geology lab exam #1
Minerals are the building blocks of
rocks
Coquina has
shells.
texture
size, shape, and relationship of mineral crystals in the rock
Shale has a platy breakage, and it
sometimes has beddings (lines).
Rock Salt is
sometimes very crystalline. It also tastes salty
Streak
the color of a mineral's powder
Contour interval
the difference in elevation from one contour line to the next On a topographic map, tells the distance in elevation between adjacent contour lines.
SLP and DLP
types of seismicity shallow long period < 10km deep long periods > 10km
You can scratch Rock Gypsum
with your fingernail.
Chemical and Biochemical Sedimentary Rocks:
• This rocks form where dissolved substances are precipitated from water. • Most common ones are limestones, and they react heavily with acid.
The process formation may include several steps:
• Weathering: physical or chemical • Erosion: loose sediments move downslope • Transportation: sediments was moved by water, air or glaciers
• Magnetism
Attraction to magnet.
pebble size
Breccia (angular fragments) and Conglomerate (rounded fragments). The more rounded the fragment, the longer the transportation. Imaging the angular edges bien cut off and smoothed off while rolling.
Phaneritic
Minerals are visible, intrusive, cooled slowly (ex. Diorite)
Porphyritic
Minerals different sizes (ex. Porphyritic andesite)
fine grained
Rock composed of mainly clay minerals and its associated with deep water environments. (Shale)
GREEN=DARK
Ultramafic (ex. Peridotite)
Rock that has a spongy appearance due to trapped gas bubbles in the lava
Vesicular texture (igneous)
• Specific Gravity
Weight
obsidian is
felsic
Intermediate:
fine grained light and dark (ex. Diorite)
Arkose is
red beige or deep red.
Ultramafic:
usually green (ex. Peridotite)
how to identify rock
-Determine if its detrital, chemical or organic by looking at the grain size and see if it reacts to acid. - For detrital rocks, look at the grain size. - For chemical rocks, describe the mineralogical composition (CaCO3, SiO2, CaSO4.2H2O, NaCl).
A mineral has to be/have a:
1. Naturally occurring 2. Inorganic 3. Solid 4. Defined Chemical Composition 5. Fixed Atomic Arrangement
Breccia and Conglomerate have
BIG fragments.
Mineral Composition
Color Index
How to make a topographic profile ????
Draw how far contour lines are apart from each other and then plot them onto a graph to see how elevation changes
• Reaction to acid (HCl)
Effervescence
RED=LIGHT=
Felsic (ex. Granite)
• Taste
Flavor
• Feel
Greasy, rough, soapy, etc.
What are contour lines?
Imaginary lines on the ground connecting equal elevation they represent high and low ground elevation.
Longitude lines
Imaginary north-south lines that run vertically around the globe parallel to the Prime Meridian(goes through greenwich england)
• Facture
Irregular or conchoidal
Latitude lines
Lines that run east to west and are parallel to the Equator. zero parallel of latitude= equator .
Glassy
Looks like glass, it's very smooth (ex. Obsidian)
Luster
Metallic, Submetallic, Non-metallic, Earthy
Aphanitic
Minerals are barely visible, usually extrusive, cooled rapidly (ex. Basalt)
• Hardness
Moh's Hardness Scale (1-10)
Pyroclastic
ONLY IDENTIFIED BY FRAGMENT SIZES
medium size
Sandstones (Arkose and Quartz Sandstone) Quartz sandstones usually come from continental shields and mountain erosions and were deposited in shallow seas. Arkose sandstones derive from recently uplifted blocks, mainly in continental areas. This type of sandstone is also associated with dry climate regions.
sedimentary environments
Sedimentary environments are the places where sediments accumulate and they are 3 in general: (pg. 40, exercise 4) • Continental: rivers, lakes, glaciers, desserts • Near shore/ Shallow Water: tidal flats, beaches, barrier islands, deltas, slits. • Offshore Marine areas: continental shelf and slopes, reefs, deep sea environments, deep sea fans. • Focus on the depositional environments that you filled out in your Sed rocks chart. • These terms are in your lecture textbook, so please review!
• Color
Should be used with caution since the same mineral can have different colors
Basic mineral groups are
Silicates and Non-silicates
• Odor
Smell
Rule of V's
Suggests which direction the stream flows by the contoured lines. The stream flows the way the V opens up.
• Cleavage
Tendency of a mineral to break along one or more planes of weakness
Organic Sedimentary Rocks
We only saw ONE organic sedimentary rock which was COAL. rocks that are made from once living things, usually consisting of carbon
stratovolcano (composite)
a steep-sided, often cone-shaped volcanic peak, formed by layers of ash, relatively sticky lava and other eruption products. most common most dangerous
crystals are not visible or barley visible
aphanitic texture
easiest way to identify igneous rocks
by their texture and mineral composition
Meaning of the spacing of contour lines
closer they are= steeper slopes further apart= flatter = indicate relatively gentle slopes or flat areas
intrusive(plutonic) igneous rocks
crystalize from magma within the earths crust (it did not reach the surface to cool or solidify) ex: gabbro and granite
Mafic:
dark colored (ex. Basalt)
There are mainly 3 types of sedimentary rocks:
detrital, chemical/biochemical, and organic.
• Non-Silicates are ____________to determine by their streak.
easier
Felsic:
fine grained light colored (ex. Granite)
• Detrital Sedimentary Rocks:
form from sediments that have been weathered and transported Named by grain size: pebble, medium grained (sand) and fine grained
Vesicular
full of cell holes (ex. Pumice and Scoria)
rocks are produced from rapidly quenched lava, that cools so quickly that there is no opportunity for minerals to crystalize to form
glassy texture
Silicates
have the anion complex (SiO4) -4 for example, Quartz has a formula of SiO2.
Minerals are _______________ by physical properties and are _____________ by their chemical composition.
identified, classified
SO2
if magma is too close to the surface, more SO2 will be generated. If the amount of SO2 shuts off quickly, it could signal that the gas is bein trapped underground, and that may trigger an eruption
When magma solidifies below the surface of the Earth, ________ are formed.
igneous rocks
Quartz is
light grey.
RSAM
measure of total seismic energy over time. dimensionless number that is generally less than 10,000. Increased very quickly before eruption
tilt
measures how much ground deformation has occurred on the volcano. It is very precise as the volcano inflates and deflates with magma input it will change accordingly
extrusive(volcanic) igneous rocks
one which crystallized from magma(now called lava) erupted on the earths surface ex: rhyolite and basalt
Crystals are visible to the naked eye
phaneric texture
crystals two distinct sizes
porphyritic texture
Chalk feels
powdery.
rock contains broken fragmented instead of crystals
pyroclastic
Limestone, Coquina and Chalk
react to acid due to their mineral composition (CaCO3).