JGE378H5 Lecture Notes - Lecture 13: Silicate Minerals, Meteorite Fall, Meteoroid
Document Summary
Bolide: large meteor that explodes in the atmosphere. Fall : meteorite falls to the ground; descent observed. Find : meteorite is found on the ground without anyone witnessing the fall. Stones: silicate minerals, similar to terrestrial rocks primitive: chondrites: modi ed (di erentiated): achondrites. Stony-irons: mixtures of silicate minerals + nickel- iron metal. What is a comet: comet: a small body orbiting the sun that consists of ice, gases, and mineral fragments ( dirty snowballs ) m away. 1500 injuries, mainly from broken glass; >7000 buildings damaged. The asteroid belt: a concentration of rocky objects orbiting the sun between mars and jupiter. Impacts and their after-e ects: tunguska, russia, 1908, chicxulub, mexico, 65 my ago impact cratering processes, mass extinctions in earth history, the big five mass extinctions, monitoring neos. Coincides with mass extinction: 75% of plant and animal species including non-avian dinosaurs.
