E-resources
-
Groppo, Chiara; Rolfo, Franco; Lombardo, Bruno
Journal of petrology, 06/2009, Volume: 50, Issue: 6Journal Article
Identifying the location and nature of the Main Central Thrust Zone (MCTZ) is a major challenge in most of the Himalayan chain. As a contribution to clarifying this conundrum, in eastern Nepal a number of metapelite samples were selected for petrological study along a transect on the eastern flank of the Arun Tectonic Window. Both to the west and east of the study area, the Makalu and Kangchendzonga transects show metamorphic units characterized by a well-documented inverted metamorphism, with metamorphic grade increasing northward from lower (Lesser Himalaya) to higher (High Himalayan Crystallines) structural levels across the MCTZ. A detailed petrological study of the selected metapelite sequence allowed us to recognize three superimposed tectonometamorphic units, which are separated by cryptic and transitional metamorphic discontinuities. These units are characterized by different P–T evolutions, peculiar zoning styles of garnets and contrasting T/depth ratios. Specifically: (1) the structurally lowest sample shows a prograde P–T path characterized by an increase in both P and T, up to peak metamorphic conditions of 550°C and 0·65 GPa; (2) two structurally intermediate samples preserve relics of a prograde history characterized by heating and decompression up to peak metamorphic conditions of 600–650°C and 0·85–0·95 GPa; (3) the structurally highest samples consist of mostly unzoned minerals and assemblages, interpreted as chemically equilibrated, that do not preserve relics of their prograde metamorphic history. Peak metamorphic conditions of 655°C, 0·75 GPa (still inside the white mica stability field), and a minimum temperature of 790°C at 1·05 GPa (beyond the stability limit of white mica) have been determined for these samples. These data provide new constraints on the location, tectonic setting and metamorphic evolution of the Himalayan units in a hitherto poorly known area.
![loading ... loading ...](themes/default/img/ajax-loading.gif)
Shelf entry
Permalink
- URL:
Impact factor
Access to the JCR database is permitted only to users from Slovenia. Your current IP address is not on the list of IP addresses with access permission, and authentication with the relevant AAI accout is required.
Year | Impact factor | Edition | Category | Classification | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Select the library membership card:
If the library membership card is not in the list,
add a new one.
DRS, in which the journal is indexed
Database name | Field | Year |
---|
Links to authors' personal bibliographies | Links to information on researchers in the SICRIS system |
---|
Source: Personal bibliographies
and: SICRIS
The material is available in full text. If you wish to order the material anyway, click the Continue button.