This week’s image is a scan of an old slide I shot in Chaco Canyon on a trip way back in the 1980’s — it’s of walls built using the McElmo (a.k.a. Type V) style of masonry:
McElmo is the last of 5 styles of masonry found at Chaco. The masonry style got its name from a creek north of Mesa Verde, based on a belief that similarities between this style and that used in masonry at Mesa Verde showed immigration from the north during the later years of occupation in Chaco. In fact, it’s been shown subsequently that this masonry shares only some very broad similarities to the Mesa Verde techniques.
In some sense McElmo masonry looks less refined than the earlier styles, but since this was all originally covered with mud plaster anyway, that may be beside the point. Oddly enough, this style of masonry was likely harder to build than the earlier styles. The earlier Chacoan masonry types used a hard, tabular type of sandstone found at the top of the canyon walls — it took some effort to obtain, but broke cleanly at right angles. McElmo masonry almost exclusively uses the softer sandstone found at the base of the canyon — far easier to get at, but much more difficult to get into shape for building purposes.