spanning these many small sites, archaeologists and crew were rushing to reveal and gather artifacts, to record and to analyse these unusual undisturbed fingers of land in the heart of the city. The ash line in this particular location was kitty-corner to a mastadon bone find of 1979/80 containing man-made stone weapons among the bones – a most important find about human occupation in southern Alberta. This discovery had occurred during the excavation for Mount Royal Village, a mixed-use shops and office complex, however this unusual animal/man site could not be accurately dated until the ash line was found 30 years later across the avenue. What’s left of the intact stratifications of subterranean land located in the central core of Calgary (found mostly in interstitial spaces between buildings that were built more than 4.5 m apart up to 1945) permits glimpses into the lives and culture of early nomadic humans as they appeared in the protected Bow Valley where clean water, shallow fords, large poplar trees, varieties of berries and grasses and large animal herds were readily available
Around 5,700 BC what is now known as Mount Mazama in Oregon erupted with monstrous force and blanketed the southern portion of Canada’s western provinces with a thin layer of white ash called tephra , today found 1-1.5m below grade. The line of ash has been discovered in both rural settings and urban locations in Calgary and provides a useful timeline marker to archaeologists who are encountering linked bones and stone weapon artifacts of the ancient mammals and early humans in the layers below this line I first encountered this volcanic ash line with archaeologist Don Hanna, who had a crew excavating ancient settlements on the city boundary of rural west Calgary. There, the ash line was clear and undisturbed. Then we went to an urban site at the southwest corner of 17 Avenue and 8 Street SW in Lower Mount Royal where the removal of a 1950s gas station and several stand alone 1920s two-storey buildings had revealed spaces between them that had never been disturbed – there was the same vivid ash line. Barely ahead of the excavation for a new single building
ASH
archaeology soi l foundations excavation urban scale
foundations | deep history by gerald forseth
ash line
ash line
Gerald Forseth
Original stratification intact: isolated structures, without foundation. Cave. 10,000 BC. Lean-to. 10,000 BC. Pit. 5,000 BC.
Mound. 1,000 BC. Tepee. 1,000 BC. Sod. 1,000 BC.
Isolated structures, with log and stone foundations. Shallow log. 1500 Log house on stones. 1600 Frame barn on stones. 1800 Spread apart urban structures, with stone and concrete foundations. Houses and bungalows. 1910
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