The Araguaia Belt is an orogen in central Brazil formed during the West Gondwana
assemblage by the end of the Neoproterozoic. Phanerozoic rocks of the Parnaíba Basin
cover the north and east portion of the belt. The Amazonian Craton limits the Araguaia
belt to the west and the Goiano Massif in the south and southeast. The metasedimentary
rocks of the belt are assemblage in the Estrondo (quartzites and schists) and Tocantins
(schists, phyllites, and metarenites) groups. Detrital zircon from quartzite of the Morro
do Campo Formation (lower Estrondo Group), dated by the Pb-evaporation method,
revealed populations of different ages for the northern (Xambioá) and southern (Paraíso
do Tocantins) regions of this orogen (Pinheiro et al., 2011). Quartzite from Xambioá
presented detrital zircon ages between 1.4 and 3.1 Ga, with the main population
between 2.6 and 3.0 Ga. In Paraíso do Tocantins the quartzite showed ages varying
between 0.7 Ga and 2.8 Ga, but those within 1.0 and 1.2 Ga are predominant. Later,
LA-MC-ICP-MS U-Pb zircon dating (Gorayeb et al., 2020) confirmed the expressive
contribution of Mesoproterozoic detrital zircon in quartzites from the southern segment
of the Araguaia Belt. However, the low sampling density and the analytical limitations
of the Pb-evaporation technique do not allow a clear definition of the source area of
these sediments. Thus, this work extended the LA-MC-ICP-MS U-Pb dating in detrital
zircon for the quartzites of the northern segment of the Araguaia Belt to obtain more
accurate ages and define the source area of these sediments. The metasedimentary rocks
of the Morro do Campo Formation form several dome-like structures along the northern
segment of the belt, in the core of which Archean and Paleoproterozoic basement
orthogneisses crop out. The studied quartzites were sampled, from north to south, at the
Xambioá, Grota Rica, Cantão, and Colmeia structures. In the Xambioá structure, the
quartzite presented the main population with ages between 1600 – 2000 Ma (62%) and
three secondary populations of ages 2420 – 2760 Ma (21%), 1430 – 1580 Ma (12%),
and 2140 – 2360 (5%). For the quartzite of the Grota Rica structure, the data revealed
the main population between 1600 – 1880 Ma (42%) and three secondary populations of
ages 2640 – 2990 Ma (25%), 1240 – 1580 Ma (24%), and 1920 – 2080 Ma (9%). The
quartzite of the Cantão structure showed the main population with ages between 1300 –
1600 Ma (54%) and three secondary populations with ages of 1600 – 1900 Ma (29%),
1030 – 1300 Ma (11%), and 800 – 950 Ma (5%). Finally, in the Colméia structure, the a main population was defined
aged between 980 – 1280 Ma (81%) and two secondary populations aged 2840
– 3000 Ma (10%) and 1850 – 2080 Ma (9%). The ages obtained showed a wide
variation of detrital zircon populations. However, quartzites from the structures of
Xambioá and Grota Rica register significant contributions of zircon grains from the
Paleoproterozoic (Siderian-Riatian-Orosirian-Statherian) and, secondarily, from the
Meso-Neoarchean. In the quartzites of the structures of Cantão and Colméia, located further
south, Mesoproterozoic detrital zircons predominate
(Ectasian/Callimian/Sthenian), and in the latter the presence of zircons
stenianos is relatively more expressive. On the other hand, the similarity between the
detrital zircon populations from Colmeia and Paraíso do Tocantins indica quartzites
that the contribution of rocks formed in the Stenian is not restricted to the southern portion of the Belt
Araguaia. Comparison of U-Pb zircon ages of rocks from Massif terrains
Goiano/Goiás Magmatic Arc and the Amazon and São Francisco cratons with the
detrital zircon ages of quartzites from the Araguaia Belt suggest the terrains of the
Goiano Massif/Goiás Magmatic Arc as the most likely source of the sediments.
These terrains encompass rocks with ages corresponding to zircon populations.
found, and constitute the crustal segment closest to the basin
precursor of the Araguaia orogen. Furthermore, they occupy a geographical position
compatible with a source area situated to the southeast of this belt, as suggested by
previous works of sedimentary origin. It is also recommended to complement the
provenance study of quartzites using the Lu-Hf method in zircon for better
characterize source areas based on ƐHf values and Hf-TDM model ages C.
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