Geology chapter 1-4

Tetragonal System

"Rectanguloid" shapes, prisms, pyramids, and complex forms.

James Hutton

A Scottish physician ______ studied rocks and landscapes throughout the British Isles and promoted "uniformitarianism."

stratigraphy

A branch of geology concerned with the systematic study of bedded rock layers and their relations in time and the study of fossils and their locations in a sequence of bedded rocks.

mafic

A mnemonic term combining and "Ma" (for magnesium) and "Fe" (for ferric iron). The term is used to describe dark-colored igneous minerals rich in iron and magnesium, as well as the rocks that bear those minerals.

fossil

A remnant or trace of an organism of a past geologic age, such as a shell, skeleton or leaf imprint, embedded and preserved in the earth's crust.

igneous rocks

A rock formed from molten materials, includes intrusive rocks (rocks cooled below the surface) and rocks formed on the Earth's surface by volcanism (and from melting associated with extraterrestrial impacts).

theory

A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena.

Nicolas Steno

Danish Catholic bishop _____ who first promoted science of the origin of fossils and the basic geologic principles associated with the science of stratigraphy.

geological time scale

Geologists have subdivided periods in Earth's history is measured periods spanning millions of years (Ma). Segments of time periods have been named to help define the chronology of events (such as mountain range formation), the formation of rock units (such as the age of a lava flow), the age of fossils, organizing geologic map units, and other purposes.

Galileo

Italian physicist and astronomer ______ used an early telescope and discovered four large moons of Jupiter. He promoted the theory the the sun, not the Earth, was to center of our solar system. In 1615 he was subjected to the Roman Inquisition. He was forced to recant his beliefs and subjected to house arrest for the remainder of his life.

fact

Knowledge or information based on real occurrences; something demonstrated to exist or known to have existed.

metamorphic rocks

Rock that was once one form of rock but has changed to another under the influence of heat, pressure, or fluids without passing through a liquid phase (melting).

geology

The scientific study of the origin, history, and structure of the earth.

stratum

a bed or layer of sedimentary rock having approximately the same composition throughout

meteor

a bright trail or streak that appears in the sky when a meteoroid is heated to incandescence by friction with the earth's atmosphere.

big bang theory

a cosmological theory holding that the observable universe originated approximately 13.8 billion years ago from the violent explosion of a very small agglomeration of material of extremely high density and temperature.

bollide

a large meteor (or asteroid or comet) that explodes in the atmosphere.

mineral

a naturally occurring, inorganic (never living) solid with a definite internal arrangement of atoms (crystal structure) and a chemical formula that only varies over a limited range that does not alter the crystal structure.

chemical compound

a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions.

rock

a relatively hard, naturally formed mineral or petrified matter; a naturally formed aggregate of mineral matter constituting a significant part of the earth's crust.

ultramafic

a rock composed chiefly of mafic minerals (rich in iron and magnesium), and less than about 45 percent silica, such as the minerals olivine, pyroxene, or amphibole.

star

a self-luminous celestial body consisting of a mass of gas held together by its own gravity in which the energy generated by nuclear reactions in the interior is balanced by the outflow of energy to the surface, and the inward-directed gravitational forces are balanced by the outward-directed gas and radiation pressures.

crystal

a solid substance with a homogeneous composition having a symmetrical geometric form with plane faces in symmetrical form.

meteorite

a stony or metallic mass of matter that has fallen to the earth's surface from outer space.

galaxy

a system of millions to billions of stars, together with gas and dust, held together by gravitational attraction. Earth is in the Milky Way galaxy.

hypothesis

a tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation.

plate techtonics

a theory that explains the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid "lithospheric plates" that move slowly over the underlying more fluid mantle.

hydrosphere

all the waters on the Earth's surface, such as oceans, lakes, rivers, and streams.

conformable boundary

an arrangement where layers of sedimentary strata are parallel, but there is little apparent erosion and the boundary between two rock layer surfaces resemble a simple bedding plane.

mantle

an inner layer of a terrestrial planet or other rocky body large enough to have differentiated in composition by density. On Earth, the mantle is a highly viscous layer between the crust and the outer core.

nebula

an interstellar cloud within a galaxy consisting of gas and dust, typically glowing from radiant energy from stars nearby within them.

disconformity

an unconformity between parallel layers of sedimentary rocks which represents a period of erosion or non-deposition.

noncomformity

an unconformity between sedimentary rocks and metamorphic or igneous rocks when the sedimentary rock lies above and was deposited on the pre-existing and eroded metamorphic or igneous rock

angular unconformity

an unconformity where horizontally parallel strata of sedimentary rock are deposited on tilted and eroded layers, producing an angular discordance with the overlying horizontal layers

core

based on geophysical studies, the innermost part of the earth is believed to consist of a 758 mile thick magnetic metallic inner core that is overlain by a 1400 mile thick zone of dense molten material in the outer core. This is overlain by the Earth's mantle.

charles lyell

compiled the first geology textbook entitled "Principles of Geology" in which he promoted concepts of the "rock cycle."

absolute dating

general term applied to a range of techniques that provide estimates of the age of objects, materials, or sites in real calendar years either directly or through a process of calibration with material of known age.

supernovas

great explosions that partial to complete demolish aging stars, releasing new matter and gas to create a new generation of stars

molecule

group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction

4.55 billion years

how old is earth?

Cubic or Isometric System

include all crystal shapes that have symmetry axes in equal lengths in 3 directions (halite, fluorite, pyrite..)

Monoclinic System

includes crystal forms that have three unequal axes; two of the axes are at right angles (90º) but the third axis is inclined at an angle not at 90º. There is one two-fold axis of symmetry.

Triclinic System

includes crystal forms where the three axes are of unequal length, and one of the axes are perpendicular to each other.

cross section

interpretation of a vertical section through the Earth's surface, most usefully a profile, for which evidence was obtained by geologic and geophysical techniques or from a geologic map.

comets

like asteroids (mostly frozen gases and ice dust, some rocky material) that leave a trail of material as they are heated as they approach the sun. There may be more than 100 million comets in the outter Solar System.

metallic bonds

metals

felsic

minerals of silica and aluminum-rich composition, and the rocks that form from them.

covalent bonds

non-metallic molecular compounds

transgression

occurs when a shoreline migrates landward as sea level (or lake level) rises.

regression

occurs when a shoreline migrates seaward as sea level (or lake level) falls.

geologists

people who study earth processes: floods, earthquakes, landslides, volcanic eruptions, manage resources, ect.

Orthorhombic System

prisms, pyramids, and combined forms (topaz)

sedimentary rock

rock that has formed through the deposition and solidification of sediment, especially sediment transported by water (rivers, lakes, and oceans), ice ( glaciers), and wind.

ionic bonds

salts

sedimentary facies

sedimentary deposits that reflect environmental conditions at the time of deposition of sediments.

science

she systematic knowledge of the physical or material world gained through observation and experimentation. goal - underlying patterns.

Hexagonal or Trigonal System

six-sided prism, pyramid-shaped, rhombahedral, and combined forms. (calcite and quartz)

sediments

solid fragments of inorganic or organic material that come from the weathering of rock and soil erosion, and are carried and deposited by wind, water, or ice.

asteroids

solid object in space consisting mostly of rock, dust, some metals, and possibly ice.

mixture

solid, liquid, or gas composed of two or more substances, but each keeps its original properties.

physical geology

that branch of geology concerned with understanding the composition of the earth and the physical changes occurring in it, based on the study of rocks, minerals, and sediments, their structures and formations, and their processes of origin and alteration.

observation

the act of noting and recording something, such as a phenomenon, with instruments, in order to gain information.

silicate minerals

the dominant group of minerals that make up the rocky crusts of the Earth, Moon, and other stony planets (Mercury, Venus, Mars, and many other moons and asteroids within the Solar System.

atmosphere

the gaseous mass or envelope surrounding a celestial body (including the one surrounding the Earth), and retained by the celestial body's gravitational field.

crust

the outermost solid shell of a rocky planet or moon, which is chemically distinct from the underlying mantle.

rock formation

the primary unit of stratigraphy, consisting of a succession of strata useful for mapping or description.

scientific method

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to demonstrate the truth or falseness of the hypothesis, and a conclusion that validates or modifies the hypothesis.

biosphere

the regions of the surface, subsurface, and atmosphere of the Earth (or possibly other planets) occupied by living organisms.

lithosphere

the rocky outer portion of the Earth, consist of the crust and upper mantle

relative dating

the science of determining the relative order of past events, without necessarily determining their absolute age

rock cycle

the series of events in which a rock of one type is converted to one or more other types and then back to the original type.

bedrock

the solid rock the occurs beneath soil or alluvium that coved the surface of the land in most locations.

historical geology

the study of the composition, relative positions, etc., of rock strata in order to determine their geological history. Historical geology is dependent on concepts and order of events related to deep time, as defined by a geologic time scale.

solar system

the system containing the sun and the bodies held in its gravitational field, including the planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto), planetary moon, the asteroids, and comets, and other interstellar matter.

cleavage

the tendency of crystalline materials to split along definite crystallographic structural planes

uniformitarianism

the theory that all geologic phenomena may be explained as the result of existing forces having operated uniformly from the origin of the earth to the present time.

catastrophism

the theory that major changes in the earth's crust result from catastrophes rather than evolutionary processes.

geological time

the time of the physical formation and development of the earth

Law of Cross-Cutting Relationships

this law states that a body of igneous rock (an intrusion), a fault, or other geologic feature must be younger than any rock across which it cuts through.

Law of Superposition

this law states that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.

Law of Original Horizontality

this law states that most sediments, when originally formed, were laid down horizontally. However, many layered rocks are no longer horizontal.

Charles Darwin

to first propose a theory of evolution, an essential component to explaining the distribution of fossils through the geologic ages.

William Smith

used Hutton's theories to create the first geologic map of the British Isles.