pozzolan (volcanic ash) on big island?

[Ccat]

Do pozzolan volcanic ash deposits exist on the big island?  This was used in the famous roman cement.

[dobanion]

I'm sure there's gotta be some out there, Kilauea does on occasion generate those types of eruptions. Probably buried under a dozen regular lava flows. I think there is a exposed section of it in the summit crater after the 2018 collapse. Don't see anybody going in there to dig it out.

[humble pi]

Do pozzolan volcanic ash deposits exist on the big island?  This was used in the famous roman cement.

Aloha Ccat, 

Short answer: no.  I did find this 32-page publication online:
"Hawaiian Trachyte Rock as a Pozzolanic Admixture in Portland Cement Concrete" - by Hideo Murakami, 1953.  
Seems to work.  

The publication is now in the public domain and can be downloaded for free here:
https://krex.k-state.edu/items/354cbf06-...0b1af/full

[dobanion]

Thanks for that. Trachyte rock. OK, did some more digging, and some newer papers note that trachyte has high pozzolon activity, which means you can replace a portion of cement with it.

Then I found this, specifically related: https://agupubs.onlinelibrary.wiley.com/...03GC000560

Hualalai Volcano is unique among Hawaiian volcanoes in that it possesses a relatively high proportion of evolved, trachytic lavas that were erupted at the beginning of the alkalic, postshield phase of volcanism. These evolved lavas yield insights into magma sources, magma supply rates, and the evolution of the subvolcanic magmatic plumbing system at this time. Trachyte lavas are exposed at the Puu Waawaa pumice dome and Puu Anahulu flow, as blocks in maars on the south flank of the volcano, and as flows in water wells drilled on the west flank of Hualalai.

Here's a peek of the side of Puu Waawaa from google maps:
https://www.google.com/maps/@19.7767967,...coh=205409&entry=ttu

I think you can see the lighter grey of the trachyte on the side of the cone.

[Olohana 1790]

while youre up there try for checkout the cone Pu'u Book 'em Danno.

ps lots of 'iliahi up that area...
aroha



free image hosting

[Ccat]

Thanks for that. Trachyte rock. OK, did some more digging, and some newer papers note that trachyte has high pozzolon activity, which means you can replace a portion of cement with it.

Then I found this, specifically related: https://agupubs.onlinelibrary.wiley.com/...03GC000560

Hualalai Volcano is unique among Hawaiian volcanoes in that it possesses a relatively high proportion of evolved, trachytic lavas that were erupted at the beginning of the alkalic, postshield phase of volcanism. These evolved lavas yield insights into magma sources, magma supply rates, and the evolution of the subvolcanic magmatic plumbing system at this time. Trachyte lavas are exposed at the Puu Waawaa pumice dome and Puu Anahulu flow, as blocks in maars on the south flank of the volcano, and as flows in water wells drilled on the west flank of Hualalai.

Here's a peek of the side of Puu Waawaa from google maps:
https://www.google.com/maps/@19.7767967,...coh=205409&entry=ttu

I think you can see the lighter grey of the trachyte on the side of the cone.

hmmm…very interesting..so there may be more building materials on the island than previously thought.  I have noticed that unusual spot there before. Had no idea what it was.

Anything that doesn’t have to be imported would be good.  Thanks!

Ccat

---

Thanks for that. Trachyte rock. OK, did some more digging, and some newer papers note that trachyte has high pozzolon activity, which means you can replace a portion of cement with it.

Then I found this, specifically related: https://agupubs.onlinelibrary.wiley.com/...03GC000560

Hualalai Volcano is unique among Hawaiian volcanoes in that it possesses a relatively high proportion of evolved, trachytic lavas that were erupted at the beginning of the alkalic, postshield phase of volcanism. These evolved lavas yield insights into magma sources, magma supply rates, and the evolution of the subvolcanic magmatic plumbing system at this time. Trachyte lavas are exposed at the Puu Waawaa pumice dome and Puu Anahulu flow, as blocks in maars on the south flank of the volcano, and as flows in water wells drilled on the west flank of Hualalai.

Here's a peek of the side of Puu Waawaa from google maps:
https://www.google.com/maps/@19.7767967,...coh=205409&entry=ttu

I think you can see the lighter grey of the trachyte on the side of the cone.

hmmm…very interesting..so there may be more building materials on the island than previously thought.  
Anything that doesn’t have to be imported would be good.  Thanks!

Ccat

[kalianna]

There are those who might take issue with taking "building materials" from a forest reserve.