Formation Standard Review Sheet
Standard #8 Mastery Earth Systems & Geology
Geologic Formation Review Sheet
Target Benchmark 8: Processes of Rock Formation, Crustal Structures, and Rock Cycle Dynamics
Name:
Date:
Period:
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Part 1: Primary Rock Formation Pathways
Identify environmental conditions, energy drivers, and characteristic rock examples for each formation pathway.
Igneous Formation
Crystallization of molten rock (magma/lava).
Driver: Earth's internal thermal heat
Intrusive: Slow cooling (large crystals)
Extrusive: Rapid cooling (fine/glassy)
Example Specimen & Setting:
Sedimentary Formation
Weathering, deposition, and lithification.
Driver: Solar radiation & gravity
Clastic: Mineral/rock fragment compaction
Chemical: Mineral precipitation from brine
Example Specimen & Setting:
Metamorphic Formation
Solid-state recrystallization under heat/pressure.
Driver: Tectonic deformation & heat
Foliated: Directional mineral banding
Non-foliated: Equigranular crystal block
Example Specimen & Setting:
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Part 2: Sequential Formation Steps
Number the chronological stages (1–4) in each geologic formation sequence.
Lithification of Clastic Strata
Sediment settles in low-energy depositional basins.
Mechanical weathering disintegrates parent bedrock.
Mineral cement precipitates between compressed clasts.
Overlying weight forces pore fluids out during compaction.
Key Mechanism: Why is cementation essential to solidify sand into sandstone?
Igneous Plutonic Emplacement
Sub-crustal rocks melt into buoyant liquid magma.
Interlocking quartz, feldspar, and mica form granite.
Magma ascends and pools inside an insulated magma chamber.
Cooling proceeds over millions of years deep underground.
Key Mechanism: How does cooling rate govern crystal diameter in igneous rocks?
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Part 3: Formation Terminology Matching
Vocabulary Key
A. Foliation
B. Lithification
C. Recrystallization
D. Contact Metamorphism
E. Stratification
Parallel alignment of platy mineral grains from directional pressure.
Sedimentary bedding formed in horizontal gravitational layers.
Thermal rock baking adjacent to molten magma bodies.
Mineral crystal restructuring in solid state without complete melting.
Standard #8 Applied Analysis
Structural Formations & Stratigraphic Sequences
Student Page 2 of 2
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Part 4: Geologic Column Formation Interpretation
Examine the formation block diagram below. Apply Steno's Principles of Formation (Superposition, Horizontality, Cross-Cutting Relationships) to complete items A–C.
Formation E: Siltstone Strata (Youngest Layer)
Formation D: Limestone Bed (Marine Deposition)
Formation C: Quartz Sandstone (Dune Sand)
Formation B: Conglomerate [Cut by Fault F]
Formation A: Basal Schist (Basement Complex)
DIKE H
A. Relative Chronology: Which formation is older, Sandstone C or Basalt Dike H? Cite the geological principle:
B. Tectonic Deformation: Fault F displaces layers A and B, but stops beneath Layer C. When did the faulting occur?
C. Thermal Contact: Where will contact metamorphism occur around Basalt Dike H?
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Part 5: Field Specimen Formation Scenarios
Specimen Alpha: Banded Gneiss Sample 8.1
A geologist finds an outcrop with light quartz-feldspar bands and dark biotite bands folded into tight wavy curves.
Reconstruct tectonic formation conditions (depth, pressure, temperature):
Specimen Beta: Vesicular Pumice Sample 8.2
A specimen collected from a volcanic cone is lightweight, glassy, and filled with thousands of tiny gas cavities (vesicles).
Explain how gas depressurization and rapid quench cooling formed this texture:
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Part 6: Standard #8 Assessment Check
1. Which process transforms an existing metamorphic formation into an igneous formation?
A Uplift, weathering, and lithification
B Subduction melting into magma followed by cooling
C Regional directional shear stress and foliation
D Hydrothermal chemical mineral replacement
2. An unconformity in a rock formation sequence represents which Earth event?
A Continuous, uninterrupted deep-marine deposition
B Instantaneous regional volcanic ash fallout
C A chronological gap caused by erosion or non-deposition
D The original horizontal plane of basaltic intrusion
Standard #8 Proficiency: Exceeds (4) Meets (3) Developing (2) Needs Support (1)
Instructor Initials: _______
