D-1 Review Questions Flashcards
What is the fundamental unit of biostratigraphy?
biozone
Which of the following is NOT a type of interval biozone?
taxon-range biozone
concurrent range biozone
partial range biozone
acme biozone
acme biozone
The types of interval biozones are:
1. taxon-range biozone
2. concurrent range biozone
3. partial range biozone
4. lineage biozone (or consecutive range biozone)
Which type of interval biozone uses two taxa with overlapping ranges?
concurrent range biozone
- taxon-range biozone - single taxon
- concurrent range biozone - two taxa overlapping
- partial range biozone - two taxa not overlapping
- lineage biozone - three or more taxa
Which type of biozone uses an interval containing high proportion of a single taxon?
interval biozone
assemblage biozone
acme biozone
lineage biozone
acme biozone
- interval biozone - succession of taxa
- assemblage biozone - at least three related or unrelated taxa
- acme biozone - abundance of single taxon
What do you call the marine organisms that are free swimming?
nektonic
- planktonic - free floating
- nektonic - free swimming
- benthonic - benthic or sea bed
- sessile - attaching
Which planktonic marine macrofossil is usually preserved as thin film having a teeth-like structure on fine grained sedimentary rocks?
graptolites
The common marine macrofossils are:
1. trilobites - arthropods, abundant in Cambrian
2. graptolites - teeth
3. brachiopods - shelly, sessile
4. ammonoids - cephalopods, includes goniatites and ammonites
5. gastropods - Mollusca, marine snails
6. echinoderms - includes crinoids (sea lilies) and echinoids (sea urchins)
7. corals
Which marine microfossil are chrysophyte algae with a siliceous frustule?
radiolaria
coccoliths
diatoms
dinoflagellates
diatoms
The common microfossils are:
1. foraminifera - calcareous tests
2. radiolaria - silica skeletons, spherical and spiny
3. coccolith - spherical calcareous cysts
4. ostracods - crustaceans, calcareous carapace
5. diatoms - chrysophyte (golden) algae, siliceous frustule
6. conodonts - tooth-like, phosphate
7. acritarchs - spiny, related to dinoflagellates
Which of the following microfossils DOES NOT have a siliceous skeleton?
radiolaria
diatoms
conodonts
none of the above
conodonts
The common microfossils are:
1. foraminifera - calcareous tests
2. radiolaria - silica skeletons, spherical and spiny
3. coccolith - spherical calcareous cysts
4. ostracods - crustaceans, calcareous carapace
5. diatoms - chrysophyte (golden) algae, siliceous frustule
6. conodonts - tooth-like, phosphate
7. acritarchs - spiny, related to dinoflagellates
The half-life of a certain substance is 250 years. How many years does it take for the amount of a substance to be 1/16th of the original amount?
1000 years
1/16 = (1/2)^4 –> The substance underwent 4 half-lives –> 250x4 = 1000 years
Which radiometric dating technique is most widely used in dating sedimentary strata because of the presence of the authigenic mineral glauconite?
Potassium-Argon
Rubidium-Strontium
Uranium-Lead
Samarium-Neodymium
Potassium-Argon
Common radiometric dating techniques:
1. Potassium-Argon - glauconite for sedimentary rocks, feldspars/micas - volcanic rocks
2. Rubidium-Strontium - igneous rocks, Rubidium is a trace element in silicates
3. Uranium-Lead - Uranium is found in zircon, monazite, sphene, and apatite – accessory minerals in igneous rocks
4. Samarium-Neodymium
5. Rhenium-Osmium
Which of the following parent isotope has a half-life of 42 billion years?
Potassium - 40
Rubidium - 87
Rhenium - 187
Thorium - 232
Rhenium - 187
Common half-lives:
1. Potassium - 40 - 1.25 billion years
2. Rubidium - 87 - 48.8 billion years
3. Samarium - 147 - 1.06 billion years
4. Rhenium - 187 - 42 billion years
5. Thorium - 232 - 14.01 billion years
6. Uranium - 235 - 0.704 billion years
7. Uranium - 238 - 4.468 billion years
8. Carbon - 14 - 5730 years
Which isotopic ratio can be used to determine the age of marine organisms made up of calcite?
86Sr/87Sr
The Curie Temperature of Magnetite is 570 °C. What will happen to the magnetite present in a rock when it is heated above its Curie Temperature?
It loses its magnetic properties.
Above the Curie Temp, the magnetic alignment will be random. Not parallel nor opposite. Hence, the mineral loses its magnetic properties.
Sampling of the ocean-floor sediments showed high 18O/16O ratio. This implies that these sediments were deposited during which type of climate?
cold climate
18O is heavier than 16O
1. warm climate - more 18O evaporates –> precipitates as ice in higher latitudes
2. cold climate - less 18O evaporates –> more 18O in oceans
Which Milankovitch cycle have the longest period?
eccentricity
- eccentricity - 100,000 years
- obliquity - 40,000 years
- precession - or wobble, 21,000 years
Rift basis produce a series of fault-bounded blocks. What do you call the raised fault block?
horst
- graben - g for ground –> so nasa baba
- horst - h for high –> so nasa taas
Which is a dome-shaped hill commonly produced by granite weathering?
bornhardts
- bornhardts - dome-shaped hills
- nubbins - or knolls, scattered blocks
- castle koppies - small and angular
Since the Philippines is located in the humid tropics which is characterized by intense leaching of soil, then by the scheme of Georges Pedro, it belongs to what weathering zone?
allitization zone
Georges Pedro’s weathering zones:
1. allitization zone - intense leaching, humid tropics
2. kaolinization - seasonal leaching, savannah
3. smectization - weak leaching, arid and temperate
4. little-chemical-weathering zone - deserts
5. podzolization zone - boreal
6. ice-cover zone - glacial
When a river creates a canyon, we can assume that identical or similar strata on opposite sides once spanned the canyon. What principle best explains this?
Principle of Lateral Continuity
Imagine that a series of sedimentary layers is deposited in a shallow marine setting. Then sea level falls, exposing some of the sedimentary layers. During this above-sea level time period, no new sediment accumulates, and some of the existing layers erode away. Later, sea level rises, resulting in the landscape becoming submerged once more. This causes a new series of sedimentary beds to be deposited. The boundary separating the two sets of beds is what type of unconformity?
Disconformity
- angular - tilted or folded sedimentary rocks that are
overlain by younger, more flat-lying strata - disconformity - erosion rather than deposition
- nonconformity - sedimentary strata overlie older metamorphic or intrusive igneous rocks
- paraconformity - no obvious erosional break
A site where sediments and volcanic debris accumulate, which is located on the backside of a volcanic arc when viewed from the trench. In these regions, tensional forces tend to prevail, causing Earth’s crust to stretch and thin and resulting in the formation of a downfaulted basin. What is this region?
back-arc
When a relatively cold, dense slab subducts, it does not follow a fixed path into the asthenosphere. Rather, it sinks vertically as it descends along an angled path. This causes the trench to retreat. What is the term to describe this mechanism?
trench rollback
Joints profoundly affect the weathering of bedrock by allowing ion-rich water to penetrate to depth and start the weathering process long before the rock is exposed at Earth’s surface. The weathering of enlarged joints create long and narrow walls. What are these features called?
fins
The slopes of many of the large normal faults in the Basin and Range Province decrease with depth and eventually join to form a low angle, nearly horizontal fault. What is this type of fault called?
detachment fault
A boudinage forms when some portions of a rock body deform in a ductile fashion and others act as brittle units. What is the main factor that resulted in this type of deformation?
type of rock
Like a spring, chemical bonds in a mineral grain stretch while under stress and then snap back to their original length. What type of deformation is this?
elastic deformation
Because the sedimentary beds in basins usually slope at low angles, basins are identified mainly by the age sequence of their strata. What is the correct age sequence of basins?
youngest rocks are at the center and the oldest on the flanks
It is estimated that the debris that rushed down the slopes of Peru’s Nevado Huascarán moved at speeds in excess of 200 kilometers per hour. What is this type of mass movement classified as?
avalanche
Although they can occur in many different climate settings, they tend to occur more frequently in semiarid mountainous regions. Because of their fluid properties, they frequently follow canyons and stream channels. What is this type of mass movement?
debris flow
When active landslides threaten infrastructure such as roads or buildings, geologists and engineers employ a variety of stabilizing methods. One of the methods is de-watering. Which is an example of this method?
installing horizontal drain pipes
When soil is saturated with water, the soggy mass may flow downslope at a rate of a few millimeters or a few centimeters per day or per year. What is this type of mass movement?
solifluction
A few hundred million years after the Big Bang, the primordial hydrogen and helium had condensed and coalesced to form the first stars and galaxies. Within the cores of these early stars, heating triggered the process of combining hydrogen nuclei to form helium nuclei, releasing enormous amounts of radiant energy. What is this process called?
nuclear fusion
Chemical analysis of rock suggests that molecular oxygen began to appear in significant amounts in the atmosphere around 2.3 billion years ago, a phenomenon termed the Great Oxygenation Event. Which of the following is NOT a positive benefit of this event?
proliferation of anaerobic life forms
he accretion of all of Earth’s major landmasses to form Pangaea spans more than 300 million years and resulted in the formation of several mountain belts. The collision of northern Europe with Greenland produced which mountain belt?
Caledonian Mountains
Examples of this group include cycads, which resemble large pineapple plants; ginkgo trees, which have fan-shaped leaves; and the largest plants of the time, the conifers, whose modern descendants include pines, junipers, and redwoods. These dominated terrestrial ecosystems throughout much of the Mesozoic era, which lasted from 252 to 66 million years ago. What is this plant group called?
Gymnosperm
Some reptiles evolved with specialized characteristics that allowed them to inhabit drastically different habitats. What group of reptiles became airborne?
pterosaurs
Coasts may be classified by their changes relative to sea level. Emergent coasts are sites of either land uplift or sea-level fall. Which of the following is a feature of emergent coasts?
marine terraces
In some wells, water rises, sometimes overflowing at the surface. What is this type of well called?
artesian
When groundwater from hot springs and geysers flows out at the surface, material in solution is often precipitated, producing an accumulation of chemical sedimentary rock. What is deposited when the water contains dissolved silica?
geyserite
At locations beyond approximately 100 degrees, Oldham observed that P and S waves were absent or very weak. Thus, he found evidence for the existence of?
inner core and outer core
