An evaluation of Deccan Traps eruption rates using geochronologic data
<p>Recent attempts to establish the eruptive history of the Deccan Traps large igneous province have used both <span class="inline-formula">U−Pb</span> (Schoene et al., 2019) and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-04-01
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| Series: | Geochronology |
| Online Access: | https://gchron.copernicus.org/articles/3/181/2021/gchron-3-181-2021.pdf |
| _version_ | 1797229248286556160 |
|---|---|
| author | B. Schoene M. P. Eddy C. B. Keller K. M. Samperton |
| author_facet | B. Schoene M. P. Eddy C. B. Keller K. M. Samperton |
| author_sort | B. Schoene |
| collection | DOAJ |
| description | <p>Recent attempts to establish the eruptive history of the Deccan Traps large igneous province have used both <span class="inline-formula">U−Pb</span> (Schoene et al., 2019) and
<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">40</mn></msup><mi mathvariant="normal">Ar</mi><msup><mo>/</mo><mn mathvariant="normal">39</mn></msup><mi mathvariant="normal">Ar</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="e75454f042fd2468cdaf878ebf81477e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-3-181-2021-ie00001.svg" width="49pt" height="15pt" src="gchron-3-181-2021-ie00001.png"/></svg:svg></span></span> (Sprain et al., 2019) geochronology. Both of these studies report dates with high precision and unprecedented coverage
for a large igneous province and agree that the main phase of eruptions began near the C30n–C29r magnetic reversal and waned shortly after the
C29r–C29n reversal, totaling <span class="inline-formula">∼</span> 700–800 <span class="inline-formula">kyr</span> duration. These datasets can be analyzed in finer detail to determine eruption rates, which
are critical for connecting volcanism, associated volatile emissions, and any potential effects on the Earth's climate before and after the
Cretaceous–Paleogene boundary (KPB). It is our observation that the community has frequently misinterpreted how the eruption rates derived from
these two datasets vary across the KPB. The <span class="inline-formula">U−Pb</span> dataset of Schoene et al. (2019) was interpreted by those authors to indicate four major
eruptive pulses before and after the KPB. The <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">40</mn></msup><mi mathvariant="normal">Ar</mi><msup><mo>/</mo><mn mathvariant="normal">39</mn></msup><mi mathvariant="normal">Ar</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="be50c6085c96da3cf61bab29242a7248"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-3-181-2021-ie00002.svg" width="49pt" height="15pt" src="gchron-3-181-2021-ie00002.png"/></svg:svg></span></span> dataset did not identify such pulses and has been largely interpreted by
the community to indicate an increase in eruption rates coincident with the Chicxulub impact (Renne et al., 2015; Richards et al., 2015). Although
the overall agreement in eruption duration is an achievement for geochronology, it is important to clarify the limitations in comparing the two
datasets and to highlight paths toward achieving higher-resolution eruption models for the Deccan Traps and for other large igneous provinces. Here,
we generate chronostratigraphic models for both datasets using the same statistical techniques and show that the two datasets agree very well. More
specifically, we infer that (1) age modeling of the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">40</mn></msup><mi mathvariant="normal">Ar</mi><msup><mo>/</mo><mn mathvariant="normal">39</mn></msup><mi mathvariant="normal">Ar</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="4cd76150b966bf4a1610c3d67ed20b62"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-3-181-2021-ie00003.svg" width="49pt" height="15pt" src="gchron-3-181-2021-ie00003.png"/></svg:svg></span></span> dataset results in constant eruption rates with relatively large
uncertainties through the duration of the Deccan Traps eruptions and provides no support for (or evidence against) the pulses identified by the
<span class="inline-formula">U−Pb</span> data, (2) the stratigraphic positions of the Chicxulub impact using the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">40</mn></msup><mi mathvariant="normal">Ar</mi><msup><mo>/</mo><mn mathvariant="normal">39</mn></msup><mi mathvariant="normal">Ar</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="103bb0deb6c931850b460c38cc0982c9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-3-181-2021-ie00004.svg" width="49pt" height="15pt" src="gchron-3-181-2021-ie00004.png"/></svg:svg></span></span> and <span class="inline-formula">U−Pb</span> datasets do not
agree within their uncertainties, and (3) neither dataset supports the notion of an increase in eruption rate as a result of the Chicxulub
impact. We then discuss the importance of systematic uncertainties between the dating methods that challenge direct comparisons between them, and we
highlight the geologic uncertainties, such as regional stratigraphic correlations, that need to be tested to ensure the accuracy of eruption
models. While the production of precise and accurate geochronologic data is of course essential to studies of Earth history, our analysis
underscores that the accuracy of a final result is also critically dependent on how such data are interpreted and presented to the broader community
of geoscientists.</p> |
| first_indexed | 2024-04-24T15:09:34Z |
| format | Article |
| id | doaj.art-69ae4b5fafc44168a44d410a1465b242 |
| institution | Directory Open Access Journal |
| issn | 2628-3719 |
| language | English |
| last_indexed | 2024-04-24T15:09:34Z |
| publishDate | 2021-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geochronology |
| spelling | doaj.art-69ae4b5fafc44168a44d410a1465b2422024-04-02T11:50:51ZengCopernicus PublicationsGeochronology2628-37192021-04-01318119810.5194/gchron-3-181-2021An evaluation of Deccan Traps eruption rates using geochronologic dataB. Schoene0M. P. Eddy1C. B. Keller2K. M. Samperton3Department of Geosciences, Princeton University, Princeton, NJ 08544, USADepartment of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, USADepartment of Earth Sciences, Dartmouth College, Hanover, NH 03755, USANuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA<p>Recent attempts to establish the eruptive history of the Deccan Traps large igneous province have used both <span class="inline-formula">U−Pb</span> (Schoene et al., 2019) and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">40</mn></msup><mi mathvariant="normal">Ar</mi><msup><mo>/</mo><mn mathvariant="normal">39</mn></msup><mi mathvariant="normal">Ar</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="e75454f042fd2468cdaf878ebf81477e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-3-181-2021-ie00001.svg" width="49pt" height="15pt" src="gchron-3-181-2021-ie00001.png"/></svg:svg></span></span> (Sprain et al., 2019) geochronology. Both of these studies report dates with high precision and unprecedented coverage for a large igneous province and agree that the main phase of eruptions began near the C30n–C29r magnetic reversal and waned shortly after the C29r–C29n reversal, totaling <span class="inline-formula">∼</span> 700–800 <span class="inline-formula">kyr</span> duration. These datasets can be analyzed in finer detail to determine eruption rates, which are critical for connecting volcanism, associated volatile emissions, and any potential effects on the Earth's climate before and after the Cretaceous–Paleogene boundary (KPB). It is our observation that the community has frequently misinterpreted how the eruption rates derived from these two datasets vary across the KPB. The <span class="inline-formula">U−Pb</span> dataset of Schoene et al. (2019) was interpreted by those authors to indicate four major eruptive pulses before and after the KPB. The <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">40</mn></msup><mi mathvariant="normal">Ar</mi><msup><mo>/</mo><mn mathvariant="normal">39</mn></msup><mi mathvariant="normal">Ar</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="be50c6085c96da3cf61bab29242a7248"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-3-181-2021-ie00002.svg" width="49pt" height="15pt" src="gchron-3-181-2021-ie00002.png"/></svg:svg></span></span> dataset did not identify such pulses and has been largely interpreted by the community to indicate an increase in eruption rates coincident with the Chicxulub impact (Renne et al., 2015; Richards et al., 2015). Although the overall agreement in eruption duration is an achievement for geochronology, it is important to clarify the limitations in comparing the two datasets and to highlight paths toward achieving higher-resolution eruption models for the Deccan Traps and for other large igneous provinces. Here, we generate chronostratigraphic models for both datasets using the same statistical techniques and show that the two datasets agree very well. More specifically, we infer that (1) age modeling of the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">40</mn></msup><mi mathvariant="normal">Ar</mi><msup><mo>/</mo><mn mathvariant="normal">39</mn></msup><mi mathvariant="normal">Ar</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="4cd76150b966bf4a1610c3d67ed20b62"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-3-181-2021-ie00003.svg" width="49pt" height="15pt" src="gchron-3-181-2021-ie00003.png"/></svg:svg></span></span> dataset results in constant eruption rates with relatively large uncertainties through the duration of the Deccan Traps eruptions and provides no support for (or evidence against) the pulses identified by the <span class="inline-formula">U−Pb</span> data, (2) the stratigraphic positions of the Chicxulub impact using the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><mi/><mn mathvariant="normal">40</mn></msup><mi mathvariant="normal">Ar</mi><msup><mo>/</mo><mn mathvariant="normal">39</mn></msup><mi mathvariant="normal">Ar</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="49pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="103bb0deb6c931850b460c38cc0982c9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-3-181-2021-ie00004.svg" width="49pt" height="15pt" src="gchron-3-181-2021-ie00004.png"/></svg:svg></span></span> and <span class="inline-formula">U−Pb</span> datasets do not agree within their uncertainties, and (3) neither dataset supports the notion of an increase in eruption rate as a result of the Chicxulub impact. We then discuss the importance of systematic uncertainties between the dating methods that challenge direct comparisons between them, and we highlight the geologic uncertainties, such as regional stratigraphic correlations, that need to be tested to ensure the accuracy of eruption models. While the production of precise and accurate geochronologic data is of course essential to studies of Earth history, our analysis underscores that the accuracy of a final result is also critically dependent on how such data are interpreted and presented to the broader community of geoscientists.</p>https://gchron.copernicus.org/articles/3/181/2021/gchron-3-181-2021.pdf |
| spellingShingle | B. Schoene M. P. Eddy C. B. Keller K. M. Samperton An evaluation of Deccan Traps eruption rates using geochronologic data Geochronology |
| title | An evaluation of Deccan Traps eruption rates using geochronologic data |
| title_full | An evaluation of Deccan Traps eruption rates using geochronologic data |
| title_fullStr | An evaluation of Deccan Traps eruption rates using geochronologic data |
| title_full_unstemmed | An evaluation of Deccan Traps eruption rates using geochronologic data |
| title_short | An evaluation of Deccan Traps eruption rates using geochronologic data |
| title_sort | evaluation of deccan traps eruption rates using geochronologic data |
| url | https://gchron.copernicus.org/articles/3/181/2021/gchron-3-181-2021.pdf |
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