Rock and mineral

• Rock cycle, rock composition, igneous rocks, sedimentary rocks, metamorphic rocks are topics that will be discussed in Lecture 4 of ESC3019 Hydrosphere and Lithosphere.
• Rocks and Minerals are naturally occurring inorganic elements or compounds having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties.
• Common minerals include quartz, feldspar, mica, amphibole, olivine, and calcite.
• A rock is an aggregate of one or more minerals, or a body of undifferentiated mineral matter.
• Common rocks include granite, basalt, limestone, and sandstone.
• Some rocks are composed entirely of one mineral, such as limestone (calcite).
• Most rocks have more than one kind of mineral, such as granite.
• Some rocks contain non-mineral matter, such as coal or obsidian.
• Islamic scholar Ibn Sina (Avicenna, 981 – 1037) proposed detailed explanations for the formation of mountains, the origin of earthquakes, and other topics central to modern geology.
• Increased pressures and temperatures cause tabular minerals to take on a preferred orientation, foliation, perpendicular to the direction of pressure.
• Soils develop as a result of the interplay of five factors: parent material, climate, organisms, relief and time.
• Soil can be defined as the solid material on the Earth’s surface that results from the interaction of weathering and biological activity on the parent material or underlying hard rock.
• Marble and limestone have similar composition but marble typically has a larger grain size.
• The study of soils as naturally occurring phenomena is called pedology, from the Greek word pedon, meaning soil or earth.
• Regional metamorphism is caused by increased heat and pressure associated with plate tectonic processes that form mountains.
• Rock names vary with grain size.
• Foliation is produced when tabular minerals grow perpendicular to the direction of pressure.
• Parent material is the material from which the soil has developed and can vary from solid rock to deposits like alluvium and boulder clay.
• Grain size increases with degree of metamorphism, also known as metamorphic grade.
• Magma chamber is formed by heat and is filled with limestone, which is later baked to form marble.
• Parent material is defined as the initial state of the soil system.
• The ancient Greek writers Aristotle (384 – 322 BC) and Theophrastus (370 – 285 BC) were the first in the Western tradition to write of minerals and their properties, as well as metaphysical explanations for them.
• The Greek philosopher Aristotle wrote his Meteorologica, and in it theorized that all the known substances were composed of water, air, earth, and fire, with the properties of dryness, dampness, heat, and cold.
• Generation in Clastic Sedimentary Rocks is the physical and chemical breakdown of any rock at Earth’s surface (weathering) to form sediment, with sediment classified by grain size.
• There are three types of sedimentary rocks: Clastic, Chemical, and Biochemical, identified by the materials that make up the rock and/or the process by which they formed.
• Lithification in Clastic Sedimentary Rocks is the deposition of sediment when the velocity of the transport medium decreases, with larger grain sizes deposited first and finest grains remaining in suspension and being deposited last, and over time, sediment is slowly compacted and grains are cemented together to form a new rock (lithification).
• Rock names in Clastic Sedimentary Rocks reflect the grain size, for example, Mudstone, Shale are made of clay and silt-sized grains, Sandstone is composed of sand-sized particles, and Conglomerate is made of gravel and larger fragments.
• Sedimentary rocks form as horizontal layers (beds) and are identified based on composition and thickness, with the oldest beds at the bottom and the youngest at the top.
• Transportation in Clastic Sedimentary Rocks is the movement of sediment from its place of origin by streams, wind, glaciers, with the size of transported grains depending on the velocity of the transport medium, and erosion producing characteristic landscapes.
• Clastic Sedimentary Rocks are composed of rock and mineral fragments, the most common type of sedimentary rock, and have three stages of formation: Generation, Transportation, and Lithification.
• The most important factors controlling the behavior of the magma are water, silica, and temperature.
• The medieval Islamic scientists expanded upon this as well, including the Persian scientist Ibn Sina (1039 - 980 AD) also known as Avicenna, who rejected alchemy and the earlier notion of Greek metaphysics that metallic and other elements could be transformed into one another.
• The same magma can form both rock types.
• Sedimentary rocks are formed through deposition and cementation of weathered rock products.
• These cycles stopped when the Flood ended, barring residual smaller-scale catastrophes occurring.
• Two types of igneous rocks are classified based on texture and composition.
• Water has a lubricating effect, making melting easier.
• Metamorphic rocks are transformed into existing rocks through heat and pressure.
• Multiple cycles occurred during the year-long Flood, driven by movements of the earth’s crust and enormous flows of water.
• Each magma type may produce two rocks – one volcanic, one plutonic.