potassium-argon
Volcanic rock chronometer
Potassium-argon refers to a radiometric dating method used to determine the age of rocks and minerals.
It measures the ratio of radioactive potassium-40 to its decay product argon-40, allowing scientists to date geological samples millions or billions of years old: Potassium-argon dating established the volcanic layer at 1.8 million years.
Study of geological ages
- radiometricMeasuring by radiation
- isotopeElemental variant by mass
- decayGradual organic breakdown
- half-lifePeriod for fifty-percent reduction
chronometry · igneous · geological time · radioactive decay · mass spectrometry
Solidified magma formations
- basaltFine-grained volcanic stone
- tuffSolidified volcanic ash
- obsidianGlassy igneous rock
- lava flowsMoving volcanic rock
feldspar · mica · hornblende · biotite · muscovite · volcanic ash · tephra · magmatic
Feminine name meaning light
- AustralopithecusExtinct hominin genus
- human evolutionOur species' biological origin
- LeakeyRenowned fossil-hunting clan
- East African RiftContinental divergence zone
geochronology
Study of geological ages
- radiometricMeasuring by radiation
- isotopeElemental variant by mass
- decayGradual organic breakdown
half-life · chronometry · igneous · geological time · radioactive decay · mass spectrometry
volcanic rocks
Solidified magma formations
lava flows · feldspar · mica · hornblende · biotite · muscovite · volcanic ash · tephra · magmatic · crystallization
Lucy
Feminine name meaning light
- AustralopithecusExtinct hominin genus
- human evolutionOur species' biological origin
- LeakeyRenowned fossil-hunting clan
East African Rift · Pleistocene · Pliocene · sedimentary layers
potassium-argonrelative dating
Sequencing events by position
stratigraphy · dendrochronology · seriation · thermoluminescence