Data for: Fluid expulsion system and tectonic architecture of the incipient Cascadia convergent margin as revealed by Nd, Sr and stable isotope composition of mid-Eocene methane seep carbonates

Samarium-neodymium, strontium, carbon and oxygen isotope data of the four studied middle Eocene hydrocarbon seep deposits and reference early-diagenetic carbonate concretions from the Humptulips Formation, Cascadia convergent margin, Washington, USA.