<p><strong>The oldest known metasedimentary rocks are about 3.8 billion years old, formed in the Eoarchaean era.</strong></p>

<p>'Metasedimentary' just means they have been metamorphosed, so they started out as sediments. They are found in the <a href="https://en.wikipedia.org/wiki/Isua_Greenstone_Belt" rel="nofollow">Isua Greenstone Belt</a> of southwestern Greenland. You can read about their discovery in Moorbath (2009). Quoting from there:</p>

<blockquote>
  <p>Published zircon dates strongly suggest that the depositional age of at least part of the [Isua supracrustal belt] could be closer to 3.8 Gyr than to 3.7 Gyr.</p>
</blockquote>

<p>According to the International Commission on Stratigraphy (Cohen et al. 2013), this puts them firmly in the <a href="https://en.wikipedia.org/wiki/Eoarchean" rel="nofollow">Eoarchaean era</a>. </p>

<p><strong>References</strong></p>

<p>Cohen, K, et al. (2013). The ICS International Chronostratigraphic Chart. <em>Episodes Journal of International Geoscience</em> <strong>36</strong> (3). <a href="http://www.stratigraphy.org/ICSchart/Cohen2013_Episodes.pdf" rel="nofollow">Link to PDF.</a></p>

<p>Moorbath, S (2009). The discovery of the Earth's oldest rocks. <em>Notes and Records</em> <strong>63</strong> (4). <a href="http://dx.doi.org/10.1098/rsnr.2009.0004" rel="nofollow">DOI: 10.1098/rsnr.2009.0004</a></p>

CC BY-SA 3.0
2016-04-26T18:22:24.740Z
2016-04-28T00:05:05.010Z
2016-04-28T00:05:05.010Z
Matt Hall
<p>Did large-scale sedimentation occur in any great amount during or soon after the Hadean/Archean period? Or did it only start later, because of the intense geological activity?</p>

<sedimentology>
What is the earliest sedimentation we know of?
Henry Stone
# What is the earliest sedimentation we know of?

(Asked by: username_0 on 2016-04-26)

Did large-scale sedimentation occur in any great amount during or soon after the Hadean/Archean period? Or did it only start later, because of the intense geological activity?

**Tags:** sedimentology


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## 1 answers

### Answer by username_1 on 2016-04-26. Score: 9 | Accepted answer

**The oldest known metasedimentary rocks are about 3.8 billion years old, formed in the Eoarchaean era.**

'Metasedimentary' just means they have been metamorphosed, so they started out as sediments. They are found in the [Isua Greenstone Belt](https://en.wikipedia.org/wiki/Isua_Greenstone_Belt) of southwestern Greenland. You can read about their discovery in Moorbath (2009). Quoting from there:

> Published zircon dates strongly suggest that the depositional age of at least part of the [Isua supracrustal belt] could be closer to 3.8 Gyr than to 3.7 Gyr.

According to the International Commission on Stratigraphy (Cohen et al. 2013), this puts them firmly in the [Eoarchaean era](https://en.wikipedia.org/wiki/Eoarchean).

**References**

Cohen, K, et al. (2013). The ICS International Chronostratigraphic Chart. *Episodes Journal of International Geoscience* **36** (3). [Link to PDF.](http://www.stratigraphy.org/ICSchart/Cohen2013_Episodes.pdf)

Moorbath, S (2009). The discovery of the Earth's oldest rocks. *Notes and Records* **63** (4). [DOI: 10.1098/rsnr.2009.0004](http://dx.doi.org/10.1098/rsnr.2009.0004)


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