#1
Which radioactive isotope is commonly used for radiometric dating of rocks?
Uranium-238
ExplanationUranium-238 undergoes radioactive decay to lead-206, allowing the determination of rock ages.
#2
Which dating method is primarily used to determine the age of ancient pottery and ceramic artifacts?
Thermoluminescence dating
ExplanationThermoluminescence dating measures the accumulated radiation in ceramics, providing an estimate of their age.
#3
Which geological dating method relies on the observation of the accumulation of annual layers in ice cores and sedimentary deposits?
Varve counting
ExplanationVarve counting examines annual sediment layers or ice core bands to estimate the age of geological deposits.
#4
Which radioactive isotope is commonly used for dating igneous and metamorphic rocks?
Potassium-40
ExplanationPotassium-40 undergoes radioactive decay to argon-40, enabling the dating of igneous and metamorphic rocks.
#5
What is the principle underlying the use of index fossils in dating geological strata?
Certain fossils are characteristic of specific time periods.
ExplanationIndex fossils help correlate and date rock layers based on the known time range of specific fossil species.
#6
Which geological dating method relies on the study of the orientation of magnetic minerals in rocks?
Paleomagnetism
ExplanationPaleomagnetism analyzes the alignment of magnetic minerals to determine past positions of continents and rock ages.
#7
What is the name of the theory proposing that Earth's continents were once joined together in a single supercontinent and have since drifted apart?
Pangaea hypothesis
ExplanationThe Pangaea hypothesis suggests continents were once connected and later drifted, supporting plate tectonics.
#8
What event marks the beginning of the Quaternary period?
The last glacial maximum
ExplanationThe last glacial maximum, a period of extensive ice sheets, marks the start of the Quaternary epoch.
#9
What is the term for the process by which an unstable atomic nucleus loses energy by emitting radiation?
Decay
ExplanationDecay is the process where an unstable nucleus releases energy in the form of radiation.
#10
What event marks the boundary between the Cretaceous and Paleogene periods?
The Chicxulub impact event
ExplanationThe Chicxulub impact, possibly a meteorite, caused mass extinctions and defines the boundary between these geologic periods.
#11
In carbon-14 dating, what is the half-life of carbon-14?
5,730 years
ExplanationCarbon-14's half-life of 5,730 years is used to estimate the age of organic materials.
#12
In which era did the first dinosaurs appear?
Paleozoic Era
ExplanationDinosaurs first appeared in the Late Triassic period within the Paleozoic Era.
#13
What is the age of the Earth estimated to be according to radiometric dating of the oldest rocks?
4.5 billion years
ExplanationRadiometric dating of rocks, like zircons, yields an estimated age of approximately 4.5 billion years for the Earth.
#14
What geological epoch immediately precedes the Holocene epoch?
Pleistocene
ExplanationThe Pleistocene epoch precedes the Holocene epoch, characterized by ice ages and megafauna.