Proterozoic age and cumulate origin for granulite xenoliths, Lesotho

Nature ◽  
1982 ◽  
Vol 299 (5882) ◽  
pp. 409-413 ◽  
Author(s):  
N. W. Rogers ◽  
C. J. Hawkesworth

2021 ◽  
Author(s):  
Tianlong Jin ◽  
Qin Wang ◽  
Vladislav Shatsky ◽  
Yue Liao


2020 ◽  
Author(s):  
Bianca Németh ◽  
Kálmán Török ◽  
Eniko Bali ◽  
Zoltan Zajacz ◽  
Csaba Szabó


2021 ◽  
Vol 33 (2) ◽  
pp. 233-247
Author(s):  
Cliff S. J. Shaw

Abstract. Granulite xenoliths from the Quaternary West Eifel Volcanic Field in Germany record evidence of magmatism in the lower crust at the end of the Permian. The xenoliths sampled two distinct bodies: an older intrusion (ca. 264 Myr old) that contains clinopyroxene with flat, chondrite-normalised rare earth element (REE) profiles and a younger (ca. 253 Myr old) intrusion that crystallised middle-REE-rich clinopyroxene. The younger body is also distinguished based on the negative Sr, Zr and Ti anomalies in primitive mantle-normalised multi-element plots. REE-in-plagioclase–clinopyroxene thermometry records the magmatic temperature of the xenoliths (1100–1300 ∘C), whereas Mg-in-plagioclase and Zr-in-titanite thermometry preserve an equilibration temperature of ca. 800 ∘C. These temperatures, together with a model of the mineral assemblages predicted from the composition of one of the xenoliths, define the pressure of crystallisation as ∼1 GPa. The xenoliths also preserve a long history of reheating events whose age ranges from 220 to 6 Myr. The last of these events presumably led to breakdown of garnet; formation of symplectites of orthopyroxene, plagioclase and hercynite; and redistribution of heavy rare earth elements into clinopyroxene. The data from the West Eifel granulite xenoliths, when combined with the existing data from granulites sampled in the East Eifel, indicate that the lower crust has a long a complex history stretching from at least 1.6 Ga with intrusive events at ca. 410 and 260 Ma and reheating from the Triassic to late Miocene.



1995 ◽  
Vol 59 (23) ◽  
pp. 4905-4920 ◽  
Author(s):  
Yi-Ming Huang ◽  
Peter Van Calsteren ◽  
Chris I. Hawkesworth


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