17-TilliteSimilar to no. 15, but with fewer and more well rounded large clasts, indicating meltwater transport of pebbles before incorporation into the till. Note the large granite pebbles (pink) set in the finer greenish rock matrix. The matrix consisted of silt and clay sediment before it was lithified and metamorphosed. Original till was deposited in Canada by ancient Precambrian glaciers about 2 billion years ago. Boulder found in Pleistocene glacial deposits in May Stone and Sand quarry. (Compare with no. 15, no. 16, and no. 18.) 
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