Intern:Age

! page under construction !

In its first concept, PANGAEA was designed to archive data from geoscientific, in particular paleoclimate research. Thus in addition to the spatial geo-codes, the system obtained a time geo-code (synthetic time axis after Negendank) to map all data versus time on a common age scale. This enables the user to extract time slices with ART or Pan2Applic from an individual subset of data extracted from the system.

Any data from geological profiles should be accompanied by its age model.

To obtain the age of a geological profile usualy three steps are required:
 * 1) The profile needs to be dated at some points with one of the various age determination methods.
 * 2) A selection of dated points (stratigraphic fixpoints) forms the age model.
 * 3) The ages for the complete profile and each single sampling/measurements point is calculated by interpolation.

!NOTE! All age parameters have the unit kiloyears [kyr] !



ad (1) Each sample, used for age determinations has one mean depth supplemented mostly by 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): For each age determination a confidence level and comments may be added, given through the parameters 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 remain in the parameter If 14C radiocarbon age datings are archived:
 * Depth [m] (1)
 * Depth min [m] (3)
 * Depth max [m] (4)
 * Age, dated [kyr] (5506) (always provide the method with this parameter!)
 * Age, min (UCL, upper confidence limit, 6170)
 * Age, max (LCL, lower confidence limit, 6169) or just
 * Age, dated standard deviation (6165).
 * 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.
 * Year [yr A.D.] (2936)
 * 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

ad (2) Following the scientific decision, which age determinations are usefull, an age model is set up consisting of a number of stratigraphic fixpoints (depth versus age). Use geocode Depth in sediment (1) and the parameter To precisely define the upper and lower limit of an age, the system provides the numeric parameter
 * Age model (6)
 * Age model, optional (6666) may be used if more age models exist
 * Age, comment (643) may contain detailed information about each stratigraphic fixpoint.
 * Age, minimum/young (6167), numeric parameter
 * Age, maximum/old (6168), numeric parameter
 * Age from (oldest) (45397), text parameter
 * Age to (youngest) (45398), text parameter

Also in an age model alawys the method used should be given (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.

ad (3) From the age model, the ages of the distinct samples are calculated (by linear interpolation or other).


 * 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.

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.

!NOTE! 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 !

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.