Earth 209 Final-3 PDF

STRATIGRAPHY AND GEOLOGICAL TIME Steno’s Principles of Stratigraphy Principle of Layer Superposition: In undisturbed strata, the oldest layer lies at the bottom and the youngest at the top. Principle of Layer Successive Formation: When a layer was forming, there was only liquid (like water) above it...

STRATIGRAPHY AND GEOLOGICAL TIME Steno’s Principles of Stratigraphy Principle of Layer Superposition: In undisturbed strata, the oldest layer lies at the bottom and the youngest at the top. Principle of Layer Successive Formation: When a layer was forming, there was only liquid (like water) above it, and none of the layers we see now on top of it had been formed yet Principle of Original Layer Horizontality: Sedimentary layers are initially horizontal; inclined layers suggest crustal disturbance Principle of Lateral Layer Continuity: Layers extend laterally until they thin out or encounter a barrier. Layer Terminations - 1774: First scientific attempt to estimate Earth’s age (~70,000 years). This challenged creationist ideas and paved the way for modern geochronology. Interpreting Stratigraphical Successions: - Sedimentological Data: Structures like mudcracks and ripple marks help determine original depositional environments. - Normal Succession: Younger layers lie atop older ones. - Relative Ages by Superposition - Relative Ages: Layers in different sections can be correlated to establish their relative chronological - Inverted Succession: Tectonic forces may disrupt this order, overturned. Contributions to Geology Nicolaus Steno: Principles of stratigraphy (above). Earth (4.54 billion years old) John Strachey: Layer terminations. Sir Charles Lyell: Principles for dating igneous and Sir William Smith: Fossil-based correlation and metamorphic rocks. geological mapping. Tomaso d’Arduinio: Use of sedimentary structures. Georges Louis Leclerc (de Buffon): Age of the Sir William Smith – Geological Society of England Created the first geological map of England, Wales, Dubbed “the map that changed the world.” and southern Scotland. Fossil Ranges Time period during which a particular species of organism existed Index Fossils: Useful for matching layers in different areas, used to identify and date the layers of rock in which they are found Sir Charles Lyell’s Principles Principle of Inclusions: The rock containing inclusions is intrusions of molten rock that form underground, they younger than the included fragments. heat and "bake" both the layer above and the layer Principle of Cross-Cutting Relations: Features like dikes below when they push in between existing rocks. are younger than the rocks they cut through. Relative Ages of Lava Flows: Lava flows across the surface heat "bakes" rock layers below. Sills are younger Radioactive Decay Radioactive Decay: Unstable isotopes Half-Life Resolution: Provides a precise method for spontaneously transform into stable daughter dating rocks and fossils. isotopes. Decay Series: Example: Uranium-238 decays to Half-Life: Time it takes for half the parent isotope to dating rocks and fossils. Lead-206 through a series of decay into the daughter isotope. alpha and beta decay Half-Life Resolution: Provides a precise method for steps. dating rocks and fossils. Geological Time Summary Relative Geological Time Scale: Stratigraphy Proterozoic: Fossils include microscopic and orders layers and fossils chronologically. macroscopic forms, longest Eons of Earth’s History: Proterozoic/Phanerozoic Boundary: Cambrian Hadean: Formation of Earth; no rock explosion where significant event of rapid increase in Record. diversity and complexity of life forms Hadean/Archean Boundary: Age of the oldest rock Phanerozoic: Visible fossils and complex life forms; record in stratigraphical record divided into Paleozoic, Mesozoic, and Cenozoic eras., Archean: Oldest rocks and earliest fossil, shortest. shortest Archean/Proterozoic Boundary: Banded iron Paleozoic Era: Periods include - Cambrian: Emergence formation (see "Earth Rusting") of diverse marine life, the development of hard parts in organisms, the formation of complex ecosystems, and Jurassic: Dominance of large dinosaurs, first birds, and significant geological changes (longest), Ordovician: Saw the separation of the Pangaea, and Cretaceous: Further the development of the first vertebrates and early evolution and diversification of dinosaurs and flowering colonization of land by plants, shortest, Silurian: Marked plants (shortest). Marked by significant extinction events by the appearance of the first vascular plants and rise of (e.g., Permian/Triassic crisis and Cretaceous/Paleogene the jawed fish, Devonian: "Age of Fish" saw the rise of impact). the first amphibians and land dwelling plants, Mesozoic/Cenozoic Boundary: Meteorite impact that Mississippian:Dominance of marine life (ie.corals and lead to the extinction of several major fossil groups in sponges), Pennsylvanian (or Carboniferous): vast coal both continental and marine realms, including dinosaurs forests, the rise of early reptiles, and the development Cenozoic Era: Longest era, periods include Paleogene: of significant mountain ranges, and Permian:Assembly Recovery and diversification of mammals and birds, of the supercontinent Pangaea, shortest era Neogene: Saw the evolution of early humans and the Paleozoic/Mesozoic Boundary: Permian/Triassic crisis spread of grasslands (longest), and Quaternary: Marks affected mostly the species in the seas and oceans, 90% the development of humans and the most recent ice became extinct during the crisis, most severe crisis in the age; fossils closely resemble modern life (longest) history of life Mesozoic Era: Periods include - Triassic: Rise of the first dinosaurs, first mammals, recovery of life (longest), FOSSIL RECORDS What are Fossils? Fossils: Vestiges of ancient life forms - Origin: Latin term meaning "to be dug out from the Earth," coined during the Renaissance, Historical meaning: Included both minerals and vestiges of life. Fossil Classifications By Age: Fossils: Older than 11,700 years. Subfossils: Younger than 11,700 years (not all considered fossils), By Nature: Body Fossils: Preserve parts of the organism (hard/soft body parts). Trace Fossils: Preserve organism activities (ie. movement traces). Chemical Fossils: Preserve only small organic components. Examples of Fossils Body Fossils: Stony coral (cnidarian), Cephalopod Mixed Fossils: Mesolimulus (horseshoe crab) with shells, Trilobite, Belemnites. movement traces. Trace Fossils: Cruziana (movement trace), Skolithos (vertical galleries), Acanthotheuthis (movement trace of belemnite) Historical Context Pre-scientific Understanding: Fossilization Process Fossils were known in early Antiquity. Transformation of a dead organism into a fossil. Example: Brachiopod fossil from King Senwosret I’s Selective process: Not all organisms fossilize due to time (Middle Kingdom, Egypt). its highly destructive nature. First Scientific Report: Conditions for Fossilization Xenophanes of Colophon (~570-475 B.C.): Rapid Burial: Sudden events (e.g., landslides) or Described marine fossils found inland, suggesting high sedimentation rates. past mixing of sea and land. Anoxic Conditions: Reduces decay, enhances Locations: Syracuse, Paros, Melita, etc. preservation Types of Fossilization Casual Fossilization: (sea-urchin) )its highly destructive nature. Petrification: Both lithification and permineralization Carbonization: Loss of elements except carbon during Lithification: Transformation of hard body parts into decay (ie. Pecopteris (fern) stony material Lepidodendron (lycopsid). Permineralization: When something turns into stone Impressions: Formed by organism weight in sediment because the pores get filled with minerals, (ie. Psaronius (ie. Pecopteris leaf) (fern tree), Dinosaur bone, Cladoxylon(woody plant)) High-Quality Fossilization: Recrystallization: Conversion of one mineral to Amber: Fossilized resin (e.g., Plesiomyrex). another (e.g., aragonite to Tar Pits: Hydrocarbon swamps (e.g., Cybister). calcite), (ie. Globotruncanella, Congealment, Dehydration: Uintacrinus (sea-lily), Micraster Preservation of soft tissues. Fossil Lagerstätten Sites with exceptional fossil preservation, including soft tissues. Examples: Burgess Shale (Canada): Middle Cambrian, e.g., Ottoia. & Chengjiang Fauna (China): Lower Cambrian, e.g., Haikouichthys (early vertebrate) LIFE EMERGENCE ON EARTH AND EARLY EVOLUTION CHON Elements - Dominant elements in life forms today: Carbon (C) (most dominant), Hydrogen (H), Oxygen (O), Nitrogen (N) (Sulfur and phosphorus are present in smaller amounts.) Earth’s Early Atmosphere - Alexandr Ivanovic Oparin (1896–1980): Postulated that CHON molecules could have formed before life, giving rise to the first cells. o Plant cells are too complex to form without a o Earth's original atmosphere was reducing, o CHON molecules could accumulate in such o "Primordial soup" was not alive. long inorganic evolution process. with little free molecular oxygen. an atmosphere. Isua Supercrustal Group Location: Greenland. Graphite levels suggest organic origin. Contains some of Earth’s oldest sedimentary rocks Rare oxides and carbonates; lack of layering. (3.8–3.7 billion years old). Experimental Confirmation - Miller-Urey Experiment (1953) o Demonstrated that simple elements can o Produced seven amino acids (e.g., glycine, chemically react to form organic CHON alanine). molecules. Polymerization Formation of larger molecules (polymers) from simple Note: Molecules do not fossilize. CHON molecules (monomers). Example: Monosaccharides = Carbohydrates, Amino acids = Protein Isolated Cells: Early Archean of Western Australia (Pilbara Strelley Pool Chert cyanobacteria: Chain-like Craton): Apex Chert (volcano-sedimentary formation). structures similar to modern purple bacteria. Evidence of early bacteria and cyanobacteria debris. Apex Chert cyanobacteria: Folded filament structures made of carbon, similar to modern iron bacteria. Stromatolites Fossilized microbial structures (layered, rock-like photosynthetic bacteria (~1 mm). structures) created by cyanobacteria Oxygen-depleted zone: Anaerobic bacteria Patchy distribution - in Mesoarchean (1–2 cm). Components (from surface to center): Stromatolite mass: Includes most of the stromatolite Growth surface: Photosynthetic (mostly rock) cyanobacteria and aerobic bacteria (~1 mm). Undermat: Non-oxygen-producing Banded Iron Formation (BIF) Alternating thin layers of: Cherts and jaspers with lower iron content. Iron oxides (e.g., hematite [Fe2O3] and Colors: Reddish (iron oxides) and green/grey magnetite [Fe3O4]). (cherts/jaspers. Oldest Eukaryotes Biomarkers (chemical fossils): 2.1–1.8 billion years Assigned to red algae (rhodophytes) and old. green algae (chlorophytes) Bitter Springs Formation (Australia): Some fossils show cellular division and True isolated eukaryote cells (1 billion years preserved nuclei. old). Eukaryote Examples: Bangiomorpha: Algal Quaternary). Filamentous microstructures Melanocyrillium: thallus (similar to escaping from Resembles modern modern red bag-like testate amoebas Primitive holdfast acritarchs. (earliest animals). for seafloor algae). Organic with attachment. Survival sometimes Age: ~1.2 billion adaptations for agglutinated years dry/cold climates. particles. (Proterozoic– Age: ~0.9 billion Quaternary). years (Upper Torridonophycus: Proterozoic– Age: ~0.8–0.9 billion years (Upper Proterozoic–Quaternary DINOSAURS Vertebrate Evolution - Vertebrates evolved from chordates in the Lower Cambrian. Early forms: Agnathans (jawless fish) and jawed fishes. Key Examples: Haikouichthys: Earliest vertebrate. Sacabambaspis: Agnathan with a cephalic shield. Fishes - Aquatic organisms with jaws, evolved in the Middle Silurian. Colonized marine, brackish, and freshwater environments. Skeletons: Bony (most species) or cartilaginous (e.g., sharks). Dunkleosteus: Largest fish predator, Upper Devonian, Ohio and Europe, fish, Macropomides: Late Cretaceous, Hjoula, Lebanon, fish Amphibians - Transitioned to land: 1. Double respiration: lungs and skin (must remain wet). 2. Aquatic reproduction: numerous unprotected eggs. Reptiles - Evolved from amphibians with adaptations for land: Shelled eggs (fewer but protected). Fully terrestrial lifestyle. Early reptiles: Diapsids (e.g., Hylonomus). Synapsid Reptiles Dominated Late Paleozoic to Early Triassic. Therapsids: Mammal-like reptiles Developed thermoregulation. (e.g., Keratocephalus size of a rhinoceros - Late Examples: Dimetrodon (predator). Devonian, Germany and Europe, therapsid) Edaphosaurus (herbivore). Diapsid Takeover and Dinosaur Origins Dinosaurs evolved from diapsid reptiles during the Petrolacosaurus - Late Early Carboniferous, Kansas Upper Triassic. USA, diapsid reptiles Earliest dinosaurs: Possibly originated in South Hylonomous - Late Carboniferous, Canada, diapsid America. reptiles Early dinosauromorphs: Small, bipedal/quadrupedal Herrerasaurus example of early dinosaurs - Upper insectivores or carnivores. Triassic, Argentina, dinosaur Dinosaur Classification - Based on pelvic structure: Saurischians (lizard-hipped): Pubis points down/forward. Ornithischians (bird-hipped): Pubis points backward Theropods - Bipedal predators with knife-like teeth, grasping hands, hollow bones. Examples: Allosaurs: Dominant predators of the Jurassic/Cretaceous..Tyrannosaurs: Apex predators (e.g., Tyrannosaurus Rex) Sauropodomorpha - Early large dinosaurs; evolved into quadrupedal giants: Plateosaurus (Prosauropod, Europe, Upper Triassic). Ultrasaurus (Sauropod, North America, Upper Jurassic). Ornithischians - Herbivores with specialized adaptations: Stegosaurus: Beak-like structure for cropping plants. Ankylosaurus: Armored "fused lizards" with osteoderms. Ceratopsians: Horned dinosaurs (e.g., Triceratops). Evolution of Flight Examples: Dimorphodon: Ate small insects (Upper Pterosauria (winged reptiles): Jurassic, Europe, pterosauria), Rhamphorhynchus: Ate Lived from Upper Triassic to Cretaceous. fish, like seagulls (Upper Jurassic, Europe, pterosauria), Initially considered gliders; later evidence Ctenochasma: Ate sea plankton and filtered out water shows active flight. with teeth (Jurassic/Cretaceous, Europe, pterosauria), Pteranodon Ate prey as whole (Upper Cretaceous, North Mesozoic. America, pterosauria). Hypotheses for flight origins: Avian Evolution: ▪ Arboreal: Gliding from trees. Birds evolved from theropods in the Late ▪ Cursorial: Flapping during ground running PLATE TECTONICS Lithospheric Plates (ocean that has fully formed and stabilized over time, Major Plates: Seven major plates (e.g., North Atlantic Ocean). American, Pacific); composed of oceanic Aborted Oceans: Rifting without seafloor lithosphere (oceanic crust + upper mantle) and/or spreading. continental lithosphere (continental crust + upper Convergent: mantle). Plates collide, forming subduction Pacific Plate: Entirely oceanic, covering the Pacific zones or mountain ranges. Ocean area. Types: Minor Plates: Fragmented from major plates; may Ocean-Ocean: Subduction creates evolve with or independently from parent plates. trenches and island arcs (e.g., Japan). Key Discoveries Ocean-Continent: Oceanic crust Alfred Wegener: Proposed "continental drift" in subducts beneath continental crust; 1915, noting geological and paleontological forms mountains (e.g., Andes). similarities across continents (e.g., South America & Continent-Continent: Collision forms Africa). mountains (e.g., Himalayas). Gondwana Supercontinent: Identified by Eduard Transform: Plates slide past each other; Suess using fossil evidence (e.g., Glossopteris flora, earthquakes common (e.g., San Andreas Fault). Mesosaurus, Lystrosaurus). Wilson Cycle Wegener’s hypothesis lacked a clear mechanism, Describes ocean formation, expansion, and closure. thus initially rejected. Stages: Continental rifting → Seafloor Oceanic Floor Features spreading → Ocean expansion → Abyssal Plains: Flat areas; depth 4-4.5 km. Convergence → Ocean closure. Mid-Oceanic Ridges: Submarine mountain chains; Current continents originated from volcanic and seismic activity common. Pangea's breakup during the Mesozoic. Oceanic Trenches: Deepest parts; sites of frequent North American Plate earthquakes. Bordered by Pacific, Eurasian, African, South Seamounts: Underwater mountains; volcanic American, Caribbean, and smaller plates (e.g., Juan origins; can form islands. de Fuca, Cocos). Island Arcs: Chains of volcanic islands parallel to Geological Evolution: First formed during the trenches. breakup of Rodinia (Proterozoic Era). Tectonic Regimes o Components: Cratonal PNA (stable Divergent: core), Deformed PNA (tectonically Plates move apart; features include rift zones (Earth's altered), and Terranes (displaced crust stretches and breaks, forming long cracks), volcanic fragments). activity (process where magma, gas, or ash escapes from Key Observations - Seafloor Age: the Earth's surface, forming volcanoes or other Younger near mid-oceanic ridges; older near features), and seafloor spreading (process where new continents. oceanic crust forms as magma rises at mid-ocean ridges Magnetic Stripes: Parallel to mid-oceanic ridges, and spreads outwards, pushing older crust away, confirming seafloor spreading. Mid-Atlantic Ridge). Earthquakes/Volcanism: Concentrated along plate Stages: Continental rift → Early oceanic boundaries. Basin (body of water that forms when crust separates and creates a depression, Red Sea) → Mature ocean LATIN NAMES – STRUCTURALLY ORGANIZED WITH DEFINITIONS AND PERIODS Early Life and Fossils Cryptozoon: Precambrian stromatolitic structure, one of the earliest forms of life evidence. Bangiomorpha: First known eukaryote with a filamentous thallus resembling modern red algae; ~1.2 billion years old. ST: Proterozoic-Quaternary Torridonophycus: Late Proterozoic algal microstructures escaping from a bag-like structure; resilient to harsh climates. ST: Upper Proterozoic- Quaternary  Melanocyrillium: Early testate amoeba-like eukaryote; ~0.8–0.9 billion years old, ST: Upper Proterozoic-Quaternary Early Vertebrates Haikouichthys: Earliest vertebrate; an agnathan from the Lower Cambrian with a primitive notochord, China. Sacabambaspis: Early Ordovician agnathan with a cephalic shield, marking early jawless vertebrates, South America. Dunkleosteus: Late Devonian large, armored placoderm predator; one of the largest fish of its time, Ohio and Europe, fish Macropomides: Late Cretaceous,, Lebanon, fish Reptilian Evolution Hylonomus: First true reptile (diapsid); from the Late Carboniferous (~80 cm in length), Canada. Mesosaurus: Early aquatic reptile; a key fossil in supporting continental drift theory. Edaphosaurus: Vegetarian pelycosaur with a thermoregulatory sail on its back. Dimetrodon: Predator pelycosaur with a dorsal sail, possibly used for thermoregulation (Early Permian, Texas) Keratocephalus: Early therapsid, mammal-like reptile; adapted for heat retention. (Late Devonian, Germany and Europe) *Dinosaurs* Early Dinosaurs Herrerasaurus: One of the oldest known dinosaurs from the Late Triassic, found in South America. Theropods Allosaurus: Large Jurassic predator; apex predator for 81 million years globally.( NA, EU, Asia, theropoda) Tyrannosaurus: Cretaceous apex predator; likely originated in Asia before appearing in North America, theropoda. Sauropodomorphs Plateosaurus: Prosauropod from the Upper Triassic, showing an early stage of sauropodomorph evolution (Europe) Ultrasaurus: A large sauropod from the Upper Jurassic (USA and North America). Ornithischians Stegosaurus: Upper Jurassic herbivore with distinctive plates and spiked tail; chewed foliage using beak and cheek muscles (North America and Europe). Ankylosaurus: Upper Cretaceous "fused lizard" with a shield of osteoderms and a robust, armored body (NA, EU, Asia) Triceratops: Large Cretaceous herbivore with three horns and a frill for display or defense (North America) Flying Reptiles Sordes: Upper Jurassic pterosaur with evidence of fur-like structures, suggesting thermoregulation (Kazakhstan). Pteranodon: Late Cretaceous flying reptile with a large crest and no teeth, suggesting specialized feeding. Evolution of Birds Rhamphorhynchus: Upper Jurassic pterosaur with a long tail and evidence of maneuverable flight. Archaeopteryx: Late Jurassic transitional species between non avian dinosaurs and birds; key understanding the origin of avian (related to birds) flight.