Chicxulub Impact: Geologically Instant Ocean Acidification

[BillTre]

TL;DR Summary

The Chicxulub impact, which volatilized massive amounts of sulfur containing rocks, caused a very rapid acidification of the oceans which can not be attributed to the Daccan eruptions.

This NY Times article discusses findings based on iostopes of Boron in ocean sediments that indicate a geologically instant acidification of the oceans following the Chicxulub impact.

The Daccan traps (resulting from an eruption of over 200,000 cubic miles of lava in about a million years) were thought to have been involved to some extent in marine extinctions at the time, but the apparent (geologically) instant acidification of the oceans at the time of the impact is taken as a refutation of that premise.

The rate of acdification due to the impact is claimed to be comparable to the current rate of acidification of the oceans due to increased CO₂ levels.

 

[davenn]

The Daccan traps

There is only a remote possibility that the Deccan Traps in India are a result of the Chicxulub impact,
from what I have read in scientific literature when I was at univ. and since then indicate a too large a
time difference between the two event.

I do like the idea that the Chicxulub impact caused an increase in the acidity levels in the oceans and
elsewhere. Mexico's volatile volcanic history would lend credence to the probability that much material
with volcanic products was blasted into the air and would have fallen over a very large region
possibly worldwideDave

 

[Mark44]

There is only a remote possibility that the Deccan Traps in India are a result of the Chicxulub impact

@BillTre isn't saying that one is the result of the other, only that the Chicxulub impact resulted in a more rapid change in acidity levels of the ocean.

My understanding is that the Deccan Traps are a result of a hot spot lying beneath the Indian Plate, similar to the effects of the hot spot in the Pacific Plate that caused eruptions that formed the Hawaiian Islands and other sea mounts in the chain, as well as a hot spot that is thought to have caused the Columbia River basalt flows and other geologic activity in Idaho, Yellowstone, and over to the Black Hills of South Dakota.

 

[davenn]

@BillTre isn't saying that one is the result of the other, only that the Chicxulub impact resulted in a more rapid change in acidity levels of the ocean.

Yeah I may have mis-read that a bit … sorry @BillTre

My understanding is that the Deccan Traps are a result of a hot spot lying beneath the Indian Plate,

Yes, agreed

 

[Dragrath]

While the Chicxulub impact and the Deccan traps were not causally linked, The Deccan traps having notably been tied to the Reunion hotspot, the impact does seem to have effected the eruptions.
https://www.sciencedaily.com/releases/2019/02/190221141511.htmEarlier this year more precise Argon dating of the various flows from the Deccan traps found that roughly three quarters to 4 fifths of the lava flows appear to have occurred thousands of years after the impact supporting the idea that the impact reinvigorated the volcanic activity. They had suggested the wrench this would throw into the pervading theory for greenhouse gas emissions having driven a earlier warming trend that forced life to adapt may have been related to the gasses escaping before the lava flows erupted which is supported by some modern volcanoes

This also appears to complicate the picture of preceding volcanic gas emissions which could fit the findings of a sudden spike in acidity as their is strong evidence that the impact hit a hydrocarbon rich area of the continental shelves instantly volatilizing a large volume of rock including all the carbon and sulfides contained in the once continuous sedimentary rock deposits that used to be there. Since the picture of when a flood basalt's gasses are emitted is largely uncertain a rapid spike in acidity could very well be spported though I haven't ead the source material(Is there any source other than the NY Times? I think I reached by article limit there earlier this year)

 

[BillTre]

@Dragrath, here is the a link to the PNAS article that was cited by the NY Times story.
Looks like its open access.

Sorry I did not include it before.

 

[Dragrath]

@Dragrath, here is the a link to the PNAS article that was cited by the NY Times story.
Looks like its open access.

Sorry I did not include it before.

Thanks looking at the paper this seems to support existing research that PH levels remained stable suggesting the Deccan traps hadn't really upset the oceanic carbon cycle prior to the impact given the recent dating finding that most of the more intense activity of the Deccan traps has now been narrowed down to after the impact and the sharp spike in carbon levels immediately after the impact it seems to be consistent with other lines of evidence suggesting that the impact vaporization of a sizable chunk of North America's continental shelf containing hundreds of millions of years worth marine sediment was likely the primary driver of extinction.

Looks like a fairly good case for geologically rapid of injection of carbon dioxide, and other PH lowering volitiles since they are technically measuring the change in the net PH and using models to determinne likely CO2 concentrations, into the atmosphere as the primary driver of extinction at least within Marine enviornments (the focus of this paper).