Collecting fossils can be a fascinating and absorbing hobby. But if it is to be of any value to the collector himself or indeed to other palaeontologists, it must be well catalogued and preserved.
After a tiring day in the field it is all too easy to come home and sit down leaving your specimens in your rucksack. Perhaps, later in the evening, you will unwrap them and put them in a convenient shoe box, with just a note of where they were collected. Since this is such a common failing, a recent course run by Bristol City Museum on Cataloguing and Preserving Fossils was of great interest.
Before setting off on a Field Trip the following guidelines should be observed.
Items to take with you:
- Newspaper, plastic bags and sticky labels for wrapping and labelling specimens. Tape measure, pencil, 0.S. Map, camera and field note book.
- When you arrive at the site make a note of the grid reference. Stand back and look at the exposure and if possible make a sketch of it, showing all the relevant features i.e. bedding, horizons, faults, folding etc. Measure the length and height of the exposure, where practicable and the depth of each horizon or stratum.
- Start collecting from one horizon at a time, labelling and wrapping as you go and entering into your field note book. The positions of large specimens may be marked on the sketch map and photographed.
On returning home specimens should be removed from the rucksack and carefully washed in warm soapy water and left to dry. Great care must be taken to see that the field label is still intact. Shales or other friable material should be treated very carefully.
Some specimens may need more than a wash. Dental picks are excellent for removing small pieces of adhering material and careful use of a hammer and cold chisel can sometimes release a fossil from its surrounding matrix. Broken specimens may be repaired with a strong glue.
Once the preparation has been completed each specimen must be labelled and entered into a Master Catalogue giving all the relevant details as follows:-
- Sequence Number
- Date collected
- Rock type and formation
- Identifying name
and finally a column for any remarks either interesting or pertinent.
Finally the labelling of the fossils is very important. Each specimen must clearly show its sequence number. That number will correspond to the same number in the Master Catalogue and when the other columns are completed a permanent record of that particular specimen will have been made. After numbering the label it can be left to soak in water for a few minutes. Then place a small quantity of glue on the fossil and press firmly into position. The label will adhere firmly to the surface and contour of the fossil and will not come off after a few weeks, like sticky labels. Indian ink should be used for marking the label and a water soluble glue which will allow the label to be removed and transferred to another part of the specimen if necessary.
Once all the labelling has been completed the fossils can then be stored in a dry place with a fairly constant humidity. Probably the best way to store them is to place each specimen in an individual shallow cardboard tray and place them in banks in drawers. The trays should be placed so that there is little movement between then, thus lessening the risk of damage, and each tray marked with the sequence number of the fossil it contains. Small or delicate specimens can be wrapped in acid free tissue paper or a soft ‘lint free’ material.
It is not always possible for the amateur to identify every specimen he finds but with this system it means that once a specimen has been given a sequence number and all relevant details entered into the Master Catalogue the final identification can be added at a later date.
There are of course many other methods of cleaning and preserving fossils and those mentioned here have been mainly applied to the Limestone fossils of the Bath area