Fiche de révision : Fundamentals of Sedimentary, Igneous, and Metamorphic Rocks

📋 Course Outline

1. Sedimentary Formation
2. Sedimentary Structures
3. Depositional Environments
4. Sedimentary Fossils
5. Igneous Cooling
6. Igneous Composition
7. Igneous Textures
8. Metamorphic Agents
9. Metamorphic Minerals
10. Metamorphic Textures
11. Deformation Types

📖 1. Sedimentary Formation

🔑 Key Concepts & Definitions

• Weathering: The breakdown of rocks at Earth's surface through physical (e.g., freeze-thaw, exfoliation) or chemical (e.g., hydrolysis, carbonation) processes.
• Erosion: The removal and transportation of weathered rock fragments by agents such as water, ice, or wind.
• Transport: The movement of sediments by agents like rivers, glaciers, or waves, which causes grain size reduction (attrition, abrasion) and sorting.
• Deposition: The process where transported sediments settle when energy decreases, forming layers.
• Lithification: The transformation of loose sediments into solid rock via compaction (pressure) and cementation (mineral precipitation).
• Diagenesis: All chemical and mineralogical changes occurring after burial, including mineral recrystallization and stabilization, before metamorphism.

📝 Essential Points

• Sedimentary rocks form at Earth's surface from weathered and eroded pre-existing rocks.
• Types of sedimentary rocks:
  • Clastic (detrital): Composed of fragments (e.g., shale, sandstone, conglomerate).
  • Chemical: Precipitated from solution (e.g., limestone, evaporites).
  • Organic: Derived from biological debris (e.g., coal, chalk).
• Sedimentary structures (e.g., bedding, graded bedding, cross-bedding, ripple marks, mud cracks) reflect depositional conditions.
• Grain size classification:
  • Clay (<0.004 mm), Silt (0.004–0.062 mm), Sand (0.062–2 mm), Gravel (>2 mm).
• Depositional environments:
  • Continental: Rivers (channel sandstones), glaciers (till), deserts (dunes).
  • Transitional: Beaches, deltas, tidal flats, estuaries.
  • Marine: Shallow marine (fossil-rich limestones), deep marine (mudstones, turbidites).
• Fossils are predominantly found in sedimentary rocks, indicating depositional environment and relative age.
• Diagenesis involves mineral changes like aragonite to calcite, and cement mineral growth, occurring at low temperature and pressure.

💡 Key Takeaway

Sedimentary formation involves weathering, erosion, transport, deposition, and lithification, creating diverse rock types and structures that record Earth's surface processes and environments.

📖 2. Sedimentary Structures

🔑 Key Concepts & Definitions

• Bedding (Stratification): The layering in sedimentary rocks formed by the deposition of sediments in distinct episodes, resulting in planar or laminar features.
• Cross-bedding: Inclined layers within beds indicating the former presence of ripples or dunes, formed by migrating bedforms in flowing water or air.
• Graded Bedding: Sedimentary layer with coarser grains at the bottom and finer grains at the top, indicating waning energy conditions such as turbidity currents.
• Ripple Marks: Small-scale undulations on sediment surfaces caused by water or wind flow, indicating current direction.
• Mud Cracks: Polygonal fractures in fine sediments that form during drying, indicating exposure to air and desiccation.
• Imbrication: Arrangement of elongated clasts in a preferred orientation due to water or ice flow, indicating current direction.

📝 Essential Points

• Sedimentary structures are direct indicators of depositional environments and processes.
• Planar bedding and laminae reflect layer-by-layer deposition; their thickness can vary from millimeters to meters.
• Cross-bedding reveals flow direction and energy conditions; inclined layers suggest migration of ripples or dunes.
• Graded bedding is characteristic of turbidity currents, often found in deep marine environments.
• Ripple marks can be symmetrical (oscillatory flow) or asymmetrical (unidirectional flow), providing clues to paleo-current directions.
• Mud cracks indicate subaerial exposure and drying, often found in tidal flats or floodplains.
• Sorting and rounding of grains give insights into transport mechanisms: wind (well-sorted, rounded) vs glacial (poorly sorted, angular).
• Depositional environments influence sedimentary structures: e.g., dunes in deserts, deltas, or shallow marine settings.

💡 Key Takeaway

Sedimentary structures serve as vital clues to understanding past depositional conditions, flow dynamics, and paleoenvironmental changes, making them essential tools in sedimentology and stratigraphy.

📖 3. Depositional Environments

🔑 Key Concepts & Definitions

• Depositional Environment: The setting in which sediment accumulates, reflecting specific physical, chemical, and biological conditions.
• Clastic (Detrital) Sedimentary Rocks: Formed from the accumulation of weathered rock fragments; classified by grain size (e.g., shale, sandstone, conglomerate).
• Chemical Sedimentary Rocks: Formed by mineral precipitation from solution, often in evaporative settings; includes limestones and evaporites.
• Organic Sedimentary Rocks: Composed mainly of biological debris; examples are coal (plant material) and chalk (shell debris).
• Fossils: Preserved remains or traces of ancient organisms, indicating specific depositional environments (marine, freshwater, terrestrial).
• Sedimentary Structures: Features like bedding, cross-bedding, ripple marks, and mud cracks that record depositional conditions.

📝 Essential Points

• Continental Environments:
  • Fluvial (rivers): Channel sandstones, point bars with cross-bedding.
  • Glacial: Poorly sorted till with large clasts.
  • Aeolian (desert): Well-sorted, frosted sand with large cross-beds.
  • Alluvial fans: Coarse breccias near mountain fronts.
• Transitional Environments:
  • Beaches/Deltas: Sandstones with ripple cross-lamination; coarsening-upward sequences.
  • Tidal flats: Mudcracks, laminations.
  • Estuaries/Lagoons: Mixed sand and mud, bioturbation.
• Marine Environments:
  • Shallow marine: Limestone with fossils, cross-bedded sandstones.
  • Deep marine: Fine mudstones, shales, turbidites (graded bedding from turbidity currents).
• Fossil Evidence:
  • Marine fossils in limestones.
  • Plant debris in coal.
  • Trace fossils indicating biological activity.
• Sedimentary Structures:
  • Graded bedding: Coarse at bottom, fine at top, indicating waning flows.
  • Cross-bedding: Indicates ripples/dunes.
  • Ripple marks and mud cracks: Record water/air action.
• Transport and Sorting:
  • Wind transport produces very well-sorted, rounded grains.
  • Glacial transport results in poorly sorted, angular clasts.
• Diagenesis: Chemical and mineralogical changes after deposition, including cementation and mineral recrystallization, which solidify sediments into rock.

💡 Key Takeaway

Depositional environments are distinguished by their sediment types, structures, and fossils, which together reveal the physical and biological conditions at the time of sediment deposition, providing vital clues to Earth's geological history.

📖 4. Sedimentary Fossils

🔑 Key Concepts & Definitions

• Fossil: Preserved remains, impressions, or traces of ancient organisms found in sedimentary rocks, used for dating and environmental interpretation.
• Trace Fossils: Evidence of biological activity such as footprints, burrows, or feeding marks, indicating behavior and depositional conditions.
• Biostratigraphy: The use of fossils within sedimentary layers to establish relative ages and correlate strata across regions.
• Fossil Preservation: The process by which remains are protected from decay, often through mineralization, carbonization, or preservation in specific environments like limestone or shale.
• Index Fossils: Widely distributed, short-lived fossils used to date and correlate sedimentary layers.
• Conditions for Fossilization: Rapid burial, low oxygen environments, and mineral-rich waters favor preservation.

📝 Essential Points

• Fossil Occurrence: Almost exclusively found in sedimentary rocks due to their formation process, which allows for the preservation of organic material.
• Environmental Indicators: Fossils reveal depositional environments—marine fossils in limestone indicate marine settings; plant debris in coal suggests terrestrial swamp conditions.
• Types of Fossils: Includes shells, bones, plant material, and trace fossils like footprints and burrows.
• Fossil Dating: Relative dating through biostratigraphy and absolute dating via radiometric methods when applicable.
• Fossil Preservation Environments: Favorable conditions include low oxygen, rapid burial, and mineral-rich waters, which inhibit decay and facilitate mineralization.
• Fossil Record Limitations: Bias toward hard parts (shells, bones); soft tissues are rarely preserved unless under exceptional conditions.

💡 Key Takeaway

Fossils in sedimentary rocks serve as vital clues for understanding Earth's past life and environments, with their preservation depending on specific conditions that favor mineralization and protection from decay. They are essential tools for relative dating and reconstructing ancient ecosystems.

📖 5. Igneous Cooling

🔑 Key Concepts & Definitions

• Crystallization: The process by which magma cools and solidifies into igneous rock, forming mineral crystals.
• Intrusive (Plutonic) Rocks: Igneous rocks that crystallize slowly beneath Earth's surface, resulting in coarse-grained textures.
• Extrusive (Volcanic) Rocks: Rocks formed from rapid cooling at or near the surface, producing fine-grained or glassy textures.
• Cooling Rate: The speed at which magma or lava loses heat, influencing crystal size and texture.
• Texture Types:
  • Phaneritic: Coarse-grained, crystals visible to the naked eye (slow cooling).
  • Aphanitic: Fine-grained, crystals too small to see without a microscope (fast cooling).
  • Porphyritic: Mixture of large phenocrysts in a fine groundmass, indicating two-stage cooling.
  • Vesicular: Rock with gas bubbles (vesicles) trapped during rapid cooling.
• Silica Content & Composition:
  • Felsic: High silica (~65–75%), light-colored, rich in quartz and feldspar.
  • Intermediate: Moderate silica (~55–65%), includes andesite/diorite.
  • Mafic: Lower silica (~45–55%), dark-colored, rich in Fe/Mg minerals.
  • Ultramafic: Very low silica (<45%), very dark, mostly olivine and pyroxene.

📝 Essential Points

• Formation of Magma: Melting occurs via decompression at divergent boundaries, flux melting at subduction zones, or heat from mantle plumes.
• Crystallization Process: As magma cools, minerals crystallize at different temperatures, forming characteristic mineral assemblages.
• Textures & Cooling History:
  • Slow cooling (deep underground): large crystals (granite, diorite).
  • Fast cooling (surface lava flows): small crystals or glass (rhyolite, basalt).
  • Porphyritic texture indicates a two-stage cooling process with initial slow cooling forming phenocrysts, followed by rapid cooling.
• Intrusive vs. Extrusive:
  • Intrusive: large, visible crystals; forms plutons, sills, dikes.
  • Extrusive: fine or glassy textures; includes lava flows, ash, tuffs.
• Mineral Composition & Color:
  • Felsic rocks are lighter and contain quartz and alkali feldspar.
  • Mafic rocks are darker, rich in pyroxene, olivine, and Ca-rich plagioclase.
• Cooling Rate & Texture Relationship:
  • Slow cooling: coarse-grained (granite, gabbro).
  • Rapid cooling: fine-grained or glassy (rhyolite, basalt, obsidian).

💡 Key Takeaway

The texture and mineral composition of igneous rocks are direct indicators of their cooling history and environment, with slow cooling producing coarse crystals and rapid cooling resulting in fine-grained or glassy textures.

📖 6. Igneous Composition

🔑 Key Concepts & Definitions

• Igneous Rocks: Rocks formed by the crystallization of magma or lava. They can be intrusive (cooling underground) or extrusive (cooling on the surface).
• Magma Formation: The process of melting rocks, primarily through decompression, flux (volatiles), or heat, producing magma enriched in silica relative to the source.
• Textures: The size and arrangement of crystals in igneous rocks, influenced by cooling rate:
  • Phaneritic: Coarse-grained, slow cooling underground.
  • Aphanitic: Fine-grained, rapid cooling at surface.
  • Porphyritic: Mixed grain sizes indicating two-stage cooling.
  • Vesicular: Gas holes in extrusive rocks.
• Silica Content & Classification:
  • Felsic: High silica (~65–75%), light-colored, rich in quartz and feldspar (e.g., granite, rhyolite).
  • Intermediate: Moderate silica (~55–65%), e.g., diorite, andesite.
  • Mafic: Lower silica (~45–55%), dark-colored, rich in Fe/Mg minerals (e.g., gabbro, basalt).
  • Ultramafic: Very low silica (<45%), very dark, e.g., peridotite.
• Intrusive vs. Extrusive:
  • Intrusive (Plutonic): Cools slowly underground, large crystals.
  • Extrusive (Volcanic): Cools quickly on surface, small or no crystals, often glassy.
• Mineralogy:
  • Felsic: Quartz, K-feldspar, biotite.
  • Mafic: Pyroxene, Ca-rich plagioclase, olivine.
  • Ultramafic: Olivine, pyroxene.

📝 Essential Points

• Crystallization: The cooling rate determines crystal size; slow cooling yields large crystals, rapid cooling results in fine or glassy textures.
• Plate Tectonics & Magma Generation:
  • Divergent Boundaries: Decompression melting of rising mantle produces basaltic magmas.
  • Convergent Boundaries: Flux melting from subducting slabs generates intermediate to felsic magmas.
  • Hotspots: Mantle plumes produce basaltic magmas.
• Intrusive Bodies:
  • Batholiths: Large, deep-seated plutons.
  • Sills & Dikes: Concordant and discordant intrusions, respectively.
• Extrusive Features:
  • Lava flows (basaltic, rhyolitic).
  • Pyroclastic deposits (tuff).
  • Vesicular textures indicate gas escape during eruption.
• Mineral Composition & Color:
  • Felsic rocks: Light, quartz, feldspar.
  • Mafic rocks: Dark, olivine, pyroxene.
  • Ultramafic rocks: Very dark, mostly olivine.
• Cooling Histories & Textures:
  • Slow cooling → coarse crystals (granite).
  • Fast cooling → fine-grained or glassy (obsidian).
  • Porphyritic textures indicate two-stage cooling.

💡 Key Takeaway

Igneous rocks' composition and texture are primarily controlled by magma source, melting processes, and cooling history, reflecting their formation environment and mineral content, which are essential for interpreting Earth's geological processes.

📖 7. Igneous Textures

🔑 Key Concepts & Definitions

• Crystallinity: The texture of igneous rocks determined by the size, shape, and arrangement of mineral crystals formed during cooling.
• Phaneritic: Coarse-grained texture where crystals are large enough to be seen with the naked eye, indicating slow cooling deep underground.
• Aphanitic: Fine-grained texture with crystals too small to see without a microscope, formed by rapid cooling at the surface.
• Porphyritic: Texture featuring large crystals (phenocrysts) embedded in a finer groundmass, indicating two-stage cooling.
• Vesicular: Texture characterized by gas bubbles or vesicles within the rock, resulting from lava cooling with trapped volatiles.
• Glassy: Non-crystalline, amorphous texture formed by very rapid cooling that prevents crystal growth, e.g., obsidian.

📝 Essential Points

• Cooling Rate and Texture: The rate at which magma or lava cools directly influences crystal size:
  • Slow cooling (intrusive): large, visible crystals (phaneritic).
  • Rapid cooling (extrusive): small crystals or glassy texture.
• Porphyritic Texture: Indicates a two-stage cooling process—initial slow cooling forming phenocrysts, followed by rapid cooling forming a fine groundmass.
• Vesicular Rocks: Form when gases escape from lava, creating holes; common in basaltic lava flows.
• Mineral Composition and Texture Relationship:
  • Felsic rocks (granite, rhyolite): high silica, often with large crystals or glassy textures.
  • Mafic rocks (gabbro, basalt): lower silica, typically fine-grained or vesicular.
• Intrusive vs Extrusive:
  • Intrusive (plutonic): slow cooling, coarse texture.
  • Extrusive (volcanic): fast cooling, fine or glassy texture.
• Textures as Indicators of Eruption/Formation Conditions: Textures reveal cooling history, environment, and sometimes eruption style.

💡 Key Takeaway

Igneous textures provide vital clues to the cooling history and environment of formation, with coarse-grained rocks indicating slow underground cooling and fine or glassy rocks signifying rapid surface cooling. Understanding these textures helps interpret volcanic and plutonic processes.

📖 8. Metamorphic Agents

🔑 Key Concepts & Definitions

• Heat (Temperature): The primary agent in metamorphism that causes mineral recrystallization and growth, increasing the chemical activity within rocks.
• Pressure (Confining and Differential): Confining pressure applies equally in all directions, causing mineral compaction; differential pressure (directed stress) induces foliation and mineral alignment.
• Chemically Active Fluids: Fluids such as water or carbon dioxide that facilitate mineral reactions, enhance metamorphic processes, and aid in mineral transport.
• Contact Metamorphism: Metamorphism caused by heat from nearby igneous intrusions, producing non-foliated rocks like marble and quartzite.
• Regional Metamorphism: Extensive metamorphism over large areas due to high pressure and temperature, typically associated with mountain-building, producing foliated rocks like schist and gneiss.
• Index Minerals: Minerals that form at specific temperature and pressure conditions, used to determine metamorphic grade (e.g., chlorite, biotite, garnet, kyanite, sillimanite).

📝 Essential Points

• Agents of Metamorphism: Heat, pressure, and chemically active fluids are the main agents that alter pre-existing rocks without melting.
• Types of Metamorphism:
  • Contact: High T, low P; produces non-foliated rocks.
  • Regional: High P and T over large areas; produces foliated rocks with a metamorphic grade sequence.
  • Burial: Low-grade, deep burial; minimal foliation.
• Foliation Development: Caused by differential stress aligning platy minerals, leading to layered textures in rocks like slate, schist, and gneiss.
• Metamorphic Grade & Minerals: Progressive increase in temperature and pressure results in new minerals (index minerals). For example, chlorite (low grade) to sillimanite (high grade).
• Textures & Structures: Foliated rocks show planar mineral alignment; non-foliated rocks are massive and granular.
• Metamorphic Zones: Characterized by specific index minerals indicating increasing metamorphic intensity.

💡 Key Takeaway

Metamorphic agents—heat, pressure, and fluids—drive the transformation of rocks by inducing mineral changes, foliation, and structural deformation, with the type and intensity of metamorphism reflecting the environmental conditions during formation.

📖 9. Metamorphic Minerals

🔑 Key Concepts & Definitions

• Metamorphic Minerals: Minerals that form or grow during metamorphism, indicating specific temperature and pressure conditions. Examples include garnet, staurolite, kyanite, and sillimanite.

• Index Minerals: Minerals that appear at specific metamorphic grades, used to estimate the temperature and pressure conditions during metamorphism. They form in a sequence reflecting increasing metamorphic grade.

• Foliation: A planar fabric in metamorphic rocks resulting from the alignment of platy minerals under directed stress, often associated with the growth of metamorphic minerals.

• Non-foliated Minerals: Minerals that do not develop a preferred orientation during metamorphism, typically forming in contact metamorphism; examples include quartz and calcite.

• Polymorphs: Minerals with the same chemical composition but different crystal structures, stable under different P/T conditions. Example: kyanite, andalusite, and sillimanite (all Al₂SiO₅).

📝 Essential Points

• Formation Conditions: Metamorphic minerals grow in response to specific temperature and pressure conditions, serving as indicators of metamorphic grade and environment.

• Metamorphic Grade & Minerals:

  • Low-grade (greenschist facies): chlorite, biotite.
  • Medium-grade: garnet, staurolite.
  • High-grade (amphibolite to granulite facies): kyanite, sillimanite, andalusite.

• Mineral Sequences: In pelitic rocks, a typical sequence is chlorite → biotite → garnet → staurolite → kyanite → sillimanite, reflecting increasing metamorphic intensity.

• Foliation Development: Minerals like micas and chlorite align under directed stress, creating foliated textures (slate, schist, gneiss). Non-foliated rocks (marble, quartzite) form where deformation is minimal or pressure is uniform.

• Polymorph Stability: The stability of kyanite, andalusite, and sillimanite depends on P/T conditions, providing precise metamorphic P-T estimates.

💡 Key Takeaway

Metamorphic minerals serve as crucial indicators of the conditions and processes during metamorphism, with index minerals providing a mineralogical record of increasing temperature and pressure, essential for understanding metamorphic history and environments.

📖 10. Metamorphic Textures

🔑 Key Concepts & Definitions

• Foliation: A planar fabric in metamorphic rocks resulting from the alignment of platy minerals or compositional banding due to directed pressure or shear. Examples include slate, schist, and gneiss.

• Non-foliated Texture: Metamorphic rocks lacking a planar fabric, formed under conditions of uniform pressure or contact metamorphism. Examples include quartzite and marble.

• Schistosity: A medium to coarse-grained foliated texture characterized by visible micas or other platy minerals aligned parallel to each other, allowing the rock to split into thin sheets.

• Gneissic Banding: A high-grade foliated texture with alternating light and dark mineral bands, indicating segregation of mineral compositions during metamorphism.

• Recrystallization: The process where mineral grains grow larger and new minerals form without melting, often resulting in a change of texture and mineralogy.

• Index Minerals: Minerals that form at specific temperature and pressure conditions, used to determine the metamorphic grade. Examples include chlorite (low grade), garnet (medium grade), and sillimanite (high grade).

📝 Essential Points

• Formation of Metamorphic Textures: Result from mineral growth, reorientation, and recrystallization under heat and pressure, without melting.

• Foliation Development: Caused by differential stress, leading to the alignment of platy minerals (e.g., micas) and the development of planes of weakness.

• Progression of Metamorphic Grade: As temperature and pressure increase, rocks evolve from slate (very fine, slaty cleavage) to phyllite (micaceous sheen), schist (visible micas), and gneiss (banded structure).

• Non-foliated Rocks: Form in environments where pressure is uniform or contact heating dominates, leading to equigranular, crystalline textures like quartzite and marble.

• Mineral Stability and Index Minerals: The presence of specific index minerals indicates the metamorphic grade, with higher-grade minerals forming at higher T/P conditions.

• Texture-Environment Relationship: Foliated textures are typical of regional metamorphism involving directed stress; non-foliated textures are typical of contact or burial metamorphism.

💡 Key Takeaway

Metamorphic textures reveal the history of pressure, temperature, and deformation a rock has experienced; foliation indicates directed stress and high-grade metamorphism, while non-foliated textures suggest uniform pressure or contact metamorphism.

📖 11. Deformation Types

🔑 Key Concepts & Definitions

• Stress: Force applied per unit area within rocks, causing deformation. Types include compression, tension, and shear.
• Strain: The resulting change in shape or size of a rock due to stress; can be elastic, ductile, or brittle.
• Brittle failure: Fracturing or cracking of rocks when they cannot deform plastically, resulting in faults or joints.
• Ductile flow: Plastic deformation where rocks bend or fold without breaking, forming structures like folds and foliations.
• Folding: Ductile deformation resulting in bends or waves in layered rocks, including anticlines and synclines.
• Fault: A fracture along which displacement has occurred; classified as dip-slip (normal, reverse, thrust) or strike-slip.

📝 Essential Points

• Stress vs. Strain: Stress causes strain; the type and magnitude of stress influence whether rocks deform brittlely or ductilely.
• Brittle vs. Ductile Deformation: Low T/P or rapid strain favors brittle failure (faults, joints); high T/P or slow strain favors ductile deformation (folds, foliation).
• Folds: Formed by ductile deformation under compression; types include anticlines (upward arches) and synclines (downward troughs). Folding can be symmetrical, asymmetrical, overturned, recumbent, or plunging.
• Faults: Result from brittle failure; normal faults (extension), reverse/thrust faults (compression), and strike-slip faults (shear). Faults are characterized by displacement and are key in tectonic processes.
• Joints: Fractures with no displacement, often due to tensile stresses; control erosion and mineralization.
• Foliation and Cleavage: Planar fabric in metamorphic rocks formed by aligned minerals; develops under differential stress, indicating ductile deformation.

💡 Key Takeaway

Deformation in rocks results from the interplay of stress and strain, producing structures like folds, faults, and joints; understanding these helps interpret Earth's tectonic history and the conditions during rock formation.

📊 Synthesis Tables

⚠️ Common Pitfalls & Confusions

1. Confusing weathering with erosion; weathering breaks down rocks, erosion transports fragments.
2. Misidentifying sedimentary structures; e.g., mistaking cross-bedding for bedding planes.
3. Overlooking the importance of depositional environment clues in interpreting sedimentary rocks.
4. Assuming all fossils are preserved equally; preservation depends on specific conditions.
5. Confusing igneous textures; e.g., mistaking porphyritic for phaneritic.
6. Mixing metamorphic agents; heat, pressure, and chemically active fluids produce different mineral assemblages.
7. Ignoring the role of diagenesis in transforming sediments into rocks.
8. Misinterpreting sedimentary structures as evidence of current direction without considering other factors.
9. Overgeneralizing depositional environments; many environments have overlapping features.
10. Confusing mineral composition with rock classification in igneous rocks.

✅ Exam Checklist

• Describe the processes involved in sedimentary formation, including weathering, erosion, transport, deposition, and lithification.
• Identify and explain common sedimentary structures and their depositional significance.
• Differentiate between continental, transitional, and marine depositional environments based on sediment types and structures.
• Recognize the types of fossils, their preservation conditions, and their use in biostratigraphy.
• Explain the cooling processes and textures of igneous rocks, including slow vs. rapid cooling effects.
• Classify igneous rocks based on mineral composition (felsic, mafic, intermediate).
• Distinguish between igneous textures: phaneritic, aphanitic, porphyritic, vesicular.
• List the main metamorphic agents: heat, pressure, chemically active fluids.
• Identify common metamorphic minerals such as garnet, staurolite, and chlorite.
• Describe metamorphic textures: foliated (slaty, schistose, gneissic) and non-foliated.
• Explain deformation types: elastic, ductile, brittle, and their geological significance.
• Recognize the relationship between deformation and metamorphic processes.