Final Cheat Sheet - ERTH 209 PDF

Stratigraphy and Geological Time Steno’s Principles of Stratigraphy → 1. Principle of Layer Superposition: In undisturbed strata, the oldest layer lies at the bottom and the youngest at the top. 2. Principle of Layer Successive Formation: At the time of a layer’s formation, no layers above it existe...

Stratigraphy and Geological Time Steno’s Principles of Stratigraphy → 1. Principle of Layer Superposition: In undisturbed strata, the oldest layer lies at the bottom and the youngest at the top. 2. Principle of Layer Successive Formation: At the time of a layer’s formation, no layers above it existed. 3. Principle of Original Layer Horizontality: Sedimentary layers are initially horizontal; inclined layers suggest crustal disturbance. 4.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 - Normal Succession: Younger layers lie atop older ones. ripple marks help determine original depositional - Inverted Succession: Tectonic forces may disrupt this order. environments. Relative Ages by Superposition - Relative Ages: Layers in different sections can be correlated to establish their relative chronological order. Contributions to Geology: Nicolaus Steno: Principles of stratigraphy. Sir William Smith: Fossil-based correlation and John Strachey: Layer terminations. geological mapping. Georges Louis Leclerc (de Buffon): Age of the Sir Charles Lyell: Principles for dating igneous and Earth. metamorphic rocks. Tomaso d’Arduinio: Use of sedimentary structures. 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: Fossils provide chronological markers for Index Fossils: Layers with identical fossils can be stratigraphic correlation. matched across regions. Sir Charles Lyell’s Principles – 1. Principle of Inclusions: The rock containing inclusions is younger than the included fragments. 2. Principle of Cross-Cutting Relations: Features like dikes are younger than the rocks they cut through. 3. Relative Ages of Lava Flows: Lava flows bake the layers below them; younger sills bake both the layers above and below. Radioactive Decay: Radioactive Decay: Unstable isotopes Half-Life: Time it takes for half the parent isotope to spontaneously transform into stable daughter decay into the daughter isotope. isotopes. Half-Life Resolution: Provides a precise method for Decay Series: Example: Uranium-238 decays to dating rocks and fossils. Lead-206 through a series of alpha and beta decay steps. Geological Time Summary: Relative Geological Time Scale: Stratigraphy 2. Archean: Oldest rocks and earliest orders layers and fossils chronologically. fossils. 3. Proterozoic: Fossils include microscopic Eons of Earth’s History: and macroscopic forms. 1. Hadean: Formation of Earth; no rock 4. Phanerozoic: Visible fossils; divided into record. Paleozoic, Mesozoic, and Cenozoic eras. Phanerozoic Eon – 1. Paleozoic Era: Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian (or Carboniferous), and Permian periods. 2. Mesozoic Era: Triassic, Jurassic, and Cretaceous periods. Marked by significant extinction events (e.g., Permian/Triassic crisis and Cretaceous/Paleogene impact). 3. Cenozoic Era: Paleogene, Neogene, and Quaternary periods; fossils closely resemble modern life.  Fossil Record What are Fossils? – 1. Fossils: Vestiges of ancient life forms. 2. Origin: Latin term meaning "to be dug out from the Earth," coined during the Renaissance. 3. Historical meaning: Included both minerals and vestiges of life. Fossil Classifications 1. By Age:1.1 Fossils: Older than 11,700 years. 1.2 Subfossils: Younger than 11,700 years (not all considered fossils). 2. By Nature: 2.1 Body Fossils: Preserve parts of the organism (hard/soft body parts). 2.2 Trace Fossils: Preserve organism activities (e.g., movement traces). 2.3 Chemical Fossils: Preserve only small organic components. Examples of Fossils: Body Fossils: o Cruziana (movement trace), Skolithos o Stony coral (cnidarian), Cephalopod (vertical galleries), Acanthotheuthis shells, Trilobite, Belemnites. (movement trace of belemnite). Trace Fossils: Mixed Fossils: o Mesolimulus (horseshoe crab) with movement traces. 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: 1. Casual Fossilization: o Carbonization: o Petrification/Lithification/Permineraliz ▪ Loss of elements except ation: carbon during decay. ▪ Transformation into stone; ▪ Examples: Pecopteris (fern), pores filled with minerals. Lepidodendron (lycopsid). ▪ Example: Psaronius (fern tree), o Impressions: Dinosaur bone, Cladoxylon ▪ Formed by organism weight in (woody plant). sediment. o Recrystallization: ▪ Example: Pecopteris leaf. ▪ Conversion of one mineral to 2. High-Quality Fossilization: another (e.g., aragonite to o Amber: Fossilized resin (e.g., calcite). Plesiomyrex). ▪ Examples: Globotruncanella, o Tar Pits: Hydrocarbon swamps (e.g., Uintacrinus (sea-lily), Micraster Cybister). (sea-urchin). o Congealment, Dehydration: o 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), 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 CHON molecules could accumulate in such long inorganic evolution process. an atmosphere. o Earth's original atmosphere was reducing, o "Primordial soup" was not alive. with little free molecular oxygen. Isua Supercrustal Group: Location: Greenland. Rare oxides and carbonates; lack of layering. Contains some of Earth's oldest sedimentary rocks Graphite levels suggest organic origin. (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 Example: Cellulose is a carbohydrate polymer formed CHON molecules. by repeating glucose units (C6H12O6). Note: Molecules do not fossilize. Isolated Cells: Early Archean of Western Australia (Pilbara ▪ Folded filament structures made Craton): Apex Chert (volcano-sedimentary formation). of carbon, similar to modern iron o Evidence of early bacteria and bacteria. cyanobacteria debris. Strelley Pool Chert cyanobacteria: Chain-like o Apex Chert cyanobacteria: structures similar to modern purple bacteria. Stromatolites: Fossilized microbial structures. 2. Undermat: Non-oxygen-producing photosynthetic bacteria (~1 mm). Components (from surface to center): 3. Oxygen-depleted zone: Anaerobic bacteria 1. Growth surface: Photosynthetic (1–2 cm). cyanobacteria and aerobic bacteria (~1 4. Stromatolite mass. mm). Banded Iron Formation (BIF): Alternating thin layers of: o Cherts and jaspers with lower iron content. o Iron oxides (e.g., hematite [Fe2O3] and o Colors: Reddish (iron oxides) and green/grey magnetite [Fe3O4]). (cherts/jaspers). Oldest Eukaryotes: Biomarkers (chemical fossils): 2.1–1.8 billion years o Assigned to red algae (rhodophytes) and old. green algae (chlorophytes). Bitter Springs Formation (Australia): o Some fossils show cellular division and preserved nuclei. o True isolated eukaryote cells (1 billion years old). Eukaryote Examples: 1. Bangiomorpha: o Algal o Chlorophyte. o Filamentous microstructures 3. Melanocyrillium: thallus (similar to escaping from o Resembles modern modern red bag-like testate amoebas algae). acritarchs. (earliest animals). o Primitive holdfast o Survival o Organic with sometimes for seafloor adaptations for agglutinated attachment. dry/cold climates. particles. o Age: ~1.2 billion o Age: ~0.9 billion o Age: ~0.8–0.9 billion years years (Upper years (Upper (Proterozoic– Proterozoic– Proterozoic– Quaternary). Quaternary). Quaternary). 2. Torridonophycus:  Dinosaurs Vertebrate Evolution - Vertebrates evolved from chordates in the Lower Cambrian. Early forms: Agnathans (jawless fish) and jawed fishes. Key Examples: 1.Haikouichthys: Earliest vertebrate. 2. 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. 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: 1. Shelled eggs (fewer but protected). 2. Fully terrestrial lifestyle. Early reptiles: Diapsids (e.g., Hylonomus). Synapsid Reptiles: Dominated Late Paleozoic to Early Triassic. Therapsids: Mammal-like reptiles o Developed thermoregulation. (e.g., Keratocephalus). o Examples: Dimetrodon (predator). Edaphosaurus (herbivore). Diapsid Takeover and Dinosaur Origins: Dinosaurs evolved from diapsid reptiles during the Upper Triassic. Earliest dinosaurs: Possibly originated in South America. Early dinosauromorphs: Small, bipedal/quadrupedal insectivores or carnivores. o Herrerasaurus: Example of early dinosaurs. Dinosaur Classification - Based on pelvic structure: 1.Saurischians (lizard-hipped): Pubis points down/forward. 2. Ornithischians (bird- hipped): Pubis points backward. Theropods - Bipedal predators with knife-like teeth, grasping hands, hollow bones. Examples: 1. Allosaurs: Dominant predators of the Jurassic/Cretaceous. 2.Tyrannosaurs: Apex predators (e.g., Tyrannosaurus Rex). Sauropodomorpha Evolution of Flight Early large dinosaurs; evolved into quadrupedal giants: Pterosauria (winged reptiles): o Plateosaurus (Prosauropod, Upper Triassic). o Lived from Upper Triassic to Cretaceous. o Ultrasaurus (Sauropod, Upper Jurassic). o Initially considered gliders; later evidence Ornithischians shows active flight. Herbivores with specialized adaptations: o Examples: o Stegosaurs: Beak-like structure for cropping ▪ Rhamphorhynchus (Upper Jurassic). plants. ▪ Pteranodon (Upper Cretaceous). o Ankylosaurs: Armored "fused lizards" with Avian Evolution: osteoderms. o Birds evolved from theropods in the Late o Ceratopsians: Horned dinosaurs Mesozoic. (e.g., Triceratops). o Hypotheses for flight origins: ▪ Arboreal: Gliding from trees. ▪ Cursorial: Flapping during ground running  Plate Tectonics 1. Lithospheric Plates o Aborted Oceans: Rifting without seafloor Major Plates: Seven major plates (e.g., North spreading. American, Pacific); composed of oceanic Convergent: Plates collide, forming subduction lithosphere (oceanic crust + upper mantle) and/or zones or mountain ranges. Types: continental lithosphere (continental crust + upper o Ocean-Ocean: Subduction creates mantle). trenches and island arcs (e.g., Japan). Pacific Plate: Entirely oceanic, covering the Pacific o Ocean-Continent: Oceanic crust Ocean area. subducts beneath continental crust; Minor Plates: Fragmented from major plates; may forms mountains (e.g., Andes). evolve with or independently from parent plates. o Continent-Continent: Collision forms 2. Key Discoveries mountains (e.g., Himalayas). Alfred Wegener: Proposed "continental drift" in Transform: Plates slide past each other; 1915, noting geological and paleontological earthquakes common (e.g., San Andreas Fault). similarities across continents (e.g., South America & 5. Wilson Cycle Africa). Describes ocean formation, expansion, and closure. Gondwana Supercontinent: Identified by Eduard o Stages: Continental rifting → Seafloor Suess using fossil evidence spreading → Ocean expansion → (e.g., Glossopteris flora, Mesosaurus, Lystrosaurus). Convergence → Ocean closure. Wegener’s hypothesis lacked a clear mechanism, o Current continents originated from thus initially rejected. Pangea's breakup during the Mesozoic. 3. Oceanic Floor Features 6. North American Plate Abyssal Plains: Flat areas; depth 4-4.5 km. Bordered by Pacific, Eurasian, African, South American, Caribbean, and smaller plates (e.g., Juan Mid-Oceanic Ridges: Submarine mountain chains; de Fuca, Cocos). volcanic and seismic activity common. Geological Evolution: First formed during the Oceanic Trenches: Deepest parts; sites of frequent breakup of Rodinia (Proterozoic Era). earthquakes. o Components: Cratonal PNA (stable Seamounts: Underwater mountains; volcanic core), Deformed PNA (tectonically origins; can form islands. altered), and Terranes (displaced Island Arcs: Chains of volcanic islands parallel to fragments). trenches. 7. Key Observations - Seafloor Age: Younger near mid- 4. Tectonic Regimes oceanic ridges; older near continents. Magnetic Stripes: Divergent: Plates move apart; features include rift Parallel to mid-oceanic ridges, confirming seafloor spreading. zones, volcanic activity, and seafloor spreading (e.g., Earthquakes/Volcanism: Concentrated along plate Mid-Atlantic Ridge). boundaries. o Stages: Continental rift → Early oceanic basin (e.g., Red Sea) → Mature ocean (e.g., Atlantic Ocean). LATIN NAMES – Structurally Organized with Definitions & 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. Torridonophycus: Late Proterozoic algal microstructures escaping from a bag-like structure; resilient to harsh climates. Melanocyrillium: Early testate amoeba-like eukaryote; ~0.8–0.9 billion years old. Early Vertebrates Haikouichthys: Earliest vertebrate; an agnathan from the Lower Cambrian with a primitive notochord. Sacabambaspis: Early Ordovician agnathan with a cephalic shield, marking early jawless vertebrates. Dunkleosteus: Late Devonian large, armored placoderm predator; one of the largest fish of its time. Reptilian Evolution Hylonomus: First true reptile (diapsid); from the Late Carboniferous (~80 cm in length).  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. Keratocephalus: Early therapsid, mammal-like reptile; adapted for heat retention. *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. Tyrannosaurus: Cretaceous apex predator; likely originated in Asia before appearing in North America. Sauropodomorphs Plateosaurus: Prosauropod from the Upper Triassic, showing an early stage of sauropodomorph evolution. Ultrasaurus: A large sauropod from the Upper Jurassic. Ornithischians Stegosaurus: Upper Jurassic herbivore with distinctive plates and spiked tail; chewed foliage using beak and cheek muscles. Ankylosaurus: Upper Cretaceous "fused lizard" with a shield of osteoderms and a robust, armored body. Triceratops: Large Cretaceous herbivore with three horns and a frill for display or defense. Flying Reptiles Sordes: Upper Jurassic pterosaur with evidence of fur-like structures, suggesting thermoregulation. 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 in understanding the origin of avian flight.