This data deposit contains the processed pressure-component OBS data and derived velocity models for a submitted paper titled "In situ lower crustal accretion by melt sill injection revealed by seismic layering". vel_tomo is the velocity model obtained from travel-time tomography, vel_fwi_1 and vel_fwi_2 are the velocity models from "trace-normalized" and "true-amplitude" FWI, respectively. These files are saved in a single-precision binary format. A python script read.py shows how to read these velocity files. processed_data.zip contains processed pressure-component OBS data (8 OBS gathers), picked travel times, and acquisition information. The processed data is saved in a double-precision binary format. A python script file 'read.py' contained in the compressed folder shows how to read these files.