Examining the graveyard through our pleasant walk in the rain we came across various graves that were obviously re-buried over time. However our group noted several biases which I will go into greater detail below. For starters here is a stacked materials graph over a period of years. This graphs shows only the death dates and in the case of multiple burials on the same slab, the earlier date is shown.
Although only speculated in my lab report, Jacob noted that there is more grave interments post-war era and during the Spanish flu era (starting in 1918) However it is difficult to know for sure what the cause of death was during these periods. Jacob speculates in his post in greater detail how the larger sample pre-spanish flu may be due to a “generational” die off post civil war.
As for the material type there certainly fondness for granite and although the chart does not show the material polish there was a common feature of the younger graves having a polished finish, monument types and family plots were the main example in this case. Throwing together (I admit a very bootlegged) serration graph we saw these results.
Our main assumptions is that there is a popular usage of metal, namely copper only after the World Wars, perhaps this may be due to a style shift or a better abundance of the material for sale. Simple stone monuments are also seen in the older graves until they are put more into granite and polished. There were more than one grave we noted where the material on the outside was simply made of concrete.
However this lab has many problems with its data sets. For example as mentioned before, reburials not matching the material types for the era buried. There is also a matter of small sample size, which in this case should be about 30 or so. Another problem is that the Calvary Graveyard is in majority, a Catholic graveyard.I can only give my own assumptions but in my family graveyard (a protestant one) the majority of the graves are in red stone or in metal temp monuments. This may be due to location of materials for headstones and the religious background playing effect. Seattle is a larger city so it would make sense for a wider array of headstones over time since there would be more manufactures to choose from. This can be seen hopefully by the wide range of materials seen in the graph and at the graveyard itself.
We only have an example from one graveyard. Here is a brief pic of the one I mentioned above.
The Kelly Cemetery (My family’s graveyard) located in central Oregon. URL Link:http://farm5.staticflickr.com/4096/4916475595_2cfe6e7b94_o.jpg. Note that some of the styles located here are completely absent from the Calvary cemetery.
There may be a preferred style here that is only used by Catholic families. For example the majority of the graves that had decorations had crosses on them and other catholic imagery. There is also a problem that there is a large number of clergy buried at the graveyard which is a large sample size of a similar style (simple stone slabs noting the rank of the clergy member). Cremations are also missing from this data set and therefor there is no data on those dates. There may be a time period when cremations were preferred but the lab did not ask for the data. The mausoleum was also off-limit at the time we were there.
Overall this posting gives a brief glimpse into the material types preferred over time, however in order to make the data better more samples are needed from this site and from many others.