Module 3

Question 1

Relative dating

Answer 1

The ability to determine that X is older than Y, but not determine how old either is.

Question 2

Absolute dating

Answer 2

The ability to determine an age that employs a number (3000 BP, 200 BC, 100,000 years ago).

Question 3

Law of superposition

Answer 3

In an undisturbed sequence, layers at the bottom will be older than layers above them.

Question 4

Stratigraphy

Answer 4

The study of soil and other layers within an archaeological site.

Question 5

Stratigraphic profile

Answer 5

A map / illustration recording the different layers within an archaeological site.

Question 6

Seriation

Answer 6

The changes in frequency over time of an artifact or other archaeological phenomenon, from first appearing, to growing in popularity, to eventual demise and falling into disuse.

Seriation is a dating technique used in archaeology to arrange artifacts, fossils, or features in chronological order based on their stylistic or typological similarities and differences. It helps archaeologists understand the relative chronological sequence of items

Question 7

Battleship curve

Answer 7

A plot of the relative frequency over time of an artifact or other archaeological phenomenon, with each bar centred.

The standard graphical result of seriation is a series of “battleship curves,” which are horizontal bars representing percentages plotted on a vertical axis. Plotting several curves can allow the archaeologist to develop a relative chronology for an entire site or group of sites

Question 8

Radioactive decay of isotopes

Answer 8

Loss of particular isotopes over time

Question 9

Three kinds of carbon

Answer 9

Three carbon isotopes, with 12 and 13 being stable and 14 radioactive

Question 10

Half-life and decay

Answer 10

The amount of time required for a radioactive element to decay to one-half of its original amount.

Question 11

Radiocarbon half-life (in round numbers)

Answer 11

5,700 years

Question 12

Half-life and maximum age limit on dating

Answer 12

Radiocarbon’s short half life results in the inability to date anything much older than 30,000-50,000 years old

Question 13

Photosynthetic pathways and radiocarbon dating

Answer 13

Different types of plants take up radiocarbon at different frequencies; means that plants of the same age will provide different radiocarbon ages

Question 14

Radiocarbon dating bone

Answer 14

Bone collagen (organic) does not always preserve well; inorganic component (appetite) can be contaminated with radiocarbon from other sources

Question 15

Reservoir effect

Answer 15

Stored amounts of older radiocarbon can make more recent specimens date far older than they actually are

Question 16

Upwelling

Answer 16

Process of bringing deep ocean water to the surface, which caries old radiocarbon; results in dates that are far older than the organism actually is.

Question 17

Calibration

Answer 17

Correcting for known fluctuations in atmospheric levels of radiocarbon by dating known-age items such as tree rings.

Question 18

Statistical estimate

Answer 18

Radiocarbon levels estimated by measuring decay over a short period of time, resulting in the possibility of error

Question 19

AMS dating

Answer 19

Accelerator Mass Spectrometry dating – directly measures amount of radiocarbon left in an organic object

Question 20

Dendrochronology

Answer 20

Tree ring datin

Question 21

Cross dating

Answer 21

Creating a tree ring dating sequence

Question 22

Old wood

Answer 22

Constructions employing old wood specimens as building materials, potentially throwing dendrochronology dates off by hundreds of years

Question 23

Potassium-argon

Answer 23

Dating volcanic sediments by comparing ratios of radioactive potassium 40 to argon 39.

Question 24

Potassium-argon dating range

Answer 24

Minimal date approximately 500,000 years ago to several billion years ago

Question 25

Uranium series dating

Answer 25

Dates determined by comparing ratios of uranium and thorium or two different uranium isotopes

Question 26

Fission track dating

Answer 26

Dates based on spontaneous fission of Uranium 238 in glass-like materials

Question 27

Obsidian hydration

Answer 27

Measuring water absorption rind of fractured obsidian to determine time elapsed since fracture occurred

Question 28

Trapped-charge dating

Answer 28

Determines when something was last exposed to light or heat, depending on method

Question 29

Thermoluminescence

Answer 29

Variety of trapped-charge dating based on last exposure to particular temperature; calculated based on amount of light emitted during reheating

Question 30

Reversals of magnetic poles

Answer 30

North and south poles occasionally reverse

Question 31

Movement of magnetic North

Answer 31

Changes in position of earth’s magnetic poles over time

Question 32

Paleomagnetic dating

Answer 32

Measuring age based on known position of earth’s magnetic poles, measured by looking at alignment of iron in soil

Question 33

Chronology

Answer 33

The measurement and study of time and constructing time sequences

Question 34

Accuracy

Answer 34

Ability to produce a correct answer

Question 35

Precision

Answer 35

Fineness of resolution

Question 36

Accuracy versus precision

Answer 36

Correct answer versus fine resolution; ideally both are present

Question 37

Reliability

Answer 37

Ability to produce same result repeatedly

Question 38

Validity

Answer 38

Are you measuring what you think you are measuring?