Radiocarbon ages, calibrations and stratigraphic relationships.

<p>All radiocarbon ages were calibrated using Calib 7.0.2 and the IntCal13 curve [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0193522#pone.0193522.ref065" target="_blank">65</a>].</p

Photograph showing the relationship of site stratigraphy to the track surface.

<p>(A) dense grey clay (XI), likely glacial marine–predates 13,400 cal BP, (B) dense brown clay paleosol (X) with preserved wood dating between 13,317 and 12,633 cal BP, (C) track #15, (D) track #17, (E) track #20, (F) superimposed tracks 14a and 14b (G) track #13, (H) bell shaped pit, (I) bell shaped pit, (J) boulder deposited sometime after 3000 years cal BP, (K)–drainage trench to facilitate excavation. Note: Stratum VIII was not found in this part of the excavation. Photo by Duncan McLaren.</p

Illustration of strata and associated radiocarbon ages (cal BP).

<p>Only radiocarbon dates on identified plant remains and charcoal have been included. Base photo by Joanne McSporran.</p

Photograph showing track #4 which has discernable toe drag marks.

<p>This track was later pedestalled and removed to the lab. (Photo by Joanne McSporran).</p

Terminal Pleistocene epoch human footprints from the Pacific coast of Canada

<div><p>Little is known about the ice age human occupation of the Pacific Coast of Canada. Here we present the results of a targeted investigation of a late Pleistocene shoreline on Calvert Island, British Columbia. Drawing upon existing geomorphic information that sea level in the area was 2–3 m lower than present between 14,000 and 11,000 years ago, we began a systematic search for archaeological remains dating to this time period beneath intertidal beach sediments. During subsurface testing, we uncovered human footprints impressed into a 13,000-year-old paleosol beneath beach sands at archaeological site EjTa-4. To date, our investigations at this site have revealed a total of 29 footprints of at least three different sizes. The results presented here add to the growing body of information pertaining to the early deglaciation and associated human presence on the west coast of Canada at the end of the Last Glacial Maximum.</p></div

Scattergram comparing length and width for the 18 tracks with full measurements.

<p>Three clusters emerge revealing that the prints were left by at least three different individuals. Variation in track size is expected as a result of slippage, foot rotation, taphonomic factors and measurement error.</p

Diagram showing the relative percentage of track azimuth measurements.

<p>It is clear from this diagram that those who left the tracks were primarily facing and/or moving in a north to northwesterly direction.</p

View across the beach at EjTa-4 with Calvert Island in the foreground and Hecate Island in the background.

<p>Photo by Jim Stafford.</p

Photograph showing track #26 with an elongated heel as a result of the pedestrian slipping forwards while walking in the clayey substrate (Photo by Joanne McSporran).

<p>Photograph showing track #26 with an elongated heel as a result of the pedestrian slipping forwards while walking in the clayey substrate (Photo by Joanne McSporran).</p

Photograph of track #17 beside digitally-enhanced image of same feature using the DStretch plugin for ImageJ.

<p>Note the toe impressions and arch indicating that this is a right footprint. Photo by Duncan McLaren.</p