Difference between revisions of "Shipping Small Fossils"

Revision as of 20:05, 1 August 2019

Statement of Purpose

This page presents recommendations on how to pack and ship small fossils to prevent damage in transit.

Contributors

Carrie Eaton

Introduction

Micropaleontology utilizes a variety of of small materials including small fossiliferous hand samples, cavity slides, thin sections, screened separates, or even small specimens mounted on microscope stubs. Each of these presents challenges not only for curation, but for the shipping of these objects for loans and research. It is important to consider the small size and potential fragility of these specimens when determining the best possible materials and methods for their transport.

Shipping Small and Fragile Fossils

For fossils that are small, but not stored in specialty micro-fossil mounts (plugs, slides, stubs, etc), one possible procedure to use when packing is to use a double-boxing or container-within-a-container to protect the small specimens. Choose an outer box that is noticeably larger than the inner box. The size of the inner box is dependent on the weight and fragility of the specimens being shipped. Fill the void space between the two boxes with a material that can absorb shock and vibration such as polyester batting, polyethylene foam, foam rubber chips, etc. This will aid in the dissipation of physical impacts to which the package may be subjected.

To protect small fossils with protruding, delicate parts, a small cavity mount made out of Ethafoam plans or rings can be used to protect the specimen for transport. Using the shape of the object as a guide, carve a cavity of material out of the Ethafoam just slightly larger than the object itself. This cavity can be partially filled with polyester batting or shredded foam to cushion the specimen. For some cavity mounts, a layer of archival, smooth-structure Tyvek or thin polyester felt can be pushed down into the cavity such that it is placed between the specimen and the cushioning material. If using an Ethafoam ring, be sure to use one that is larger than the specimen and mount this ring to a rigid box, foam plank, or archival foam board to prevent shifting. A cavity mount can then be packed into a larger box using the double-boxing method described above for better protection.

Packing Micro-Fossil Mounts for Shipping

Slides

Microfossils and other small specimens need to be stored in small containers. The smallest specimens are often mounted on slides of varying types, including cardboard or wood cavity slides with metal sleeves, plastic cavity slides with plastic covers, glass slides, or alumninum SEM 'plugs' or 'stubs'. Cavity slides (wooden or plastic) can be wrapped tightly with a flexible material to ensure the cover is pressed tightly to the slide backing. Flexible cardboard cut into strips or 1/16" polyethylene packing foam can be wrapped around the slide, making sure that the material is pressed tightly on both the front and back sides, and then taped closed. A set of wrapped slides can be placed into a larger box and packed with a soft and flexible stuffing. If there is a concern of the fossils detaching or being dissociated from the slide, each individually wrapped slide can be placed inside a small plastic sample bag before boxing. Any loose samples will then be contained within the sample bag and associated with their sample number, and not be lost or mixed with others.

Plastic slide covers on plastic cavity slides are prone to creating static, which can attract loose specimens. The tiny, loose microfossils can be difficult to separate from the plastic cover without risking the loss of the specimen. Brushing the cover piece very carefully with an anti-static agent, or an anti-static brush, is sometimes enough to safely loosen the specimen. It is recommended that you do any brushing of microfossil mounts underneath a microscope in the event that the specimen comes out of its container. Given the risk with static, is it recommended that a small amount of reversible adhesive is placed underneath the specimen when using a plastic cavity slide.

A note about glass slides with containing rings

The glue holding most home-made slide rings will become progressively weakened over the years and the adhesive will eventually fail. For this reason, scientifically significant specimens mounted with this method should ideally not be shipped as-is, but should be remounted into a more stable or permanent system before being transported.

Specimens mounted to aluminum stubs

Microfossils examined using microscopy (such as scanning electron microscopy, or SEM) are often mounted in place onto aluminium stubs. These stubs are frequently stored in rigid plastic boxes with small inserts to hold several stubs in one box. If a single stub needs to be shipped or transported, an individual stub holder can be used instead. In instances where the SEM stubs are not snug inside the holders within the stub box, you may need to use a thin material underneath the stub to create a tighter fit. A thin strip of teflon tape, or even plastic wrap, works well to create a tighter fit between the stub itself and the holder inside the stub box. Microfossil stubs will have a tight fit inside a good stub box, and this extra layer of material would not be necessary.

Since the fossils are mounted directly to the surface of the aluminum stub, you want to be sure to not put anything on top of the stub directly. Any material in direct contact with the stub can abrade the stub when moved or vibrated and cause the fossilto detach from the top of the stub. In most stub boxes, there is a gap between the top of the stubs and the lid. In the event that detachment may occur, you can carve out circles of Ethafoam to encase each stub in a small cavity mount and prevent dissociation. The carved Ethafoam should be as tall as the lid and, when the lid of the stub box is shut, will prevent any detached fossils from getting mixed with others since each stub is individually surrounded by a cylinder of Ethafoam.

Links

PadCAD, an online tool for designing protective cushions for the shipment of fragile objects: https://app.pch.gc.ca/application/padcad/index.app?lang=en

References

Collins, Chris, ed. 1995. The Care and Conservation of Palaeontological Material. ISBN 0 7506 1742 X

Callomon, Paul, personal comm.

Di Giacomo, Maria, personal comm.

Yanega, Doug, personal comm.