Asthenosphere - The layer of the Earth that lies below the lithosphere. It is a layer of solid rock where the extreme pressure and heat cause the rocks to flow like a liquid, Fossils - the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers, Index fossils - any animal or plant preserved in the rock record of the Earth that is characteristic of a particular span of geologic time or environment; must be distinctive or easily recognizable, abundant, and have a wide geographic distribution and a short range through time., Invertebrates - an animal without a backbone, Geologic Time Scale - divides up the history of the earth based on life-forms that have existed during specific times since the creation of the planet., Cyanobacteria - one of the earliest life forms from Precambrian time, Law of Superposition - one of the principles of geology scientists use to determine the relative ages of rock layers; oldest rock strata will be on the bottom and the youngest at the top., Mantle - lies between Earth's dense, superheated core and its thin outer layer, the crust., Trilobite - example of an index fossil used to find the relative ages of rock layers, Extinct - the complete disappearance of a species from Earth, Petrified - the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals., Vertebrates - an animal that has a backbone and a skeleton., Inner Core - the dense center of Earth; is composed of iron and nickel heated up to a temperature of around 9,800 degrees F., Period - A division of geologic time that is longer than an epoch and shorter than an era., Epoch - a division of time that is a subdivision of a period; smallest unit of geologic time, Paleontologist - scientist who studies the history of life on Earth through the fossil record., Lithosphere - the rigid outer part of Earth, consisting of the crust and upper mantle., Outer Core - a liquid layer, composed of mostly iron and that lies above Earth's solid inner core and below its mantle., Eon - the largest division of geologic time, comprising two or more eras., Eras - a very long span of geologic time; the second longest portions of geological time, Crust - the thinnest layer of the Earth; can be either continental and oceanic ,

Geologic Time & Earth's Layers Quiz

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