Tectono‐Metamorphic Evolution of the Northern Dom Feliciano Belt Foreland, Santa Catarina, Brazil: Implications for Models of Subduction‐Driven Orogenesis

Abstract

Orogenic systems vary widely in terms of their geometry, duration, and scale. The classic collisional orogen can be described using models that involve the termination of a Wilson cycle, where the opening and closing of a large ocean basin between continental bodies culminates in the continental collision. Accretionary orogens, in contrast, form at continental-oceanic convergent plate boundaries in the absence of continental collision, and develop during continuous subduction by crustal thickening due to short-term coupling across the subduction plate boundary (Cawood et al., 2009). Within-plate deformation can also occur away from plate margins, triggered by the transmission of stress from active plate boundaries through the lithosphere (Aitken et al., 2013;Raimondo et al., 2014). Large-scale intracontinental orogens are comparatively less common than collisional or accretionary orogens, but examples are recognized in both ancient and modern settings (Cunningham, 2005;Faure et al., 2009;Hand & Sandiford, 1999). Although the defining characteristics of collisional, accretionary, and intracontinental orogens make them distinct, Cawood et al. (2009) proposed that they represent three interrelated endmembers between which lies a wide spectrum of orogen types. Thus, continental collision at the termination of a Wilson cycle is genetically linked to preceding accretionary orogeny. Similarly, tectonic switching during accretionary orogeny can produce large-scale crustal thickening in within-plate settings (Lister & Forster, 2009), resulting in orogens that develop as the consequence of intracratonic rift inversion, similar to what occurs within an accretionary back-arc setting but at a distance from the developing arc (Collins, 2002;Thompson et al., 2001).The South Atlantic Neoproterozoic Orogenic System (SANOS, sensu Konopásek et al., 2020) comprises an extensive system of orogenic belts that formed during the late Neoproterozoic amalgamation of Western Gondwana

Garnet growth and mineral geochronology constrains the diachronous Neoproterozoic convergent evolution of the southern Dom Feliciano Belt, Uruguay

“…As pre-orogenic rifting is estimated to have ended only by c. 660-650 Ma (Hoffman, 2021;Konop asek et al, 2020), convergence and crustal thickening likely shortly followed crustal thinning. Thus, the burial of the hinterland domain to depths of at least c. 40 km (Figure 14a) and the intrusion of porphyritic granites (e.g., sample UA38) suggests significant thickening of an already hot, thinned crust at c. 655 Ma, coeval with the timing of crustal thickening recorded in the northern Dom Feliciano Belt (Percival et al, 2022). The garnet from sample UB02, on the other hand, does not show evidence for the preservation of an earlier higher-pressure metamorphic event, and thus the garnet Lu-Hf age of 638.5 ± 2.2 Ma Ma from this sample is the best estimate F I G U R E 1 3 Results of U-Pb dating in zircon and monazite for samples from the Cerro Olivo complex (a-g) and the Campanero Unit (h-l).…”

“…In contrast with the southern Dom Feliciano Belt, sinistral deformation is almost completely absent from the major shear zones of the northern Dom Feliciano Belt, and there is only minor reactivation along these shear zones after c. 580 Ma (Hueck et al, 2018; Percival et al, 2022). Instead, it appears that deformation in the northern extension of the system at c. 580 Ma was confined almost completely to the eastern half of the orogen (Figure 15c).…”

“…The exhumed roots of orogenic belts and their interactions with foreland domains reveal fundamental details about the evolution of orogenic crustal thickening, and assessing the nature of these events requires the integration of structural and metamorphic petrological observations with geochronological data (e.g., Meira et al, 2019; Percival et al, 2022; Tajčmanová et al, 2006). Correlating the growth of dated minerals with specific structures and tectonic events allows the construction of P–T–t paths, which can then be used to interpret the development of orogens on a large scale (e.g., Coelho et al, 2017; Goscombe et al, 2017, 2018; Larson et al, 2020; Schulmann et al, 2009).…”

“…Early crustal thickening is characterized by west‐directed thick‐skinned thrusting and development of a high‐grade metamorphosed hinterland, which coincides with early thin‐skinned thrusting and development of peak metamorphic conditions in the foreland. After the early compressional movement along the thrust system ended, deformation in the orogen transitioned into a transpressional phase, leading to the development of large sub‐vertical shear zones overprinting previous flat‐lying deformation fabrics and down‐grading peak metamorphic assemblages (Battisti et al, 2018; De Toni, Bitencourt, Konopásek, et al, 2020; Percival et al, 2022).…”

“…Recent studies in the northern and central Dom Feliciano Belt have recognized the coupled tectono‐metamorphic evolution of the orogenic foreland and hinterland domains. In the northern Dom Feliciano Belt (Santa Catarina state), low‐ to medium‐grade metamorphism in the foreland records the progressive west‐directed over‐thrusting of the hinterland at c. 660–650 Ma, marking the earliest evidence of crustal thickening in the orogen (De Toni, Bitencourt, Konopásek, et al, 2020; Percival et al, 2022). The same relationship is inferred in the central sector of the belt (Rio Grande do Sul state) (Battisti et al, 2018; De Toni et al, 2021).…”