[phenixbb] superpose mrc maps (and also mtz files)

Dear Scientific community, I got a few .mrc maps from collaborators. Is there a way in phenix to superpose models and corresponding mrc maps. Using superpose maps I get the error:" This file format CCP4 map is not supported as input for this field; only files of type 'Reflections' are allowed. Also the program Structure comparison does not recognize .mrc files. On top there are also a few mtz files I would like to superpose on the .mrc files. Many thanks, br Georg.