Castles and Coprolites

Following on from my post a couple of weeks ago , here is another snippet of geoarchaeological observations from my recent road trip across the US. As I mentioned in the previous blog, the coast to coast trip was a great chance to observe the gradual changes in geology, vegetation and climate that happen across the continent, and how these link with the archaeological preservation. In the humid subtropical climate of the Florida pan-handle we saw a lot of water action and salt precipitation occurring at Fort Pickens, with relatively degraded brick structures that are only around 180 years old. The contrast in New Mexico is significant. The climate here is semi arid to arid, and the preservation of the brick structures (about 1000 years older than those at Fort Pickens) in the Chaco Culture National Park is fantastic. However we do still see other types of weathering occurring. Whereas most people would be taking pictures of the fantastic structures (actually, I did that too...), I ...

Plant voids in different materials in thin section I mentioned these features briefly in a previous post on wall plasters - these micrographs all show pseudomorphic voids in different contexts. It would actually be technically correct to call these pseudomorphic plant voids, as there can be other 'pseudomorphs' found in geological thin sections, which occur where a void/space originally formed by one type of material is replaced by another type. This leads to the crystal shape being that of the original mineral rather than the mineral that is currently present. Pseudomorphic plant voids in an archaeological context occur in materials where plant remains were once present but have now decayed. This leaves an 'impression' of the plant remains, which can give important clues on the use of plant materials in archaeological contexts.  It gives us a different insight to that of the charred macrobotanical record. Materials such as those shown above may not contain pla...

Degraded brickwork at Fort Pickens, Pensacola Limited blogging from me over the past couple of weeks, due to a lack of internet rather than a lack of activity. In fact I've been incredibly busy with archaeologically and geologically themed adventures, travelling from Pensacola (Florida) to Powell Butte (Oregon) via Texas, New Mexico, Utah and Idaho. A 5 day drive across a major chunk of the US, it's been amazing to see the changes in the landscape, geology and climate, some of them gradual and some more dramatic. One thing that is particularly interesting from a geoarchaeological perspective is the difference in preservation of different sites that we've visited, related to the local environment. Salt stalactites Here for example we have Fort Pickens, a historic monument that was contructed in 1829, completed in 1834, and remained in use until 1947. Despite being quite recent in archaeological terms, much of the brickwork has started to degrade and/or has...