Geologists obtain a wide range of information from fossils. They help us to understand evolution, and life in general; they provide critical information for understanding depositional environments and changes in Earths climate; and they can be used to date rocks.
Are fossils useful for dating igneous rocks?
In this case, fossils can be useful tools for understanding the relative ages of rocks. Each fossil species reflects a unique period of time in Earths history.
How do you date rocks?
The nuclear decay of radioactive isotopes is a process that behaves in a clock-like fashion and is thus a useful tool for determining the absolute age of rocks. Radioactive decay is the process by which a “parent” isotope changes into a “daughter” isotope.
Can we date fossils directly?
Innovations to existing dating methods are eliminating these barriers. For example, revisions to a method called electron spin resonance allow scientists to date rare fossils, like hominin teeth, because they can directly date the fossil without visibly damaging the specimen.
How can you use fossils to read rocks?
The fossils present in a rock exposure or in a core hole can be used to determine the ages of rocks very precisely. Detailed studies of many rocks from many places reveal that some fossils have a short, well-known time of existence. These useful fossils are called index fossils.
What is a rock layer full of fossils called?
ONE WAY to find out more information about dinosaurs is to discover more dinosaur fossils. The type of rocks in which dinosaur fossils (and almost all other fossils) are found is called sedimentary rock. Sedimentary rock generally occurs as flat layers called strata (single layers called stratum).
What are the best rocks to find fossils in?
Almost all fossils are preserved in sedimentary rock. Organisms that live in topographically low places (such as lakes or ocean basins) have the best chance of being preserved.
How do you tell if a rock is a fossil?
Mostly, however, heavy and lightly colored objects are rocks, like flint. Paleontologists also examine the surfaces of potential fossils. If they are smooth and do not have any real texture, they are probably rocks. Even if it is shaped like a bone, if it does not have the right texture then it is probably a rock.