Chapter Six: Chronology Building Flashcards
What are relative dating techniques?
placement of events in a relative sequence or before, contemporary to, or after another event (old, older, oldest)
What are some examples of relative dating techniques? (3)
- stratigraphy
- index fossil concept (diagnostic fossils), time markers (diagnostic artifacts), chronostratigraphic markers (diagnostic stratigraphy)
- seriations
What are absolute (chronometric) dating techniques?
determining the age of an event in an age-in-years scale
What are some examples of absolute dating techniques? (3)
- dendrochronology
- radiometric techniques (radiocarbon, radiopotassium)
- trapped-charge (TL, OSL, ESR)
What is index fossil concept? (2)
- relative dating of strata or sites based on presence of distinct, time-sensitive fossils, artifacts, or even strata
- organisms of a given period will have distinctive traits and those traits change through time
What is biostratigraphy (diagnostic fossils)? (2)
- first developed by William “Strata” Smith
- stratigraphical system of organized fossils (1817)
What are diagnostic artifacts? (4)
- artifact forms shown to be diagnostic of a particular time period
- first used in archaeology by Oscar Montelius (1885)
- subdivided Bronze Age of Europe studying artifact types
- artifact types will be similar in style and design during a given time period and place; changes to style and design over time
When have archaeologists combined biostratigraphy and diagnostic artifacts? (4)
- Olsen-Chubbuck site, eastern CO.
- Bison occidentalis bone bed with projectile points
- Olsen-Chubbuck projectile points associated with the B. occidentalis remains
- Cody Complex: 21 complete Scotsbluff and Eden points
What are chronostratigraphic markers?
correlated diagnostic strata
What made Nels Nelson’s master sequence at Pueblo San Cristobal, NM so important? (3)
- combined typology and stratigraphy
- master sequence: site with deep stratigraphic profile that provides a chronological sequence of changing artifact types and styles
- chronological sequence: following one thing after another in time
Describe Nels Nelson’s master sequence and the seriation method of relative dating. (2)
- orders artifacts based on frequency of several artifact styles relative to a chronological sequence
- assumption: one cultural style slowly replaces an earlier style over time
What are radiometric absolute/chronometric dating techniques? (3)
- rely on measurable decay of radioactive isotopes
- radiocarbon, radiopotassium/argon-argon dating
- half-life: time required for half the radioactive isotopes to decay to more stable isotopes
What are non-radiometric absolute/chronometric dating techniques? (2)
- dendrochronology (tree-ring dating)
- electron emission through radioactive damage “trapped charge” dating (thermoluminescence, optically-stimulated luminescence, electron-spin resonance)
