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abalone view pendant view pendant

large ocean gastropod (Haliotis sp.) whose shell has attractive nacreous lining; cut into various shaped and perforated to make ornaments often placed in graves; probably obtained in trade with coastal people.

absolute date 

the year in which an artifact was manufactured or deposited in the site; an age that can be determined by dating methods such as radiocarbon dating.

archaeologist

a scientist who studies material found in the ground at places people have used, to learn about human life in the past. 

archaeological deposit 

accumulation of soil and debris (may include midden or other waste material such as ruins of buildings) from past human activities. 

archaeology: 

the study of material remains left by humans, usually in the ground, to learn about past cultures. Archaeology is often confused with paleontology. They differ  in that archaeology is the study of human life in the past, and paleontology is the study of  plant and animal life in the past (such as dinosaurs). 

artifact 

item such as a tool or ornament made, altered or used by humans.

awl

a common type of bone tool found in the Emeryville Shellmound and other California sites.  Usually the bone has bee split and ground to a point.  These tools probably were used for sewing, basket making and many other purposes.

C14 

Carbon-14, the radioactive carbon used for radiocarbon dating.

CEQA 

California Environmental Quality Act; California State law requiring the state and local agencies to consider the potential effects of proposed projects on the environment (which includes archaeological sites).

charmstone view photo  

also called plummet stone. Artifact formed from a small ovoid or elongate cobble, usually finely shaped and often polished; one end frequently perforated, or shows evidence of having been wrapped with cordage, probably so it could be suspended from a cord; often battered on one end and one or more faces; may have been used for ceremonial or magic purposes.

chert 

a rock of various colors, high in silica, commonly found in the Bay Area; breaks with shell-shaped fractures and can be worked into finely made tools. 

chronology 

the "time line" of an archaeological site; the sequence of events as well as the specific and general times at which they occurred.

curation 

storage of artifacts and samples by a museum to protect the archaeological collection and make it available for display or the use of other researchers.

data recovery plan 

plan prepared in advance of the excavation, which includes strategies and methods for carrying out the excavation and collecting information and samples to address the planned research questions. 

EIR 

Environmental Impact Report; public document reporting the results of environmental analyses of projects under CEQA. 

ethnographic 

refers to the writings of people who have personally observed native cultures and described them. For Native Californians, many ethnographic writings were made by European explorers and priests, who came to California in the 1700s. Often these are the only source available about the artifacts and cultural practices of a native group. The ethnographic period refer to the time before contact with Europeans had changed the prehistoric practices of native groups. 

geomorphologist 

scientist who studies the layers of midden and natural soil in a site to get information about the history of the deposit; evidence of past flooding, times when the site was covered with vegetation, and periods of erosion may provide significant information about changes over time in the site's environment. 

hand excavation 

excavation of an archaeological site with hand tools such as pick, 
shovel, trowel or dental pick. 

hunter-gatherers 

people who obtain their food and raw materials by hunting and foraging for wild animals and plants, rather than by raising domestic animals or growing crops.

lithic 

rock materials; in archaeological sites, refers to the materials used to manufacture stone tools by chipping or grinding.

mechanical excavation 

use of machines, such as backhoe, trencher or scraper, to assist in the archaeological excavation.  

midden 

soil incorporating decomposed food waste (shell and animal bone), ash, charcoal and other organic debris, and tools and other living debris, built up at places  where people have lived or worked; the soil of archaeological sites. Shell midden is midden soil with significant quantities of shellfish shells. 

mortar  view photo 

stone bowl made by grinding and shaping the inside ands sometimes the outside of a large cobble; usually made of sandstone, vesicular basalt or granite; used for grinding food, particularly nuts and seeds.

Native American 

any of the first people to occupy North, Central and South America;  California "Indians" 

obsidian 

volcanic glass that can be worked into sharp-edged tools; is not present in the geology of the Bay Area and had to be obtained through travel or trade; nearest sources are Napa and Sonoma counties. 

obsidian fluorescence 

chemical analysis of obsidian to determine its geological source (that is, where it came from).

obsidian hydration 

Obsidian absorbs a small amount of water (hydrates) over time, and  gradually developed a "rind" which represents the extent to which the water has  penetrated. By cutting a small slice out of the edge of a tool and measuring the hydrated  band on edge of the tool, scientists can estimate the length of time since the tool was  made. Since obsidian from different sources and found in different climates and  circumstances hydrates at different rates, this is usually used only as an approximate way  of comparing the ages of tools. 

Ohlone

San Francisco Bay Area Native American group whose ancestors probably occupied the Emeryville Shellmound. In the past, archaeologists called these people  "Costanoans", or coast people. Ohlone originally was the name of a small tribelet on the  San Mateo Coast. The name was adopted by local Native Americans in the 1970s,  because they preferred that their group have a name in a native language. Probably there  was no native name for all of the people of the San Francisco Bay Area as a group,  because they spoke many different dialects. Instead, each local group of tribelets had its own name, such as Ramytush for the people of the San Francisco Peninsula and Huichin for the people of the East Bay. 

Olivella 

olive snail, a marine snail; whole shell or cut fractions used to make small beads that were strung, or sewn or appliquéd onto other objects;  often found in graves. 

paleobotanist 

specialist who studies seeds and other carbonized plant remains from  archaeological sites or other sources to learn about past environments and human use of  plants. 

pestle

elongate grinding or pounding tool used with a mortar, often to grind nuts or seeds. 

prehistory 

time before writing was invented; all Native American cultures found archaeologically in California are considered prehistoric because  they left no written records. Sites occupied by Native Americans during the period after the Spanish arrived are considered protohistoric (of the early historic period) when they contain non-native historic artifacts, such as trade beads, ceramics or metal items. 

projectile point chert point and obsidian point (commonly called arrowhead) 

a pointed implement chipped from stone, usually obsidian or chert, to be attached to a spear or arrow shaft and used for hunting; small points were used on arrows, larger points on spears (to use by thrusting) or darts (to be thrown with a throwing stick). 

radiocarbon dating (also called C14 dating)

While they are alive, all living things absorb different types of carbon from the atmosphere. Some of this carbon, Carbon-14, is slightly radioactive. When a living thing dies, it stops absorbing carbon and the Carbon- 14 starts to decay at a known rate. Specialist labs can measure how much Carbon-14 is left in organic material (such as bone, charcoal, wood, shell or organic soil), compared with the amount of other carbon remaining, to determine the age of the material. This is the most common kind of dating used for things found in archaeological sites. 

red ochre

hematite, a red or sometimes brownish yellow mineral, powdered for use as a pigment. 

relative age 

age of an artifact or layer in comparison with items that are younger or  older. 

research design 

set of questions about the site; the excavation will be planned to get information relevant to these questions. 

tule reeds

a type of reeds that grew in the bay marshlands.  These reeds were used for basketry, rope, mats to cover houses, and boats.

stratigraphy view photo 

the arrangement of layers (or strata) of soil and midden as found in the ground or in an archaeological site. Since we know that the lower layers  in most circumstances are those that were deposited first, examination of the sequence of layers can provide a story of the sequence of use of the site. Singular of strata is stratum, a single layer. 

zooarchaeologist

archaeological specialist who identifies and studies animal bone found in archaeological sites to learn about animals populations present in the past and how they were used by humans.