Sunday, January 15, 2012

Archaeology-Excavation-Report


What is Archaeology
A subdiscipline of anthropology. Anthropology  is the study of humankind.Archaeology is the study of the human past through material remains.
Material remains are collectively referred to as the archaeological record. This includes artifacts (e.g., stone tools, ceramic vessels); features (e.g., housepits, hearths); and ecofacts (e.g., animal bones, plant remains).
Archaeologists have three main goals:
1-Reconstruct Culture History: understand the distribution of archaeological remains through time and space.
2-Reconstruct Past Lifeways: determine past behavior through material remains.
3-Explain the Process of Culture Change: understand how and why cultures change through time.

Forms of Archaeological Data
1-Artifacts: portable objects whose form has been created or modified by human activity (e.g., projectile points, pottery vessels). Artifacts retain their appearance after the archaeologist takes them from the ground.
2-Features: non-portable artifacts that cannot be removed from the ground without altering or destroying their original form (e.g., housepits, burials, hearths).
3-Ecofacts: non-artifactual material remains that are not directly created or modified by human activity but have cultural relevance and provide information about past human behavior (e.g., animal bones, sediment, pollen).
4-Sites: spatial clusters of artifacts, features, and ecofacts. Sites identify where humans have occupied the landscape (e.g., Birch Creek, Stonehenge).
5-Regions: the largest definable spatial clusters of archaeological data. Regions can be a geographical, ecological, or cultural concept. Definition of a region allows the archaeologist to investigate a wider range of past activities that extend beyond a single site (e.g., Great Basin, Columbia Plateau, Southwest).
Archaeological Research Design
Archaeologists use the deductive scientific approach.
    • Form a Hypothesis: Ask a question that can be tested through observation.
    • Test the Hypothesis: Collect data through observation.
    • Accept or Reject the Hypothesis based on collected data.
A research design is a systematic plan that ensures that archaeological research is organized, efficient, and valid.
Seven Steps of an Archaeological Research Design
1.  Formulation of Research: Defining a research problem. Background research is usually conducted to refine the research problem. Defining a research problem also indicates where to look for archaeological data and what types of data to collect.
2.  Implementation of Research: Involves all arrangements necessary to conduct fieldwork. These types of arrangements can include obtaining permission to carry out field research, raising funds to finance the research, acquiring equipment and supplies, and recruiting staff members and excavators.
3.  Data Acquisition: Acquiring archaeological data.
a.  Archaeological Reconnaissance: locating and identifying archaeological sites.
b.  Surface Survey: recording as much as possible about sites without excavation. This often includes photography, mapping, probing, and surface collection of artifacts.
c.   Excavation: uncovering and recording a buried archaeological site.
4.  Data Processing: Collected archaeological material must be processed in the field. Data processing involves cleaning, numbering, cataloging, drawing, photographing, and taking notes of the archaeological data.
5.  Data Analysis: Data analysis is usually conducted in a permanent laboratory after fieldwork is completed. Some types of data analyses include:
a.  Artifacts: classification, technology, function.
b.  Chronology: age determination through absolute and relative dating techniques.
c.   Faunal Remains: identification of animal species.
d.  Floral Remains: identification of plant species.
e.  Geological Analysis: sediment analysis.
6.  Data Interpretation: The synthesis of all the results of data collection, processing, and analysis in an attempt to answer the original research question. Interpretation enables the archaeologist to reconstruct and explain the past.
7.  Publication of Results: The data, data analysis, and interpretation are published. Publication allows the research and its results to be used and retested by other people.
Three-Dimensional Space
1-The archaeologist must know her or his location in three-dimensional space in reference to a known point.
2-Horizontal Provenience: Site datum and site grid.
    • Datum: The site datum is a known location in three-dimensional space that serves as a reference point for all horizontal and vertical measurements taken at the site. The datum is a known point in three-dimensional space, but it is entirely arbitrary.
    • Grid: The site grid is laid out in reference to the datum. When referring to grid units, the coordinates of the SW corner of the unit are used.
3-Total Station (a.k.a. EDM, transit, theodolite, the instrument): A total station is a survey instrument that can measure horizontal and vertical angles, slope, and horizontal and vertical distances. The total station is another piece of equipment that archaeologists use to know their position in three-dimensional space. Measurements recorded by the total station will produce an x, y, and z value. The x-value represents the northing, the y-value represents the easting, and the z-value represents the elevation.
4-Birch Creek Site Datum and Grid
The site datum at Birch Creek is located to the south of the housepit block. The coordinates of the site datum are N1000 E1000.
All units are referred to with a northing and an easting coordinate, and all measure 1 meter square.
Units located to the north of datum have a northing greater than 1000, and units located to the south of datum have a northing less than 1000.
Units located to the west of datum have an easting less than 1000, and units located to the east of datum have an easting greater than 1000.
5-Vertical Provenience
Vertical measurements will also use the site datum as a reference point.
The elevation of the site datum in three-dimensional space is z=1000.
All levels will be recorded in reference to the datum point, but a few steps are needed to get the elevations.
During excavation, a laser level will be used to take vertical depth measurements in the excavation unit.
The laser level sends out a signal that creates an invisible horizontal plane across the site. The excavator will slide the laser level up and down the pole in order to locate the laser level signal.
When the receptor is close to being inline with the horizontal plane it will beep repeatedly. When the receptor is directly inline with the laser signal it will make a constant ringing sound. Using the measurements on the laser level rod, a 3-meter tape is used to measure the depth of the unit below the laser level.
Each morning after the EDM is set up, a shot will be taken of the laser level. The elevation of the laser level will be used to determine the depth of the excavation level below the site datum.

HOW TO USE ABSOLUTE DATING

In the field of archaeology two methods of dating are used---relative and absolute. Something is dated relatively using methods of stratigraphy, linguistic dating and climate chronology to name a few. However, these methods cannot date an object precisely, because the object is dated in comparison with something else; it's not dated in its own right.
However, absolute dating gives a more exact date for an object, because it uses methods like radio carbon or thermoluminescence dating techniques. How one dates an object using absolute dating depends on the object itself; the same dating method can't be used on all objects.

1.      Using Absolute Dating Methods

Determine the material makeup of the object being dated. The elemental makeup of an object determines its dating method. Once you determine the makeup of the object, you'll then employ one of the methods of dating below to determine its age.
1-Use Uranium-Thorium to date objects like marine sediment, bone, wood, coral, stone and soil. This method relies on measuring the half-life of uranium-238 and thorium-230 found in an object.
2-Utilize thermoluminescence dating if you have rocks, minerals and pottery to date.

3-Draw on radio-carbon dating to date materials that are organic like wood, bone, shells and tufa (sedimentary rocks made up of organic materials).

4-Consider racemization for once living organisms that are older than 50,000 years old. This is the cut-off for effective radio-carbon dating.Racemization measures certain types of amino acids in an organism after it dies and can measure the date of an item ranging from typically 5,000 to 100,000 years old. However, samples as old as 200,000 years old have been measured with this method.

5-Utilize potassium-argon (K-Ar) dating for rock and ash substances. This method measures the oldest of objects; Lucy, thought to be the first human ancestor before Ardi was discovered, was dated using this technique combined with relative dating techniques.

6-Find the absolute date of soil sample by using the oxidizable carbon ratio technique, which measures the organic carbon in the soil.
7-Employ the OSL (optically stimulated luminescence) method for silty and sandy sediments that have had little exposure to light; glacial deposits can be measured this way.

8-Use fission track dating to find the absolute date for objects like pottery, glass and fireplace hearths that have been exposed to heat. This method measures the isotopes of both Uranium U-238 and U-235 found in these objects.

9-Date minerals using the electron spin resonance dating method. Minerals like sedimentary quartz, fossilized teeth and egg shells are among the items that can be dated using this technique.

10-Rely on dendrochronology to date petrified trees and forests. It uses the rings found in trees to set to determine the age of the tree. This method can also be used as a relative dating method to date the objects in the forests found in the vicinity of the wood.

11-Consider astronomical dating techniques to find an absolute date for large archaeological features like Stonehenge. This is done by comparing the angle of the sunrise in prehistoric times compared with the angle of the modern sunrise.

12-Draw on archaeomagnitism when trying to date rocks. This principle relies on dating the shift in the earth's magnetic field, which is recorded in a rock's magnetic particles. As the earth's magnetic field shifts, so do the position of these particles in a rock.

DENDROCHRONOLOGY
Dendrochronology is the science of studying and dating tree rings. It can be used to determine the age of a particular tree. When several trees in a specific area are studied, the tree rings can give clues to geological or environmental occurrences in that area.

1-Counting Rings

By counting the number of rings on a tree trunk you can tell the age of the tree. Each year a new layer of wood, or a ring, is added to the growing tree. The rings have both a light growth section and a narrower, dark section. Scientists can use a method called coring to take a small, but long, crosswise section out of the trunk in order to count the rings and not harm the tree.

2-Ring Width

In years where the growth conditions are favorable, the tree will add rings that are wide. If the tree has gone through a period of drought or cold or was stressed in any way, it will add narrow rings to its trunk. Disease, insect damage, and competition for nutrients from other trees or plants can also cause narrow rings.

3-Cross Dating

Dendrochronolgists use cross dating to make the study of the rings more accurate. By sampling and comparing the tree ring data from many specimens within an environmentally similar area, scientists can identify the exact year of a ring's formation.

4-Skeleton Plotting

One method of cross dating is called skeleton plotting. Scientists note the variations of tree ring width on strips of graph paper. Each graph represents an individual tree. Scientists then compare the graphs, looking for similar patterns.

5-Conifer Ring Formation

The rings of conifers, or evergreens, are different than those of angiosperms, those trees that have leaves that turn brown and fall off in the winter. In conifers, the earlywood, or light section, has cells that are large in diameter but with thin walls. The latewood, or dark section, has smaller cells but the cell walls are much thicker.

6-Angiosperm Ring Formation

Angiosperms have vessel cells that are part of the tree's vascular system. These cells do not appear in conifers. In the earlywood, these vessel cells are larger in diameter than in the latewood.

Radiocarbon Dating Technique

Scientists have been dating fossils and rocks for more than 100 years. They use two similar methods with names that often confuse people. The process of radiocarbon dating was invented shortly after World War II and estimates the age of new fossils using a carbon isotope. Radiometric dating is usually used on much older material. The radiocarbon process is fairly simple, but its inventor needed ingenious techniques to prove the method works.

1-History

W.F. Libby unintentionally discovered radiocarbon dating in the mid-1950s through Serge Koff's work on cosmic radiation. Libby theorized from Koff's work that certain atmospheric reactions should indicate that carbon-14 exists in sizable quantities in nature. He then realized that carbon-14 could date organic objects because of its long half-life and necessity in the photosynthesis process .

2-Formation of carbon-14

Neutrons from cosmic radiation hit nitrogen (the main component of the atmosphere) to form carbon-14, although neutrons sometimes react with oxygen and carbon itself. A similar reaction occurs in nuclear weapons testing, which accounts for close to 5 percent of the amount of carbon-14 in our atmosphere. Most carbon-14, however, is stored in the oceans.

3-Dating

Scientists easily date plant matter because it photosynthesizes carbon-14. Dating animals requires that they have consumed plant material before dying. Carbon-14 does not get replaced after death, and the expected half-life of carbon-14 is well-documented. Dating methods need to determine the amount of carbon-14 left to age the organism. A common Geiger counter can measure the electrons given off by a burnt piece of material. The final step is plugging information into the exponential decay formula .

4-Limitations

Radiocarbon dating does not work 100 percent of the time. Smaller sizes of organic matter create greater statistical variation on dates. The care taken when excavating a sample reduces chances of cross-contamination with atmospheric carbon-14 and contamination from nearby samples. The half-life of carbon-14 limits dating to no more than 50,000 years and no less than a few hundred years .

What is Magnetic Dating.

The dating of artifacts by archeologists is the use of specific techniques to discover the object's age. Magnetic dating -- object dating systems based around variations in the earth's magnetic field -- is one of their valuable tools.

1-History

After World War II, geologists developed methods for measuring movements in the earth's magnetic pole. In the late 1960s archaeologists began to use these techniques for dating. There are two kinds of magnetic dating.

2-Paleomagnetism

Paleomagnetism is magnetic dating based upon the reversal of the earth's magnetic poles; this has occurred in irregular intervals every 100,000 years or so. A sample is compare to a master list of the magnetic pole situations throughout the eons to determine its age.

3-Archaeomagnetism

The other kind of magnetic dating, archaeomagnetism, is possible because the position of the magnetic north pole is not stable and moves around. If a clay object is heated to a hot enough temperature, the iron inside it will preserve the position of the pole at that moment. This frozen, magnetic information is used to date the object.

4-Significance

While other forms of dating are based around the decay of a particle, such as carbon-dating based around the decay of carbon, magnetic dating allows archaeologists to figure out the age of more varied and older artifacts.

What Is Thermoluminescence Dating.

Thermoluminescence dating is the use of heat on archeological or geological samples to produce a light signal that is proportional to an accumulated radiation dose. It is used to date rocks, minerals and ceramics for dates between approximately 300 to 10,000 B.P. (before present). It is usually used in conjunction with other methods of historical dating, such as carbon 14 or stratigraphy.

1-Process

When a material is heated or exposed to sunlight, electrons are excited and can be trapped in small imperfections in the molecular lattice of the sample, for example pottery or sediment. When the sample is exposed to heat, these trapped electrons are once again excited and recombine with the parent material. When this happens, they give off energy in the form of light that can be measured.

2-Methodology

Thermoluminescence dating requires two measurements for a successful date estimate. The first measurement is how much radiation the sample has been exposed to over the years. The second evaluates how much natural radiation is found both within and around the sample. Using these measurements, you can calculate how long the sample has been exposed to the radiation. This gives you the estimate for how long it has been since the sample was last heated.

3-Considerations

Since thermoluminescence dating requires information about radiation levels at the site the sample was taken from, if that site is destroyed or inaccessible, it may not be possible to use thermoluminescence dating techniques. With this knowledge in mind, you can plan ahead and remove the necessary background material along with the sample to make thermoluminescence dating possible.

4-Limitations

Thermoluminescence dating can only be used to date the object to the last time that it was heated to 350 degrees Celsius or higher, such as a clay vessel being fired, or a rock used as part of a fire hearth. It cannot be used on organic material.
This method also does not take into account any significant changes that may have occurred over the years to the sample or its environment. Results are best if a number of samples from the same area or archaeological dig can be compared. There can be a fairly large margin of error in this method, which is why it is best to corroborate the results with other dating methods if possible.

5-Benefits

Thermoluminescence dating can be used on samples for which radiocarbon dating is not possible. It is commonly used on pottery, ceramics, rocks, minerals and geological sediments. It can also be useful for comparing samples, even if the absolute age is not closely determined.

6-Warning

Thermoluminescence dating requires the sample to be exposed to heat over a period of time, which means that the sample may be compromised in the process.
Stratigraphy
Stratigraphy is one of the oldest and most widely used tools for dating a fossil and involves looking at the specific types of rock or fossils above and below the fossil sample. By properly identifying the time in which the rocks above and below the fossil were formed, it will allow scientists to gain a rough estimation for the date of the fossil.

How to Write an Archaeological Report

Archaeologists use data compiled from archival research, field work and laboratory analysis to document an archaeological site. The National Park Service published "The Secretary of the Interior's Standards and Guidelines for Archaeology and Historical Preservation" (48 FR 44716). This document defines the standards and guidelines for archaeological documentation. It is designed to provide archaeologists with technical advice about archaeological documentation methodologies. Each state also has its own set of standards and guidelines. An archaeologist uses this documentation to compile an archaeological report.

1-Delineate the project area. The report must describe the geographic boundaries of the site. Include a description of not only the area's physical environment but its history. If previous excavations have occurred at the site, include these findings.

2-Perform archival research. The report must include a literature review. Archival research is conducted prior to field work. Atlases, ethnographies, historical maps, oral histories, photographs and tax records place the site within both a historical and cultural context.

3-Define the research design. The report must articulate the project goals. List the research questions to be addressed, the plan of attack and the expected results. Make note of unexpected findings while you are in the field.

4-Summarize the field work. The report must document features and artifacts uncovered through the use of remote sensing, walkover surveys, shovel testing and excavations. Include sampling and recording techniques. Note problems with bad weather, site access and visibility. Include copies of field notes, maps and photographs.

5-Analyze the artifacts. The report must list each artifact recovered from the site. Laboratory analysis includes: studying the artifact types and distribution across the site; dating artifacts using dating methods, such as radiometric and carbon-14 dating, flora and faunal analysis; analyzing pollen samples; and analyzing soil samples.

6-Present the findings. The report must summarize the site data. Use figures, charts, graphs and tables to present the information in an easy-to-understand way.

7-Discuss the results. The report must evaluate the project in terms of the goals and objectives of the project. Provide recommendations for ongoing research at the site.

8-Attach an appendix. The report must list all photographs, figures, charts, graphs and tables presented in the report with the page number where they are found.
9-Include a bibliography. The report must include a list of all sources consulted during the project.

Excavation
Archaeological excavation existed even when the field was still the domain of amateurs, and it remains the source of the majority of data recovered in most field projects.
It can reveal several types of information usually not accessible to survey, such as stratigraphy, three-dimensional structure, and verifiably primary context.
Modern excavation techniques require that the precise locations of objects and features, known as their provenance or provenience, be recorded. This always involves determining their horizontal locations, and sometimes vertical position as well .
Likewise, their association, or relationship with nearby objects and features, needs to be recorded for later analysis. This allows the archaeologist to deduce which artifacts and features were likely used together and which may be from different phases of activity.
For example, excavation of a site reveals its stratigraphy; if a site was occupied by a succession of distinct cultures, artifacts from more recent cultures will lie above those from more ancient cultures.
Excavation is the most expensive phase of archaeological research, in relative terms. Also, as a destructive process, it carriesethical concerns. As a result, very few sites are excavated in their entirety. Again the percentage of a site excavated depends greatly on the country and "method statement" issued.
In places 90% excavation is common. Sampling is even more important in excavation than in survey. It is common for large mechanical equipment, such as backhoes (JCBs), to be used in excavation, especially to remove the topsoil (overburden), though this method is increasingly used with great caution.
Following this rather dramatic step, the exposed area is usually hand-cleaned with trowels or hoes to ensure that all features are apparent.
The next task is to form a site plan and then use it to help decide the method of excavation. Features dug into the natural subsoilare normally excavated in portions to produce a visible archaeological section for recording.
A feature, for example a pit or a ditch, consists of two parts: the cut and the fill. The cut describes the edge of the feature, where the feature meets the natural soil. It is the feature's boundary. The fill is what the feature is filled with, and will often appear quite distinct from the natural soil.
The cut and fill are given consecutive numbers for recording purposes. Scaled plans and sections of individual features are all drawn on site, black and white and colour photographs of them are taken, and recording sheets are filled in describing thecontext of each.
All this information serves as a permanent record of the now-destroyed archaeology and is used in describing and interpreting the site.

Grid Excavation

A grid excavation is a very common type of excavation archaeologists use at a dig site. This type of excavation is done, according to Smithsonian, when "an archaeologist seek[s] to understand the progression of time at a site." Smithsonian also states that "workers dig evenly spaced square holes, leaving baulks (wall-like unexcavated areas) between the squares...[which] allow archaeologists to examine a site's general stratigraphy and are later removed to reveal whatever might lie within them."

Vertical Excavations

Vertical excavation techniques are used to expose layers of strata in urban sites which have been occupied during multiple time periods. One vertical excavating method, the Wheeler Box Grid system creates a grid of excavated square areas while the rest of the excavation are is left intact. This allows the study of the succession of cultures or time-scale of a particular culture without being too invasive on other important features of an excavation.

Horizontal Excavations

Horizontal excavations are used to uncover large sections of a site. Although more invasive than vertical excavations, it allows a more in-depth study of a site's layout and function that other excavating techniques cannot offer. Vertical and horizontal excavation techniques complement each other and are often used on the same site at different times to provide a broader understanding of the site's function and time-scale.
Shoveling and Screeing
Most excavation teams use sharp skim shovels. These shallow shovels are used to carefully scrape the excavation and slowly peal thin layers of earth. Archaeologists using this technique will be looking out for soil changes and artifacts. Once the soil is removed from the site it is screened with meshes to recover small artifacts field researchers may have missed.
Troweling
Archaeologists will often use trowels, wooden picks or even pain brushes instead of shovels when they are working on a site where there is a high probability of finding artifacts or other ancient remains. These tools allow diggers to have a better feel for the changes in the soil and help reduce the risk of damaging an artifact.
Analysis
Once artifacts and structures have been excavated, or collected from surface surveys, it is necessary to properly study them, to gain as much data as possible. This process is known as post-excavation analysis, and is usually the most time-consuming part of the archaeological investigation. It is not uncommon for the final excavation reports on major sites to take years to be published.
At its most basic, the artifacts found are cleaned, cataloged and compared to published collections, to classify themtypologically and to identify other sites with similar artifact assemblages. However, a much more comprehensive range of analytical techniques are available through archaeological science, meaning that artifacts can be dated and their compositions examined.
The bones, plants and pollen collected from a site can all be analyzed (using the techniques of zooarchaeology,paleoethnobotany, and palynology), while any texts can usually be deciphered.
These techniques frequently provide information that would not otherwise be known and therefore contribute greatly to the understanding of a site.
Field survey
The archaeological project  continues with a field survey. Regional survey is the attempt to systematically locate previously unknown sites in a region. Site survey is the attempt to systematically locate features of interest, such as houses and middens, within a site. Each of these two goals may be accomplished with largely the same methods.
Survey was not widely practiced in the early days of archaeology. Cultural historians and prior researchers were usually content with discovering the locations of monumental sites from the local populace, and excavating only the plainly visible features there. 
Gordon Willey pioneered the technique of regional settlement pattern survey in 1949 in the Viru Valley of coastalPeru, and survey of all levels became prominent with the rise of processual archaeology some years later.
Survey work has many benefits if performed as a preliminary exercise to, or even in place of, excavation. It requires relatively little time and expense, because it does not require processing large volumes of soil to search out artifacts. (Nevertheless, surveying a large region or site can be expensive, so archaeologists often employ sampling methods.)
As with other forms of non-destructive archaeology, survey avoids ethical issues (of particular concern to descendant peoples) associated with destroying a site through excavation. It is the only way to gather some forms of information, such as settlement patterns and settlement structure. Survey data are commonly assembled into maps, which may show surface features and/or artifact distribution.
The simplest survey technique is surface survey. It involves combing an area, usually on foot but sometimes with the use of mechanized transport, to search for features or artifacts visible on the surface. Surface survey cannot detect sites or features that are completely buried under earth, or overgrown with vegetation.
Surface survey may also include mini-excavation techniques such as augers, corers, and shovel test pits. If no materials are found, the area surveyed is deemed sterile.
Aerial survey is conducted using cameras attached to airplanes, balloons, or even Kites. A bird's-eye view is useful for quick mapping of large or complex sites. Aerial photographs are used to document the status of the archaeological dig. Aerial imaging can also detect many things not visible from the surface.
 Plants growing above a buried man made structure, such as a stone wall, will develop more slowly, while those above other types of features (such as middens) may develop more rapidly. Photographs of ripening grain, which changes colour rapidly at maturation, have revealed buried structures with great precision.
Aerial photographs taken at different times of day will help show the outlines of structures by changes in shadows. Aerial survey also employs infrared, ground-penetrating radar wavelengths, LiDAR and thermography.
Geophysical survey can be the most effective way to see beneath the ground. Magnetometers detect minute deviations in the Earth's magnetic field caused by iron artifacts,kilns, some types of stone structures, and even ditches and middens.
Devices that measure the electrical resistivity of the soil are also widely used. Archaeological features whose electrical resistivity contrasts with that of surrounding soils can be detected and mapped. Some archaeological features (such as those composed of stone or brick) have higher resistivity than typical soils, while others (such as organic deposits or unfired clay) tend to have lower resistivity.
Regional survey in underwater archaeology uses geophysical or remote sensing devices such as marine magnetometer, side-scan sonar, or sub-bottom sonar.
Survey Techniques
Survey: Archaeological site surveying is the process of locating and initially evaluating sites in a given area.
There are 11 main steps in archaeological surveying:
·         1. Preliminary research
·         2. Selection of sampling design
·         3. Identification of sites
·         4. Precise locating and recording of their position
·         5. Assignment of designating code
·         6. Basic recording of the characteristics of sites, including topographic characteristics, major environmental features, vegetational cover, cultural features and surface collections, direction of exposure, and degree of disturbance
·         7. Basic recording of subsurface features where possible, including soil types, depth and nature of cultural deposits, stratification, and geology
·         8. Assessment of the significance of each site and its suitability for further investigation or excavation (related to a particular theoretical problem at hand)
·         9. Assessment of the likelihood of future disturbances or destruction at each site
·         10. A synthesis of information about the survey area at large, including predictions about the site population, site densities and clustering, and most frequent environmental associations
·         11. Description of the overall impact of development on the total site inventory or the area (if a salvage situation) and general recommendations concerning future research
Sampling Design
1-Judgmental Sampling: Units of study are selected on the basis of the researcher's opinion of the relative "productivity" of different areas.
2-Probabilistic Sampling: Samples are obtained by random or systematic selection of sampling units.
There are four main types of probabilistic sampling:
·         1. Simple Random Sampling: Each sampling unit in the entire field is numbered, and a certain percentage of units will be selected using a random number table
·         2. Systematic Sampling: The first sample unit is selected using a randomizing procedure, and all other units are chosen by a predetermined procedure (every fifth unit)
·         3. Stratified Systematic Sampling: The survey area is stratified into subclasses with each subclass serving as an independent universe; systematic sampling is then conducted within each independent universe
·         4. Stratified Random Sampling: The survey area is stratified into subclasses with each subclass serving as an independent universe; random sampling is then conducted within each independent universe.
General Excavation Guidelines
1-When you encounter something in digging, STOP! Do not remove the object, but carefully excavate around it looking for possible associated materials.
2-Keep your unit walls vertical and corners at a true 90 degrees.
3-Do not remove artifacts from sidewalls. If the artifact is not removed during the removal of a level, leave the artifact in the wall.
4-When troweling, keep the trowel edge at a low angle to the ground. This helps to prevent gouging the floor of your unit.
5-Keep the floor of your unit as level as possible when excavating.
6-Keep your unit clean. Avoid large piles of backdirt; it is difficult to see what is happening in your unit if too much backdirt accumulates at the bottom.
Screening
7-Sifting excavated earth through screens enables the archaeologist to recover many materials that might otherwise be overlooked (e.g., tiny flakes, animal bones).
8-All backdirt will be screened. Screens of 1/8-inch mesh will be used at the Birch Creek Site.
9-Don't dump out the material in your screen until we are confident that you know how to identify artifacts.
Note-Taking
10-Because the archaeological record is destroyed through excavation, it is extremely important that detailed notes are taken throughout the excavation process.
11-Plan View and Profile: Plan view maps and profile maps are an important part of the note-taking process. A plan view is a map of all significant features, artifacts, ecofacts, etc., drawn for each level of every excavation unit. Profile drawings are accurate vertical maps of the stratigraphy, artifacts, features, etc., exposed in the walls, or "profiles," of excavations.

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