how to find fossils

How to find fossils


see also: What to do once you find a fossil


Fossils are found in sedimentary rocks most of the time. Sometimes fossils can be found under volcanic ash or even preserved under a lava flow, but this is very rare.
NOTE: Sedimentary rocks do not always have fossils in them.
Layers are a characteristic of sedimentary rocks. The bottom layers are naturally the oldest.

Some types of rocks found in the layers:

Limestone, mainly calcium carbonate, common in warm, shallow seas, often has fossils.
Shale is a fine grained rock formed from silt and clays. It preserves fossils well.
Sandstone is widespread in desert deposits and on shallow water sediments.
Ripple marks and Mud cracks are characteristics of many sedimentary rocks formed in shallow waters. Ripple marks are common in shale. Mud cracks are form when mud drys quickly. These imply the presence of sunlight, water and moderate temperature conditions related to the possibilities of life.

WHERE TO LOOK

Sedimentary is your best bet for finding something. Too find some where that has fossils is quite hard if you don't already know where a site is. If you don't know where a site is you could ask the local Rock Club or a Museum. You could also look in freshly exposed rock, like look in road or railway cut. Visit mine dumps quarries and places where rocks are being excavated for new construction. Cliffs, river banks, headlands and other naturally exposures are also good. Remember that all these places have an element of danger. Watch for traffic at road cuts and get permission before entering quarries.

LOOKING IN CREEK BEDS AND BANKS
trace fossils in river

1.Start at the bottom of the creek
2.Look for fragments of bone
3.Follow them up the creek looking for larger, more angular bits as you go
4.When the bits of bone stop. Look up on the banks for the fossils
5.Find the larger piece of bone and excavate it

LOOKING AT INDEX FOSSILS

An index fossil is a fossil that is useful in working out the age of a bed of rock. You need several index fossils in combination to got a good date.

A good index fossil needs:

  1. To be easy to identify
  2. Common
  3. Exists over a short geological time range
  4. Has worldwide distribution
3 index fossils in the first area determine the age in the second area.
A simple example shown below

fauna

A more complex example shown below

bugs


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