Geology 201 Lab Midterm

true north, magnetic north, and grid north

Canada's official map index system divides into large, numbered blocks based on lat+long designed to locate areas, not points

designed to locate points, not areas numeric code only, no number/letter combos uses a decimal system rather than degrees-minutes-seconds 2cm = 1km ex. zone 11 699 100 easting 5657 250 northing

divide earth with lines W-E = longitude N-S = latitude ex. 114°9'40" W 51°1'40" N

least reliable physical property. felsic = light mafic = dark

quality of light reflected from a mineral: metallic, vitreous, earthy

measure of how easily a mineral can be scratched

refers to the colour of a powdered mineral

a mineral's ability to split easily along flat points of weakness.

the shape of an unbroken mineral crystal; shape it naturally forms

made up of a single material

made up of several materials

consisting of the remains of organisms or formed due to the activity of organisms

resulting from non-biological chemical reactions

rock composed of many crystals

rock composed of fragments of: rocks, crystals, or fossils that show signs of physical reworking from current transport or erosion

does not contain crystals or grains, typically glassy

a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition

any evidence of life in the rock record. includes plant and animal remains as well as traces of biological activities (footprints)

aggregate of mineral crystals, fossils, grains, or a mass of natural glass

the crystallization of molten magma or lava (intergrown crystals)

rock that forms below Earth's surface (longer to cool, typically larger crystals)

rock that forms from the cooling and crystallization above the Earth's surface (less time to cool, typically smaller crystals)

coarse-grained, crystals are large enough to be seen by naked eye, formed by slow cooling (intrusive)

fine grained, crystals cannot be seen with the naked eye, formed by fast cooling (extrusive)

A texture formed when a rock cools so fast it doesn't have time to crystallize

an igneous texture consisting of large crystals embedded in a matrix of much smaller crystals

large crystals in porphyritic rocks (igneous)

describes a rock containing vesicles caused by gas being trapped during crystallization

dark-colored rocks that are silica poor and iron and magnesium rich. examples: olivine, pyroxene, plagioclase, and amphibole

examples: plagioclase, hornblende, quartz, pyroxene, biotite, k-feldspar

light colored rocks that are silica rich and iron and magnesium poor. examples: plagioclase, k-feldspar, quartz, amphibole, and biotite

sediments by compaction and cementation, evaporation of water & organic remains

• a term for the texture of sedimentary rocks in which the minerals form a pattern of interlocking crystals

• consist of inter-grown crystals (may resemble igneous rocks)

• a term for the texture of sedimentary rocks in which an aggregate of grains have been subsequently cemented together

clastic: deposition and subsequent cementation and compaction of sediment chemical: precipitation of minerals out of a solution (ex. limestone and rock salt)

consists of packed clasts that are partial or in full contact with one another (majority of rock)

consists of smaller grains that fill spaces between the larger framework grains

bind the framework and matrix to form sedimentary rocks

non-solid space between grains that is filled with fluid or gas

a sedimentary rock made from small rounded stones that have been cemented together

coarse sedimentary rock consisting of angular fragments; or rock broken into angular fragments by faulting

refers to the uniformity of grain size; well sorted sediments will have grains of approximately equal size

horizontal sedimentary beds that are roughly parallel to each other

Small waves of sediment formed by running water or blowing wind

indicate water or wind flowing in one direction (think river)

indicate water or wind flowing in an oscillatory pattern (think tide/waves)

refers to large scale equivalent of ripple cross lamina (dip towards dominant current direction)

type of bedding in which particle sizes become progressively heavier and coarser toward the bottom layers

it reacts WEAKLY with HCl

igneous and sedimentary rocks that undergo a significant change in pressure or temperature. NO MELTING OCCURS

formation of metamorphic rock bodies that are hundreds of square kilometers in size *convergent boundaries/mountain ranges

formation of a metamorphic rock caused by magma coming into contact with existing rock

an arrangement of minerals in flat or wavy parallel bands.

chlorite (green) biotite/muscovite garnet (red) kyanite (blue)

large crystals that form in solid rock by the reorganization of atoms during metamorphism

the original rock from which a metamorphic rock formed

a metamorphic rock with clean, flat breakage along closely spaced planes due to parallel arrangement of microscopic crystals of clay and mica (slaty texture). Slates are shinier than shales, generally having an egg-shell sheen

a metamorphic rock with very closely spaced parallel planes and glossy appearance due to the parallel alignment of microscopic mica crystals (phyllitic texture).Phyllite is shinier than slate because the reflective mica crystals are larger, giving the rock a satin sheen

a metamorphic rock with approximately parallel arrangement of mica crystals large enough to see with the naked eye (schistose texture). To fully name a schist, you must include one to two of its most common index minerals.

a metamorphic rock with discrete layers of different mineral content giving the rock a banded appearance (gneissic texture). Typically, the dark bands are composed of hornblende and/or biotite, whereas the light bands are composed of quartz and feldspars

slate phyllite schist

gneiss

quartzite

marble

metaconglomerate

amphibolite

unaltered, desiccation, embedding

hard parts remain unchanged (shells, bones, teeth)

freezing or mummification under dry (desert) or acidic (bog) conditions

in wax and amber (desiccation also occurs in this mold)

recrystallization, replacement, permineralization, petrification, and carbonization

minerals change to a more stable form without changing chemical composition. often involves an increase in crystal size and makes shells more dull

minerals making up a fossil are completely replaced by a new mineral with a different composition

pores, or empty body chambers are filled with a mineral

organic tissue of fossil is replaced by a new mineral. note: pores within the tissue are permineralized

volatiles like water are removed (often via heat and compaction) leaving a thin, carbon film

molds and casts

impressions of remains external: organism stamped into sediment internal: interior of organism is filled with sediment and shell dissolves away, leaving behind an internal mold note: mold is a negative (inverse of original shape)

exact replicas of remains if an external mold is filled with sediment/minerals, a cast is created. note: cast is a positive (same as original shape)

sediments are originally deposited on horizontal or nearly-horizontal surfaces

rocks that are highest in an undeformed sedimentary structure are the youngest and rocks that are lowest are oldest

the rock that cuts across a structure is younger than the structure it cuts through

recent deposits that have not yet been cemented or compacted enough to make up rocks, forming sand and gravel deposits rather than sandstone or conglomerate units

unconsolidated clastic (or detrital) material deposited by a stream or other body of running water

solid rock that underlies soils or other unconsolidated, superficial material

hills of sediment (generally a quarter of a mile or more in length) that have been streamlined by glacier flow

ridges made of sands and gravels deposited by glacial meltwater flowing through tunnels within and underneath glaciers, or through meltwater channels on top of glaciers

multi-threaded channels that branch and merge to create the characteristic braided pattern

single-channel that winds through a valley

a U-shaped lake or pool that forms when a wide meander of a river is cut off, creating a free-standing body of water

brachiopod

dinosaur bone fragment

bivalve

trilobite cephalon

amber

coral in dolostone

bivalve shell

wood

walnut