<p>Perhaps some of the oldest limestones are the banded Espanola Formation from 2.3 billion years ago. The Oxygenation of the environment happened 2.4 billion years ago. I'll find some references and chemistry info when my web connection works, here are <a href="https://www.google.com/search?q=%22Espanola%20Formation%22%20limestone&amp;tbm=isch&amp;ved=2ahUKEwjjsvOrtfvnAhXSwYUKHdCWDkwQ2-cCegQIABAA" rel="nofollow noreferrer">some starter pages</a>. </p>

CC BY-SA 4.0
2020-03-02T09:01:15.410Z
2020-03-02T10:54:08.713Z
2020-03-02T10:54:08.713Z
bandybabboon
<p>It is readily apparent from the fossil record that the first limestone was laid down hundreds of millions of years ago, but how long ago was the very first limestone formed? It could be approximately dated by its fossils, but what if it was in the Precambrian and contained no fossils - how could it be accurately dated then?</p>

CC BY-SA 4.0
2020-03-09T11:29:27.153Z
There was a cluster of limestones formed at 3.5 Ga according to https://doi.org/10.1016/0016-7037(89)90031-8
Gimelist
<earth-history><fossils><limestone>
How long ago was the first limestone formed?
Michael Walsby
# How long ago was the first limestone formed?

(Asked by: username_0 on 2020-02-26)

It is readily apparent from the fossil record that the first limestone was laid down hundreds of millions of years ago, but how long ago was the very first limestone formed? It could be approximately dated by its fossils, but what if it was in the Precambrian and contained no fossils - how could it be accurately dated then?

**Tags:** earth-history, fossils, limestone

> **Comments:**
> **username_1**: There was a cluster of limestones formed at 3.5 Ga according to https://doi.org/10.1016/0016-7037(89)90031-8  

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## 1 answers

### Answer by username_2 on 2020-03-02. Score: 1

Perhaps some of the oldest limestones are the banded Espanola Formation from 2.3 billion years ago. The Oxygenation of the environment happened 2.4 billion years ago. I'll find some references and chemistry info when my web connection works, here are [some starter pages](https://www.google.com/search?q=%22Espanola%20Formation%22%20limestone&tbm=isch&ved=2ahUKEwjjsvOrtfvnAhXSwYUKHdCWDkwQ2-cCegQIABAA).


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