the sedimentary rocks. THREE TYPES OF SEDIMENTARY ROCKS a. Clastic Sedimentary rock - formed from accumulation of clasts: little pieces of broken rocks and shells. THREE TYPES OF SEDIMENTARY ROCKS b. Chemical - formed when dissolved minerals precipitate from a solution. Example: Halite - formed when a body of seawater becomes closed off and evaporates. THREE TYPES OF SEDIMENTARY ROCKS c. Organic - rocks formed from the accumulation of animal debris Example: Coal - composed of organic matter in the form of plants fragments.  - from the words “meta” (change) and “morph” (form) -forms from pre-existing rocks: either metamorphic, igneous, sedimentary or other metamorphic rocks that have been altered by agents of metamorphism. Metamorphism - transformation of one rock type into another. Types of Metamorphism 1. Regional-due to changes in pressure and temperature over large region of the crust. It may happen when rock is buried deep below the surface of the earth. 2. Contact-the rock minerals and textures are changed mainly by heat due to contact with magma. Classification: 1. Texture - refers to the size arrangement and grains within the rock. Foliation - any planar arrangement of mineral grains or structural features within the rock. a. Foliated rocks – can be arranged in terms of increasing metamorphism, and it appeared layered or banded with compressed mineral grains. Example: mica b. Non-foliated rocks – usually made up of only few minerals. METAMORPHIC ROCK TYPES FOLIATED NON FOLIATED Slate Schist Quartzite Marble Gneiss Phyllite Hornfels CREDITS: This presentation template was created by Slidesgo, including icons by Flaticon and infographics & images by Freepik