Magma genesis controlled by tectonic styles in the northern part of the Arabia plate during Cenozoic time
Mohamad Amer Al-Kwatli
Pierre Yves Gillot
Jean Claude Lefèvre
Anthony Hildenbrand
Jean-Michel Kluska
10.6084/m9.figshare.3453527.v1
https://geolsoc.figshare.com/articles/dataset/Magma_genesis_controlled_by_tectonic_styles_in_the_northern_part_of_the_Arabia_plate_during_Cenozoic_time/3453527
<p>Widespread lava fields in the northern part of the Arabian platform are the subject of an open geodynamic debate on the origin
of the intraplate volcanism. We present new K–Ar ages and whole-rock geochemical data for lava flows from Syria, which allow
us to propose a new model of volcano-tectonic evolution highlighting how tectonics have controlled magma genesis in the region
during the last 18 Ma. The Cenozoic Syrian lavas are alkaline and subalkaline rocks, typical of magma erupted in such a continental
intraplate context. Basaltic samples from different Syrian volcanic provinces show significant variations in terms of incompatible
trace element signatures. Crustal contamination plays a negligible role during magma migration and differentiation, and crystal
fractionation is essentially restricted to olivine and clinopyroxene. Our results suggest that the Syrian lavas have been
generated by variable degrees of partial melting (<em>c.</em> 1–10%) from different levels of a locally heterogeneous lithospheric mantle. The light/medium rare Earth element (LREE/MREE)
ratios not only illustrate how the degree of partial melting has changed spatially and temporally during the last <em>c.</em> 18 Ma, but also indicate that the degree and the style of extensional tectonics has changed through time. We conclude that
the Cenozoic Syrian volcanism is a consequence of extensional tectonics, under periodical influence of the north- and eastwards
convergence at the Arabia–Eurasia margin, which induces rotational tectonic styles. This controls the partial melting at various
depths in the mantle. The volcanism of northern Arabia developed in the framework of the Red Sea rifting and initiated at
the same time as the southern Red Sea volcanism. It extends up to historical time, progressively smoothed to the north in
a contradictory relation with the compressional/extensional setting of the Arabia–Eurasia margin.
</p>
2016-06-21 11:29:11
LREE
magma
Cenozoic
Syrian
mantle
18 Ma
intraplate
genesis
Red Sea volcanism
tectonic styles
Red Sea rifting
lava
trace element signatures
Arabia
extensional tectonics
Geology