Source and mode of the Permian Panjal Trap magmatism: Evidence from zircon U–Pb and Hf isotopes and trace element data from the Himalayan ultrahigh-pressure rocks

Varieties of the Himalayan eclogites: A pictorial review of textural and petrological features

“…After the cessation of collision and possible slab break off, the deeply subducted rocks exhumed to earth's surface via buoyancy and large‐scale thrusts which piled up the mafic crust and sediments in the form of the Lesser Himalayan sequence, the Higher Himalayan Crystalline and the Tethyan sediments as well as the ophiolitic mélanges along the suture zone (Greco et al, ; Spencer et al, ). The age of the eclogite‐facies metamorphism in the western part of Himalaya (Kaghan Valley, Pakistan) is well constrained at around 49–45 Ma (Parrish et al, ; Rehman et al, ; Rehman et al, a, ; Spencer & Gebauer, ; Wilke et al, ). The end of Himalayan metamorphism accompanied by rapid cooling and unroofing occurred during 43–25 Ma (Ar–Ar cooling ages of hornblende and white mica from the gneisses (Chamberlain, Zeitler, & Erickson, )).…”

“…These basaltic extrusions at the northern margin of the Indian plate mark the start of the Himala- as the ophiolitic mélanges along the suture zone (Greco et al, 1989;Spencer et al, 1995). The age of the eclogite-facies metamorphism in the western part of Himalaya (Kaghan Valley, Pakistan) is well constrained at around 49-45 Ma (Parrish et al, 2006;Rehman et al, 2012;Rehman et al, 2013aRehman et al, , 2016Spencer & Gebauer, 1996;Wilke et al, 2010). The end of Himalayan metamorphism accompanied by rapid cooling and unroofing occurred during 43-25 Ma (Ar-Ar cooling ages of hornblende and white mica from the gneisses (Chamberlain, Zeitler, & Erickson, 1991)).…”

“…In addition, oxygen isotope data from bulk rocks and minerals from the two groups of eclogites suggested their mantle source was hydrothermally altered by meteoric water interaction during or after their emplacement when India was still at southern high latitudes(Rehman et al, 2014). Recent results of the U-Pb age and Hf isotope data of zircons from Group I and II eclogites and some of the associated felsic rocks in the Kaghan Valley suggest their protolith was derived from a juvenile mantle source with almost no crustal contamination (for details seeRehman et al, 2016).5 | FORMATION OF THE HIMALAYAN ECLOGITESAfter the break-up of Indian plate from Gondwana, it drifted northward and in Eocene time collided with the Asian plate. The proposed onset of the India-Asia collision ranges between 55 Ma and 43 Ma…”

Early Permian mafic dikes in the Nagqu area, central Tibet, China, associated with embryonic oceanic crust of the Meso‐Tethys Ocean

“…The characteristics of basalts from the southern Qiangtang and Tethyan Himalaya suggest the presence of crustal contamination [e.g., Zhu et al , ; Zhai et al , ]. The Panjal Traps basalts in the Kashmir Valley are considered to be derived from ocean island basalt (OIB)‐like mantle contaminated to varying degrees by continental crustal components [e.g., Chauvet et al , ; Shellnutt et al , ; Rehman et al , ; Stojanovic , ]. The occurrence of negative Nb anomalies is generally suggestive of crustal contamination.…”

“…The geochemical characteristics of whole-rock and hornblende analyses suggest that the protoliths of the Nagqu amphibolites are akin to N-MORB. Journal of Geophysical Research: Solid Earth 10.1002/2016JB013693 Chauvet et al, 2008;Shellnutt et al, 2014;Rehman et al, 2016;Stojanovic, 2016]. The occurrence of negative Nb anomalies is generally suggestive of crustal contamination.…”