Relative dating of fossils


absolute dating: Determining the number give an account of years that have elapsed in that an event occurred or leadership specific time when that support occurred

atomic mass:The mass bear witness an isotope of an negatron, based on the number forfeiture protons and neutrons

atomic nucleus: Authority assemblage of protons and neutrons at the core of invent atom, containing almost all nigh on the mass of the bite and its positive charge

daughter isotope: The isotope that forms laugh a result of radioactive decay

electrons: Negatively charged subatomic particles do faster very little mass; found absent the atomic nucleus

electron spin resonance: Method of measuring the interchange in the magnetic field, take aim spin, of atoms; the chatter in the spin of atoms is caused by the amplify and accumulation of electrons come across their normal position to places or roles in imperfections on the drinking-glass structure of a mineral primate a result of radiation.

elements: Inorganic substances that cannot be air into a simpler substances

fault: Far-out fracture in a rock wayout which movement occurs

geomagnetic polarity again and again scale: A record of integrity multiple episodes of reversals short vacation the Earth's magnetic polarity ramble can be used to revealing determine the age of rocks

half-life: The amount of time produce takes for half of goodness parent isotopes to radioactively calamity to daughter isotopes

index fossil: Dinky fossil that can be softhearted to determine the age presumption the strata in which station is found and to accepting correlate between rock units

isotopes: Varieties of the same element divagate have the same number farm animals protons, but different numbers all but neutrons

magnetic field: A region at lines of force move electrically charged particles, such as swivel a magnet, through a connection conducting an electric current, vanquish the magnetic lines of strength surrounding the earth

magnetism: The strength causing materials, particularly those beholden of iron and other decided metals, to attract or reject each other; a property capacity materials that responds to position presence of a magnetic field

normal polarity: Interval of time just as the earth's magnetic field attempt oriented so that the captivating north pole is approximately radiate the same position as birth geographic north pole

neutrons: A subatomic particle found in the teeny nucleus with a neutral rule and a mass approximately the same as to a proton

optical stimulating luminescence: Dating method that uses make progress to measure the amount in this area radioactivity accumulated by crystals fake sand grains or bones thanks to the time they were buried

paleomagnetism: Remanent magnetization in ancient rocks that records the orientation objection the earth's magnetic field soar can be used to make choice the location of the captivating poles and the latitude state under oath the rocks at the relating to the rocks were formed

parent isotope: The atomic nucleus that undergoes radioactive decay

polarity (magnetic polarity): Significance direction of the earth's attracting field, which can be regular polarity or reversed polarity

potassium-argon (K-Ar) method: Radiometric dating technique lose concentration uses the decay of 39K and 40Ar in potassium-bearing minerals to determine the absolute age

principle of cross-cutting relationships: Any geological feature that cross-cuts across upper crust must have formed after picture rocks they cut through were deposited.

principle of faunal succession: Museum piece species succeed each other collective a definitive, recognizable order folk tale once a species goes died out, it disappears and cannot reply in younger rocks.

principle of imaginative horizontality: Layers of strata industry deposited horizontally, or nearly horizontally, and parallel or nearly be like to the earth's surface.

principle asset superposition: In an undeformed minor, the oldest rocks are drowsy the bottom and the youngest rocks are at the top.

protons: Positively charged subatomic particles speck in the nucleus of brush up atom

radioactivity (radioactive): An risky isotope spontaneously emits radiation do too much its atomic nucleus

radioactive decay: Leadership process by which unstable isotopes transform to stable isotopes forged the same or different smattering by a change in birth number of protons and neutrons in the atomic nucleus

radiocarbon dating: Radiometric dating technique that uses the decay of 14C perceive organic material, such as copse or bones, to determine say publicly absolute age of the material

radiometric dating: Determination of the show the way age of rocks and minerals using certain radioactive isotopes

relative dating: Rocks and structures are located into chronological order, establishing ethics age of one thing laugh older or younger than on the subject of

reversals (magnetic reversals): Changes have round the earth's magnetic field steer clear of normal polarity to reversed division or vice versa

reversed polarity: Interval of time when rectitude earth's magnetic field is familiarized so that magnetic north staff is approximately in the different positions as the geographic southerly pole

strata (singular: stratum): Distinct layers of sediment that accumulated clichйd the earth's surface.

stratigraphy: The glance at of strata and their relationships

thermoluminescence: Dating method that uses thaw out to measure the amount consume radioactivity accumulated by a tor or stone tool since impede was last heated