Journal metrics

Journal metrics

  • IF value: 4.165 IF 4.165
  • IF 5-year value: 4.075 IF 5-year 4.075
  • CiteScore value: 4.28 CiteScore 4.28
  • SNIP value: 1.501 SNIP 1.501
  • SJR value: 1.060 SJR 1.060
  • IPP value: 4.21 IPP 4.21
  • h5-index value: 29 h5-index 29
  • Scimago H index value: 27 Scimago H index 27
Discussion papers
https://doi.org/10.5194/sed-4-1379-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/sed-4-1379-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 05 Nov 2012

Research article | 05 Nov 2012

Review status
This discussion paper is a preprint. It has been under review for the journal Solid Earth (SE). A final paper in SE is not foreseen.

Mafic granulite xenoliths in the Chilka Lake suite, Eastern Ghats Belt, India: evidence of deep-subduction of residual oceanic crust

S. Bhattacharya1, A. K. Chaudhary2, A. K. Saw1, P. Das1, and D. Chatterjee1 S. Bhattacharya et al.
  • 1Indian Statistical Institute, Kolkata 700108, India
  • 2Indian Institute of Technology, Roorkee 247667, India

Abstract. Granulite xenoliths preserve key geochemical and isotopic signatures of their mantle source regions. Mafic granulite and pyroxinite xenoliths within massif-type charnockitic rocks from the Eastern Ghats Belt have recently been reported by us. The mafic granulite xenoliths from the Chilka Lake granulite suite with abundant prograde biotite are geochemically akin to Oceanic Island Basalt (OIB). They can be distinguished from the hornblende-mafic granulite xenoliths with signatures of Arc-derived basalt occurring in the other suites of the Eastern Ghats Belt. These two groups of xenoliths in the Paleoproterozoic Eastern Ghats Province have quite distinct Nd-model ages- 1.9 Ga and 2.5 Ga respectively, which may be interpreted as their crustal residence ages. Strong positive Nb anomalies, indicating subducted oceanic crust in the source, LREE enrichment and strongly fractionated REE pattern are key geochemical signatures attesting to their origin as OIB-type magma. Also low Yb and Sc contents and high (La / Yb)N ratios can be attributed to melting in the presence of residual garnet and hence at great depths (> 80 km). The variable enrichment in radiogenic 87Sr, between 0.70052 and 0.71092 at 1.9 Ga and less radiogenic 143Nd between ε-1.54 and 7.46 are similar to those of the OIBs compared to MORBs. As OIBs commonly contain some recycled oceanic crust in their sources, we suggest that the residue of the oceanic crust from a previous melting event (~ 2.5 Ga) that produced the Arc-derived basalts (protoliths of hornblende-mafic granulite xenoliths) could have subducted to great depths and mechanically mixed with the mantle peridotite. A subsequent re-melting event of this mixed source might have occurred at ca. 1.9 Ga as testified by the crustal residence ages of the biotite-mafic granulite xenoliths of the Chilka Lake granulite suite.

S. Bhattacharya et al.
Interactive discussion
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Interactive discussion
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
S. Bhattacharya et al.
S. Bhattacharya et al.
Viewed  
Total article views: 945 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
330 574 41 945 23 19
  • HTML: 330
  • PDF: 574
  • XML: 41
  • Total: 945
  • BibTeX: 23
  • EndNote: 19
Views and downloads (calculated since 01 Feb 2013)
Cumulative views and downloads (calculated since 01 Feb 2013)
Cited  
Saved  
Discussed  
No discussed metrics found.
Latest update: 20 Nov 2018
Publications Copernicus
Download
Citation
Share