TEKS Correlations

Grades 4-7

Science

1. Scientific processes. The student conducts field and laboratory investigations following home and school safety procedures and environmentally appropriate and ethical practices. The student is expected to:
(A) demonstrate safe practices during field and
laboratory investigations; and (B) make wise choices in the use and conservation of resources and the disposal or recycling of materials

4. Scientific processes. The student knows how to use a variety of tools and methods to conduct science inquiry. The student is expected to:

Grade 4: (A) collect and analyze information using tools including calculators, safety goggles, microscopes, cameras, sound recorders, computers, hand lenses, rulers, thermometers, meter sticks, timing devices, balances, and compasses.

Grade 5: (A) collect and analyze information using tools
including calculators, microscopes, cameras, sound recorders, computers, hand lenses, rulers, thermometers, compasses, balances, hot plates, meter sticks, timing devices, magnets, collecting nets, and safety goggles.

Grade 6: (A) collect, analyze, and record information using tools including beakers, petri dishes, meter sticks, graduated cylinders, weather instruments, timing devices, hot plates, test tubes, safety goggles, spring scales, magnets, balances, microscopes, telescopes,
thermometers, calculators, field equipment, compasses, computers, and computer probes.

Grade 7: (A) collect, analyze, and record information to
explain a phenomenon using tools including beakers, petri dishes, meter sticks, graduated cylinders, weather instruments, hot plates, dissecting equipment, test tubes, safety goggles, spring scales, balances, microscopes, telescopes, thermometers, calculators, field equipment, computers, computer probes, timing devices, magnets, and compasses.

Step 5: Artifact and Object Preservation

Goal: to familiarize students with the need to carefully preserve found materials for the purposes of research and reporting to the scientific community and the general public.

Objective: students will learn scientific methodologies to preserve the materials found during the excavation for preservation.

Materials Needed:

old toothbrushes
boxes or bags
padding (tissue paper or quilt batting)

Activity Description:

ARTIFACTS:

• Make sure the artifact slip is complete and kept with the artifact. Complete any information not filled out during the excavation.
• Clean the artifacts. Use a toothbrush to clean off any dirt clinging to the object. You may use a small amount of water if the artifact is not rusty. Do not use water on any objects that are very fragile.
• Place artifact in appropriately labeled box or bag. Use a substance like quilt batting or tissue paper to protect fragile objects.

FORMS:

• Check all forms. Make sure all forms are filled out completely and signed by the workers.

LANDMARK LAB PROCEDURES - explanation

CLEANING, PRESERVATION AND REPAIR

Bones
Bones from archaeological sites are very susceptible to drying, cracking and breakage from friction with other objects. The first process must be to clean the bone as dirt will cause the bone to crack and attract insects. Very stable bones may be washed with a soft toothbrush and water but do not immerse in water or leave to soak. Water-soaked bone may crack as it dries. For more fragile bones, acetone should be used. Acetone evaporates so it does not soak the bone. Also, it drives out water in the bones. As acetone evaporates rapidly, keep the container tightly covered when not in use. Acetone should be used in a well-ventilated area or under a ventilator hood.

Paintbrushes, dental picks and toothpicks, etc. may be used in cleaning but careful attention should be paid so as not to scratch or otherwise disturb the bone's surface. Do not use metal utensils on the surface of the bone. Marks left by man's butchering activities may be obscured by improper cleaning methods.
The preservative being used, polyvinyl acetate (PVA, viscosity 15), has been chosen because it soaks into the bone supporting and protecting both its surface and inner structure. Also, the affects of PVA are long-lasting. PVA (10% solution) is mixed with acetone; a thin solution should be maintained. As the acetone evaporates, acetone may need to be added. Before preserving bones, they should be examined for evidence of butchering or use as a tool. If this evidence is found, consult the lab supervisor before applying preservative.

After cleaning and preservation, broken bones may be glued together with PVA of viscosity of 25. If two pieces of bone were found broken in the ground, they should be left separated as the break may have resulted from man's activities. Often it will be necessary to set the two pieces in a sand box to keep them stable while the glue dries. Keep sand away from the area being glued to prevent gluing sand onto the bone.

If small animal bones need to be cleaned, this should be done carefully with acetone and a paint brush. They can be placed in a capsule or glass vial. A small piece of neutral tissue paper may be inserted to keep the item from moving around in the container.

Lithics (Stone)
Lithics generally need little conservation other than cleaning. Cleaning may be accomplished with water and paintbrushes. Many studies utilize microscopic investigation of the edges of lithic tools. Curators may want to leave at least a few stone artifacts from each site uncleaned or avoid cleaning the edges. Again, check with the lab supervisor or Collections Manager before cleaning is begun. Sometimes calcium carbonate deposits occur on stone artifacts covering flake scars and other important attributes. These can be removed with dilute HCl if the stone does not contain a significant amount of calcium carbonate, or a similar substance which will be dissolved by the HCl. These deposits are sometimes used for relative dating so the curator may want to leave a small amount on each or several lithics.

Ceramics
Most ceramics need only to be washed lightly with water and a paintbrush. Fragile sherds may need to be washed with acetone and preserved with a very thin PVA solution. Unfired clay should be lightly rubbed between the fingers to remove dirt and then preserved. Again, chemical deposits are often found on the surface which may be removed as described above. If crushed bone, shell, or other carbonate-based material is used as temper, no acid should be applied. Sherds broken during excavation can be glued together using a thicker PVA solution. DO NOT tape the pieces together to hold them in place while the glue dries. A sandbox can hold the pieces in place. Repair of missing pieces with plaster or clay is not recommended.

Shell
Shells or areas of shell that are stable may be cleaned with a dry brush. If necessary, water can be used sparingly but only if the shell does not begin to flake off. Otherwise, they should be left "as is." Areas that are chalking and weak spots may be consolidated with 10% PVA preservative. A 20% PVA adhesive can be used to repair recently broken pieces. A 10% PVA preservative should be brushed onto a small area and allowed to dry, before writing the number on the area. It can then be coated with the same material.

Plant material
Generally nothing can be done to clean and preserve plant material without destroying it. Plant material should be housed in vials or boxes to protect it from crushing. Avoid placing cotton, polyester padding, or other fibrous material next to the material as the fibers become embedded in the plant material.

Recording Treatment
A record of all conservation treatment should be kept on each artifact and may be included on the catalog sheet, locational inventory or in a separate notebook.

PACKAGING

Polyvinyl chloride bags should not be used for housing any artifacts. PVA or polyethylene bags are acceptable. Labels should be on acid-free paper, written with acid-free ink. They should include the following information: catalog number, feature or site number, stratum, and identification.

Bone tools and flakes should be wrapped with neutral pH tissue paper or padding and placed in a ziploc polyethylene bag with a label. Lithic flakes and debitage, and pottery sherds may be wrapped individually in acid-free tissue paper and several placed in one bag. Preferably, each flake should be wrapped individually and placed in its own bag with a label. Lithic tools need to be individually wrapped in their own bag with a label.

PACKING FOR TRANSPORTATION

Boxes should be of a strong cardboard material. Smaller size boxes (not larger than 1 1/2' x 2') should be used especially for heavy materials like stone implements. Padding may be of any soft material, e.g., newspaper, styrofoam, tissue paper, shredded foam, or paper towels depending on the materials being packed. Each bone should be individually wrapped except perhaps for bone scrap. Bone tools and very fragile bones or other fragile items should be very carefully packed, preferably with cotton or polyester padding. Boxes containing very fragile items should be so marked on the outside. Bone, lithics, pottery, microfaunal and floral material, and other types of material should be boxed separately.
As items are packed, an inventory is made for the collection as a whole and for each individual box. Each box is numbered and the items in that box listed on an inventory for that numbered box.