Abstract
The Rio Maria Formation is a siliciclastic sedimentary sequence deposited in an eiperic sea formed along of eastern edge of the Carajás Province - the oldest Archean province of the Amazonian Craton - being intruded by rapakivi-type granite (1.88 Ga). Four facies associations have been recognized: prodelta-distal bar, delta-front/shoreface, delta-plain/distributaries and fluvial channels. Large-scale hummocky-swaley cross-stratifications (>; 1 m) attest storm waves-influenced in upper shoreface deposits (tempestites). Bipolar cross-beddings with drape and reactivation surfaces reflect tidal-influence. Quartzarenite, sublitharenite and subarkose modal frameworks indicate stable continental block (craton interior) source. Heavy-minerals assemblages (e.g. zircon, tourmaline, staurolite, epidote, etc.) provide evidence of contribution from felsic plutonic igneous and metamorphic rocks. Well-rounded zircon grains can be associated to reworked sediments or metamorphic sources. These litotypes can be related to Rio Maria Block, which includes granitoid and metassedimentary rocks of the Rio Maria granite-greenstone terrain (3.0 - 2,86 Ga).
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
