Analysis of Plant Remains Lab 7 Introduction to Environmental Archaeology

Environmental Reconstruction  Botanical remains offer clues to diet, environment, seasons, and changes in biotics  When combined with landscape studies (and ethnographies) botanical information can provide evidence of past environment

Terms  Linnaean taxonomic system  Archaeobotany, paleobotany  Macro-plant remains  Micro-plant remains  Chemical remains

Goals  Archaeologists seek remains of plants at sites through careful collection of soil samples  Techniques vary but the most common approach is flotation or washing soils. Both methods allow processing of large volumes of soil (pounds rather than ounces)

Identification  Difficult  Soil separation allows sorting of botanicals from insect, mineral, and other soil components.  Use of reference collections  Online reference collections

Special data sets  Phytoliths  Pollen  Both can yield significant information about past environments. Although not indestructible they are very durable until brought to the lab.

Phytoliths

Procedures  Teams of four (5 teams)  Teams will be assigned a flask or bag of soil.  Record the flask/bag number  The soils will be wet-screened through standard mesh separation sieves. [Small mesh retains smaller sized botanicals, etc., allowing larger material to pass through to next screen size. Process can be run in reverse].

 The goal is to collect material graded by size and to examine the material under a microscope for basic identification (see page in text. We will use the same form. The team will be responsible for the forms. Individual write-ups should be collected as a packet and attached to the lab forms.  You will need to make microscope slides or review material in petrie dishes.

Weigh your sample

Dry sieving in a stack. Wet sieving in a single screen.

 In this exercise it will not be required to identify actual family, genus, species but you will have a chance to try by using a variety of online reference collections. Bonus points for successful IDs.  If we can get the high power digital microscope to work we will also capture images.

Procedural notes  Washed soils will need to be air dried. Use the coffee filters for small samples.  Trays for team samples will be available in the Lab  Do not discard anything. Soils that pass through all sieves can be collected for drying.  A known quantity of a reference seed will be included in your sample to evaluate recovery efficiency.

Final note  Each team will have a designated time to carry out the soils washing. The expectation is two teams for each lab period will complete their sample. You do not have to use all sieves I the set. Three or four should be enough.  We will discuss interpretation and sample storage in a future class period.