Figure 2
From: Rare earth element geochemistry of outcrop and core samples from the Marcellus Shale
Rare earth element abundance in Marcellus Shale outcrop (open symbols; NÂ =Â 12 for all analytes) and core samples (closed symbols; NÂ =Â 6). Geochemical background (Bkgd.), anomalous (A0), strongly anomalous (A1) mass fraction ranges of world black-shales according to Ketris and Yudovich [10].