EAS 201 Exam Questions With Verified Answers

EAS 201 Exam Questions With Verified Answers Principle of superposition - ANSWER oldest layer = bottom, newest layer = top Principle of original horizontality - ANSWER sediment originally deposited in layers that were nearly horizontal and parallel to the surface on which they were accumulating, tilted rocks = crustal disturbance Principle of original lateral continuity - ANSWER all strata extend in all directions until they terminate by THINNING at the margins of the basin, end abruptly against some barrier to deposition or turn into different sediment Uniformitarianism (Actualism) - ANSWER James Hutton's method of interpreting rock exposures by observing present-day processes --> "the present is the key to the past" Unconformity - ANSWER hiatus in the rock record that formed because layers were not deposited for a time or else layers were removed by erosion Unconformity (nonconformity) - ANSWER a surface of erosion that separates younger sedimentary stata above older below Unconformity (disconformity) - ANSWER a surface or erosion in which the orientation of older strata, below, are parallel to younger strata above Unconformity (Angular) - ANSWER a surface of erosion between two groups of sedimentary rocks in which the orientation of the older strata, below, are at an angle to the younger strata above Principle of cross-cutting relationships (inclusions) - ANSWER fragments within larger rock masses are older than the rock masses in which they are enclosed despite colour, lighter rock can be older than darker Concept of inclusion - ANSWER the stuff within the 'matrix' must be older Formation (principle of biologic succession) - ANSWER William Smith - certain rock units that could be identified by the particular assemblages of fossils they contained Biostratigraphy - ANSWER William Smith - the life forms of each age in history were unique for particular periods, allows geologists to correlate contemporaneous formations around the world Half life - ANSWER The time required for one half of the atoms of a radioisotope to emit radiation an decay products Daughter element - ANSWER The chemical product in a radioactive decay equation produced from decayed parent elements. Mineral - ANSWER a naturally occurring, inorganic, solid element or compound with a definite chemical composition and a regular internal crystal structure Mineral formation - ANSWER -crystallization from magma -crystal growth in the solid state -precipitation from solution Cation - ANSWER positive charged ion Anion - ANSWER negative charged ion Ionic compound - ANSWER cations and anions, NaCl Covalent - ANSWER share of electrons rather than the donation/accepting of them, diamonds polymorph - ANSWER minerals with the same chemical composition, but different structure (diamond vs graphite) silicates - ANSWER most abundant minerals in crust (Feldspars = very abundant, quartz = abundant classified by linking of the silica tetrahedral, their composition ferromagnesian minerals - ANSWER group of minerals in which Fe and Mg serve as the cations that bind the silica tetrahedra together, generally dark minerals in m