MOCK EXAM Flashcards
Which of the following statements best explains the significance of the Kármán Line in defining the boundary between Earth’s atmosphere and outer space?
A. The Kármán Line is located at an altitude where atmospheric pressure drops to zero, marking the start of outer space.
B. The Kármán Line is the altitude at which the gravitational pull of Earth becomes negligible, indicating the beginning of outer space.
C. The Kármán Line is the altitude where the atmosphere becomes too thin for aerodynamic flight, marking the boundary between the atmosphere and outer space.
D. The Kármán Line is the point where the temperature of the atmosphere drops to absolute zero, signifying the start of outer space.
The Kármán Line is the altitude where the atmosphere becomes too thin for aerodynamic flight, marking the boundary between the atmosphere and outer space.
Which of the following seismic discontinuities marks the boundary between the Earth’s mantle and the outer core, characterized by a sudden change in seismic wave velocities?
A. D” Layer
B. Gutenberg Discontinuity
C. Lehmann Discontinuity
D. ULVZ
Gutenberg Discontinuity
A geologist is studying a region where two lithospheric plates are converging. The area is characterized by intense seismic activity, volcanic arcs, and the presence of a deep oceanic trench. Based on these observations, which type of plate boundary is most likely present, and what specific geological process is occurring?
A. Continental-continental convergence; formation of a mountain range due to crustal thickening.
B. Oceanic-continental convergence; subduction of the oceanic plate beneath the continental plate, leading to volcanic arc formation.
C. Oceanic-oceanic convergence; subduction of one oceanic plate beneath another, resulting in the formation of an island arc and trench.
D. Transform boundary; lateral sliding of plates past each other, causing earthquakes but no significant volcanic activity.
Oceanic-oceanic convergence; subduction of one oceanic plate beneath another, resulting in the formation of an island arc and trench.
Which of the following best describes the primary mechanism that initiated the formation and movement of tectonic plates on Earth?
A. The differentiation of Earth’s core, leading to the formation of rigid lithospheric plates that float on the semi-fluid asthenosphere.
B. The cooling and solidification of Earth’s early magma ocean, driven by mantle convection currents and slab pull forces.
C. The gravitational collapse of early continental crust, resulting in the fragmentation and lateral movement of lithospheric plates.
D. The accumulation of sedimentary layers on the ocean floor, causing the lithosphere to break into plates due to differential loading.
Answer: The cooling and solidification of Earth’s early magma ocean, driven by mantle convection currents and slab pull forces.
Differentiation of Earth’s core: While important, this process primarily describes the formation of Earth’s layers rather than the initiation of plate movement.
Gravitational collapse of early continental crust: This is not a recognized mechanism for plate tectonics; rather, it oversimplifies complex geological processes.
Accumulation of sedimentary layers: This does not initiate tectonic movements; it’s more a consequence of geological processes rather than a driving mechanism.
A geologist is assessing the impact of extensive groundwater extraction from a coastal aquifer. They observe a decline in the water table, increased salinity in nearby wells, and land surface sinking. Which combination of processes best explains these observations?
A. Saltwater intrusion and cone of depression
B. Cone of depression and upconing
C. Upconing and ground subsidence
D. Saltwater intrusion and ground subsidence
Answer: Saltwater intrusion and ground subsidence
Saltwater intrusion and cone of depression: While a cone of depression occurs due to over-pumping, it does not fully encompass the subsidence aspect.
Cone of depression and upconing: Upconing refers to the upward movement of saltwater into freshwater zones, which isn’t directly indicated by the observations.
Upconing and ground subsidence: Upconing is not as relevant as saltwater intrusion in explaining increased salinity in wells; thus, this option does not adequately address the primary processes at play.
Which of the following provides the most reliable evidence for the general direction of tectonic plate movements.
A. The alignment of volcanic island chains
B. The distribution of earthquake epicenters
C. The orientation of magnetic stripes on the ocean floor
D. The pattern of sediment deposition in ocean basins
The orientation of magnetic stripes on the ocean floor
What is the average rate of movement and general direction of the Pacific Plate?
7-11 cm/year, moving northwest
Determine which process best explains the formation of the Ninety East Ridge (NER). The NER is a mid-ocean ridge on the Indian Ocean floor named for its near-parallel strike along the 90th meridian at the center of the Eastern Hemisphere. It is approximately 5,000 km in length and can be traced topographically from the Bay of Bengal southward towards the Southeast Indian Ridge (SEIR), though the feature continues to the north where it is hidden beneath the sediments of the Bengal Fan.
A. Subduction of the Indian Plate beneath the Eurasian Plate
B. Divergence of the Indian Plate and the Australian Plate
C. Movement of the Indian Plate over a stationary hotspot
D. Transform faulting between the Indian Plate and the Antarctic Plate
Movement of the Indian Plate over a stationary hotspot
It is a type of mountain building characterized by subduction beneath a continent rather than oceanic lithosphere. Subduction along these active continental margins is associated with long-lasting magmatic activity that builds continental volcanic arcs. The result is crustal thickening, with the crust reaching thicknesses of more than 70 kilometers (45 miles).
A. Island Arc-Type
B. Cordilleran-Type
C. Andean-Type
D. Alpine-Type
Answer: Andean-Type because this type of mountain building specifically occurs when an oceanic plate subducts beneath a continental plate, leading to the formation of continental volcanic arcs.
Island Arc-Type: Involves oceanic-oceanic subduction, forming volcanic islands.
Cordilleran-Type: Generally refers to mountain ranges formed by various processes, including continental collisions, but is less specific than Andean-Type.
Alpine-Type: Typically involves continental collisions rather than subduction beneath a continent.
Interpret the following scenarios to determine which type of deformation is most likely to occur in the vicinity of an active subduction zone experiencing significant volcanic activity.
A. Horizontal extension and normal faulting
B. Vertical uplift and reverse faulting
C. Horizontal compression and strike-slip faulting
D. Vertical subsidence and thrust faulting
Answer: Vertical uplift and reverse faulting
Horizontal extension and normal faulting: This typically occurs in divergent boundaries, not at subduction zones.
Horizontal compression and strike-slip faulting: While horizontal compression occurs, strike-slip faulting is more characteristic of transform boundaries.
Vertical subsidence and thrust faulting: Thrust faulting does occur at subduction zones, but vertical subsidence is not a primary feature; instead, uplift is more common in these settings.
P-waves cause _____ compression and expansion, while S-waves cause _____ shearing.
Vertical compression; horizontal shearing
Very high/Critical flood susceptibility areas are likely to experience flood heights of ____ and/or flood duration of more than ____
more than 2.0 meters; 3 days
Moderate flood susceptibility areas are likely to experience flood heights of ____ and/or flood duration of ____
0.5 to 1.0 meters; 1 to 3 days
These leucocratic intrusive orthogneiss suite are common in Archean terranes. They have typical granitic composition but only a small portion of potassium feldspar.
TTG (Tonalite-Trondhjemite (Plagiogranite)-Granodiorite)
is an extrusive rock high in both magnesium and silica, thought to be usually formed in fore-arc environments, typically during the early stages of subduction.
A. Boninites
B. Trondhjemites
C. MORBs
D. Tonalites
Answer: Boninites
TTG (Tonalite-Trondhjemite (Plagiogranite)-Granodiorite)- These leucocratic intrusive orthogneiss suite are common in Archean terranes. They have typical granitic composition but only a small portion of potassium feldspar.
MORBs- At ocean spreading centers, partial melting of lherzolite generates voluminous and geochemically distinct containing minerals such as plagioclase, augite, hypersthene, pigeonite, diopside, and olivine.
During a field study, a geologist discovers a volcanic rock with a porphyritic texture, containing phenocrysts of plagioclase and pyroxene in a fine-grained matrix. The geologist concludes that the rock likely formed from a magma that experienced two stages of cooling. Which of the following best describes the likely environment of formation?
A. Continental hotspot
B. Oceanic hotspot
C. Subduction zone
D. MOR
Answer: Oceanic hotspot because the porphyritic texture and presence of plagioclase and pyroxene suggest a magma that cooled slowly at depth before erupting, typical of hotspot volcanism.
A. Continental hotspot: Generally produces rhyolitic or andesitic rocks, not typically characterized by the described mineralogy.
C. Subduction zone: While it can produce porphyritic textures, it usually involves more complex interactions and different mineral assemblages due to the melting of subducted materials.
D. MOR (Mid-Ocean Ridge): Primarily produces basaltic rocks with rapid cooling, lacking the two-stage cooling process indicated by the porphyritic texture.
It is a sedimentary unit with consistent characteristics (lithology, grain size, texture, structures, etc.) that formed under specific depositional conditions.
a. Strata/Stratum
b. Formation
c. Sedimentary Facies
d. Lithofacies
Answer: Sedimentary Facies
a. Strata/Stratum: Refers to layers of sedimentary rock that are distinct from one another, but does not specifically denote consistent characteristics formed under specific conditions.
b. Formation: A geological unit that is typically larger than a facies and encompasses multiple facies. It may consist of various sedimentary facies but does not imply uniformity in characteristics.
d. Lithofacies: Similar to sedimentary facies, but it emphasizes the lithological characteristics. While it may be applicable, “sedimentary facies” is more commonly used in the context of depositional environments.
A geologist is studying a metamorphic rock sample and identifies the presence of garnet, staurolite, and kyanite. The geologist infers that the rock underwent regional metamorphism at high pressure and moderate temperature. Which of the following protoliths is most likely to have produced this metamorphic assemblage?
A. Basalt
B. Shale
C. Limestone
D. Sandstone
Answer: Shale. This sedimentary rock is rich in clay minerals and is the typical parent rock for the formation of garnet, staurolite, and kyanite during regional metamorphism under high pressure and moderate temperature conditions. These minerals are common in pelitic (clay-rich) metamorphic rocks formed from shale.
Basalt: This igneous rock typically undergoes different metamorphic processes, leading to the formation of minerals such as amphibole and pyroxene.
Limestone: This sedimentary rock primarily transforms into marble under metamorphism, producing calcite and dolomite.
Sandstone: This sedimentary rock primarily transforms into quartzite
It is the process of transforming detrital grains into sedimentary rocks.
A. Diagenesis
B. Lithification
C. Compaction
D. Cementation
Answer: Lithification
Diagenesis - Broader, also includes Lithification
Cementation - Only a part of Lithification
A geologist is tasked with assessing the erosion rates of a riverbank composed of various sedimentary layers. The geologist collects samples from different depths and analyzes the grain size distribution, mineral composition, and cohesion properties. Based on the following data, which layer is most likely to experience the highest rate of erosion?
A. Layer 1: Fine-grained siltstone, high clay content, moderate cohesion
B. Layer 2: Coarse-grained sandstone, low clay content, low cohesion
C. Layer 3: Medium-grained shale, high clay content, high cohesion
D. Layer 4: Fine-grained limestone, low clay content, moderate cohesion
Answer: Layer 2 (Coarse-grained sandstone): This layer has low cohesion and consists of larger grains that are more easily dislodged by water flow, making it highly susceptible to erosion.
Layer 1 (Fine-grained siltstone): While it has moderate cohesion, the fine grain size typically leads to lower erosion rates compared to coarser materials.
Layer 3 (Medium-grained shale): High clay content and high cohesion provide better resistance to erosion.
Layer 4 (Fine-grained limestone): Moderate cohesion and fine grain size also contribute to lower erosion rates.
A hydrologist is tasked with estimating the average annual precipitation over a watershed using the isohyetal method. The watershed is divided into several zones by isohyetal lines, each representing different precipitation amounts. The areas and corresponding precipitation values for each zone are as follows:
Zone 1: 12 km², 750 mm
Zone 2: 18 km², 850 mm
Zone 3: 30 km², 950 mm
Zone 4: 25 km², 1200 mm
What is the correct average annual precipitation for the watershed?
1. Calculate Total Precipitation for Each Zone:
Zone 1: 12 km2 × 750 mm = 9000 km 2⋅mm
Zone 2: 18 km2 × 850 mm = 15300 km2⋅mm
Zone 3: 30 km2 × 950 mm = 28500 km2⋅mm
Zone 4: 25 km2 × 1200 mm = 30000 km2⋅mm
2. Sum Total Precipitation:
Total Precipitation = 9000+15300+28500+30000=82800 km2⋅mm
3. Sum Total Area:
Total Area = 12+18+30+25=85 km2
4. Calculate Average Annual Precipitation:
Average Annual Precipitation = Total Precipitation/Total Area = 82800/ 85
Average Annual Precipitation = 974.12 mm
Calculate the total porosity given the following: total volume of the earth material= 100 cm3; volume of water remaining in the material after gravity drainage= 10 cm3; volume of water that was drained from the earth material= 30 cm3
- Total Porosity(ϕ) = Pore Volume (Vp) / Total Volume (Vt)
- Pore Volume (Vp) = Volume of water remaining in the material after gravity drainage (Vrem) + Volume of water that was drained from the earth material (Vd)
ϕ = (Vrem + Vd) / Vt
ϕ = (10 + 30)/100
ϕ = 0.4
These dunes develop through the saltation of sand grains up their gentle sloping windward slope, and settle by the angle of repose down the leeward or slipface.
a. Barchan
b. Transverse
c. Parabolic
d. Star
Answer: Barchan - limited sand supply
b. Transverse: These dunes are typically long ridges oriented perpendicular to the wind direction; abundant sand supply
c. Parabolic: Parabolic dunes have a U-shape and are formed in areas with vegetation; they also have their tips pointing into the wind, which does not match the description.
d. Star: Star dunes have multiple arms and form in areas with variable wind directions; they do not fit the description of having a gentle windward slope and a steep slipface
A geologist is examining a roche moutonnée in a glaciated valley. The roche moutonnée exhibits a smooth, polished surface on the upstream side and a rough, jagged surface on the downstream side. Which of the following glacial processes best explains the formation of these contrasting surfaces?
A. Abrasion and plucking by glacial ice
B. Frost wedging and solifluction
C. Glacial deposition and moraine formation
D. Ice thrusting and nivation
A. Abrasion and plucking by glacial ice
This law states that as depositional environments migrate laterally, the sediments of one environment come to lie on top of sediments of the adjacent environment.
Walther’s Law
This reversal occurred about 2.58 million years ago, when the Earth’s magnetic field changed from normal polarity to reverse polarity.
Gauss–Matuyama reversal
This was the most recent magnetic field reversal, occurring around 780,000 years ago. It’s an important chronozone boundary in the Quaternary magnetic polarity reversal timescale. The reversal took about 30,000 years to evolve, and lasted longer in high latitudes than in low- to mid latitudes
Matuyama–Brunhes
the first and oldest coral called Gshelia sp. found in a clast near the base of the Punso Conglomerate found by Easton and Melendres in 1963. This coral is aged approximately _____
Pennsylvanian
A geologist is studying a sequence of sedimentary rock layers and needs to determine their relative ages. The sequence includes a volcanic ash layer that has been radiometrically dated to 250 million years ago. The geologist also observes the following features:
Layer A: Contains fossils of trilobites.
Layer B: Contains fossils of ammonites.
Layer C: Contains fossils of dinosaurs.
Layer D: Contains the volcanic ash layer.
Based on the principles of relative and absolute dating, what is the correct order of the layers from oldest to youngest?
Correct Order from Oldest to Youngest: Layer A (Trilobites), Layer B (Ammonites), Layer D (Volcanic Ash, dated to 250 million years ago), Layer C (Dinosaurs)
Which of these fish classes are believed to be the origin of land terrestrial vertebrates?
A. Actinopterygii
B. Sarcopterygii
C. Chondrichthyes
D. Placodermata
Answer: Sarcopterygii (Lobe-finned Fish) or Crossopterygii (to cross from sea to land) - Fossils like Tiktaalik and Acanthostega
Actinopterygii: This group includes ray-finned fish, which do not share the same evolutionary lineage leading to tetrapods.
Chondrichthyes: This class includes cartilaginous fish like sharks and rays, which are not directly related to the evolution of terrestrial vertebrates.
Placodermata: An extinct class of armored prehistoric fish that did not give rise to tetrapods.
A geologist is studying the fossil record to understand the broadscale evolutionary patterns of organisms. The geologist observes a significant increase in the diversity of marine life, including the appearance of many new species of fish, corals, and mollusks, following a mass extinction event. Which of the following evolutionary processes is most likely responsible for this increase in diversity?
A. Convergent evolution
B. Adaptive radiation
C. Genetic drift
D. Stabilizing selection
Answer: Adaptive Radiation: This is the correct answer. Adaptive radiation occurs when a single ancestral species rapidly diversifies into a wide variety of forms to adapt to different environments or ecological niches. Following a mass extinction, many ecological niches become available, allowing surviving species to evolve and fill these roles, leading to increased diversity.
Convergent Evolution: This process occurs when unrelated species evolve similar traits due to similar environmental pressures
Genetic Drift: This is a random process that can lead to changes in allele frequencies in a population
Stabilizing Selection: This type of natural selection favors average phenotypes and reduces variation within a population, which would not contribute to an increase in diversity.
A paleontologist discovers a sequence of sedimentary rock layers containing fossils of various marine organisms. The lowest layer contains trilobites, the middle layer contains ammonites, and the uppermost layer contains bony fish. Based on this fossil record, which of the following evolutionary patterns is most likely illustrated by this sequence?
A. Adaptive radiation following a mass extinction event
B. Gradualism in the evolution of marine biodiversity
C. Punctuated equilibrium with rapid speciation events
D. Convergent evolution among unrelated marine species
Punctuated equilibrium with rapid speciation events
Which formation contains index fossil for Jurassic Ammonites?
A. Minilog Formation
B. Pandan Formation
C. Mansalay Formation
D. Aksitero Formation
Mansalay Formation
Motion vectors in the archipelago and vicinity are in the order of a few to several cm/yr. When _____ is held fixed, the slowest movements can be detected in Zamboanga at less than 2 ± .15 cm/yr westwards. Virac Island moves the fastest at over 7 ± .17 cm/yr northwestwards.
Microcontinental Palawan
The Zambales Ophiolite Complex is composed of two distinct blocks with different ages. The Acoje block has an age of _____, while the Coto block has an age of Eocene.
Late Jurassic to Early Cretaceous
These are sills that have thickened to produce
domes, wherein the doming arches the
overlying rocks, and consequently faulted.
a. Laccolith
b. Bysmalith
c. Lopolith
d. Phacolith
Answers: Bysmalith– intrusive that has been cut by a fault
Laccolith– dome like
Lopolith– funnel shape
Phacolith– intrusives along folds
It is a relatively conformable succession of genetically related strata, bounded at the top and base by unconformities and correlative conformities.
a. Sequence
b. Depositional System
c. Systems Tract
d. Parasequence
Answer: Sequence
Depositional System – a 3-D assemblage of lithofacies, genetically linked by active (modern) or inferred (ancient) processes and environments
Systems Tract – a subdivision of depositional system. 4 main kinds, Highstand (sediment deposited during
high sea level), Falling-stage (sediment deposited as sea falls from high to low), Lowstand (sediment deposited during
low sea level and early rising sea level), Transgressive (sediment deposited during rising sea level)
Parasequence – a relative conformable succession of genetically related beds or bedsets (within a parasequence set) bounded by marine flooding surface or their correlative surfaces
These refers to a sharp change in channel slope resulting from differential rates of erosion above and below
a. Rapid
b. Slip-off
c. Knickpoint
d. Terrace
Knickpoint
Formation of incised valleys occur during:
a. Lowstand Systems Tract
b. Transgressive Systems Tract
c. Falling Stage Systems Tract
d. Highstand Systems Tract
Falling Stage Systems Tract
This refers to the death assemblage where not all species present in the community are represented as fossils, and not all the fossil species within the assemblage lived in the community.
a. Biocoenosis
b. Thanatocoenosis
c. Thaphocoenoesis
d. Paleocoenosis
Answer: Thaphocoenoesis
Biocoenosis - strata containing organisms that lived and were buried in the area (assemblage that contains virtually all of the species that existed when the community was alive)
Thanatocoenosis -strata containing organisms that lived somewhere else and were brought into the area after death (a death assemblage where all the fossils represented existed within the community, but not all community members are present as fossils (species are missing))
The Cambrian is the first geological period of the Paleozoic Era, is succeeded by the Ordovician. This period was established by:
a. Charles Lapworth
b. Sir Roderick Impey Murchison
c. Adam Sedgwick
d. William Conybeare
Answer: Charles Lapworth – Ordovician
Sir Roderick Impey Murchison – Permian, Silurian
Adam Sedgwick - Cambrian
William Conybeare - Carboniferous
Refer to various ways by which the mobile agencies obtain and remove rock debris.
a. Weathering
b. Erosion
c. Mass wasting
d. Flow
Answer: Erosion
Weathering – disintegration (mechanical) or decomposition (chemical) of rocks in response to different environments
Mass wasting – downslope movement of rock/soil under the direct influence of gravity
Flow – type of mass movement with very high water content (viscous)
These are folds that do not increase in size upwards or downwards but maintain a similar shape. Individual beds thicken at their crest and thin on their limbs.
a. Harmonic – folds that are repeated with similar shape along the axial trace
b. Concentric – folds whose wellrounded arcs approximate halfcircles so that limbs and hinges are inseperable (or they can be said to consist of hinges only)
c. Similar
d. Supratenuous - folds that are characterized by thinning at the crests, gradual thickening along the flanks, and maximum thickening in the troughs. They are also known as “compaction folds”
e. Parallel – constant bed thickness
Answer: Similar
Harmonic – folds that are repeated with similar shape along the axial trace
Concentric – folds whose wellrounded arcs approximate halfcircles so that limbs and hinges are inseperable (or they can be said to consist of hinges only)
Supratenuous - folds that are characterized by thinning at the crests, gradual thickening along the flanks, and maximum thickening in the troughs. They are also known as “compaction folds”
Parallel – constant bed thickness
