chroncontrols

89369 rows


Description

This table stores data for Chronology Controls, which are the age-depth control points used for age models. These controls may be geophysical controls, such as radiocarbon dates, but include many other kinds of age controls, such as biostratigraphic controls, archaeological cultural associations, and volcanic tephras. In the case of radiocarbon dates, a Chronology Control may not simply be the raw radiocarbon date reported by the laboratory, but perhaps a radiocarbon date corrected for an old carbon reservoir, a calibrated radiocarbon date, or an average of several radiocarbon dates from the same level. A common control for lake-sediment cores is the age of the top of the core, which may be the year the core was taken or perhaps an estimate of 0 BP if a few cm of surficial sediment were lost.

Columns

Column Type Size Nulls Auto Default Children Parents Comments
chroncontrolid serial 10 nextval('ndb.seq_chroncontrols_chroncontrolid'::regclass)
chroncontrolranks.chroncontrolid fk_chroncontrolranks_chroncontrolsC
chroncontrolscal14c.chroncontrolid fk_chroncontrolscal14c_chroncontrolsC
eventchronology.chroncontrolid evc_ccidR
geochroncontrols.chroncontrolid fk_geochroncontrols_chroncontrolsR
relativechronology.chroncontrolid rc_ccidR

An arbitrary Chronology Control identification number.

chronologyid int4 10 null
chronologies.chronologyid fk_chroncontrols_chronologiesC

Chronology to which the ChronControl belongs. Field links to the Chronolgies table.

chroncontroltypeid int4 10 null
chroncontroltypes.chroncontroltypeid fk_chroncontrols_chroncontroltypesC

The type of Chronology Control. Field links to the ChronControlTypes table.

depth float8 17,17 null

Depth of the Chronology Control in cm.

thickness float8 17,17 null

Thickness of the Chronology Control in cm.

age float8 17,17 null

Age of the Chronology Control.

agelimityounger float8 17,17 null

The younger age limit of a Chronology Control. This limit may be explicitly defined, for example the younger of the 2-sigma range limits of a calibrated radiocarbon date, or it may be more loosely defined, for example the younger limit on the range of dates for a biostratigraphic horizon.

agelimitolder float8 17,17 null

The older age limit of a Chronology Control.

notes text 2147483647 null

Free form notes or comments about the Chronology Control.

recdatecreated timestamp 22 timezone('UTC'::text, now())
recdatemodified timestamp 22 null
analysisunitid int4 10 null
analysisunits.analysisunitid fk_chroncontrols_analysisunitsR
agetypeid int4 10 null
agetypes.agetypeid fk_chroncontrols_agetypesR

Indexes

Constraint Name Type Sort Column(s)
chroncontrols_pkey Primary key Asc chroncontrolid
ccrchronage_idx Performance Asc age
ccroldage_idx Performance Asc agelimitolder
ccryoungage_idx Performance Asc agelimityounger

Relationships