Anthropology 310 - Archaeological Field Methods

Can ya' dig it?!

Anthropology 310: Archaeological Field Methods

Professor: Dr. Terry Jones (Spring 2009)

At the break of the day on the beautiful coast of Montana De Oro State Park, a group of Cal Poly students starts the mile-long hike out to archaeological site, CA-SLO-1370. With coffee gripped tightly in hand, students will spend their day excavating to discover what the Chumash culture left behind by exploring a shell midden. Throughout the ten- week period that the excavations took place students found many ecofacts and artifacts. What was mainly found included debitage, which is the by product of stone tool production (specifically, chert and obsidian), projectile points, shells (including whole abalone), mammal and fish bones. Students participate in the excavation of units or dry screening to collect the cultural material found in the midden. Furthermore, students learn to scientifically identify and label all ecofacts and artifacts observed at the site.

Students dry screen in a classroom setting, that is truly one of a kind...

Dry screening for artifacts and ecofacts.

The process of dry screening begins with an accurate measurement of the desired unit. The unit is then dug in 10 cm levels, the dirt is put in buckets and then transfered to a student to be dry screened. A trowel becomes a very useful tool when sifting through the dirt and can be used for meticulous digging. After the dirt is collected, students learn to identify and collect artifacts and ecofacts. After each 10 cm level the material is collected, counted, bagged and labeled to be sent to the lab for further analysis.

View from adjacent beach where students enjoy their lunch break.

In this picture, three units measuring 2 meters by 1 meter are dug at 10 cm levels.

Entering each new level, measurements are taken frequently to ensure accuracy and that the unit stays the appropriate size. After each 10 cm level, a level record is taken to document the artifacts and ecofacts that were seen and collected.  Furthermore, a level record ensures that anything seen in the unit is recorded and mapped out accurately. 

Erosion can be seen leading up to the archaeological site. Part of the reason this site was chosen for excavation was that the site is being eroded by the ocean. Some of the material at this site has already been lost and can be seen protruding from the cliff at this site. In general, archaeological sites are not excavated unless threatened by development, natural processes, etc.

Abalone shells can be found in the depths of the units. The second stratum can also be seen surfacing. A detailed site record is kept for all units. At certain levels we find more delicate objects in situ, such as abalone, that require more careful precautions for excavation. Students dig around them in a delicate manner to not modify their provenience. When the level is completely excavated the objects are mapped in on the level record and removed and recorded. At this site at deeper levels, the density of the dirt increases which requires more labor to extract the dirt.

View along the coast during the hike to the site.

Snakes and gophers cause bioturbation which interfere with the units. Their movement causes the dirt in the unit to shift therefore compromising our accuracy. In addition, the soil at this site is very soft leaving it vulnerable to human interference which causes cave ins within our units. A separate collection process is performed for each disturbance in the unit. Appropriately, a separate level record is written to ensure the only items found are from the current level.

Due to the erosion, stratigraphy can be seen clearly.

Dry screening again... On several occasions, visitors with different interest and backgrounds in archaeology come to assist at the site. Whenever an archaeological site is excavated a Native American monitor has to be present.

Erosion from the ocean can be seen peeling away the land.

Good times to be had out on the site.

Students come away with a better understanding of archaeology that can be applied in other aspects of academics in Social Sciences. Archaeological Field Methods proved to be a class where the learning process continues outside the classroom. Cal Poly... Learn By Doing.