Advanced

Magmatic source and metamorphic grade of metavolcanic rocks from the Granjeno Schist : Was northeastern Mexico a part of Pangaea?

Torres Sánchez, Sonia Alejandra; Augustsson, Carita; Barboza Gudiño, José Rafael; Jenchen, Uwe; Ramírez Fernández, Juan Alonso; Abratis, Michael and Scherstén, Anders LU (2015) In Geological Journal
Abstract

The geochemistry of the metavolcanic rocks from the Granjeno Schist in northeastern Mexico indicates an origin in different tectonic environments: mid-ocean ridge and ocean island. High ratios of Hf/Th and Th/Nb (4.4-14 and 0.08-0.15), low ratios of LaN/YbN and LaN/SmN (0.74-1.7 and 0.60-1.4) and depleted LREE patterns in metabasalt display mid-ocean ridge characteristics. In contrast, the pattern of trace-element ratios and REEs in metabasalt and metapillow lava 60km to the west indicates a magma source with ocean-island basalt characteristics. Both areas were metamorphosed during the Late Carboniferous (300±4Ma). Estimated metamorphic conditions deduced from white mica and chlorite compositions, distinguish greenschist facies (350°C... (More)

The geochemistry of the metavolcanic rocks from the Granjeno Schist in northeastern Mexico indicates an origin in different tectonic environments: mid-ocean ridge and ocean island. High ratios of Hf/Th and Th/Nb (4.4-14 and 0.08-0.15), low ratios of LaN/YbN and LaN/SmN (0.74-1.7 and 0.60-1.4) and depleted LREE patterns in metabasalt display mid-ocean ridge characteristics. In contrast, the pattern of trace-element ratios and REEs in metabasalt and metapillow lava 60km to the west indicates a magma source with ocean-island basalt characteristics. Both areas were metamorphosed during the Late Carboniferous (300±4Ma). Estimated metamorphic conditions deduced from white mica and chlorite compositions, distinguish greenschist facies (350°C and 4kbar) for the mid-ocean ridge basalt, and prehnite-pumpellyite facies (250°C and 2.5kbar) for the ocean-island-type basalt. This metamorphism took place at an active continental margin during Pennsylvanian time. Our new tectonic model, which differs from earlier models, suggests that the origin of the Granjeno Schist is related to a subduction zone located at the western margin of Pangaea, active after Laurentia-Gondwana collision.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
Gondwana, Granjeno Schist, Late Carboniferous, Northeastern Mexico, Pangea, Rheic Ocean
in
Geological Journal
publisher
John Wiley and Sons Ltd
external identifiers
  • Scopus:84931843655
ISSN
0072-1050
DOI
10.1002/gj.2702
language
English
LU publication?
yes
id
05d921a2-41d8-4a18-bad6-23bd79bf93fb
date added to LUP
2016-05-24 09:04:20
date last changed
2016-11-13 04:39:52
@misc{05d921a2-41d8-4a18-bad6-23bd79bf93fb,
  abstract     = {<p>The geochemistry of the metavolcanic rocks from the Granjeno Schist in northeastern Mexico indicates an origin in different tectonic environments: mid-ocean ridge and ocean island. High ratios of Hf/Th and Th/Nb (4.4-14 and 0.08-0.15), low ratios of LaN/YbN and LaN/SmN (0.74-1.7 and 0.60-1.4) and depleted LREE patterns in metabasalt display mid-ocean ridge characteristics. In contrast, the pattern of trace-element ratios and REEs in metabasalt and metapillow lava 60km to the west indicates a magma source with ocean-island basalt characteristics. Both areas were metamorphosed during the Late Carboniferous (300±4Ma). Estimated metamorphic conditions deduced from white mica and chlorite compositions, distinguish greenschist facies (350°C and 4kbar) for the mid-ocean ridge basalt, and prehnite-pumpellyite facies (250°C and 2.5kbar) for the ocean-island-type basalt. This metamorphism took place at an active continental margin during Pennsylvanian time. Our new tectonic model, which differs from earlier models, suggests that the origin of the Granjeno Schist is related to a subduction zone located at the western margin of Pangaea, active after Laurentia-Gondwana collision.</p>},
  author       = {Torres Sánchez, Sonia Alejandra and Augustsson, Carita and Barboza Gudiño, José Rafael and Jenchen, Uwe and Ramírez Fernández, Juan Alonso and Abratis, Michael and Scherstén, Anders},
  issn         = {0072-1050},
  keyword      = {Gondwana,Granjeno Schist,Late Carboniferous,Northeastern Mexico,Pangea,Rheic Ocean},
  language     = {eng},
  publisher    = {ARRAY(0x856b328)},
  series       = {Geological Journal},
  title        = {Magmatic source and metamorphic grade of metavolcanic rocks from the Granjeno Schist : Was northeastern Mexico a part of Pangaea?},
  url          = {http://dx.doi.org/10.1002/gj.2702},
  year         = {2015},
}