TREKKING THROUGH AVALONIA: NEWFOUNDLAND'S EAST COAST TRAIL AS A SCENIC WINDOW INTO NEOPROTEROZOIC STRATIGRAPHY AND TECTONICS

Newfoundland's East Coast Trail (ECT) is an important attraction for residents and visitors alike. The ECT currently loops around the northeast tip of the Avalon Peninsula, follows the coast through the greater St. John's area, then along the rugged Atlantic shore from Cape Spear (the easternmost point of North America) to Cappahayden, north of famous Cape Race. The ECT links coastal communities and Canada's oldest city with many sites of natural, cultural and historical significance. This 336 km hiking corridor is remarkable in its own right, but it also has a geoscience connection, because it allows geologists to quite literally trek through Avalonia.

This long and scenic venture traverses late Precambrian (Cryogenian and Ediacaran) rocks of the Harbour Main, Conception, St. John's and Signal Hill groups, which collectively define much of the Neoproterozoic history of Avalonia. The spectacular Harbour Main Group, largely of volcanic origins, is succeeded by the deep-water turbiditic sedimentary rocks of the Conception Group, best known for their remarkable Ediacaran (Neoproterozoic) fossil assemblages. The first Precambrian fossils were in fact described from outcrops in historic downtown St. John's, and they can still be seen today. The Conception Group passes upward into the mixed assemblage of the St. John's Group, which records shallowing of the basin. The sequence is capped by the spectacular Signal Hill Group, in which sandstones, redbeds and conglomerates define a transition to terrestrial environments. The trail does not presently cross the early Paleozoic sedimentary rocks that sit above the fundamental unconformity representing the Cambrian marine transgression, but these are easily accessible near its northern end. The southern termination of the ECT is close to the UNESCO World Heritage site at Mistaken Point, where the oldest complex organisms known in the geological record occur. This presentation highlights the many sites and sights that geologically-minded hikers could and should experience in trekking through Avalonia, and provides an update on a long-term (but admittedly intermittent) project to integrate information about these key localities and develop an article or document that might guide visitors on their journey.