Quaternary glaciomarine events, Springdale-Hall's Bay Area, north-central Newfoundland

Abstract

Quaternary glaciomarine deposits form a complex sedimentary succession in the Springdale - Hall's Bay area of north-central Newfoundland. Marine incursion due to isostatic depression was extensive throughout the Indian Brook and South Brook valleys, reaching at least 8 km inland. Sedimentological, palaeontological, and geomorphological analyses have permitted reconstruction of the history of sea level change for the area since ca. 12,500 B.P. -- A succession of ice-proximal deltas, representing the proximal units associated with the marine incursion, and a series of successively lower terraces are present. Stratified coarse sediment sequences mark the marine limit of 75 m above present sea level. -- Clay and silt were deposited by a combination of suspension settling and sediment gravity flows in low energy, distal locations. Dropstones indicative of ice rafting are present throughout the clay strata. Vanadium concentrations indicate deposition in brackish-marine environments. Shells of Mya arenaria, Mya truncata, Balanus hameri, Macoma balthica, and Hiatella arctica found in life positions also indicate brackish depositional environments. Four ¹⁴C dates were obtained from the marine fossils giving an age range of 11,300 +/-120 to 12,470 +/- 380 years BP.