Caledonian orogeny

The Caledonian orogeny was a mountain-building event that occurred in northwestern Europe between the early Cambrian and the end of the Silurian periods (approximately 542 to 416 million years ago). This geological process resulted from the opening and subsequent closure of the Iapetus Ocean. The final collision involved the northwestern European continent and a North American-Greenland continent, creating a significant mountain range.1

The remnants of this range extend from Ireland and Wales, through northern England, eastern Greenland, and Norway, to Spitsbergen. The main suture zone, found across central Ireland and along the England-Scotland border, separates the two distinct continental blocks. Subsequent uplift and erosion exposed deep crustal rocks, leading to the deposition of sandstones and conglomerates during the Devonian Period. The East Greenland orogen represents the western flank of this larger Caledonian orogenic belt.12