LF 4 occurs as discrete rafts and is common in the central and northern section of the stratigraphic sequence (Fig. 3f). It comprises well-sorted, grey-brown clay that OTS 964 is compositionally similar to LF 1. However, LF 4 displays crude bedding, presumably originally horizontal. Individual beds are ∼10 cm thick and are visible only by a change in colour, not grain size. Small pebble-granule inclusions (<5 cm) are dispersed throughout the unit and are largely composed of quartzite and sandstone with rare granite. Distinctly larger clasts (<40 cm) are occasionally observed in the unit, and are commonly striated, associated with load structures, and composed of quartzite. To better differentiate between LF 1 and LF 4, electrical conductivity and pH analyses were undertaken on five samples of LF 1 and three samples of LF 4 from various locations along the bluffs. These analyses indicate that both units have similar pH values (LF 1 = 5.62–7.14 and LF 4 = 3.1–6.85). However, conductivity measurements indicate that LF 1 has consistently low conductivity values of 0.031–2.28 mS/cm whereas LF 4 has consistently higher values ranging from 10.3 to 16.8 mS/cm. The distinctly higher conductivity values for LF 4 may reflect enhanced porewater salinity as a result of more recent deposition (relative to LF 1) in a saline, marine environment. LF 4 is interpreted to be a glaciomarine diamict with striated dropstones, principally composed of reworked Kk Fm.
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