10.6084/m9.figshare.3454043.v1
Jin-Yang Zhang
Jin-Yang
Zhang
Chang-Qian Ma
Chang-Qian
Ma
Jian-Wei Li
Jian-Wei
Li
Yuan Ming Pan
Yuan Ming
Pan
Reappraisal of Early Cretaceous highly enriched mantle beneath the Dabie Orogen: evidence from mineralogy and geochemistry
of the Xiaohekou complex
Geological Society of London
2016
mantle
Cretaceous
sample
Dabie Orogen
plagioclase
geochemistry
Sr
Xiaohekou
crystallization
EMI
data
crustal
MELTS
source
olivine gabbronorite dykes
geochemical
Geology
2016-06-21 11:51:39
Dataset
https://geolsoc.figshare.com/articles/dataset/Reappraisal_of_Early_Cretaceous_highly_enriched_mantle_beneath_the_Dabie_Orogen_evidence_from_mineralogy_and_geochemistry___of_the_Xiaohekou_complex/3454043
<p>An Early Cretaceous highly enriched mantle beneath the Dabie Orogen, previously proposed on the basis of exceedingly enriched
isotopic signatures documented in intermediate–mafic–ultramafic complexes, has been re-evaluated by new field, mineralogical
and geochemical data from the best exposed Xiaohekou complex. The Xiaohekou complex consists of three pyroxenite cores intruded
by olivine gabbronorite dykes and successively surrounded outward by gabbroic rocks, leucogabbros and monzonites. Textural
and compositional data for pyroxenes and plagioclase as well as whole-rock geochemistry suggest two-stage crystallizations.
The Sr–Nd isotopic values correlate with the SiO<sub>2</sub> and MgO contents, and one gabbronorite sample from the margin of the complex has sodic plagioclase and highly enriched Sr–Nd
isotopic ratios, also pointing to fractional crystallizations and crustal contamination. One gabbro sample from the centre
of the complex and three from olivine gabbronorite dykes have the lowest Sr but highest Nd isotopic values close to those
of typical Enriched Mantle I (EMI). These data together with isotopic and MELTS modelling suggest that an EMI-like mantle
source plus crustal assimilation and crystallization can explain all field, mineralogical and geochemical characteristics
of the Xiaohekou complex, without the need to invoke a mantle source more enriched than EMI beneath the Dabie Orogen.
</p>