Transport, Weathering & Bonding

Question 1

What are some transportation agents for sediments?

Answer 1

wind, water, gravity, glacier

Question 2

What are the various grain sizes and their measurement?

Answer 2

boulder >256mm
cobble 64-256mm
pebble 4-64mm
granule 2-4mm
sand (1/16)-2mm
silt (1/256)-(1/16)mm
loam between silt & clay
clay <(1/256)mm

Question 3

What is the percentage breakdown of the types of sedimentary rocks?

Answer 3

siltstone, mudstone, and shale ~75%
limestone & dolostone ~14%
sandstone & conglomerate ~11%

Question 3

How do interference ripples form?

Answer 3

In a beach environment, when waves hit each other perpendicularly, creating an egg carton shape.

Question 4

What are the three classifications of sedimentary rocks?

Answer 4

Detrital, chemical: inorganic & chemical: biochemical

Question 5

What is an Orthoconglomerate?

Answer 5

intact, grain supported fabric

Question 6

What is a Paraconglomerate?

Answer 6

Unstable, matrix-supported fabric

Question 7

What are two tools used to classify compositions of sandstones?

Answer 7

Ternary Diagram and Point Counting

Question 8

In terms of mudrock, what would you call a rock that is silt predominate ( > 66%) and has no connotations to breaking characterists?

Answer 8

Siltrock

Question 9

In terms of mudrock, what would you call a rock that is silt predominate ( > 66%) and breaks fissile?

Answer 9

siltshale

Question 10

In terms of mudrock, what would you call a rock that is silt predominate ( > 66%) and breaks massive?

Answer 10

siltstone

Question 11

In terms of mudrock, what would you call a rock that is 50-50 silt & clay, and has no connotation to breaking characteristics?

Answer 11

mudrock

Question 12

In terms of mudrock, what would you call a rock that is 50-50 silt & clay, and has fissile breakage?

Answer 12

mudshale

Question 13

In terms of mudrock, what would you call a rock that is 50-50 silt & clay has massive breakage?

Answer 13

mudstone

Question 14

In terms of mudrock, what would you call a rock that is >60% clay, and has no connotation to breaking characteristics?

Answer 14

clayshale

Question 15

In terms of mudrock, what would you call a rock that is >60% clay and has fissile breakage?

Answer 15

clayshale

Question 16

In terms of mudrock, what would you call a rock that is >60% clay, and has massive breakage?

Answer 16

claystone

Question 17

When telling the difference between inorganic chemical and biochemical sedimentary rx, if you see layers of salt, what type would it be?

Answer 17

Inorganic chemical

Question 18

When telling the difference between inorganic chemical and biochemical sedimentary rx, if you see shells what would it be?

Answer 18

biochemical

Question 19

Describe inorganic chemical sedimentary rocks

Answer 19

Direct precipitations of minerals from water. Typically you have weathering from the ground and ions seeping into a water source. Because it’s a hot and dry atmosphere, there is a high evaporation rate. More ions roll into the water source, and the H2O evaporates leaving the water source more and more saturated. The surface level stays the same but the concentration changes.

Question 20

What is chalk made out of?

Answer 20

microscopic marine organisms (skeletons). Some examples of them are coccoliths (2 microns) and foraminifera (10th of a mm).

Question 21

What is reef rick?

Answer 21

When corals precipitate out clacitic skeletons. Considered limestones. Annenomes precipitate out their skeleton

Question 22

Why do we think stromalites largely dissapeared about 5-550 million years ago?

Answer 22

Cambrian explosion. Suddently a lot of Oxygen in atmo. So organisms (mostly snails) ate them all. Now they live in hyper saline environments where snails don’t tend to go.

Question 23

What is Folk’s classification?

Answer 23

Classification for carbonates that classifies oolites, fossils, pellets and intraclasts (all of the above) into either sparry calcite cement (crystalline) or micrite matrix (lime mud). And issue is that sometimes hard to tell the matrix except when using thin section. So not so easy in the field

Question 24

What is Dunhams classification for carbonates?

Answer 24

Looking at weather a rock is mud supported or grain suppoted (mudstone, wackestone, packstone and grainstone from more to less mud). The ones with lots of mud are low energy. The grainstone is more crystalline. If the original components bound together at deposition. Intergrown skeletal material, lamination contrary to gravity, or cavities floored by sediment roofed over by organic material but too large to be interstices... boundstone. Easier classification for the field

Question 25

What are oncolites?

Answer 25

Made from oncoids, layered structures formed by the growth of one or more species of microorganisms usually containing Cyanobacteria.

Question 26

What are polymorphs?

Answer 26

Two or more minerals with the same chemical composition but different atomic structures

Question 27

What are the main mineral groups?

Answer 27

1. native elements (like gold, copper) 2. oxides (metal+O2) 3. hydroxides (OH or H2O) 4. sulfides (sulfur like galena PbS) 5. sulfates (SO4) 6. carbonates (CO3 calcite, dolomite) 7. phosphates (PO4) 8. halides (halogen row) 9. silicates (silicate + oxygen like quartz)

Question 28

Why do silicates have 4 oxygens and 1 silicon atom?

Answer 28

Because of packing (coordination number). The size of the Si says that only 4 O's can fit around it.

Question 29

What is Pauling's rule?

Answer 29

In essence, this rule says that very small cations will bond to only a few anions, while very large cations may bond to many anions. In other words, as the radius of the cation increases, so too will the coordination number.

Question 30

What is the difference between the term "atom" and "elements"?

Answer 30

Elements are atoms but are a more specific name based on number of protons.

Question 31

What is the difference, in brief, of covalent and ionic bonding

Answer 31

Covalent is shared, ionic is donated.

Question 32

What is an example of an isolated tetrahedron? What is the charge of the tetrahedron structure?

Answer 32

Olivine -4

Question 33

What is an example of a paired tetrahedron? What is the charge of the structure?

Answer 33

Si2O7 6- -3

Question 34

What is an example of a single chain tetrahedron? What is hte charge of the structure?

Answer 34

Proxene -2

Question 35

What is an example of a double chain tetrahedron? What is the charge of the structure?

Answer 35

Hornblende/amphibole group Alternating -2 and -1

Question 36

Examples of sheet silicate? What is the overall charge of the structure?

Answer 36

micas, clays -1

Question 37

What are some examples of the 3-d network, technosilicates?

Answer 37

K-feldspa, quartz

Question 38

What are the rules for mineral composition?

Answer 38

1. similar ionic radius 2. similar charge