Complex sentence: He worked for the Geological Survey of Canada for over 40 years and authored or co-authored 70 publications, mostly concerning Carboniferous stratigraphy, paleobotany and paleontology of Atlantic Canada.
Split into simpler sentences: He worked for the Geological Survey of Canada for over 40 years and authored or co-authored 70 publications. Most of them concerning Carboniferous stratigraphy, paleobotany and paleontology of Atlantic Canada.