Age-depth model output

[DBM]

I am new to OxCal and have a simple age-depth model I ran using P-
sequence with three dates (k-parameter = 1). I would like to derive
an age-depth model where I have estimated ages (and likelihoods) for
each depth of a 130cm sediment core. I would like to create a plot
similar to Figures 5, 7 shown in the preprint "Deposition models for
Chronological Records", (Bronk Ramsey 2007.) While I can view the age-
depth model in OxCal it only shows me information for the depths I
included in the input. How do I get estimated values and associated
likelihoods for each depth of interest? I likely missed something
simple here but after searching have been unable to figure out how to
do recreate figures like those in the preprint.

Thank you,


DBM

[Christopher Ramsey]

You can either add extra points in by hand using eg:

Date(){z=50;};

at the points you want dates for. Or you can use an optional third
parameter for the P_Sequence as in:

Plot()
{
// this will give 0.1 increments every cm (ie 1 per every 10cm); k
is set here as 1 and there are only three dates
P_Sequence("",1,0.1)
{
Boundary(){z=125;}; // set bottom boundary slightly deeper than
bottom date
R_Date("A",705,15)
{
z=117;
};
R_Date("B",690,20)
{
z=95;
};
R_Date("C",10,10)
{
z=15;
};
Boundary(){z=10;}; // set top boundary slightly higher than top date
};
};

It is better to set the boundary depths here like this. In this case
there is barely enough information for the depth model to work but
you do get the interpolation you want as in the paper.

I am aware that a better method for interpolating the age model would
be good - it is near the top of the to-do list for the program.

Christopher

[DBM]

Thanks for this information. It was very helpful. A have a follow up
question: with the P_sequence approach it appears as though the
interpolation between 14c dates is linear. If I wanted to derive an
interpolated date for each depth (each centimeter) I assume I would
just calculate the slope between any two modeled 14c dates (median or
mean) and this would give a coarse interpolation for each depth
(assuming sedimentation between modeled dates was constant). This
would be a simpler approach for deriving dates for each depth than the
Date(){z=....;}; or the optional P_Sequence("",1,0.1) approach you
listed below. I know your response was intended to answer my previous
question which was a little different. Would this be the preferred
method for deriving dates for each cm of a sediment core? Thanks
Christopher,

Dave