unit 1 partv2

Law of Original Horizontality

Layers of sedimentary rock are originally deposited flat.

Laws of Cross-Cutting Relationship

Rock layers must be older than the intrusion that disturbs them.

Law of Lateral Continuity

At the time of deposition, sedimentary layers are continuous for long distances.

Direct Dating

Getting a date for the object/event you want to know the date of.

Indirect Dating

getting a date from an object/event that the one you want to know the date of

Target Dating

The action/event you want to date.

Seriation

Dating using typological sequences based on styles that change over time.

Absolute Dates

Provides a calendar date and determines an age range.

Relative Dating

Gives an approximate date in relation to another item.

Stylistic Seriation

Dating relies on placing artifact assemblages in serial order based on stylistic changes in their features.

Frequency Seriation

Places artifact assemblages in serial order by examining the relative frequency of different types of artifacts.

Terminus Post Quem

Time after which.

Varves

Paired layers of outwash gravel and sediment deposited in glacial lakes by retreating ice sheets.

Dendrochronology

Dating based off tree rings.

Radioactive Decay

The loss of radioactivity of elements in archaeological deposits.

Half-Life

The number of years it takes for half of that radioactive element to decay.

Daughter Element

The stable decay product of a radioactive element.

Radiocarbon Dating

Measures the decay of Carbon-14 (C-14).

Isotopes

Elements that exist in both stable and unstable (radioactive) forms.

Atomic Weight

The total number of protons and neutrons in an atom.

Marine Reservoir Effect

Affects radiocarbon dating of shells.

Y Chromosome

Compares DNA from male sex chromosomes of individuals and populations to establish migration patterns.

mtDNA (mitochondrial DNA)

Compares DNA found in mitochondria of cells to establish migration patterns.

Archaeomagnetic Dating

For clay; records the direction of magnetic north at the time clay was heated due to changes in Earth's magnetic fields.

Electron Spin Resonance (ESR)

For materials that decay with heat; effective for confirming dates obtained using other methods.

Thermoluminescence (TL)

For ceramics and glass; measures light energy released when heated to determine last heating.

Fission Track

For glassy volcanic materials; determines age based on natural splitting of Uranium-238.

Uranium Series Dating

For travertine; provides accurate dates for materials between 50,000 and 500,000 years old.

Potassium-Argon (K/Ar) Dating

For igneous material; measures the ratio of Potassium-40 to Argon-14 to determine age.