Subduction dynamics at the middle America trench : new constraints from swath bathymetry, multichannel seismic data, and 10BE

Kelly, Robyn K.

doi:10.1575/1912/2458

Cited by 6 publications

(12 citation statements)

References 92 publications

(261 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because these glasses are strongly evolved the trace element character reflects both the original melting process and the subsequent fractional crystallization so that the enrichment of the mantle wedge cannot be accurately assessed. The possible role of sediment subduction in petrogenesis can be considered by plotting the range of known compositions for trench sediments compiled by Kelly [2003] and analyzed from Deep Sea Drilling Project (DSDP) Site 495 by D. Cardace (Washington University, unpublished data, 2004). These show relatively low La/Yb values and do not seem to be the cause of the greater enrichment seen in the tephras, at least not via simple assimilation.…”

Section: Trace Element Charactermentioning

confidence: 99%

“…One sample dated at 1.45 Ma has an extreme ɛ Nd value, falling off the general trend defined by the other samples, and implying very high degrees of continental recycling. Comparison with known values of trench sediments [ Kelly , 2003] shows that this is not a simple mixing relationship because the LREE enrichment of the glasses is higher than trench sediments. The Nicoya Complex, which is presumed to be representative of the crust into which the arc was emplaced, cannot be causing the Nd isotope excursion because this is very positive in ɛ Nd (Figure 13).…”

Section: Isotope Chemistrymentioning

confidence: 99%

“…Central American arc fields are from GEOROC. Trench sediment data are from Kelly [2003] and Morris et al [1990].…”

Section: Isotope Chemistrymentioning

confidence: 99%

“…Plot of ɛ Nd and δ 7 Li shows that while the majority of tephra glasses could be explained by a petrogenesis mixing recycled MORB crust and subducted sediments, an additional, likely forearc component is required that may be comparable to the Nicoya Complex exposed onshore. Nd isotope data of sediments are from Kelly [2003] and unpublished data of D. Cardace (Washington University). Li isotope data of sediments are a revision of published data of Chan and Kastner [2000].…”

Section: Isotope Chemistrymentioning

confidence: 99%

See 3 more Smart Citations

Pulsed subduction accretion and tectonic erosion reconstructed since 2.5 Ma from the tephra record offshore Costa Rica

Clift

Chan

Blusztajn

et al. 2005

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

[1] Tephra layers recovered by Ocean Drilling Program from the forearc and trench regions offshore the Nicoya Peninsula of Costa Rica allow the temporal evolution of the volcanic arc to be reconstructed since 2.5 Ma. Major and trace element analyses by microprobe methods reveal a dominant tholeiitic character and a provenance in the Costa Rican area. The tephra show long-term coherent variability in geochemistry. One tephra dated at 1.45 Ma shows minimum values in e Nd and maximum Li/Y consistent with very high degrees of sediment recycling at this time. However, overall Li/Y and d 7 Li increase with SiO 2 content, suggesting addition of heavy Li through forearc tectonic erosion and crustal assimilation. Peak values in d 7 Li starting at 1.45 Ma and lasting $0.5 m.y. indicate enhanced tectonic erosion of the forearc possibly caused by subduction of a seamount at 1.45 Ma. The tephra record indicates significant temporal variability in terms of sediment subduction, reconciling the geologic evidence for long-term tectonic erosion and geochemical evidence for recent sediment accretion in the modern Central American arc.

show abstract

Section: Trace Element Charactermentioning

confidence: 99%

Section: Isotope Chemistrymentioning

confidence: 99%

“…Central American arc fields are from GEOROC. Trench sediment data are from Kelly [2003] and Morris et al [1990].…”

Section: Isotope Chemistrymentioning

confidence: 99%

Section: Isotope Chemistrymentioning

confidence: 99%

See 2 more Smart Citations

Pulsed subduction accretion and tectonic erosion reconstructed since 2.5 Ma from the tephra record offshore Costa Rica

Clift

Chan

Blusztajn

et al. 2005

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

show abstract

“…A tab called, Plank et al . (); includes ICP‐MS major and trace element data and many new 10 Be/ 9 Be measurements (Kelly, ) for the modern volcanic front in Nicaragua and Costa Rica. The tab, REEs Altered, is a cautionary tale concerning the occasional extreme redistribution of REEs in lava varieties that do not outwardly appear severely weathered (Patino et al ., ).…”

Section: Metadatamentioning

confidence: 99%

RU_CAGeochem, a database and sample repository for Central American volcanic rocks at Rutgers University

Carr

Feigenson

Bolge

et al. 2014

Geoscience Data Journal

View full text Add to dashboard Cite

University from 1974 to the present. The database is decidedly uneven because of the impressive improvement of analytical techniques over the span of data collection. Further complications arose because most of the sampling and analysis were part of the educational process for many different undergraduate and graduate students using different types of instruments. This note presents, as a reasonably coherent whole, geochemical data and metadata for about 1400 samples collected by at least 40 students and colleagues. Many unpublished Sr, Nd, and Pb isotopic ratios are included here but most of the new data are metadata that provide greatly improved descriptions of the tectonic settings, locations, and status of the samples as well as estimates of data quality.

show abstract

Evolution of geochemical variations along the Central American volcanic front

Saginor

Gazel

Condie

et al. 2013

Geochem Geophys Geosyst

View full text Add to dashboard Cite

[1] New geochemical analyses of volcanic rocks in El Salvador add to existing data from Nicaragua and Costa Rica to create a comprehensive set of geochemical data for Central American volcanics. These data coupled with previously published 40 Ar/ 39Ar ages covering the past 30 Ma show that Costa Rica and Nicaragua had similar U/Th and Ba/La values until 10 Ma when the region developed the distinctive along arc variations that made this margin famous. U/Th values increased in Nicaragua since the Miocene, while remaining unchanged along the rest of the volcanic front. This coincides temporally with the Carbonate Crash, which caused a transition in Cocos plate sediments from low-U carbonates to high-U, organic rich hemipelagic muds. Increases in uranium are not observed in Costa Rica because its lower slab dip produces a more diffuse zone of partial melting and because of the contribution from Galapagosderived tracks dilutes this signal. Ba/La has been used as a geochemical proxy for contributions from the subducting slab; however, our analyses indicate that the Ba concentrations do not vary significantly along strike either in the subducting sediment or the volcanic front. Along-arc variation is controlled by changes in La, an indicator of the degree of partial melting or source enrichment. Trace element models of five segments of the volcanic front suggest that a subducting sediment component is more important to magmas produced in El Salvador and Nicaragua than in Costa Rica, where the geochemistry is controlled by recent (<10 Ma) recycling of Galapagos tracks.

show abstract

Subduction dynamics at the middle America trench : new constraints from swath bathymetry, multichannel seismic data, and 10BE

Cited by 6 publications

References 92 publications

Pulsed subduction accretion and tectonic erosion reconstructed since 2.5 Ma from the tephra record offshore Costa Rica

Pulsed subduction accretion and tectonic erosion reconstructed since 2.5 Ma from the tephra record offshore Costa Rica

RU_CAGeochem, a database and sample repository for Central American volcanic rocks at Rutgers University

Evolution of geochemical variations along the Central American volcanic front

Contact Info

Product

Resources

About