Fossil Huntress — Palaeo Sommelier30 Des 2020

Geologic Time & Radioisotope Dating

We live on an amazing planet with a 4.5 billion year history of life evolving from a single cell to multicellular life to the sheer volume of diversity of species we see through time and walking the Earth today. How do we know the timeline for this? How do we date the rock units and mountains and stones beneath our feet?

We use simple observation out in the field to look at rock and observe that generally speaking, older rock units tend to be deeper than the younger rock on top. We use index fossils like ammonites or Triassic paperclams to help give us a better understanding. We also turn to chemistry and use the decay rates of radioisotopes to help give us a time stamp on a rock unit. We use Carbon-14 for rock younger than 50 thousand years or Potassium-40 or Uranium for rock older than 50 thousand years. It was through the decay rate of uranium that we arrived at a relative age of the Earth of 4.5 billion years.

We have new techniques evolving out of various fields of science to help us gain a deeper understanding of the Earth. Donald Prothero has been taking deep-sea drilling cores which tell us of shifts in the magnetic field of the Earth. His work will let us date the fossils we find to within 100,000 years — a significant insight over the plus or minus 2-million-year dating that radioisotopes give us.

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Episoder(121)

What Killed the Dinosaurs?

Today on the show, we travel back in time to the Late Cretaceous, some 66 million years ago, when death fell from the sky.

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Ammonoids & Conodonts: Triassic Exposures of Nevada

Step into the sunbaked folds of West Union Canyon, just beyond Berlin-Ichthyosaur State Park in Nevada, and you are quite literally walking along one of North America’s most important geological fault...

9 Apr 7min

Descendants of the Cambrian: Sea Anemones

At first glance, anemones look like soft blossoms anchored to rock, their tentacles swaying with the tide. But look a little closer and you’ll see a skilled predator at work. Each of those delicate ar...

8 Apr 3min

Hawai'i: Islands Born of Fire

Long, long ago—millions of years before you or me, before the canoes of the Polynesian voyagers, before the first birds ever touched these shores—there was only ocean. A vast blue desert stretching fa...

27 Sep 20256min

Dinosaurs, Ammonites, Trilobites: What is Paleontology

Join in the exploration of the fascinating science of paleontology — that lens that examines ancient animals, plants & ecosystems from wee single-celled organisms to big & mighty dinosaurs.

22 Apr 20256min

Stone, Bone & Water: Cretaceous Capilano Fossil Field Trip

Cretaceous Capilano Fossil Field Trip — From downtown Vancouver, drive north through Stanley Park and over the Lion’s Gate Bridge. Take the North Vancouver exit toward the ferries. Turn right onto Tay...

12 Apr 20257min

Woolly Mammoths: Trumpeting Through the Tundra

Woolly Mammoths – Picture a towering, shaggy titan lumbering across a frozen expanse, as winds howl through its dense, draping fur. This is the Woolly Mammoth—an Ice Age icon that could stand up to 11...

7 Apr 202511min

Theropods of a Feather: Living Dinosaurs, the Birds

Welcome to the Fossil Huntress Podcast. Today on the show we’re talking about living dinosaurs—our avian friends, the birds. From the tiniest hummingbird to the towering ostrich, these feathered creat...

1 Apr 20258min