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Details Title: Geological Time Description: Vocab Total Flash Cards: 33 Created: 02/09/2006 18:52:16	To study from this set of flash cards, or to create your own your own study flash cards, register HERE. If you are already a registered user, CLICK HERE.
Cards Term Absolute Dating Definition Using various radioactive decay dating techniques to assign ages in years before the present to rocks Term Angular uncomformity Definition An uncomformity below which older rocks dip at a different angle (usually steeper) than overlying strata. Term Biostratigraphic unit Definition An association of sedimentary rocks defined its fossil content. Term Biostratigraphic unit Definition An association of sedimentary rocks defined its fossil content. Term Carbon 14 dating technique Definition Absolute dating technique relying on the ratio of C14 to C12 in an organic substance, useful back to about 70,000 years ago. Term Correlation Definition Demonstration of the physical continuity of rock units or biostratigraphic units, or demonstration of time equivalence as in time-stratigraphic correlation. Term Disconformity Definition A boundary across which seismic wave velocity or direction of travel changes abruptly, such as the mantle-core boudary. Term Fission track dating Definition The absolute dating proccess in which small linear tracks (fission tracks) resulting from alpha decay are counted in mineral crystals. Term Guide FossIL Definition An easily identifiable fossil with an extensive geographic distribution and short geologic range useful for determining the relative ages of rocks in different areas. Term Half-Life Definition The time neccessary for half of the original number of radioactive atoms of an element to decay to a stable daughter product; for example, the half-life for potassium 40 is 1.3 billion yrs. Term LIthOStraTIGraphic Unit Definition A body of rock, such as a formation, defined solely by its physical attributes. Term NONconformity Definition An unfconformity in which stratified sedimentary rocks overlie an erosion surface cut into igneous or metamorphic rocks. Term Principle of cross-cutting relationships Definition A principle holding that an igneous intrusion or fault must be younger than the rocks it intrudes or cuts across. Term Principle of fossil succession Definition A principle holding that fossils and especially groups or assemblages of fossils, succeed one another through time in a regular and predictable order. Term Principle ofinclusions Definition A principle holding that inclusions or fragmentsin a rock unit are older than the rock unit itself; for example,granite inclusions in sandstone are older than the standstone Term principle of lateral continuity Definition A principle holding that rock layers extend outward in all directions until they terminate Term kepler Definition Lithosphere Term caparnicus Definition The planets orbit the sun. The Geo-centric theory vs. Hylio centric theory We are the center of the earth, everything went around us. Term Galelio Definition Planets revolve around the earth 1st and 2nd law of motion - body in motion stays in motion, body in rest stays at rest; strength of materials Term Aristotle Definition The universe never has a beginning nor end; scienctific method; water cycle Term Steno Definition Law of; Superposition, original horizontality, lateral continuity Term Hutton Definition Cross-cutting Relationships, uniformatarianism Term George Louis de Buffon Definition Determined earth's age by meltingan iron ball-75,000 yrs Term Abraham Gottlieb Werner Definition All rocks owe their origins to the oceans; Neptunism Term Principle of original horizontality Definition according to this principle, sediments are deposited in horizontal or nearly horizontal layers. Term Principle of Superposition Definition a principle holding that in a vertical sequence of undeformed sedimentary rocks, the relative ages of the rocks can be determinded by their position in sequence-oldest at the bottom followed by successively younger layers. Term Principle of uniformitarianism Definition A principle holding that we can interpret past events by understanding present day processes, based on the idea that natural processes have always operated in the same way. Term Radio active decay Definition The spontaneous change of an atom to an atom of a different element by emission of a particle from its nucleus (alpha and beta decay) or by election capture Term Relative dating Definition The process of determining the age of an event; involves placing geologic events in their correct chronological order but does not involve consideration of when the events occurred in number of years ago. Term Time-stratigraphic unit Definition A body of strata that was deposited during a specific interval of geologic time; for example, the Devonian system was deposited during the Devonian period Term Time Unit Definition Any of the units such as eon, era, period, epoch, and age used to refer to specific intervals of geologic time. Term Tree ring dating Definition The process of determining the age of a tree or wood in a structure by counting the number of annual growth rings. Term Uncomformity Definition A break in the geologic record represented by an erosional surface seperating younger strata from older rocks.