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GENERAL SCIENCE PART 3 EARTH SCIENCE BY: MARK KENNETH DAIRO EARTH SCIENCE THE HISTORY OF EARTH AN OVERVIEW OF GEOLOGICAL TIME SCALE HADEAN EON: (4.54 – 4.0 Ga) HADEAN EON: (4.54 – 4.0 Ga) Formation of Earth Accretion from solar nebula Formation of the Moon (giant impact hypo...

GENERAL SCIENCE PART 3 EARTH SCIENCE BY: MARK KENNETH DAIRO EARTH SCIENCE THE HISTORY OF EARTH AN OVERVIEW OF GEOLOGICAL TIME SCALE HADEAN EON: (4.54 – 4.0 Ga) HADEAN EON: (4.54 – 4.0 Ga) Formation of Earth Accretion from solar nebula Formation of the Moon (giant impact hypothesis) GIANT IMPACT HYPOTHESIS HADEAN EON: (4.54 – 4.0 Ga) Early Condition Molten surface Heavy bombardment by asteroids and comets Formation of early crust HADEAN EON: (4.54 – 4.0 Ga) Significant events Differentiation of Earth's core and mantle Outgassing and formation of early atmosphere and oceans FACTS!!! ARCHEAN EON: (4.0 – 2.5 Ga) ARCHEAN EON (4.0 – 2.5 Ga) FORMATION OF THE FIRST CONTINENTAL CRUST Emergence of stable continental landmasses Formation of greenstone belts and cratons ARCHEAN EON (4.0 – 2.5 Ga) ORIGIN OF LIFE First prokaryotic cells (bacteria and archaea) Evidence from stromatolites and microfossils FIRST PROKARYOTIC CELL Stromatolites: stony structures built by colonies of microscopic photosynthesising organisms called cyanobacteria ARCHEAN EON (4.0 – 2.5 Ga) Early Atmosphere and Oceans Presence of methane, ammonia, water vapor, and carbon dioxide Lack of free oxygen (anoxic atmosphere) ARCHEAN EON (4.0 – 2.5 Ga) PLATE TECTONICS Early form of plate tectonic activity.  PLATE TECTONIC THEORY The theory of plate tectonics emerged in the mid-20th century, building on earlier concepts like continental drift proposed by Alfred Wegener. It was supported by evidence from seafloor spreading, the distribution of earthquakes and volcanoes, and the fit of continental margins. PLATE TECTONIC THEORY (LAYERS) Lithosphere and Plates: The Earth's outer shell, or lithosphere, is broken into tectonic plates. These plates include continental and oceanic plates. Asthenosphere: Beneath the lithosphere is the asthenosphere, a semi-fluid layer on which the tectonic plates float and move. PLATE TECTONIC THEORY (PLATE BOUNDARIES) Divergent Boundaries: Plates move apart, forming new crust as magma rises below the Earth's surface. An example is the Mid-Atlantic Ridge. PLATE TECTONIC THEORY (PLATE BOUNDARIES) Convergent Boundaries: Plates move towards each other, causing one plate to be forced beneath another in a process called subduction. This can form mountain ranges, volcanic activity, and deep ocean trenches. The Himalayas are an example of a mountain range formed by convergent boundaries PLATE TECTONIC THEORY (PLATE BOUNDARIES) Transform Boundaries: Plates slide past each other horizontally, leading to earthquakes along faults. The San Andreas Fault in California is a well- known example. PLATE TECTONIC THEORY (MECHANISM OF MOVEMENT) Mantle Convection: Heat from the Earth's core causes convection currents in the mantle, which drag the plates along. Ridge Push: Elevated mid-ocean ridges create a force that pushes plates away from the ridge. Slab Pull: The weight of a subducting plate pulls the trailing lithosphere into a subduction zone. PROTEROZOIC EON: (2.5 Ga – 541 Ma) PROTEROZOIC EON: (2.5 Ga – 541 Ma) Great Oxidation Event Oxygenation of the atmosphere due to photosynthesis by cyanobacteria Formation of Banded Iron Formations (BIFs) “Early occurrence occurs in Archean Eon” Banded Iron Formations (BIFs)  Emergence of Eukaryotic Cells PROTEROZOIC EON: Endosymbiotic theory (origin of mitochondria and chloroplasts) (2.5 Ga – 541 Ma) Appearance of first multicellular organisms (algae and early animals) ENDOSYMBIOTIC THEORY PROTEROZOIC EON: (2.5 Ga – 541 Ma) Time of Supercontinents Supercontinent Nuna (1.8 – 1.5 Ga) Supercontinent Rodinia (1.1 Ga – 750 Ma) Supercontinent Gondwana (500 Ma) BREAKTIME!!!  Phanerozoic Eon: (541 Ma - present) OVERVIEW!!! Visible Life Abundant and diverse fossil record Major evolutionary milestones Divisions of Phanerozoic Paleozoic Era: Marine life explosion, first land plants and animals Mesozoic Era: Age of reptiles (dinosaurs), first mammals and birds Cenozoic Era: Age of mammals, rise of humans Continental Drift and Plate Tectonics Ongoing movement of continents Formation of modern continents and ocean basins  PALEOZOIC ERA (CAMBRIAN PERIOD) Cambrian Explosion Rapid diversification of life forms Emergence of most major animal phyla Marine Ecosystems Development of complex ecosystems in shallow seas  Marine Life Flourished PALEOZOIC ERA High biodiversity in oceans Dominance of brachiopods, bryozoans, and mollusks (ORDOVICIAN First Jawless Fish (Agnatha) Evolution of early vertebrates PERIOD) End of Period Major glaciation event leading to mass extinction DUE TO COLONIZATION OF PLANTS (Ordovician-Silurian extinction) PHYLOGENY OF VERTEBRATES PALEOZOIC ERA (SILLURIAN PERIOD) First Jawed Fish (Placoderms) Evolution of gnathostomes (jawed vertebrates) Colonization of Land First vascular plants (cooksonia) Early terrestrial arthropods (millipedes, scorpions) Reef Building Coral reefs became widespread PHYLOGENY OF VERTEBRATES PALEOZOIC ERA (DEVONIAN PERIOD) Age of Fishes Diversification of fish, including lobe- finned fish (sarcopterygians) and ray- finned fish (actinopterygians) First Amphibians Transition from fish to tetrapods (e.g., Ichthyostega, Acanthostega) Early Forests Emergence of first large trees (Archaeopteris) End of Period Mass extinction event affecting marine life DUE TO CLIMATE CHANGE. PHYLOGENY OF VERTEBRATES  PALEOZOIC ERA (CARBONIFEROUS PERIOD) Extensive Forests Formation of vast coal swamps Dominance of lycophytes, ferns, and seed ferns First Reptiles Evolution of amniotes (e.g., Hylonomus) Insects Flourished Gigantic insects (e.g., Meganeura) Mississippian and Pennsylvanian Subdivisions Mississippian: Limestone deposits, marine invertebrates Pennsylvanian: Coal formation, diversification of amphibians PHYLOGENY OF VERTEBRATES PALEOZOIC ERA (PERMIAN PERIOD) Pangea Supercontinent Assembly of supercontinent Pangea Drastic climate changes and arid conditions Evolution of Synapsids Early mammal-like reptiles (e.g., Dimetrodon) Permian-Triassic Extinction Event Known as the “Great Dying” due to catastrophic volcanic eruption in Siberia. Largest mass extinction in Earth's history. 96% of marine species and 70% of terrestrial species went extinct. KEY EVENTS IN PALEOZOIC ERA Cambrian Explosion Rapid diversification of marine life Colonization of Land Plants and arthropods first to invade land Development of Complex Ecosystems Evolution of vertebrates, plants, and arthropods Mass Extinctions Ordovician-Silurian, Late Devonian, and Permian-Triassic extinctions GENERAL SCIENCE PART 3 EARTH SCIENCE BY: MARK KENNETH DAIRO REVIEW!!! SIBERIAN TRAPS - is a large region of volcanic rock, known as a large igneous province, in Siberia, Russia. It is believed to be the primary cause of the Permian–Triassic extinction event MESOZOIC ERA (252 – 66 Ma)  MESOZOIC ERA (TRIASSIC PERIOD) Post-Permian Extinction Recovery Diversification of life following the Permian-Triassic extinction Early Dinosaurs and Mammals Evolution of first dinosaurs (e.g., Eoraptor, Herrerasaurus) First true mammals (e.g., Morganucodon) Marine Reptiles Rise of ichthyosaurs and plesiosaurs Flora Dominance of gymnosperms (conifers, cycads) End of Period Triassic-Jurassic extinction event due to volcanic eruptions in the Central Atlantic Magmatic Province (CAMP), paving the way for dinosaur dominance  MESOZOIC ERA (JURASSIC PERIOD) Dominance of Dinosaurs Large sauropods (e.g., Brachiosaurus, Diplodocus) Theropods (e.g., Allosaurus) Stegosaurus and other herbivores First Birds Evolution of Archaeopteryx from small theropods Marine Life Plesiosaurs, ichthyosaurs, and ammonites Flora Continued dominance of gymnosperms First true ferns and ginkgos Pangaea Breakup Continued rifting of supercontinent Pangaea into Laurasia and Gondwana SUPERCONTINENTS SUPERCONTINENTS (PANGAEA-TO- PRESENT)  MESOZOIC ERA (CRETACEOUS PERIOD) Flowering Plants (Angiosperms) Rapid diversification and spread of flowering plants Co-evolution with pollinating insects Diversification of Dinosaurs Large theropods (e.g., Tyrannosaurus rex) Ceratopsians (e.g., Triceratops) Hadrosaurs (duck-billed dinosaurs) Rise of Modern Mammals Diversification of placental and marsupial mammals Marine Life Mosasaurs, plesiosaurs, and ammonites End of Period Cretaceous-Paleogene (K-Pg) extinction event Extinction of non-avian dinosaurs, paving the way for mammalian dominance Cretaceous-Paleogene extinction event Causes Asteroid Impact Chicxulub crater, Yucatán Peninsula, Mexico Effects: Massive explosion, firestorms, atmospheric dust blocking sunlight Volcanic Activity Deccan Traps, India Effects: Long-term eruptions, sulfur dioxide and carbon dioxide release, global cooling, and warming  KEY EVENTS IN MESOZOIC ERA Pangea Breakup Gradual breakup of Pangaea into smaller continents Significant changes in climate and ocean currents Evolution of Birds From small theropod dinosaurs (e.g., Archaeopteryx) Diversification of Reptiles Dominance of dinosaurs on land, marine reptiles in the sea, and pterosaurs in the air Rise of Mammals Small, nocturnal mammals evolving alongside dinosaurs CENOZOIC ERA (66 Ma – Present) CENOZOIC ERA (PALEOGENE PERIOD) Paleocene Epoch Recovery from K-Pg extinction Rapid diversification of mammals and birds Development of early primates Eocene Epoch Warm climate, tropical forests widespread Evolution of early horses, bats, and whales Oligocene Epoch Cooling climate, formation of Antarctic ice sheets Expansion of grasslands, further evolution of mammals (e.g., elephants, early apes) CENOZOIC ERA (NEOGENE PERIOD) Miocene Epoch Continued cooling and drying climate Evolution of modern plant families, grasses, and herbivores Diversification of apes, early human ancestors (e.g., Proconsul) Pliocene Epoch Further climatic cooling, expansion of savannas Evolution of hominins (e.g., Australopithecus) Formation of the Isthmus of Panama, altering ocean currents and climate CENOZOIC ERA (QUATERNARY PERIOD) Pleistocene Epoch Repeated glacial and interglacial cycles (Ice Ages) Evolution and spread of Homo sapiens Extinction of megafauna (e.g., mammoths, saber-toothed cats) Holocene Epoch Warm interglacial period Development of human civilization, agriculture, and urbanization Significant environmental impact due to human activities GLACIAL VS. INTERGLACIAL PERIOD KEY EVENTS IN CENOZOIC ERA Climatic Changes General trend of cooling and drying Formation of polar ice caps and glacial cycles Evolution of Mammals Mammals became the dominant land animals Evolution of diverse groups (e.g., primates, cetaceans, ungulates) Floral Evolution Spread of grasses and development of grasslands Evolution of modern plant families THE LAYERS OF THE EARTH OVERVIEW Major Layers Crust Mantle Core Composition and Characteristics Each layer has distinct physical and chemical properties THE CRUST: Outermost layer Thin and solid Rigid and brittle Contains Earth's landforms and ocean basins Accounts for less than 1% of Earth's volume THE CRUST: Continental Crust: Thick (30-70 km) less dense composed mainly of granitic rocks (Felsic) Oceanic Crust: Thin (5-10 km) more dense composed mainly of basaltic rocks (Mafic) MAFIC VS FELSIC  MAFIC ROCKS FELSIC ROCKS Composition Rich in magnesium (Mg) and iron (Fe) Rich in silica (SiO₂) and aluminum Contains minerals like olivine, (Al) pyroxene, amphibole, and biotite Contains minerals like quartz, feldspar (both plagioclase and orthoclase), and muscovite Color dark-colored (black, green, dark gray) light-colored (white, pink, light gray) Density Higher density compared to felsic rocks Lower density compared to mafic rocks Formation Commonly found at mid-ocean ridges Commonly found in continental crust and volcanic islands Formed from slow cooling of magma Formed from rapid cooling of magma beneath the Earth's surface at or near the Earth's surface Example Basalt, gabbro Granite, rhyolite THE MANTLE Layer between the crust and core Semi-solid Primarily composed of silicate minerals (peridotite) Accounts for about 84% of Earth's volume THE MANTLE Lithosphere: Rigid layer, includes the crust and the uppermost part of the mantle Asthenosphere: Partially molten, plastic-like layer in the upper mantle THE MANTLE SUBLAYERS Upper Mantle: Extends to about 410 km deep Transition Zone: Between 410 and 660 km deep Lower Mantle: Extends to about 2,900 km deep SEISMIC WAVES SEISMIC WAVES: Seismic waves are caused by the sudden movement of materials within the Earth, such as slip along a fault during an earthquake  Love waves vs. Rayleigh waves Property Love Waves Rayleigh Waves Horizontal shearing Elliptical, rolling Movement (side-to-side) (vertical and horizontal) Faster than Rayleigh Speed Slower than Love waves waves Travel Medium Surface of the Earth Surface of the Earth Side-to-side horizontal Ground Motion Elliptical, rolling motion motion Significant horizontal Significant rolling and Damage shaking ground shaking  P-waves vs S-waves Property P-Waves S-Waves Faster (5-8 km/s in the Slower (3-4.5 km/s in the Speed crust) crust) Compressional Movement Shear (transverse) (longitudinal) Travel Medium Solids, liquids, and gases Solids only Detection First to be detected Second to be detected Back and forth in the Perpendicular to the Motion direction of wave direction of wave THE CORE Innermost layer Composed primarily of iron and nickel THE CORE SUBLAYER Outer Core: Liquid, extends from 2,900 km to 5,150 km deep Inner Core: Solid, extends from 5,150 km to 6,371 km deep THE CORE CHARACTERISTICS Outer Core: Responsible for Earth's magnetic field Inner Core: Extremely hot and dense, high pressure keeps it solid CORE MAGNETIC FIELD (GEODYNAMO) The Earth's core generates a powerful magnetic field through the motion of molten iron and nickel in its outer core, creating the Geodynamo effect that extends outwards, guiding compasses. GENERAL SCIENCE PART 3 EARTH SCIENCE BY: MARK KENNETH DAIRO REVIEW!!! ROCKS ROCK CYCLE The rock cycle is a continuous process by which rocks are created, altered, destroyed, and formed again. Igneous, sedimentary, and metamorphic rocks are all part of this cycle. ROCK Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. CYCLE All magma develops underground, in the lower crust or upper mantle, because of the intense heat there. ROCK CYCLE Igneous rock at Earth's surface breaks down into sediments by weathering. Erosion carries the sediments and deposits them in layers. Over time, these layers are deposited, compacted, and cemented to form sedimentary rock. These processes are known as LITHIFICATION. LITHIFICATION ROCK CYCLE If sedimentary rocks are buried deep enough within the crust to be subjected to increased temperature and pressure, they may change into metamorphic rock. Igneous rock may also be transformed into metamorphic rock, and metamorphic rock exposed to the Earth's surface may be eroded to be transformed into sedimentary rock. ROCK CYCLE TYPES OF ROCKS  IGNEOUS ROCKS Igneous rocks are “fire-born,” meaning that they are formed from the cooling and solidification of molten (melted) rock. IGNEOUS ROCKS Formation: Cooling and solidification of magma or lava. Types of Igneous rocks: Intrusive rocks: Formed below the Earth's surface, slow cooling, large crystals (e.g., Granite). Extrusive rocks: Formed at or near the Earth's surface, rapid cooling, small crystals (e.g., Basalt). CHARACTERISTICS OF IGNEOUS ROCKS TEXTURE: Plutonic rock (Coarse-grained): Slow cooling, large crystals (e.g., Granite). Volcanic rock (Fine-grained): Rapid cooling, small crystals (e.g., Basalt).  PLUTONIC VS. VOLCANIC ROCKS PLUTONIC ROCK VOLCANIC ROCK A type of igneous rock that forms A type of igneous rock that forms under the surface of Earth’s crust upon exposure to air Located underneath the earth’s crust Located above the ground Mineral content is low Mineral content is high Medium to large grains Fine grains Solidifies due to slow cooling Solidifies due to exposure to air underneath the Earth CHARACTERISTICS OF IGNEOUS ROCKS COMPOSITION: Mafic: Rich in magnesium and iron, dark- colored (e.g., Basalt). Felsic: Rich in silica, light-colored (e.g., Granite).  IGNEOUS ROCKS Igneous rocks are “fire-born,” meaning that they are formed from the cooling and solidification of molten (melted) rock. TYPES OF ROCKS  SEDIMENTARY ROCKS Sedimentary rocks are formed from deposits of pre-existing rocks or pieces of once-living organism that accumulate on the Earth's surface. SEDIMENTARY ROCKS Formation: Deposition, compaction, and cementation of sediments. Types: Clastic: Formed from fragments of other rocks (e.g., Sandstone). Chemical: Formed from mineral precipitation (e.g., Limestone). Organic: Formed from the remains of living organisms (e.g., Coal). SEDIMENTARY ROCKS CHARACTERISTICS OF SEDIMENTARY ROCKS Texture: Grain size: Coarse, medium, fine. Roundness: Well-rounded, rounded, angular. Sorting: Well-sorted, poorly sorted. Grains and matrix CHARACTERISTICS OF SEDIMENTARY ROCKS Provenance: Provenance refers to the origin or source of the sediments that make up sedimentary rocks. CHARACTERISTICS OF SEDIMENTARY ROCKS Provenance: Terrigenous sediment: These sediments originate from the continents from erosion, volcanism, and wind-transported material. Biogenic sediment: These are sediments derived from calcareous (skeleton) and silicious (diatoms) composition Hydrogenous sediment: These are sediments come from chemical reactions in the water. Cosmogenous sediment: These are sediments that come from space, filtering in through the atmosphere or carried to Earth on meteorites. CHARACTERISTICS OF SEDIMENTARY ROCKS Composition: Mineral content: Quartz, calcite, clay minerals. Cement type: Silica, calcite, iron oxide. TYPES OF ROCKS  METAMORPHIC ROCKS Metamorphic rocks form when rocks are subjected to high heat, high pressure, and hot mineral-rich fluids  LOOKING BACK!!! Metamorphic rocks result from the forces active during plate tectonic processes. The collision of plates, subduction, and the sliding of plates along transform faults create differential stress, friction, shearing, compressive stress, folding, faulting, and increased heat flow. WHAT IS METAMORPHISM? Any change in the mineralogy or physical structure of a rock by natural processes without melting it into magma. METAMORPHIC ROCK Formation: Heat and pressure altering existing rocks. Types: Foliated: Layered or banded appearance (e.g., Slate). Non-foliated: No distinct layers (e.g., Marble). CHARACTERISTICS OF METAMORPHIC ROCK Texture: Foliation: Parallel alignment of mineral grains. Banding: Alternating layers of different minerals. CHARACTERISTICS Composition: OF METAMORPHIC Influenced by the parent rock (protolith) and the ROCK conditions of metamorphism. HOW TO IDENTIFY ROCKS? Igneous Rocks: Look for grain size and texture. Check for presence of vesicles (holes from gas bubbles). Sedimentary Rocks: Look for layers and fossils. Check for grain size and sorting. Metamorphic Rocks: Look for foliation or banding. Check for recrystallized minerals. SUMMARY Igneous rocks form from cooled magma or lava. Sedimentary rocks form from compacted sediments. Metamorphic rocks form from existing rocks altered by heat and pressure.