In 2019, Memorial University of Newfoundland Adjunct Professor and Lecturer Dr. Andy Kerr set his sights on the Bay of Islands Ophiolite Complex, beginning with a July trek of the Blow Me Down Mountains with Cabox Aspiring Geopark Chairperson Paul Wylezol, followed by an October article entitled Exploring a Famous Ophiolite: A Guide to the Bay of Islands Igneous Complex in Gros Morne National Park, Western Newfoundland for Geoscience Canada, of which he is scientific editor.
Andy, who is also a geological adviser for Cabox Aspiring Geopark and the International Appalachian Trail (IAT), also accompanied Paul and fellow Cabox/IATNL director Arne Helgeland on a May 2019 geological tour of the IAT and Lochaber Geopark in Scotland.
Andy and Paul’s trek of the Blow Me Down Ophiolite Massif started at the Route 450 intersection with Salt Water Road above Frenchman’s Cove. From there they hiked the Hummock Trail to Blow Me Down Brook, then after crossing the clear-water stream
climbed up The Sands promontory to the top of the mountains.
Along the lower section of the long gravelly slope they found a myriad of examples of ultramafic rock, from pyroxenite to various forms of peridotite – including harzburgite and dunite – to serpentinite.
Near the top of the 600 meter high slope, which is composed primarily of earth’s mantle overlaid by a section of oceanic crust, they discovered a rocky outcrop made of numerous slabs of ultramafic peridotite fused to mafic gabbro, an intrusive igneous rock formed by the slow cooling of magnesium and iron-rich magma into a crystalline mass deep beneath the Earth’s surface. This would appear to be a section of the Mohorovicic Discontinuity (aka Moho), which is the boundary between earth’s crust and mantle below.
From the top of the Blow Me Down Mountains, Andy and Paul could see the rust-colored North Arm Ophiolite Massif, which is a 2-3 day hike from Table Mountain in Gros Morne National Park, the most northerly of the four Bay of Islands Ophiolites (the other being the Lewis Hills). Andy had just traveled from the “Tablelands”, where he had been doing research for his upcoming article, embedded below.
