Lesson 3 Flashcards
What are the polymorphs of Quartz
a-quartz, b-quartz, crystoballite, tridimite
“T or F: All natural and most synthetic substances on earth are made
from the ninety naturally occurring chemical elements”
True
“The nucleus, at the _____ of the atom,
contains one or more particles with a_____ electrical charge
(protons) and usually some particles of similar mass that have
no charge (neutrons”
Center, positive.
“A ______ is a chemical combination of two or more chemical
elements, bonded together in particular proportions, that
has a distinct set of physical properties”
Compound
“_______ materials are solids in which the atoms or ions are arranged in
regular, repeating patterns.”
Crystalline
Describe a mineral
A mineral is a naturally occurring inorganic solid substance with a specific chemical composition and a crystalline structure.
What is the largest compositional group of minerals
Silicates
“__________ is the general term used to describe those
silicates—usually dark-colored (black, brown, or green)—that contain
iron and/or magnesium, with or without additional elements.”
Ferromagnesian
“T or F: Rocks containing a high proportion of ferromagnesian minerals,
then, also tend to weather easily, which is an important
consideration in construction.”
True
“Micas are ______ silicates, built on an
atomic scale of stacked-up sheets of linked silicon and oxygen
atoms.”
Sheet
What are the three major rock type
Igneous, Sedimentary, Metamorphic
“______are formed from the products of the mechanical
breakup of other rocks.”
Clastic sedimentary rocks
An example of a natural glass
Obsidian
” When hot magma formed at depth rises to
shallower levels in the crust, it heats the adjacent, cooler rocks,
and they may be metamorphosed; this is _______”
Contact Metamorphism
“Each magnetic mineral has a
______ temperature, the temperature below which it remains
magnetic, but above which it loses its magnetic properties”
Curie Temperature
Enumerate the Goldschimdt geochemical classification
Lithophile, Siderophile, Chalcophile, Atmophile
Enumerate the components of an atomic structure
Proton, Neutron, Electron
Enumerate the types of bonding
Ionic, Covalent, Metallic
Enumerate the top 5 most abundant element in the crust and its percentage
Oxygen ( 46.6%), Silicon (27.7%), Aluminum (8.1%), Iron (5.0%), Calcium (3.6%)
Differentiate Polymorph from Isomorph
Polymorph minerals have the same chemical composition but different crystal structures, resulting in distinct physical properties. Isomorph minerals, on the other hand, have different chemical compositions but similar crystal structures and properties due to the substitution of ions or atoms within their structures.
Enumerate Minerals of Olivine Group
Minerals of the olivine group include:
Forsterite (Mg2SiO4)
Fayalite (Fe2SiO4)
These elements do not occur in the solar system because all of their isotopes are unstable and decay rapidly
technicium and promethium
Enumerate the silicate minerals and their Oxygen Ratio
Nesosilicate (1:4), Inosilicate (1:3), Inosilicate double (4:11), Phyllosilicate (2:5), Tectosilicate (1:2) , Sorosilicate (2:7), Cyclosilicate (1:3)
What are the Polymorphs of Al2SiO5
Kyanite, Silimanite, Andalusite
Enumerate the polymorphs of Quartz
Stishovite, Coesite, alpha quartz, beta quartz, Cristobalite, Tridiymite
What elements stand out with surprisingly low abundance despite having low atomic numbers?
lithium, beryllium, boron
Give examples of isomorphs
Garnet, Spinel, Olivine (peridot)
Give an example of a double replacement
“Reactants: KAlSi3O8 (K-feldspar) + H2CO3 (carbonic acid)
(Weathering of Feldspar)
Products: AlSi3O8(OH)3 (kaolinite) + KHCO3 (potassium bicarbonate)”
Enumerate the Moh’s Scale of Hardness
Talc
Gypsum
Calcite
Fluorite
Apatite
Orthoclase Feldspar
Quartz
Topaz
Corundum
Diamond
Enumerate the crystal habits
Bladed, Acicular, Prismatic, Platy, Equat, Tabular
Enumerate the four major types of Luminescence
Flourescence, Phosphorescence, Thermoluminescence, Triboluminescence.
What is the continuous series (plagioclase series)
Anorthite, Bytownite, Labradorite, Andesine, Oligoclase, Albite.
What are the two types of weathering, cite an example of both.
”
The two types of weathering are mechanical (physical) weathering and chemical weathering. Mechanical weathering involves the physical breakdown of rocks into smaller pieces without changing their chemical composition, such as through freeze-thaw cycles breaking apart rocks. Chemical weathering involves the alteration of rocks and minerals through chemical reactions, such as the dissolution of limestone by acidic rainwater.”
Differentiate Weathering and Erosion.
Weathering breaks down rocks, while erosion transports the resulting fragments.
Enumerate the particle name of Gravel and its size range.
Boulder (>256), Cobble ( 64-256), Pebble (4-64) Granule (2-4)
Enumerate the types of Chemical weathering and give examples
Dissolution (Affects carbonates and salts when a chemical reaction breaks down minerals into new compounds), Hydrolysis (Water acts to ‘loosen’ chemical bonds to break down minerals, Oxidation (When an element loses an electron, commonly when it bonds with oxygen) , Hydration ( Absorption of water into some minerals and causes them to expand.
Explain the Goldich dissolution series and give real life examples of such reaction.
The Goldich dissolution series describes the order in which minerals weather and dissolve due to chemical reactions with water. For instance, minerals like olivine and pyroxene are more susceptible to dissolution, while quartz and clay minerals are more resistant. This series helps explain the formation of landscapes like the sandstone arches, where more soluble minerals dissolve, leaving behind the resistant quartz grains, shaping distinctive rock formations.
Discuss the key differences of Diagenesis and Metamorphism
Diagenesis involves low-temperature and pressure changes in sedimentary rocks, converting sediment into sedimentary rock. Metamorphism involves higher temperature and pressure changes, transforming pre-existing rocks into new metamorphic rocks with distinct textures and mineral compositions.
Explain the concept of differential weathering
Differential weathering refers to the uneven breakdown of rocks due to varying resistance to weathering agents like water, wind, and temperature. Different parts of a rock mass may weather at different rates depending on their composition, structure, and exposure, leading to distinct features such as protrusions, ridges, and valleys over time.
“Define igneous rock and explain how and why volcanic
and plutonic rocks differ in texture.”
Igneous rocks form from the solidification of molten rock material, either magma (beneath the Earth’s surface) or lava (on the Earth’s surface). Volcanic rocks, formed from lava, typically exhibit a fine-grained texture due to rapid cooling, while plutonic rocks, formed from magma deep underground, tend to have a coarse-grained texture due to slower cooling rates, allowing larger mineral crystals to form.
Draw the rock cycle
What role do fossils play in the study of sedimentary rocks?
Fossils found in sedimentary rocks provide valuable information about past environments, climates, and life forms.
How do geologists use the concept of stratigraphy to interpret the relative ages and depositional environments of sedimentary rocks?
Stratigraphy is the study of rock layers (or strata) and their relative ages, helping geologists interpret the Earth’s history and past environments based on the sequence and characteristics of sedimentary rocks.
Explain the process of weathering and its role in the formation of sedimentary rocks.
Weathering is the process of breaking down rocks and minerals at or near the Earth’s surface through physical, chemical, and biological processes. It contributes to the formation of sedimentary rocks by breaking down existing rocks into sediments, which are then transported and deposited in layers.
How do the Bowen’s reaction series and fractional crystallization explain the formation of different mineral compositions within igneous rocks?
Bowen’s reaction series describes the sequence of mineral crystallization from a cooling magma based on temperature. Fractional crystallization occurs when minerals crystallize out of a magma at different temperatures, leading to the formation of different mineral compositions within igneous rocks.
Explain the concept of metamorphic facies and how it relates to the mineral assemblages observed in metamorphic rocks.
Metamorphic facies are sets of mineral assemblages that form under specific pressure and temperature conditions during metamorphism. They provide insights into the metamorphic conditions experienced by rocks. Different facies represent different metamorphic environments and can indicate the intensity of metamorphism.
Discuss the role of hydrothermal fluids in the formation of ore deposits and the relationship between mineralization and tectonic processes.
Hydrothermal fluids play a crucial role in the formation of ore deposits by transporting and depositing metals in the Earth’s crust. These fluids are often associated with magmatic activity or circulating through fractures in rocks. Ore deposition occurs when the fluids cool and precipitate minerals, often in response to changes in temperature, pressure, or chemical conditions related to tectonic processes.
Explain the differences between porphyritic, aphanitic, and phaneritic textures in igneous rocks, and discuss the factors that influence their formation.
Porphyritic textures feature large crystals (phenocrysts) embedded in a fine-grained matrix (groundmass). Aphanitic textures are fine-grained with crystals too small to be visible to the naked eye. Phaneritic textures have coarse-grained crystals that are visible to the naked eye. Factors influencing their formation include cooling rates, magma composition, and crystallization conditions.
Compare and contrast the formation mechanisms and characteristics of clastic, chemical, and organic sedimentary rocks, providing examples of each.
Clastic sedimentary rocks are formed from the accumulation and lithification of fragments of pre-existing rocks. Chemical sedimentary rocks form from the precipitation of minerals from solution, while organic sedimentary rocks are derived from the accumulation of organic materials such as shells, plant debris, or carbon-rich sediments.
Describe the process of diagenesis in the formation of sedimentary rocks and its effects on pore fluids, mineral composition, and rock texture.
Diagenesis is the process of physical and chemical changes that occur in sedimentary rocks as they are buried and compacted over time. It includes processes such as lithification, cementation, recrystallization, and compaction, which can alter the mineral composition, texture, and porosity of sedimentary rocks.
