<p>To answer the other parts of you question, the main minerals composing <a href="https://en.wikipedia.org/wiki/Basalt" rel="nofollow noreferrer">basalt</a> are calcic plagioclase <a href="https://en.wikipedia.org/wiki/Feldspar" rel="nofollow noreferrer">feldspar</a>, amphibole, and pyroxene. Olivine can be also be a significant constituent. The two main minerals are plagioclase and pyroxene. Plagioclase is in the continuous series, whereas pyroxene and amphibole are in the discontinuous serious.</p>
<p>There are two types of basalt:</p>
<ul>
<li><strong>Tholeiitic basalt</strong> which contains pyroxene (augite and orthopyroxene
or pigeonite) and calcium-rich plagioclase are common <a href="https://en.wikipedia.org/wiki/Phenocryst" rel="nofollow noreferrer">phenocryst</a>
minerals. Olivine may also be a phenocryst. The <a href="https://en.wikipedia.org/wiki/Matrix_(geology)" rel="nofollow noreferrer">groundmass</a>, or matrix,contains interstitial quartz or tridymite or cristobalite</li>
<li><strong>Alkali basalt</strong> which contains mineral assemblages that lack
orthopyroxene but contain olivine.</li>
</ul>
<p>Regarding <a href="https://en.wikipedia.org/wiki/Basalt#Weathering" rel="nofollow noreferrer">weathering of basalt</a>, basalt on the surface of the Earth weathers rapidly. Because of the low potassium content of most basalts, weathering converts the basalt to calcium-rich clay (montmorillonite) rather than potassium-rich clay (illite).</p>
<p>Chemical weathering also releases readily water-soluble cations such as calcium, sodium and magnesium, which give basaltic areas a strong buffer capacity against acidification. Calcium released by basalts binds CO<sub>2</sub> from the atmosphere forming CaCO<sub>3</sub> acting thus as a CO<sub>2</sub> trap.</p>

CC BY-SA 4.0
2022-06-14T11:52:29.317Z
2022-06-14T11:52:29.317Z
Fred
<p>The Goldich series does not contain rocks such as basalt. It contains the minerals that make up the rocks, generally igneous rocks such as basalt. Thus we have to be somewhat general, but we should expect to see basalt in the <strong>upper range of the Goldich series.</strong></p>
<p>As with most rocks, the mixture of minerals includes <strong>both continuous and discontinuous components</strong> in the series.</p>
<p><strong>Felsic vs mafic</strong></p>
<p>Igneous rocks commonly found at the surface are classified as <strong>felsic</strong> or <strong>mafic</strong>, which correlates with their silica content: felsic is higher silica an mafic is lower silica. The latter corresponds to minerals that are higher on the Goldich series, such as pyroxenes.</p>
<p><strong>The big reveal: basalt is mafic</strong></p>
<p>So basalt, being a rock, does not have its own entry in the Goldich series, but <strong>it is the classic example of a mafic rock.</strong> Therefore relatively low silica, and high on the Goldich series. A typical weight-percent composition is given by Shrivasta et al. <a href="https://www.researchgate.net/figure/Composition-of-basalt-in-wt_tbl3_301348713" rel="nofollow noreferrer">1</a>:</p>
<p><a href="https://i.sstatic.net/kxbYv.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/kxbYv.png" alt="enter image description here" /></a></p>
<p>The silica level is similar to that in pyroxenes and in calcium-rich plagioclase feldspar (which are themselves major component minerals in basalt), so we should expect basalt to appear in the upper range of the Goldich series. Since basalt contains both pyroxenes and feldspar, it has both discontinuous and continuous components.</p>
<p><strong>Reference</strong></p>
<ol>
<li>Shrivastava, J. &amp; Rani, Nishi &amp; Pathak, Vamdev. (2016). &quot;Geochemical Modeling and Experimental Studies on Mineral Carbonation of Primary Silicates for Long-term Immobilization of CO 2 in Basalt from the Eastern Deccan Volcanic Province.&quot; <em>Journal Indian Geophysical Union</em>. Special volume -1. 42-58.</li>
</ol>

CC BY-SA 4.0
2022-06-14T10:10:48.657Z
2022-06-14T12:35:23.663Z
2022-06-14T12:35:23.663Z
Oscar Lanzi
<p>In relation to this experiment: <a href="https://www.remineralize.org/rem_publications/action-of-microorganisms-in-basalt-powder/" rel="nofollow noreferrer">https://www.remineralize.org/rem_publications/action-of-microorganisms-in-basalt-powder/</a></p>
<p>It is said that applying basalt rock dust to soil can improve soil fertility especially so if a complete soil food web is present due to biological weathering by bacteria and fungi - which help to release plant nutrients into the exchangeable and soluble pool.</p>
<p>Does basalt have a high rate of weathering and is it in the ‘discontinuous series’ or ‘continuous’ series?</p>
<p><a href="https://en.wikipedia.org/wiki/Goldich_dissolution_series" rel="nofollow noreferrer">Goldich dissolution series</a></p>

<geology><geochemistry><minerals>
Where is basalt in the Goldich dissolution series?
Dave Kirkby
# Where is basalt in the Goldich dissolution series?

(Asked by: username_0 on 2022-06-13)

In relation to this experiment: <https://www.remineralize.org/rem_publications/action-of-microorganisms-in-basalt-powder/>

It is said that applying basalt rock dust to soil can improve soil fertility especially so if a complete soil food web is present due to biological weathering by bacteria and fungi - which help to release plant nutrients into the exchangeable and soluble pool.

Does basalt have a high rate of weathering and is it in the ‘discontinuous series’ or ‘continuous’ series?

[Goldich dissolution series](https://en.wikipedia.org/wiki/Goldich_dissolution_series)

**Tags:** geology, geochemistry, minerals


---

## 2 answers

### Answer by username_1 on 2022-06-14. Score: 2

To answer the other parts of you question, the main minerals composing [basalt](https://en.wikipedia.org/wiki/Basalt) are calcic plagioclase [feldspar](https://en.wikipedia.org/wiki/Feldspar), amphibole, and pyroxene. Olivine can be also be a significant constituent. The two main minerals are plagioclase and pyroxene. Plagioclase is in the continuous series, whereas pyroxene and amphibole are in the discontinuous serious.

There are two types of basalt:

* **Tholeiitic basalt** which contains pyroxene (augite and orthopyroxene
  or pigeonite) and calcium-rich plagioclase are common [phenocryst](https://en.wikipedia.org/wiki/Phenocryst)
  minerals. Olivine may also be a phenocryst. The [groundmass](https://en.wikipedia.org/wiki/Matrix_(geology)), or matrix,contains interstitial quartz or tridymite or cristobalite
* **Alkali basalt** which contains mineral assemblages that lack
  orthopyroxene but contain olivine.

Regarding [weathering of basalt](https://en.wikipedia.org/wiki/Basalt#Weathering), basalt on the surface of the Earth weathers rapidly. Because of the low potassium content of most basalts, weathering converts the basalt to calcium-rich clay (montmorillonite) rather than potassium-rich clay (illite).

Chemical weathering also releases readily water-soluble cations such as calcium, sodium and magnesium, which give basaltic areas a strong buffer capacity against acidification. Calcium released by basalts binds CO2 from the atmosphere forming CaCO3 acting thus as a CO2 trap.


---

### Answer by username_2 on 2022-06-14. Score: 2

The Goldich series does not contain rocks such as basalt. It contains the minerals that make up the rocks, generally igneous rocks such as basalt. Thus we have to be somewhat general, but we should expect to see basalt in the **upper range of the Goldich series.**

As with most rocks, the mixture of minerals includes **both continuous and discontinuous components** in the series.

**Felsic vs mafic**

Igneous rocks commonly found at the surface are classified as **felsic** or **mafic**, which correlates with their silica content: felsic is higher silica an mafic is lower silica. The latter corresponds to minerals that are higher on the Goldich series, such as pyroxenes.

**The big reveal: basalt is mafic**

So basalt, being a rock, does not have its own entry in the Goldich series, but **it is the classic example of a mafic rock.** Therefore relatively low silica, and high on the Goldich series. A typical weight-percent composition is given by Shrivasta et al. [1](https://www.researchgate.net/figure/Composition-of-basalt-in-wt_tbl3_301348713):

[![enter image description here](https://i.sstatic.net/kxbYv.png)](https://i.sstatic.net/kxbYv.png)

The silica level is similar to that in pyroxenes and in calcium-rich plagioclase feldspar (which are themselves major component minerals in basalt), so we should expect basalt to appear in the upper range of the Goldich series. Since basalt contains both pyroxenes and feldspar, it has both discontinuous and continuous components.

**Reference**

1. Shrivastava, J. & Rani, Nishi & Pathak, Vamdev. (2016). "Geochemical Modeling and Experimental Studies on Mineral Carbonation of Primary Silicates for Long-term Immobilization of CO 2 in Basalt from the Eastern Deccan Volcanic Province." *Journal Indian Geophysical Union*. Special volume -1. 42-58.


---

