TY - JOUR
T1 - The orogenic crixás gold deposit, goiás, brazil
T2 - A review and new constraints on the structural control of ore bodies
AU - Ulrich, Stanislav
AU - Hageman, Steffen
AU - Marques, Juliana Charão
AU - Figueiredo, Frederico Lana A.R.
AU - Ramires, João E.F.
AU - Frantz, José Carlos
AU - Petersen, Klaus
PY - 2021/10
Y1 - 2021/10
N2 - A review of the current knowledge of lithostratigraphy, geochronology, mineralogy, al-teration, fluid chemistry and structural data is provided in order to discuss the main controls on mineralization in the Crixás gold deposit and the existing structural framework and evolution. Gold mineralization at Crixás represents orogenic upper mesothermal to lower hypothermal types devel-oped within the overturned Paleoproterozoic (Rhyacian) stratigraphic sequence. The structural data indicates that upright folding of the stratigraphy and formation of a distinct S1 foliation characterizes D1 deformation. This controls the formation of laminated quartz veins, precipitation of Au-rich sulfides, and the development of NW trending orebodies. Localized F2 folding of D1 structures and strong L2 stretching lineations characterizes the D2 event. This localized F2 folding created oreshoots trending W-WNW within distinct orebodies. The D2 deformation is associated with the precipitation of native Au. The ‘bulk plunge’ of these orebodies is a combination of both plunges defined by D1 and D2 deformation events. A critical assessment of lithostratigraphic and structural data reveal two possible tectonic scenarios operating during the Paleoproterozoic. The first possible tectonic scenario considers sagduction and the development of a regional-scale synclinorium, followed by tilting and localized folding of D1 structures. The second scenario, which is similar to the current model, considers accretion producing a synclinorium, followed by thrusting. Based on the current knowledge, both models are considered to be permissible and a series of focused research studies are proposed to test both the current and the new tectonic models.
AB - A review of the current knowledge of lithostratigraphy, geochronology, mineralogy, al-teration, fluid chemistry and structural data is provided in order to discuss the main controls on mineralization in the Crixás gold deposit and the existing structural framework and evolution. Gold mineralization at Crixás represents orogenic upper mesothermal to lower hypothermal types devel-oped within the overturned Paleoproterozoic (Rhyacian) stratigraphic sequence. The structural data indicates that upright folding of the stratigraphy and formation of a distinct S1 foliation characterizes D1 deformation. This controls the formation of laminated quartz veins, precipitation of Au-rich sulfides, and the development of NW trending orebodies. Localized F2 folding of D1 structures and strong L2 stretching lineations characterizes the D2 event. This localized F2 folding created oreshoots trending W-WNW within distinct orebodies. The D2 deformation is associated with the precipitation of native Au. The ‘bulk plunge’ of these orebodies is a combination of both plunges defined by D1 and D2 deformation events. A critical assessment of lithostratigraphic and structural data reveal two possible tectonic scenarios operating during the Paleoproterozoic. The first possible tectonic scenario considers sagduction and the development of a regional-scale synclinorium, followed by tilting and localized folding of D1 structures. The second scenario, which is similar to the current model, considers accretion producing a synclinorium, followed by thrusting. Based on the current knowledge, both models are considered to be permissible and a series of focused research studies are proposed to test both the current and the new tectonic models.
KW - Crixás Greenstone Belt
KW - Gold mineralization
KW - Tectonics
UR - http://www.scopus.com/inward/record.url?scp=85115867336&partnerID=8YFLogxK
U2 - 10.3390/min11101050
DO - 10.3390/min11101050
M3 - Review article
AN - SCOPUS:85115867336
SN - 2075-163X
VL - 11
JO - Minerals
JF - Minerals
IS - 10
M1 - 1050
ER -