The dataset details the soil profiles described from the narrow diameter cores collected from 474 sampling sites across UK saltmarshes collected between 2018 - 2021. The work was carried out under the NERC programme - Carbon Storage in Intertidal Environment (C-SIDE), NERC grant reference NE/R010846/1 Full details about this dataset can be found at https://doi.org/10.5285/55760544-b0a6-4845-a2e0-1cf533996c64