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)

Devonian Fossils from Miguasha on the Gaspé Peninsula

Today on the show, we'll explore the first fossil finds from Miguasha Provincial Park, a protected area near Carleton-sur-Mer on the Gaspé Peninsula of Quebec in Canada, from the mid-1800s. Miguasha i...

30 Mar 202518min

The Burgess Shale – A Window into Deep Time

Welcome to the Fossil Huntress Podcast. Today, we're taking a journey half a billion years back in time to one of the most extraordinary fossil sites on the planet — the Burgess Shale — nestled high i...

28 Mar 20258min

King of the Trilobites: The Discovery of Isotelus rex

Today we’re setting sail—back in time—to meet the king of the trilobites: Isotelus rex, the largest complete trilobite ever discovered.Now, I know trilobites are often tiny—beautiful, delicate little ...

27 Mar 20259min

Time Travelers in Stone: What Are Trilobites?

Welcome to The Fossil Huntress Podcast—your window into the deep time of ancient oceans, lost worlds, and beautiful traces left behind. I'm your host, Heidi Henderson, coming to you from the rain-kiss...

26 Mar 202511min

The Bone Wars: Cope & Marsh

Welcome back to the Fossil Huntress Podcast, the show where we dig into the dirt—literally—to uncover the most fascinating stories from Earth’s deep past. Here you'll find ammonites, trilobites, dinos...

25 Mar 20255min

What is Paleontology & What is a Fossil?

Welcome to the Fossil Huntress Podcast, the podcast where we dig into the past—literally! Join in the exploration of the fascinating science of palaeontology — that lens that examines ancient animals,...

24 Mar 20254min

Sclater, Wallace & Darwin: The Evolution of Evolution

On today's show, you'll hear about a paper delivered on a chilly December evening in 1857 by Philip Sclater that hugely inspired Alfred Wallace and eventually led to the publication of the Origin of S...

6 Jan 202530min