The Solânea Complex (572 ± 8 Ma) compr
ises var
ious
intrus
ions that total 200 km
2. It cuts Palaeoproterozo
ic m
igmat
ized orthogne
isses of the Serr
inha–Pedro Velho Complex, wh
ich
is part of the São José do Campestre Mass
if, North Tecton
ic Doma
in of the
Borborema Prov
ince, NE Braz
il. It
is a post-coll
is
ional
intrus
ion const
ituted of coarse-gra
ined b
iot
ite–amph
ibole monzogran
ites, f
ine-gra
ined leucogran
ites and d
ior
ites. Major, trace and rare earth elements data, used to constra
in the or
ig
in and nature of these rocks,
ind
icate that the monzogran
ites d
isplay chem
ical features of weakly peralum
inous ferro-potass
ic trans-alkal
ine gran
ito
ids, s
im
ilar to coeval occurrences descr
ibed
in eastern N
iger
ian. Sm–Nd data together w
ith the whole rock geochem
ical data suggest that: (I) the monzogran
ites were generated by part
ial melt
ing of tonal
it
ic gne
iss from the lower crust, leav
ing beh
ind a granul
it
ic res
idue; (II) the d
ior
ites or
ig
inated by part
ial melt
ing of an enr
iched l
ithospher
ic mantle; (III) the evolut
ion of the Solânea Complex
involved magma m
ix
ing between the monzogran
ites and d
ior
ites. K-feldspar and amph
ibole fract
ionat
ion appear to have occurred dur
ing the evolut
ion of the monzogran
ites.
Leucogranites constituting an elliptical shaped intrusion (80 km2), the Dona Inês Pluton, are intruded to the north of the Solânea Complex. They also occur as small intrusions cross-cutting the border of the Solânea Complex. Geochemical and isotopic data suggest that the leucogranites were generated by melting of crustal Palaeoproterozoic rocks. Rb–Sr data gave an age of 544 ± 16 Ma.
Trans-alkaline magmatism is associated with ductile–brittle deformation in the Serrinha–Pedro Velho Complex of the São José do Campestre Massif. This event follows the peak of an extensional-related high-temperature metamorphism (upper amphibolite to granulite facies), with estimated age of 578 to 574 Ma. If a pre-Gondwana reconstruction is considered, this event is seen to extend to the African side of Gondwana in eastern Nigeria.