Guide to Fossil Collecting

Fossils are the remains of  dead creatures that have been preserved in the rocks.   They may be a few thousand  or even 500 million years old.   If you want to be a geologist you have to have a basic understanding of fossils,  the study of which is called paleontology.

In the Middle Ages the finding of  seashells in rocks away up in the mountains was attributed to the Great Flood,  when Noah and his Ark saved all the animals.  Fossils then were a curiosity and subject to much speculation.   The idea that a point on the  earth’s surface could very slowly rise or sink vertically by many miles was not even contemplated.    Now we know better.

Rocks are classified into three types,  igneous, metamorphic and sedimentary.   The first two have  crystallized  deep within the earth  (except volcanic lavas), and don’t contain fossils.  Erosion of igneous  (e.g., granite) and metamorphic (mica schist) rocks produce the materials for deposition of sedimentary rocks,  which includes  shales,  sandstones and limestones, which are the commonest.    It is these rock  types  which may contain fossils.

A beach, stream or river bed is a good place to roam looking for fossils.  The stones found here may have come from a great distance.   Also, on a sea beach you will see modern shells, logs, dead fish  and seaweed which eventually may become buried by sand and mud,  thus potentially being  fossils in the making.  Beach and shallow water deposits of shelly sands and  muds when deeply buried,  harden into sedimentary rocks having fossils.

Sometimes estuaries and deltaic regions accumulate a lot of organic matter if the hinterland is forested. Such regions may produce peat, which on burial changes to  lignite, brown coal and black coal.   These coal measures are a good source of plant fossils,  such as leaves, fern fronds and possibly amber with insect inclusions. Deep water sediments tend not to have fossils, i.e., are unfossiliferous,  and may cover large regions, e.g., greywacke, a dark hard fine-grained sedimentary rock being typical.

What sort of fossil collector do you want to be?    There is a  range of activities to choose from:   
1. Serious and scientific study by any age group … students and grown-ups
2. Casual  interest  in geology
3. Ornamental, and the display artist

Fossils can be found on excursions to the mountains or beach, particularly if there are limestone rocks out cropping.  A geological hammer and a couple of steel chisels are useful to chip away any fossil shell discovered.   Road cuttings and old quarry excavations have good exposures of  rock strata.   The younger limestones of  Pliocene to Miocene Age (4 to 30 million years old) often have  fossil molluscs,  gastropods,  brachiopods,  echinoderms, corals  and shark teeth.  It is important to record in a notebook what you have collected (sketch) and where from.   Good specimens are valuable and can be swapped with your friends, or even sold on eBay.

Science teachers have much resource material concerning fossils available on the Internet.  This can be used to get students interested in collecting and studying fossils.    Check out your nearest Mines and Energy government department to buy a geological map of your area and any booklets they may have  to do with fossils or the geology of local sedimentary rocks.   This will guide you where to go and help in identification of what you find.  

Another source of fossils is to buy them from a mineral and fossil dealer that advertises on the Internet.   Also, on eBay there is a section under Collectables – Rocks, Fossils and Minerals which is worth browsing through to buy inexpensive fossils.  There are some parts of the world which are prolific in fine fossils which are in demand for display purposes, around the home or  office, and are shown like you would a beautiful painting, but the fossil depicts life on earth as it was maybe 300 million years ago or more.   

The Atlas Mountains in Morocco seem to have an inexhaustible supply of fossil squids and trilobites particularly, and are readily available  from dealers and most rock shops worldwide. You could of course do a bus tour of Morocco and meet the locals around Fes who ply their wares to bargain with the tourist.  They have excellent boxed collections of ammonites, trilobites, orthoceras, belemnites, brachiopods and shark teeth for about $20.  The orthoceras (bullet-shaped squid) in black limestone are carved into  animals and ornaments.   Ammonites of  3  to 4 feet  in diameter are found  at roadside shops, but these are a bit heavy to bring home.

Ammonites of  6  to 12 inch size  when polished up make nice display items for the office or home, as do rock slabs with  fossil ferns and fish.  Closer to home is the Fiddler’s Green Formation in New York State, which has designated as State Fossil, the amazing “Eurypterids”, a type of sea scorpion,  found as perfect specimens up to 6  feet  long, which are much in demand by museums and collectors.    Perfect specimens of trilobites,  ammonites and other fossils  may sell for hundreds, even thousands of dollars and so be comparable to a  prized painting.

In conclusion,   fossil collecting can be fun and educational.  Young and old can find some aspect of fossil collecting to challenge their mind and make life more enjoyable.   It can be an incentive to go hiking in the hills or visit a new country, and make new friends.  Go to it!