In addition to a sea floor mapping project, the researchers will make chemical analyses of water samples that will help them determine the temperature, salinity and composition of a strong circumpolar current that flows around the boundary of the Arctic Ocean.
Although APXS and ChemCam will tell you which chemical elements are present, they don't tell you how precisely those atoms are arranged into the crystalline structures that make up the rock, and both this mineralogy and the chemical composition are ideally needed to assign a rock name.