BJU Space/Earth 13
BJU - Space and Earth Science - Chapter 13
|An instrument that combines a mass spectrometer and an accelerator and can be used to measure the very small amounts of elements and their different isotopes in a sample ||Accelerated Mass Spectrometer
|A sample tested by the radiocarbon dating method that gives a sample age different from an age that has been determined by other means.
|That portion of the upper mantle extending from the rigid lithosphere down to about 300 km or deeper beneath the continents, which is believed to be plastic enough that the rock can flow. ||Asthenosphere|
|A graph that is used to correct the age of a sample of organic material obtained by radiocarbon decay to a calendar date. This is necessary because carbon-14 concentration in the earth's atmosphere has varied throughout its history.
|A radioactive form of carbon used in the radioactive dating method determining the age of organic matter.
|The central region of the interior of a celestial object. In the earth, it is the extremely dense metallic center surrounded by the rocklike mantle.
|The relatively solid outermost layer of the earth.
|A nuclear change in which the nucleus of an atom spontaneously emits a subatomic particle or an energetic electromagnetic ray.
|A concept underlying nearly all naturalistic historic science that refers to the unobservable distant past in terms of millions or billions of years ago.
|The determination of a radiocarbon calibration curve by using a series of overlapping tree ring records from a population of ancient, dead tree trunks.
|In general, a sharp change in a measured quantity as one crosses a boundary between two materials. In seismology, it is the boundary between two layers of the earth below the crust, where earthquake waves abruptly change speed.
|The study of the structures, materials, and processes of the solid part of the earth.
|That branch of geology that deals with the origin and history of the earth's structures, materials, and processes.
|A method of determining the rate of radioactive decay in a sample by mixing it with a liquefied chemical that glows momentarily each time a carbon-14 atom decays. A special instrument that counts and records the number of flashes per unit of time.
||Liquid Scintillation Counting|
|The rigid, rocky outer layer of the earth consisting of the crust and the outer mantle that act together as a unit. It averages 77 km thick under the oceans to nearly 300 km thick under the continents. ||Lithosphere
|The portion of the earth's interior between the crust and the core. ||Mantle|
|The boundary between the earth's crust and mantle. It varies from about 7 km under oceans to about 50 km under continental mountain chains.
|In mineralogy, describes materials that are obtained from living or once-living organisms.
|A radioactive dating method still in use by naturalistic geologist that is based on the amount of argon-40 in a sample compared to its content of potassium-40, from which it is assumed to have decayed. (method discredited by creationary geologists.)
|The rate at which nuclear particles and rays are emitted by a radioactive substance.
|Earthy matter suspended in or deposited by water, wind, or ice.
|A scientist who studies earthquakes. ||Seismologist|
|In general, a flat, horizontal, well-defined layer. Typically a layer of sedimentary rock, usually horizontal but often tilted to various angles or folded by movements within the earth's crust. ||strata|
|A method of radioactive dating based on the amount of lead isotopes in the sample compared to its content of uranium isotopes, from which the lead is assumed to have decayed.