Geology 209 - Midterm 1 Study Flashcards

Objective

An observation that is completely free of bias.
i.e., Anyone and everyone would make the same observation.

Subjective

An observation which is influenced by the observers personal bias.

Quantitative

An observation which is based on numerical data. These observations are preferred because they can be used in calculations.

Qualitative

An observation which is based on non-numerical data. While these types of observations are not preferred they can still be useful.

Scientific Method

The idea in science that phenomena and ideas need to be scrutinized using hypothesizing, experimentation, and analysis. This can eventually result in a consensus or scientific theory.
i.e., Make an observation, Think of interesting questions, Formulate a Hypotheses, Develop testable predictions, Gather data or test predictions, If False; Refine, Alter, Expand or Reject Hypotheses, If true; Develop general theories why it was true.

Principle of Uniformitarianism

Idea championed by James Hutton that the present is the key to the past, meaning the physical laws and processes that existed and operate in the past still exist and operate today.

Catastrophism

The idea that large, damaging events are the cause of most geologic events.

Rock Cycle

The process of changing rocks on Earth into different forms, namely igneous, sedimentary, and metamorphic.

Pseudoscience

A method of investigation the claims to be scientific, but does not hold up to full scientific scrutiny. Examples include astrology, paranormal studies, young-Earth creationism, and cryptozoology (i.e. the study of creatures like Bigfoot and the Loch Ness Monster)

Plate tectonics

The theory that the outer layer of the Earth (the lithosphere) is broken in several plates, and these plates move relative to one another, causing the major topographic features of Earth (e.g. mountains, oceans) and most earthquakes and volcanoes.

Continental Drift

Evidence for movement on the Earth's Surface.

Alfred Wegener

German Meteorologist. Saw how continental shapes sort of matched and the recognized key land-based fossils are found in SA, Africa, Antarctica, Australia, and India.

Earth's three main Chemical Layers

1. Crust. 2. Mantle. 3. Core.

Magma Rises?

From the mantle and forms new ocean floor at mid-ocean ridges.

MOR

Is like a factory for making new ocean floor (Hint: Somewhere it will have to be recycled).

Mantle

Middle chemical layer of the Earth, made of mainly iron and magnesium silicates. It is generally denser than the crust (except for older oceanic crust) and less dense than the core.

Earth's Core

3,500 km (2,200 mi) thick and made of iron and nickel. The core consists of two parts, a liquid outer core, and a solid inner core.

Inner Core

The innermost physical layer of the Earth, which is solid.

Outer Core

The outer physical layer of the core, which is liquid. Movement within the outer core is believed to be responsible for Earth's magnetic field and flips of the magnetic field.

Metallic

Minerals with a luster similar to metal and contain metals, including valuable elements like lead, zinc, copper, tin, etc.

Eon

The largest span of time recognized by geologists, larger than an era. We are currently in the Phanerozoic eon. Rocks of a specific eon are called eonotherms.

Earth's five main physical layers determined by response to stress?

1. Lithosphere, 2. Asthenosphere, 3. Mesosphere, 4. Outercore, 5. Inner core.

Lithosphere

Strong outer shell of the Earth that is made up of the crustand uppermost mantle to a depth of about 140 km on average (near zeroat MOR); it is solid and brittle. The tectonic plates that move on the Earth's surface are ________________?

Asthenosphere

Weak, ductile layer of mantle that deforms very slowly to accommodate the horizontal and vertical motions of plate tectonics. The ______________ extends from 140 km depth down to ~ 340 km. It is solid and ductile. This 'single' layer moves with convection currents created by heat from the core and drives plate motion.

Mesosphere

(Lower mantle) it is more rigid and immobile compared to asthenosphere; many transitions in mineralogy in upper parts of the ________________.Liquid outer core is about 2300 km thick and solid inner core is about 1220 km thick

Mantle Convection

Warm material rises under mid-ocean ridges, cools and then sinks at subduction zones; convey or belt analogy.

Which kind of plate boundary is associated with earthquake activity?

All the above

At which kind of plate boundary is new oceanic lithosphere formed?

Oceanic Divergent Boundary

1.) What is the approximate velocity of the fastest-moving tectonic plates on earth?

Same as your Fingernail

1.) The term "subduction" means?

When one tectonic plate is forced downwards into the mantle due to density differences

Hot Spot

Area of volcanic activity produced by a thermal plume rising from the mantle.

Continent-Continent Convergence

When two continental plates collide. The crust crumples and thickens, creating high mountains and a wide plateau.

Mid-Ocean Ridge Transform Fault

Spreading centers are offset by mid-ocean ridge transform faults, where the two oceanic plates slide horizontally past each other.

Continental Transform Fault

The San Andreas fault in California, where the pacific plate slides past the North American Plate, is an example of a transform fault that offsets continental crust.

Ocean-Continent Convergence

When an oceanic plate meets a continental plate, the oceanic plate subducts, and a volcanic belt of mountains is formed at the continental plate margin. The Oceanic plate will always subduct beneath a continental plate because the oceanic plate is denser.

Ocean-Ocean Convergence

When two oceanic plates converge, they form deep-sea trench and volcanic island arc. Colder, older plate will subduct. Here, the Pacific plate is subducting beneath the Philippine plate.

Continental Plate Separation

In east Africa, in earlier stage of rifting and spreading has created parallel valleys in a zone with volcanoes and earthquakes. Continental rifting breakup pattern is like the seams of a soccer ball; one or more arms may fail.

Oceanic Plate Separation

Rifting and spreading along a narrow zone have created the Mid-Atlantic Ridge, a mid-ocean mountain chain where volcanoes and earthquakes are concentrated.

Naturally occurring

To qualify as a mineral the substance must be found and made in nature.

Solid Crystalline Substance

Atoms that compose the mineral are arranged in an orderly, repeating, three-dimensional array.

Inorganic

Crystallize from magma, precipitate from solutions such as seawater in response to changing temperature or grow in response to changing T & P deep in the crust.

Specific Chemical Composition

What makes each mineral unique is the combination and arrangement of atoms in an internal structure. Mineral chemical composition can vary within defined limits.

Elements

Substances, which cannot be separated or subdivided into simpler substances by chemical means. We know 92 naturally occurring elements.

Valence

The outermost shell is the _________ shell and affects chemical bonds.

Isotopes

Some elements have different number of neutrons and are referred to as ______________

What is H?

Hydrogen

What is Li?

Lithium

What is Na?

Sodium

What is He?

Helium

What is C?

Carbon

What is N?

Nitrogen

What is O?

Oxygen

What is F?

Fluorine

What is Is?

Silicon

What is P?

Phosphorous

What is S?

Sulfur

What is Cl?

Chlorine

What is V?

Vanadium

What is Cr?

Chromium

What is Mn?

Manganese

What is Fe?

Iron

What is Co?

Cobalt

What is Ni?

Nickel

What is Cu?

Copper

What is Zn?

Zinc

Chemical Reaction

Combination of two or more elements to form a mineral.

Mineral Chemistry

Minerals are chemical compounds: each has a chemical formula.

Composition of the Earth's crust?

Oxygen (O) and Silicon (Si) are the two most abundant elements in Earth's crust.

Silicate Minerals

The majority of the crustal rocks belong to the group of _________________?

Formation of Minerals 3 basic ways

1) Precipitation directly from anaqueous (water) solution with a temperature change
2) Crystallization from a magma with a temperature change
3) Biological precipitation by the action of organisms.

Precipitation directly from anaqueous (water) solution with a temperature change

Precipitation of ions in the water. Ions are derived from the chemical weathering of rocks. They will precipitate if water is saturated. It can occur when temperature falls or when water evaporates.

A great example is salts in Bonneville Salt flatson western margin of Great Salt Lake, Utah.

Crystallization from a magma with a temperature change

High temperature breaks chemical bonds and minerals melt releasing freely moving ions to the melt. When the magma starts to cool, mineral crystals can form. The longer it takes to cool, the bigger the crystal

Biological precipitation by the action of organisms

An ammonite bioprecipitates aragonite CaCO3. Aragonite is a polymorph (same composition, different arrangement) of calcite. These and many other shells

etc. accumulate to make limestone.

Olivines

Primary mineral of mantle and of the rock called peridotite. Olivine is built by independent tetrahedra. It is a dark ferro-magnesium or mafic mineral group.

Pyroxenes

This is another mafic mineralgroup. Pyroxenes are built from long single chains of silica tetrahedra. Common in mafic igneous rocks such as peridotite, basalt, and gabbro.

Amphiboles

Double chained silicate trahedra. It has a bladed crystal habit and is a mafic mineral of igneous and metamorphic origin. A common mineral in the group is hornblende pictured above.

Sheet silicates

These minerals share all three bottom corners of the oxygen-silica tetrahedra forming sheets and the top corner can bond with other atoms. Micas (igneous and metamorphic rocks) and clay minerals (sedimentary rocks) are sheet silicates. The sheets are held together by weak Van der Waals bonds = strong sheet-like cleavage.

Framework silicates

Includes minerals in which all four corners of the silicate trahedra are shared in a 3D framework. They include feldspar and quartz (felsic minerals), which are the two most common minerals in the Earth's crust. Feldspar is most common (two types, K-spar and plagioclase).

Examples of Non-silicate minerals

Carbonates, Oxides, Halides, Sulfides, Sulphates, and Phosphates.

What is an example of Sulphates?

Epsom Salts

Oxides

Metal ions covalently bonded with oxygen. Most common is iron oxide (rust) Fe2O3

Also includes hematite and magnetite.

The red colour in rocks is from iron (Fe) oxides

Sulphides

Metal ions bonded with sulphur. Significant metal ore deposits are sulphides. Includes galena (lead sulphide), sphalerite (zinc sulphide), pyrite (iron sulphide; fool's gold) and chalcopyrite (copper iron sulphide).

Crystals

Fundamental units of matter organization, which have regular, repeating architecture (unit cell) reflecting packing atoms.

Sulfates

Minerals contain a cation, such as Calcium, bonded with a sulfate ion (SO42). Include minerals like gypsum CaSO4. 2H2O. Found associated with evaporitic settings.

Phosphates

Have tetrahedral phosphate unit (PO43) combined with various anions (-ive) and cations (+ive). Best know mineral in this group is apatite Ca5(PO4)3(F,Cl,OH)

Mineral Properties

Crystal form, Hardness, Cleavage/fracture, Lustre, Colour, Streak, Other Properties. (e.g., magnetism, taste).

Crystal Form

A good diagnostic property for very well formed minerals!

Good crystal form is rare in nature

Hardness

Resistance to scratching. Soft minerals are always scratched by harder ones.... Moh's scale is relative, not quantitative.

Moh's Scale of Hardness

The Girls Can Flirt And Other Quaint Things Can Do.

Talc, Gypsum, Calcite, Fluorite, Apatite, Orthoclase, Quartz, Topaz, Corundum, Diamond.

Cleavage

Minerals either cleave along parallel planes or they fracture irregularly (i.e., no __________) ... this is caused by chemical structure.

Lustre

How a crystal face reflects light

Metallic, Glassy, Adamantine, Dull, Earthy, Greasy.

List the events below in the correct order from oldest to youngest:

A) Rock at the top was formed
B) Rock at the bottom was formed
C) Rock at the bottom was tilted to vertical
D) Geologist visits the site

BCAD

Which of the following is an objective statement?

I observed that it snowed in Calgary on Sunday.

The term "science" comes from the latin scientia, which means "having ________________?"

Knowledge

Sedimentary rocks cover approximately ________________ of the Earth's surface?

75%

The rock that is formed by lithification of angular coarse-grained sediments that are 72mm in diameter is called?

Breccia

Chemical weather is favoured by _________________ climates?

Tropical

The compound _____________ combines with water to form natural carbonic acid that breaks down minerals in both silicate rocks and carbonate rocks?

Carbon Dioxide

What is a common mineral of Igneous rocks?

Olivine

What is a common mineral of sedimentary rocks?

All of the above