Soil moisture and Electrical Resistivity Tomography (ERT) measurements within the top metre of soil at Church Field, Chimney Meadow National Nature Reserve. Church Field lies on a clay lens which overlies surrounding sand and gravel soils. Apart from the A and B horizons, the clay was found to be fairly homogenous down to the maximum depth of 1.1m of the access pit. On the 1:250,000 Soil Map of South East England the location falls into the soils category 832 Kelmscott Association which comprise mostly permeable fine loamy soils over limestone gravel and variably affected by groundwater and with some risk of flooding. However, on the more detailed 1:25,000 scale Sand and Gravel Resources Map of the Thames Valley the clay lens is depicted as Oxford Clay substrate without sand and gravel cover, surrounded by sand and gravel terraces cropping out at the surface. Full details about this dataset can be found at https://doi.org/10.5285/59da8e86-04cc-4f46-a23c-65513d025326