Beaufort sea - data derived ages for forams

Documentation for tracking down the ages for the foram data to reproduce the data as provided by L.G. The data for the foram counts come from supplementary table in https://link.springer.com/article/10.1007/s41063-018-0058-7#Sec17 and the age model is provided in the ostracode data table from Sciencebase https://www.sciencebase.gov/catalog/item/6197a410d34eb622f692ce0e

To track this issue, I am going to focus on GGC30, depths 10cm to 12cm

"Raw counts" foram data from supplementary table

These data are provided in a table with three sheets that have data for three different cores, "GGC30" "MC29" and "JPC32". For each of those sheets, the depths of the sample are provided as rows, such as GGC30 depth 10 cm to 12cm, and columns are the different species. The cells are filled with counts when that species was present at that depth. The ages, using the age model from L.G., are not provided.

Data for GGC30, depths 10cm to 12cm:

"Aged counts" foram data from L.G.'s table that she sent me directly

These data have the three cores merged together in one sheet, which has the top and base depths for each core as rows, and species as columns. Here you can see the same data from the "raw counts" - the data are the same, but the "composite depth" and the "calendar age" fields been added on. Specifically, the calendar year is provided as 1870:

"Age model" - information on ages based on biogenic silica in sheet of Sciencebase release

These data are in a sheet of the table that has the ostracode data, derived from Sciencebase. The sheet "T4 biogenic silica" has rows for each core with depths as top and bottom plus a column that is "calendar year". Assuming this is the age model that we're supposed to use to align the foram data with the calendar ages, I would expect to find "GGC30" depth 10-12 cm in this table with an age of 1870.

the problem:

In the age model, GGC30 depth 10-12cm doesn't exist in this table (green row) and 1870 doesn't exist in this table (blue rows)

"Isotope model" data - information on calendar year in sheet of Sciencebase release

These data are in a sheet of the table that has the ostracode data, derived from Sciencebase. The sheet "T3 O_C isotopes" has a field that says "composite cum depth" and then an "Age depth model" that has years. In this table, there is a row that has "composite cum depth" of 31 and a year of "1870"

the problem:

Even thought the composite depth of 31 and year match the "aged data" table L.G. sent me, it is not clear in this table how the GGC30 10-12 cm == composite depth of 31 cm. I don't see any information in this table that allows me to cross-walk these composite depths to the depths in the raw counts table: