brooke valentine dating - Rock dating methods

Earlier research had shown that isotopes of some radioactive elements decay into other elements at rates that can be easily predicted.

By examining the existing elements, scientists can calculate the initial quantity, and thus how long it took for the elements to decay, allowing them to determine the age of the rock.

Several attempts to scientifically date the planet have occurred over the past 400 years.

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A couple weeks later they sent up an aerial drone to photograph and record data about the ancient site. Since the 1960s the site was known to have a buffalo jump, where Indians herded buffalos off cliffs and then harvested the meat, organs, skin, bones and ligaments for food, clothing, housing and implements.

government archaeologists set a controlled fire in April 2015 to reveal a unique site in northern Montana that has large Native American stone effigies, cairns, circles and structures used centuries ago to drive cattle into catchment areas for slaughter. Bureau of Land Management personnel burned off brush and prairie grasses to allow a better view of and easier access to the structures.

As science progressed, these methods were proven to be unreliable; for instance, the rise and fall of the ocean was shown to be an ever-changing process rather than a gradually declining one.

In an effort to calculate the age of the planet, scientists turned to the rocks that cover its surface.

Samples returned from the Apollo and Luna missions revealed ages between 4.4 and 4.5 billion years, helping to constrain the age of Earth.

In addition to the large bodies of the solar system, scientists have also studied smaller rocky visitors to that fell to Earth. Some are cast off from other planets after violent collisions, while others are leftover chunks from the early solar system that never grew large enough to form a cohesive body.

In an effort to further refine the age of Earth, scientists began to look outward.

The material that formed the solar system was a cloud of dust and gas that surrounded the young sun.

The oldest rocks on Earth found to date are the Acasta Gneisses in northwestern Canada near the Great Slave Lake, which are 4.03 billion years old.

Rocks older than 3.5 billion years can be found on all continents.

Gravitational interactions coalesced this material into the planets and moons at roughly the same time.

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