EurekaMag.com logo
+ Site Statistics
References:
47,893,527
Abstracts:
28,296,643
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

A geochemical and geochronological database for the Yellowstone Plateau volcanic field; implications for the origin of post-caldera basalt and the future of the Yellowstone magmatic system


, : A geochemical and geochronological database for the Yellowstone Plateau volcanic field; implications for the origin of post-caldera basalt and the future of the Yellowstone magmatic system. Abstracts with Programs - Geological Society of America 36(4): 10

We have compiled a database of geochemical and geochronological data for basaltic rocks in the Yellowstone Park area that contains over 150 analyses and 20 dates. Our database includes samples from modern studies (1963-1995) in addition to 39 new chemical analyses and 9 (super 40) Ar/ (super 39) Ar dates. Basaltic eruptions were coeval with the three Yellowstone Caldera cycles (2.1-0.6 Ma) and may preserve the long-term record of their mantle source and any crustal interaction. The most recent basalts (<0.6 Ma) occur in the Norris-Mammoth corridor (NMC) north of the Yellowstone Caldera. Our first goal was to determine if the most recent basaltic volcanism within the NMC represents the initiation of a new caldera cycle or the dying phases of the last cycle. Isotopic ratios of the <0.6 Ma basalts suggest a relationship of epsilon Nd and (super 87) Sr/ (super 86) Sr to periods of caldera formation. (super 87) Sr/ (super 86) Sr changed from 0.707 to 0.703 and epsilon Nd from -7 to -0.4 at the inception of the first caldera cycle (2.1 Ma) suggesting injection of asthenospheric basalt into the crust. This injection may have triggered partial melting of the crust that ultimately led to generation of a rhyolitic magma chamber and caldera formation. The isotopic signatures of the <0.6 Ma basalts show both high and low values of (super 87) Sr/ (super 86) Sr and epsilon Nd; however, ages of the basalts are not precise enough to determine a chronology. There are two scenarios: 1) a new injection of basalt has occurred, and a new caldera cycle has begun or; 2) the system is in a post-caldera phase. To determine which of these scenarios is correct, high precision (super 40) Ar/ (super 39) Ar dates must be determined for the basalts. This work is currently underway. Our second goal was to answer questions about the mantle source for the Yellowstone basalts and their degree of lithospheric contamination. Although, many previous studies suggested that the basalts were contaminated and provided little information about their mantle source, our new data and the re-plotting of older data show that most of the basalt is similar to OIB in character. Many samples are similar to typical Great Basin OIB-type basalt in the Lunar Crater Field of central Nevada that are interpreted as melts of the asthenospheric mantle. The Yellowstone database may provide important information about the source of basalts and the future of Yellowstone eruptions.


Accession: 029655801

Submit PDF Full Text: Here


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Related references

Shaul Hurwitz; Robert N.H.rris; Cynthia A.W.rner; Fred Murphy, 2012: Heat flow in vapor dominated areas of the Yellowstone Plateau Volcanic Field Implications for the thermal budget of the Yellowstone Caldera. Characterizing the vigor of magmatic activity in Yellowstone requires knowledge of the mechanisms and rates of heat transport between magma and the ground surface. We present results from a heat flow study in two vapor dominated, acid-sulfate ther...

Gansecki C.A.; Mahood G.A.; McWilliams M.O., 1996: Super 40 Ar/ super 39 Ar geochronology of rhyolites erupted following collapse of the Yellowstone Caldera, Yellowstone Plateau volcanic field; implications for crustal contamination. Single-crystal laser-probe (super 40) Ar/ (super 39) Ar dating of 133 grains of sanidine and plagioclase has enabled us to resolve the eruption ages of the Upper Basin Member rhyolites--the lava flows and related tuffs that erupted within the Yell...

Nastanski Nicole M.; Spell Terry L., 2004: Do the young extracaldera rhyolites north of Yellowstone Caldera mark the beginnings of a 4th volcanic cycle in the Yellowstone Plateau volcanic field?. The Yellowstone Plateau volcanic field has produced voluminous, caldera-forming eruptions of high-silica rhyolite at approximately 2.0, 1.3, and 0.64 Ma. Volcanism since 0.64 Ma produced rhyolite domes/flows (Plateau Rhyolite). The Obsidian Creek...

Nastanski Nicole M.; Spell Terry L., 2004: Extracaldera rhyolites north of the Yellowstone Plateau volcanic field caldera complex; an evolving silicic magma system and site of future large volume eruptions?. The Obsidian Creek (OC) and Roaring Mountain (RM) member extracaldera rhyolites erupted north of the YPVF caldera complex at approximately 526-106 ka ( (super 40) Ar/ (super 39) Ar) to 80 ka (K/Ar) as porphyritic and aphyric high silica rhyolite d...

Kyriazis S.F.; Vazquez J.A., 2006: Magmatic evolution of the post-caldera magma reservoir at Yellowstone revealed by compositional zoning in the crystals of Central Plateau Member rhyolites. Eos, Transactions, American Geophysical Union 87(Fall Meeting Suppl

Wes Hildreth; Robert L.C.ristiansen; James R.O.Neil, 1984: Catastrophic isotopic modification of rhyolitic magma at times of caldera subsidence, Yellowstone Plateau volcanic field. Journal of Geophysical Research 89(B10): 8339-8369

Rosenberg, R.; Harris, R.N.; Hurwitz, S.; Fulton, P.M.; Davis, M.G.; Werner, C.A., 2009: Quantifying heat flow from a restless caldera; shallow measurement from a vapor dominated area of the Yellowstone Plateau volcanic field. Eos, Transactions, American Geophysical Union 90.52, Suppl

Koch, R.D.; Ramsey, D.W.; Christiansen, R.L., 2011: Database for the Quaternary and Pliocene Yellowstone Plateau volcanic field of Wyoming, Idaho, and Montana. U. S. Geological Survey Data Series

Christiansen Robert L., 1973: Rhyolitic Ash Flows Of The Yellowstone Plateau Volcanic Field; Wyoming, Idaho, Montana; And Generation Of The Rhyolite-Basalt Association. Quaternary, caldera complex, granitic magma, independent generation of rhyolite and basalt.

Morgan L.A.; Doherty D.J.; Bonnichsen Bill, 1989: Evolution of the Kilgore Caldera; a model for caldera formation on the Snake River plain-Yellowstone Plateau volcanic province. Bulletin - New Mexico Bureau of Mines and Mineral Resources 131: 195