Earth science relative dating
Earth science relative dating - hilly hindi dating
The age of the fossil must be determined so it can be compared to other fossil species from the same time period.Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms.
Each time a new layer of sediment is deposited it is laid down horizontally on top of an older layer.Despite seeming like a relatively stable place, the Earth's surface has changed dramatically over the past 4.6 billion years.Mountains have been built and eroded, continents and oceans have moved great distances, and the Earth has fluctuated from being extremely cold and almost completely covered with ice to being very warm and ice-free." First, the relative age of a fossil can be determined.Relative dating puts geologic events in chronological order without requiring that a specific numerical age be assigned to each event.In addition to being tilted horizontally, the layers have been faulted (dashed lines on figure).
Applying the principle of cross-cutting relationships, this fault that offsets the layers of rock must have occurred after the strata were deposited.
These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth's surface is moving and changing.
As these changes have occurred, organisms have evolved, and remnants of some have been preserved as fossils.
Layers of rock are deposited horizontally at the bottom of a lake (principle of original horizontality).
Younger layers are deposited on top of older layers (principle of superposition).
Second, it is possible to determine the numerical age for fossils or earth materials.