Fossil collecting

Collecting fossilized shark's teeth is an easy way to begin collecting fossils. They are often found in abundance on public beaches. The teeth shown here were collected in Castle Hayne, North Carolina, and are from the Eocene and Cretaceous divisions. College of Wooster students collecting fossils as part of their invertebrate paleontology course. This is a roadside outcrop of Ordovician limestones and shales in southeastern Indiana.

Fossil collecting (some times, in a non-scientific sense, fossil hunting) is the collection of fossils for scientific study, hobby, or profit. Fossil collecting, as practiced by amateurs, is the predecessor of modern paleontology and many still collect fossils and study fossils as amateurs. Professionals and amateurs alike collect fossils for their scientific value.

Process

Locating fossils

Rock type

Fossils are generally found in sedimentary rock with differentiated strata representing a succession of deposited material.^[1] The occurrence of fossil bearing material depends on environmental factors before and after the time of preservation. After death, the first preserving factor is a rapid burial in water bodies or terrestrial sediment which would help in preserving the specimen. These rocks types are usually termed clastic rock, and are further subdivided into fine, medium and coarse grained material. While fossil's can be found in all grain typed, more detailed specimens are found in the fine grained material.^[2] A second type of burial is the non-clastic rock, form where the rock is made up of the precipitation of compacted fossil material, types of rock include limestone and coal. The third fossil bearing material is the evaporates, which precipitate out of concentrated dissolved salts to form nodular deposits, examples include rock salt and phosphate concentrations. The evaporates are usually associated with gastropod, algae, vertebrate, and trace fossils. Fossils are not to be found in areas of igneous rock (except in some beds between lava flows). In rocks which have undergone metamorphism, fossils are generally so distorted that they are difficult to recognize or have been destroyed completely.^[3]

Preservation

After burial various factors are at work to endanger the current fossil's preserved state. Chemical alteration would change the mineral composition of the fossil, but generally not its appearance, lithification would distort its appearance, the fossil itself may be fully or partially dissolved leaving only a fossil mold.^[2][4]

Exposure

Areas where sedimentary rocks are being eroded include exposed mountainous areas, river banks and beds, wave washed sea cliffs, and engineering features like quarries and road cuts. Coal mining operations often yield excellent fossil plants, but the best ones are to be found not in the coal itself but in the associated sedimentary rock deposits called coal measures. and foreshore exposures are often good places to search for fossils, but always be aware of the state of the tides in the area. Never take chances by climbing high cliffs of crumbling rock or clay (many have died attempting it). Dried up natural lake beds ^[5] and caves in the form of pitfall traps ^[6] frequently also have high concentrations of fossils (e.g., Cuddie Springs and Naracoorte Caves in Australia).

Appearance

Generally in appearance, a fossil will be either a different colour to the surrounding rock, because of the different mineral content, will have a defining shape and texture or a combination of both.^[4]

Collecting techniques

The techniques used to collect fossils vary depending on the sediment or rock in which the fossils are to be found. For collecting in rock a geological hammer, a variety of cold chisels and a mallet are used to split and break rocks to reveal fossils. Since the rock is deposited in layers, these layers may be split apart to reveal fossils. For soft sediments and unconsolidated deposits, such as sands, silts, and clays, a spade, flat-bladed trowel, and stiff brushes are used. Sieves in a variety of mesh sizes are used to separate fossils from sands and gravels. Sieving is a rougher technique for collecting fossils and can destroy fragile ones. Some times, water is run through a sieve to held remove silt and sand. This technique is called wet sieving

Fossils tend to be very fragile and are generally not extracted entirely from the surrounding rock (the matrix) in the field. Cloth, cotton, small boxes and aluminum foil are frequently used to protect fossils being transported. Occasionally, large fragile specimens may need to be protected and supported using a jacket of plaster before their removal from the rock.If a fossil is to be left in situ, a cast may be produced, using plaster of paris or latex. Whilst not preserving every detail, such a cast is inexpensive, easier to transport, causes less damage to the environment, and leaves the fossil in place for others to enjoy. Fossilized tracks are frequently documented with casts. Subtle fossils which are preserved solely as impressions in sandy layers, such as the Ediacaran fossils, are also usually documented by means of a cast, which shows detail more clearly than the rock itself.

Safety is emphasized while fossil collecting and hard hats, safety goggles, steel toe boots, and protective gloves are used.

Preparation and cleaning

Documentation

A knowledge of the precise location a fossil is essential if the fossil is to have any scientific value. Details of the parent rock strata, the location of the find, and other fossil material associated with the find help scientists to place the fossil in context, in terms of the time, location and situation in which the organism lived.^[7] Data logs, photographs, and sketchs may accompany detailed field notes to assist in the locating of a fossiliferous outcrop. Individual fossils are ideally cataloged with a locality number and a unique specimen number. This allows a collection to be easily searched and specimens located. Catologing of collections is almost universal in large institutions like museums.

Collecting ethics

Main article: Fossil collecting code

To collect fossils, there are various legal realities that must be observed. Permission should be sought before collection begins on private land.^[8]

Hammering the rocks in national parks and other areas of natural beauty is often discouraged and in most cases is illegal.

Societies and clubs

Many include fossil collectors. Lapidary clubs also include fossil collectors. In addition, paleontological societies and fossil clubs exist. There is some overlap between fossil collecting, mineral collecting, and amateur geology.

Notable fossil collectors

• Mary Anning
• Robert Bakker
• Phil Currie
• Paul Sereno

See also

• Fossil park
• Lapidary club
• List of fossil sites
• Mineral collecting
• National Fossil Day
• Paleontologist
• Paleozoology
• Prehistoric life

References

1. ^ "Where to look for fossils". San Diego Natural History Museum. http://www.sdnhm.org/kids/fossils/ffwhere.html. Retrieved 2007-09-06. 
2. ^ ^{a b} Potts, Joanna (2003). Guide to Fossils. London: Phillips. pp. 31–34pp. ISBN 0-540-08374-7. 
3. ^ "Stratigraphy Fossil-Bearing Rocks". The Rochester Academy of Science. http://www.rasny.org/fossil/NYstrat.htm. Retrieved 2007-09-11. 
4. ^ ^{a b} "How to look for fossils". San Diego Natural History Museum. http://www.sdnhm.org/kids/fossils/ffmore.html. Retrieved 2007-09-06. 
5. ^ "Dinnertime at Cuddie Springs: hunting and butchering megafauna?". Judith Furby, School of Archaeology, The University of Sydney, NSW 2006. Archived from the original on 2007-11-14. http://web.archive.org/web/20071114003012/http://acl.arts.usyd.edu.au/research/cuddie/cuddie.html. Retrieved 2007-09-11. 
6. ^ "Development of the Naracoorte Caves". South Australian Parks Web. Archived from the original on 2007-09-01. http://web.archive.org/web/20070901122951/http://www.parks.sa.gov.au/naracoorte/caves/index.htm. Retrieved 2007-09-11. 
7. ^ "Discover what you have". San Diego Natural History Museum. http://www.sdnhm.org/kids/fossils/ffwhat.html. Retrieved 2007-09-06. 
8. ^ "Do's and don'ts for fossil hunters". American Museum of Natural History. Archived from the original on 2007-08-10. http://web.archive.org/web/20070810175630/http://ology.amnh.org/paleontology/stuff/findfossils_2.html. Retrieved 2007-09-06. 

External links

• List of fossil localities in the United States and Canada
• Fossil collecting locations in Europe and the rest of the World
• Fossil hunting for beginners