Exam 2 Flashcards
Which of the following is NOT a sediment transport medium
-glaciers
-wind
-ocean currents
-lava flows
-rivers
lava flows
Which of the following is a plausible environment of deposition for a sandstone?
-Mid Ocean Ridge
-High Energy River System
-Large, deep lake
-Coral Reef
High Energy River System
Pebbles present in a conglomerate are rounded because:
-they have been physically rounded by transportation
-pebbles have rounded cleavage
-pebbles grow like rounded crystals in a conglomerate
-water dissolves the rock from around the pebbles, leaving rounded concretions
they have been physically rounded by transportation
Chances are, you probably put salt on your food. How does this type of sale (halite) form?
-It is an igneous material that crystallizes from magma or lava
-it is a metamorphic mineral that grows under high pressure and temperature
-it forms as a precipitate or residue left behind after a lake or sea evaporates.
-it forms as an oxidation (rust) product of sand
It forms as a precipitate or residue left behind after a lake or sea evaporates
What is the difference between sand and sandstone
-sandstone is lighter in color than sand
-sand refers to a grain size, while sandstone is sand sized particles cemented together.
-sandstone can never be cemented by CaCO3
-only sand can be thinly bedded. Sandstone cannot.
-sandstone can only be made up of grains >4 inches in diameter
sand refers to a grain size, while sandstone is sand sized particles cemented together.
In the oceans, sediments are generally the thickest:
-along the margins of the continents
-along the mid ocean ridge
-in the deep ocean basins
-near hotspots
-along the equator
along the margins of continents
Clastic sedimentary rocks are classified, in part, by grain size. Place match the following rock types with their relative grain size where size increases from (A), the smallest grain size, to (D) the largest grain size.
-Shale
-Siltstone
-Sandstone
-Conglomerate
A - Shale
B - Siltstone
C - Sandstone
D - Conglomerate
In general, limestone has a composition of:
-SiO2
-Fe2O3
-CaCO3
-NaCl
-CO2
CaCO3
Which of the following statements is false?
* Fossils generally do not contain the original material from the dead organism, but rather are impressions, replacements, or casts.
* In terms of sediment transport, wind is more energetic than a glacier.
* Ripples observed in a sandstone can be used to interpret the sandstone’s environment of deposition as including a current of wind or water.
* An important way to increase the settling rate of fine particles (like plankton shells) in the open ocean is via fecal pellets.
* The principle of Uniformitarianism holds that understanding/observing geologic processes that occur today is critical for understanding the rock record, and thus understanding the processes/environments that occurred in the past.
In terms of sediment transport, wind is more energetic than a glacier.
You would NOT expect to find schist outcrops at the summit of Mt. Rainier.
True or False
True
Match the metamorphic rock with its protolith. (options - sandstone, shale, limestone, basalt)
* Quartzite
* Schist
* Marble
* Eclogite
Quartzite - Sandstone
Schist - Shale
Marble - Limestone
Eclogite - basalt
During metamorphism:
a. minerals may dissolve
b. new minerals may grow
c. the composition of the rock will change significantly
d. a & b
e. b & c
d. a & b
Which of the following is NOT true:
1. Metamorphism can involve a change in temperature
2. Metamorphism can involve a change in pressure
3. Metamorphism occurs above the melting temperature of rocks
4. Metamorphism usually involves the breakdown of water-bearing minerals
5. All of the above
Metamorphism occurs above the melting temperature of rocks
Which of the following statements is NOT true:
* Contact metamorphism involves relatively high temperature with relatively low or moderate pressures.
* Contact metamorphism generally occurs near an igneous intrusion (magma chamber)
* Regional metamorphism involves moderate to high temperatures and pressures.
* Regional metamorphism generally involves convergent tectonic activity (plate collision).
* Metamorphism typically occurs within a few hundred meters of the surface of the earth.
- Metamorphism typically occurs within a few hundred meters of the surface of the earth.
Folded rocks are most commonly associated with which type of plate boundary?
-convergent
-divergent
-transform
-they are formed in the stable interior of continents
-convergent
Which of the following is NOT true:
* A depositional contact with limestone on top of gabbro would be a nonconformity
* A depositional contact with Permian sandstone on top of Cambrian limestone would be a nonconformity
* A depositional contact with Cretaceous shale on top of Devonian sandstone would be a disconformity
* A depositional contact with Jurassic conglomerate on top of Triassic sandstone is not an unconformity
* A depositional contact with flat lying Silurian sandstone on top of tilted and eroded Cambrian sedimentary rocks would be an angular unconformity
- A depositional contact with Permian sandstone on top of Cambrian limestone would be a nonconformity
Orogeny
Mountain Building event
When did Himalayan Orogeny begin?
~55 Ma
