320 likes | 409 Views
Today – 1/23. Critter in the news Reading background History of dinosaur discoveries. ScienceDaily.com. P-T extinction. Before: simple and complex marine ecosystems exist in equal numbers After: complex marine ecosystems outnumber simple ones 3 to 1
E N D
Today – 1/23 • Critter in the news • Reading background • History of dinosaur discoveries
P-T extinction • Before: simple and complex marine ecosystems exist in equal numbers • After: complex marine ecosystems outnumber simple ones 3 to 1 • Discovered because of the web and a new analytical approach
3-point XC opportunity • Tonight, 7:30 pm, Kuiper Space Sciences 308 • Surface of Titan, a moon of Saturn • Check in with me before • Sit with me or 1-page summary
Admistration • First short writing assignment comments • Pick up papers in G-S 205 • Posting grades
Last time: • River types – meandering vs. braided • Carbon isotopes • K-T impact • P-T scenario
3500 K 4800 K 5500 K
MORs and Magnetic Striping www2.nature.nps.gov/geology/usgsnps/animate
Magnetic striping of the seafloor • Convecting liquid outer core generates Earth’s magnetic field • Heat from the core and radioactive decay drives mantle convection and plate tectonics making new rocks at mid-ocean ridges • New rocks record polarity of Earth’s magnetic field!
Magnetostratigraphy • Drill a bunch of cores going up through layers • Analyze them to determine the pattern of magnetic polarity through time • Match them (like tree rings) to the appropriate part of the known pattern for Earth throughout time, read off the date
Insert pic of AC • Petrified tree? • AC shot from above! With inset of teeth
What fossils tell us about dinosaurs • How they looked - size, shape, skin • How they behaved - diet, locomotion, social life, as parents • Physiology - thermal regulation, growth patterns • History of life - speciation and extinction, relationships among groups • Environmental reconstruction, rock ages geochemistry, paleogeography, interaction between physical and biological worlds
← Griffin inspired by Protoceratops? ↓ web.ukonline.co.uk/conker/ www.dinoland.dk
www.oum.ox.ac.uk/geolcoll.htm 1677 – Robert Plot publishes first known description of a dinosaur bone. However, he mistakes it for the femur of a giant human!
www.lhl.lib.mo.us/events_exhib/exhibit/ex_paper_dino.shtml 1815 – William Buckland finds Megalosaurus jaw
1831 1830’s – Meet Meg, plus the happy water lizard home.uchicago.edu/~shburch/dinopaper.html 1833
1836 – Gideon Mantell discovers the teeth of Iguanodon www.lhl.lib.mo.us/events_exhib/exhibit/ex_paper_dino.shtml
Iguanodon – notice the sprawling legs 1842 – Richard Owen defines the “Dinosauria”, which translates as “terrible lizards”
Benjamin Waterhouse Hawkins’ 1853 dinosaur reconstructions being prepared for display in the Crystal Palace, Hyde Park, London http://www.ric.edu/rpotter/cryspal.html
Importance of Hawkins • First attempt at full-scale reconstruction • Super-popularized dinosaurs • Cemented wrong views!
Nicholas Steno – “Father of stratigraphy” • Second half of the 1600’s • Said fossils were remains of organisms • Principle of Original Horizontality – rock layers laid down horizontally, any deviation from this due to later disturbance • Law of Superposition – lower layers are older, upper layers are more recent
Early 1800’s geology comes alive! • 1795 – Theory of the Earth by James Hutton: how rock layers form, hot inside, old, uniformitarianism, natural selection • 1815 – Geologic map by William Smith: biostratigraphy • 1830-1833 – Principles of Geology by Charles Lyell: stratigraphy • 1859: On the Origin of Species by Darwin