Intern:Age

A word about geological ages:


 * For ages, resulting from different analysis (AMS, Lead210, OSL etc) the parameter Age, dated (5506) will be used.
 * Age models resulting from the interpretations of the datings are imported with ID=6 or 6666 (optional models).
 * The geocode-age for the calculated age of a certain sample is imported with ID=2205.

The parameter Age, calculated is used in conjunction with the Advanced Retrieval Tool (ART) only. It is exclusively used by the system to dynamically calculate/interpolate ages from age models during export with ART (configuration under DATA, on the List config card, in the Geocodes list box). DO NOT USE FOR 4D IMPORT !

Each sample, used for age determinations in sediments, has one mean depth or, even better two depth, defining the upper and lower boundary of the sampled horizon. At a minimum an import table for datings should include (ID in brackets) It is important to define the correct relation between Age and the Method of dating which can be found by give dynamik link list: method begins with Age,...
 * Depth (1), mean
 * Depth (3+4), min + max (optional)
 * Age, dated in kyr (1506)



If 14C data are archived, always
 * specify the calibration used for converting 14C-years to calendar years in the method (e.g. INTCAL 98, Suigetsu)
 * specify the reservoir correction used for marine 14C dates

For each age a confidence level may be added, given through the parameters
 * Age, min (UCL, upper confidence limit, 6170)
 * Age, max (LCL, lower confidence limit, 6169) if the limits are different. Otherwise use
 * Age, dated standard deviation (6165).

All age parameters have the unit kiloyears [kyr] !


 * Age, dated material (2836) is a text parameter to add a description of the material which was used for the age determinations.
 * Age, comment (643) may be used for any dating related comments.

If data are provided versus year A.D. (anno domini) or in counted years (e.g. varves, growth bands, tree rings), the original year values are kept in the parameter
 * Year (2936, unit yr A.D.); and
 * AGE, converted to kyr related to 1950=0 should be added. The geocode AGE is the common (synthetic) time axis (after Negendank) of all geological data in the system.

Following the scientific decision, which age determinations are usefull, an age model is set up consisting of a number of stratigraphic fixpoints. Use parameter
 * Age model (6) or, if more age models exist
 * Age model, optional (6666) may be used. In
 * Age, comment (643) may contain information, why a certain point/age was choosen.

To precisely define the upper and lower limit of an age, the system provides the numeric parameter
 * Age, minimum/young (6167)
 * Age, maximum/old (6168) or the text parameter
 * Age from (oldest) (45397)
 * Age to (youngest) (45398)

Also with age models it is important to define the correct relation between Age model and the method used; see give dynamik link list: method begins with “Age model... A Hiatus is defined by using its depth twice with upper and lower time limit of the hiatus. Data from geological profiles should consequently be accompanied by its age model.

From the age model, the ages of the distinct samples are calculated (by linear interpolation or other). ! Never use the parameter Age, calculated for import ! Age, calc is used for the export of calculated ages only by using the values in the age model.

The geocode AGE should be included with all data related to geological time. It is calculated for the age model. AGE is the common time axis of the system, allowing to combine any type of geological data, e.g. corals, ice, sun spots and reconstructed sea surface temperatures.

All parameters important to geological ages can be retrieved from the parameter dictionary as dynamic list.

Example of a table ready for import
If data sets include a common time scale, some independent sets might be exported and plotted versus one time axis: see the multi proxy example.