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Location and geologic map of the Transantarctic Mountains, Antarctica, showing the metasedimentary units discussed in the text. The inset shows the position of Adelaidean rocks and the Delamerian (Australia) and Ross (Antarctica) Orogens before Cretaceous-Cenozoic rifting, with the black circle indicating the study area. The locations of other recent geochronological studies in the Transantarctic Mountains and South Australia relevant to the discussion are indicated.
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Detrital zircon U-Pb ages constrain the age and provenance of the Skelton Group in southern Victoria Land, one of several Proterozoic-Cambrian metasedimentary units that form basement to the Ross Orogen in East Antarctica. The age of the youngest detrital zircons combined with previous dating of crosscutting intrusive rocks indicates deposition of...
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Citations
... The generally minor Stenian population of zircon at c. 1160 Ma suggests provenance from the Musgrave Province (Smithies et al. 2008;Wade et al. 2008;Smithies et al. 2011;Smits et al. 2014), but as noted in Lloyd et al. (2022), they may be sourced from an as yet undiscovered but inferred late Mesoproterozoic (c. 1300-1000 Ma) source to the east (Wysoczanski & Allibone, 2004;Fergusson et al. 2007;Mackay, 2011;Korsch et al. 2012). This Stenian zircon population is generally more abundant in samples closer to the eastern and western margins of the basin (Figs. 7, 1). ...
The glaciogenic nature of the Yudnamutana Subgroup was first recognized over a century ago, and its global significance was recognized shortly after, with the eventual postulation of a global Sturtian Glaciation and Snowball Earth theory. Much debate on the origin and timing of these rocks, locally and globally, has ensued in the years since. A significant corpus of research on the lithology, sedimentology, geochronology and formal lithostratigraphy of these sequences globally has attempted to resolve many of these debates. In the type area for the Sturtian Glaciation, South Australia’s Adelaide Superbasin, the lithostratigraphy and sedimentology are well understood; however, formal stratigraphic nomenclature has remained complicated and contested. Absolute dates on the stratigraphy are also extremely sparse in this area. The result of these longstanding issues has been disagreement as to whether the sedimentary rocks of the Yudnamutana Subgroup are truly correlative throughout South Australia, and if they were deposited in the same time span recently defined for Sturtian glacial rocks globally, c. 717 Ma to c. 660 Ma. This study presents a large detrital zircon study, summarizes and compiles existing global geochronology for the Sturtian Glaciation and revises the formal lithostratigraphic framework of the Yudnamutana Subgroup. We show equivalence of the rocks that comprise the revised Sturt Formation, the main glaciogenic unit of the Yudnamutana Subgroup, and that it was deposited within the time span globally defined for the Sturtian Glaciation.
... In situ igneous and metamorphic 40 Ar/ 39 Ar cooling ages are compiled from data presented in this paper, as well as [37,45,46,48,51,52,54,[79][80][81][82][83]. U-Pb crystallization ages from [33][34][35][36][37][38][44][45][46][47][48]82,[84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99]. 40 Ar/ 39 Ar cooling ages for detrital muscovite from the Starshot Formation along Ramsey Glacier are from [54] and those within the central Transantarctic Mountains (CTAM) are from [37]. ...
... Detrital zircon Yb/Gd data include all zircons regardless of concordance with Th/U > 0.1 (~igneous proxy) and Th, U, Y, Yb, and Gd values > 0. Interpreted zircon ages are 206 Pb/ 238 U ages for grains with 206 Pb/ 207 Pb ages < 1500 Ma. 40 Ar/ 39 Ar cooling ages are compiled from data presented in this paper, as well as [37,45,46,48,51,52,54,[79][80][81][82][83]. U-Pb igneous crystallization ages are presented in [33][34][35][36][37][38][44][45][46][47][48]82,[84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99]. ...
... Detrital zircon Yb/Gd data include all zircons regardless of concordance with Th/U > 0.1 (~igneous proxy) and Th, U, Y, Yb, and Gd values > 0. Interpreted zircon ages are 206 Pb/ 238 U ages for grains with 206 Pb/ 207 Pb ages < 1500 Ma.40 Ar/ 39 Ar cooling ages are compiled from data presented in this paper, as well as[37,45,46,48,51,52,54,[79][80][81][82][83]. U-Pb igneous crystallization ages are presented in[33][34][35][36][37][38][44][45][46][47][48]82,[84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99]. ...
Changes in magmatism and sedimentation along the late Neoproterozoic-early Paleozoic Ross orogenic belt in Antarctica have been linked to the cessation of convergence along the Mozambique belt during the assembly of East-West Gondwana. However, these interpretations are non-unique and are based, in part, on limited thermochronological data sets spread out along large sectors of the East Antarctic margin. We report new 40Ar/39Ar hornblende, muscovite, and biotite age data for plutonic (n = 13) and metasedimentary (n = 3) samples from the Shackleton–Liv Glacier sector of the Queen Maud Mountains in Antarctica. Cumulative 40Ar/39Ar age data show polymodal age peaks (510 Ma, 491 Ma, 475 Ma) that lag peaks in U-Pb igneous crystallization ages, suggesting igneous and metamorphic cooling following magmatism within the region. The 40Ar/39Ar ages are similar to ages in other sectors of the Ross orogen, but younger than detrital mineral 40Ar/39Ar cooling ages indicative of older magmatism and cooling of unexposed inboard areas along the margin. Detrital zircon trace element abundances suggest that the widespread onset of magmatism in outboard localities of the orogen correlates with a ~560–530 Ma decrease in crustal thickness. The timing of crustal thinning recorded by zircon in magmas overlaps with other evidence for the timing of crustal extension, suggesting that the regional onset of magmatism with subsequent igneous and metamorphic cooling probably reflects slab rollback that coincided with possible global plate motion changes induced during the final assembly of Gondwana.
... However, they could have alternately been sourced from a yet-undiscovered but inferred Musgravelike, late Mesoproterozoic (c. 1300-1000 Ma) source to the east [27,[91][92][93]. The five youngest zircons present in sample FR3_008, younger than 1000 Ma, are enigmatic. ...
... Moreover, as stated earlier, no local source of young zircon is known. This lends some support to the notion of a potential [27,[91][92][93] Stenian-Tonian source to the east. ...
Continental rifts have a significant role in supercontinent breakup and the development of sedimentary basins. The Australian Adelaide Superbasin is one of the largest and best-preserved rift systems that initiated during the breakup of Rodinia, yet substantial challenges still hinder our understanding of its early evolution and place within the Rodinian supercontinent. In the past decade, our understanding of rift and passive margin development, mantle plumes and their role in tectonics, geodynamics of supercontinent breakup, and sequence stratigraphy in tectonic settings has advanced significantly. However, literature on the early evolution of the Adelaide Superbasin has not been updated to reflect these advancements. Using new detrital zircon age data for provenance, combined with existing literature, we examine the earliest tectonic evolution of the Adelaide Superbasin in the context of our modern understanding of rift system development. A new maximum depositional age of 893 ± 9 Ma from the lowermost stratigraphic unit provides a revised limit on the initiation of sedimentation and rifting within the basin. Our model suggests that the basin evolved through an initial pulse of extension exploiting pre-existing crustal weakness to form half-grabens. Tectonic quiescence and stable subsidence followed, with deposition of a sourceward-shifting facies tract. Emplacement and extrusion of the Willouran Large Igneous Province occurred at c. 830 Ma, initiating a new phase of rifting. This rift renewal led to widespread extension and subsidence with the deposition of the Curdimurka Subgroup, which constitutes the main cyclic rift sequence in the Adelaide Superbasin. Our model suggests that the Adelaide Superbasin formed through rift propagation to an apparent triple junction, rather than apical extension outward from this point. In addition, we provide evidence suggesting a late Mesoproterozoic zircon source to the east of the basin, and show that the lowermost stratigraphy of the Centralian Superbasin, which is thought to be deposited coevally, had different primary detrital sources.
... However, they could have alternately been sourced from a yet-undiscovered but inferred Musgravelike, late Mesoproterozoic (c. 1300-1000 Ma) source to the east [27,[91][92][93]. The five youngest zircons present in sample FR3_008, younger than 1000 Ma, are enigmatic. ...
... Moreover, as stated earlier, no local source of young zircon is known. This lends some support to the notion of a potential [27,[91][92][93] Stenian-Tonian source to the east. ...
Continental rifts have a significant role in supercontinent breakup, and the development of sedimentary basins. The Australian Adelaide Superbasin is one of the largest and best-preserved rift systems that initiated during the breakup of Rodinia, yet substantial challenges still hinder our understanding of its early evolution and place within the Rodinian supercontinent. In the past decade, our understanding of rift and passive margin development, mantle plumes and their role in tectonics, geodynamics of supercontinent breakup, and sequence stratigraphy in tectonic settings has advanced significantly, however literature on the early evolution of the Adelaide Superbasin has not been updated to reflect these advancements. Using new detrital zircon age data for provenance, combined with existing literature, we examine the earliest tectonic evolution of the Adelaide Superbasin in the context of our modern understanding of rift system development. A new maximum depositional age of 893 ± 9 Ma from the lowermost stratigraphic unit provides a revised limit on the initiation of sedimentation and rifting within the basin. Our model suggests that the basin evolved through an initial pulse of extension exploiting pre-existing crustal weakness to form half-grabens. Tectonic quiescence and stable subsidence followed, with deposition of a sourceward-shifting facies tract. Emplacement and extrusion of the Willouran Large Igneous Province occurred at c. 830 Ma initiating a new phase of rifting. This rift renewal led to widespread extension and subsidence with deposition of the Curdimurka Subgroup, which constitutes the main cyclic rift sequence in the Adelaide Superbasin. Our model suggests that the Adelaide Superbasin formed through rift propagation an apparent triple junction, rather than apical extension outwards from this point. Additionally, we provide evidence suggesting a late Mesoproterozoic zircon source to the east of the basin, and show that the lowermost stratigraphy of the Centralian Superbasin, which is thought to be deposited coevally, had different primary detrital sources.
... The group <450 Ma (Late Ordovician to Carboniferous) indicated as post-Ross Orogeny, was introduced for the grains that fall in this age interval. The Th/U ratio of zircon has been used to determine the growth process of zircons: grains with Th/U ratio <0.1 are considered metamorphic growth (Williams and Claesson, 1987;Hanchar and Millar, 1993;Wysoczanski and Allibone, 2004), while when the ratio is higher than 0.1, the zircon is considered of magmatic origin. LA-ICP-MS raw data are available as Supplemental information (see footnote 1). ...
... Zircon ages correlating to the Grenville Orogeny (1300-901 Ma) reflect the contribution of three different possible sources: (i) Neoproterozoic metamorphic rocks, (ii) Cambro-Ordovician metamorphic rocks, and (iii) Devonian Taylor Group sedimentary strata. Neoproterozoic meta-morphic rocks (Beardmore, Skelton, and Wilson groups) have additional major populations, such as Paleoproterozoic (2500-1601 Ma) (Goodge et al., 2004a(Goodge et al., , 2004bWysoczanski and Allibone, 2004;Cooper et al., 2011;Estrada et al., 2016;Paulsen et al., 2016), which are, on the contrary, poorly represented in the analyzed samples of this study. Nevertheless, these units may have partially contributed to the tillite composition, especially the Skelton Group which constitutes part of the basement in the Dry Valley region (Cox et al., 2012). ...
... Zircon grains of this age interval are documented in 590-565 Ma granitoid glacial erratics close to the Nimrod Glacier in the CTAM (Goodge et al., 2010(Goodge et al., , 2012Goodge, 2020), as well as in granitoids and metamorphic rocks in the Koettlitz Glacier area of SVL (Hagen-Peter and . Zircons showing 700-551 Ma ages are also present in several Neoproterozoic and Cambro-Ordovician meta-sedimentary rocks of the Wilson, Bowers, and Robertson Bay terranes in NVL, the Skelton Group in SVL, the Beardmore and Byrd groups in CTAM, and the Swanson Formation in MBL (Pankhurst et al., 1998;Goodge et al., 2004aGoodge et al., , 2004bGoodge et al., , 2010Goodge et al., , 2012Wysoczanski and Allibone, 2004;Cooper et al., 2011;Yakymchuk et al., 2015;Estrada et al., 2016;Paulsen et al., 2016;Goodge, 2020). Moreover, Ross-Pan-African zircons widely occur in the upper units of the Devonian Taylor Group (Elliot et al., 2015;Paulsen et al., 2017). ...
The Lower Permian tillites of the Beacon Supergroup, cropping out in Victoria Land (Antarctica), record climatic history during one of the Earth’s coldest periods: the Late Paleozoic Ice Age. Reconstruction of iceextent and paleo-flow directions, as well as
geochronological and petrographic data, are poorly constrained in this sector of Gondwana. Here, we provide the first detrital zircon U-Pb age analyses of both the Metschel Tillite in southern Victoria Land and some tillites correlatable with the Lanterman Formation in northern Victoria Land to identify the source regions of these glaciogenic deposits. Six-hundred detrital zircon grains from four diamictite samples were analyzed using laser ablation–inductively coupled plasma–mass spectrometry. geochronological and petrographic compositional data of the Metschel Tillite indicate a widespread reworking of older Devonian Beacon Supergroup sedimentary strata, with minor contribution from Cambro-Ordovician granitoids and meta-sedimentary units as well as Neoproterozoic metamorphic rocks. Euhedral to subhedral Carboniferous–Devonian zircon grains match coeval magmatic units of northern Victoria Land and Marie Byrd Land. This implies, in accordance with published paleo-ice directions, a provenance from the east-southeast sectors. In contrast, the two samples from northern Victoria Land tillite reflect the local basement provenance; their geochronological age and petrographic composition indicates a restricted catchment area with multiple ice centers. This shows that numerous ice centers were present in southern Gondwana during the Late Paleozoic Ice Age. While northern Victoria Land hosted discrete glaciers closely linked with the
northern Victoria Land-Tasmania ice cap, the west-northwestward flowing southern Victoria Land ice cap contributed most of the sediments comprising the Metschel Tillite.
... 650 Ma rhyolitic flows that require Neoproterozoic deposition (Cooper et al., 2011). Despite the dominant~1.1 Ga detrital zircons seen in these metasediments (Wysoczanski and Allibone, 2004;Cooper et al., 2011), the only known Rodinian-aged crust in Southern Victoria Land is a single ~940 Ma metamorphosed sandstone (Wysoczanski and Allibone, 2004). From the Neoproterozoic to Ordovician, the Skelton Group was extensively intruded by the Ross Orogen Granite Harbour Intrusive suite (e.g., Grindley and Warren, 1964;Cox et al., 2000;Allibone and Wysoczanski, 2002;Read et al., 2002;Read, 2010;Cox et al., 2012;Hagen-Peter et al., 2015;Cottle, 2016, 2018). ...
... 650 Ma rhyolitic flows that require Neoproterozoic deposition (Cooper et al., 2011). Despite the dominant~1.1 Ga detrital zircons seen in these metasediments (Wysoczanski and Allibone, 2004;Cooper et al., 2011), the only known Rodinian-aged crust in Southern Victoria Land is a single ~940 Ma metamorphosed sandstone (Wysoczanski and Allibone, 2004). From the Neoproterozoic to Ordovician, the Skelton Group was extensively intruded by the Ross Orogen Granite Harbour Intrusive suite (e.g., Grindley and Warren, 1964;Cox et al., 2000;Allibone and Wysoczanski, 2002;Read et al., 2002;Read, 2010;Cox et al., 2012;Hagen-Peter et al., 2015;Cottle, 2016, 2018). ...
Osmium isotopes, whole rock and mineral geochemical data from peridotite xenoliths from two Miocene McMurdo Volcanic Group cinder cones in the Transantarctic Mountains (TAM) in Southern Victoria Land, Antarctica, reveal that the underlying mantle preserves evidence for major mid-Proterozoic lithosphere formation despite the crust being dominated by late Neoproterozoic-Ordovician (∼0.65-0.47 Ga) rocks. The Hooper Crags xenolith suite is dominated by harzburgites with highly refractory olivine Mg# (up to 92.3) and depleted bulk rock major and platinum group element + Re abundances, with ¹⁸⁷Os/¹⁸⁸Os ratios indicating depletion in the mid-Proterozoic. Pipecleaner Glacier xenoliths, 18 km distant, are lherzolites with olivine Mg# (< 91) and fertile major and platinum group element abundances, with Os isotope abundances defining an aluminochron that also indicates mid-Proterozoic depletion. Although exposed crust along this portion of Antarctica reveals only minor evidence for Proterozoic magmatism, the major episode of lithosphere formation indicated by the Os isotope data is supported by published bulk rock Sm-Nd isotope and zircon εHf mantle model ages of Neoproterozoic to Ordovician plutonic rocks. The heterogeneous circum-cratonic mid-Proterozoic mantle under Southern Victoria Land has therefore persisted on a Ga timescale, including through the formation and destruction of Rodinia and Gondwana supercontinents as well as extensive crustal melting and emplacement of the Ferrar large igneous province. This longevity may be due to the thick (>250 km) East Antarctic Craton lithosphere shielding the immediately adjacent circum-cratonic mantle from being affected by convective asthenosphere-driven erosion. This contrasts with mantle lithosphere accreted distally to the East Antarctic Craton (represented by the now-detached Zealandia continent), which did not attain extreme thickness and has therefore been more susceptible to tectonic reworking and lateral translation.
... A minimum age of~550 Ma, bracketed by crosscutting plutons, indicates that the rocks are indeed Precambrian (Rowell et al., 1993;Encarnación and Grunow, 1996;Read and Cooper, 1999). Detrital zircon age distributions in the Skelton and Koettlitz groups show a preponderance of Grenville-age zircons relative to Paleoproterozoic and Archean components, and a lack of Ross-age detrital grains appears to confirm a Neoproterozoic depositional age (Wysoczanski and Allibone, 2004;Goodge et al., 2004b). Similarity between their age patterns and those from Goldie and basal Shackleton sandstones farther south, and the calcareous nature of the associated Koettlitz units, suggest that the Skelton and Koettlitz units may record platform deposition in the latest Neoproterozoic. ...
... Rhyolite clasts from this section gave U\ \Pb zircon ages of~650 Ma (Cooper et al., 2011), indicating that they were erupted and re-deposited as conglomeratic material in the same general timeframe as the Beardmore Group farther south. The similarity of detrital zircon age signatures in Skelton Group sandstones with those of the Beardmore Group (Goodge et al., , 2004bWysoczanski and Allibone, 2004;Cooper et al., 2011), as well as the similar ages of bimodal volcanism in the Skelton and Nimrod glacier areas, indicates that their deposition is related to extension and rifting during supercontinental breakup of Rodinia. ...
... Because of the regional metamorphic grade and intimate relationship with granitic melts and anatectites, there is no clear evidence of late Neoproterozoic to early Paleozoic sedimentary rocks in southern Victoria Land corresponding to those elsewhere in the TAM. As noted above, Skelton Group metasedimentary rocks have detrital zircon ages indicating deposition as old as about 1050-950 Ma. Wysoczanski and Allibone (2004) concluded that the Skelton rocks are likely correlative with Beardmore Group and Adelaidean successions, and they proposed a depositional age greater than~600 Ma. Detrital zircons from the Hobbs Formation of the Koettlitz Group are~670 Ma and older, likewise indicating a Neoproterozoic depositional age concurrent with rift-stage volcanism (Goodge et al., 2004b). ...
The Transantarctic Mountains (TAM) are one of Earth's great mountain belts and are a fundamental physiographic feature of Antarctica. They are continental-scale, traverse a wide range of latitudes, have high relief, contain a significant proportion of exposed rock on the continent, and represent a major arc of environmental and geological transition. Although the modern physiography is largely of Cenozoic origin, this major feature has persisted for hundreds of millions of years since the Neoproterozoic to the modern. Its mere existence as the planet's longest intraplate mountain belt at the transition between a thick stable craton in East Antarctica and a large extensional province in West Antarctica is a continuing enigma. The early and more cryptic tectonic evolution of the TAM includes Mesoarchean and Paleoproterozoic crust formation as part of the Columbia supercontinent, followed by Neoproterozoic rift separation from Laurentia during breakup of Rodinia. Development of an Andean-style Gondwana convergent margin resulted in a long-lived Ross orogenic cycle from the late Neoproterozoic to the early Paleozoic, succeeded by crustal stabilization and widespread denudation during early Gondwana time, and intra-cratonic and foreland-basin sedimentation during late Paleozoic and early Mesozoic development of Pangea. Voluminous mafic volcanism, sill emplacement, and layered igneous intrusion are a primary signature of hotspot-influenced Jurassic extension during Gondwana breakup. The most recent phase of TAM evolution involved tectonic uplift and exhumation related to Cenozoic extension at the inboard edge of the West Antarctic Rift System, accompanied by Neogene to modern glaciation and volcanism related to the McMurdo alkaline volcanic province. Despite the remote location and relative inaccessibility of the TAM, its underlying varied and diachronous geology provides important clues for reconstructing past supercontinents and influences the modern flow patterns of both ice and atmospheric circulation, signifying that the TAM have both continental and global importance through time.
... The new ages establish important Gunn and Warren (1962) and Cook and Craw (2001). Ages are compiled from Goodge andDallmeyer (1992, 1996), Rowell et al. (1992Rowell et al. ( , 1993Rowell et al. ( , 1997, Goodge et al. (1993Goodge et al. ( , 2002Goodge et al. ( , 2004aGoodge et al. ( , 2004bGoodge et al. ( , 2012, Hall et al. (1995), Millar and Storey (1995), Encarnación and Grunow (1996), Cooper et al. (1997), Van Schmus et al. (1997), Encarnación et al. (1999), Cox et al. (2000), Encarnación (2000a, 2000b), Cook and Craw (2001), Allibone and Wysoczanski (2002), Mellish et al. (2002), Myrow et al. (2002), Read et al. (2002), Vogel et al. (2002), Curtis et al. (2004), Paulsen et al. (2004Paulsen et al. ( , 2008Paulsen et al. ( , 2013Paulsen et al. ( , 2015Paulsen et al. ( , 2017, Stump et al. (2004Stump et al. ( , 2006Stump et al. ( , 2007, Wysoczanski and Allibone (2004), Cooper (2006a, 2006b), Talarico et al. (2007), Cooper et al. (2011), Hagen-Peter et al. (2015, and Martin et al. (2015). F p Fairweather Formation; G p Greenlee Formation; T p Taylor Formation. ...
... Detrital zircon ages are compiled for the Liv and Beardmore Groups (A) from Stump et al. (2007) and Paulsen et al. (2015Paulsen et al. ( , 2017; for the Byrd Group (B) from Goodge et al. (2002Goodge et al. ( , 2004b and Paulsen et al. (2017); and for the Skelton Group (C) from Stump et al. (2007), Cooper et al. (2011), andPaulsen et al. (2017). Volcanic and plutonic U-Pb crystallization ages are compiled from data presented in this article as well as Goodge et al. (1993Goodge et al. ( , 2004bGoodge et al. ( , 2012, Rowell et al. (1993), Hall et al. (1995), Encarnación and Grunow (1996), Cooper et al. (1997), Van Schmus et al. (1997), Encarnación et al. (1999), Cox et al. (2000), Cook and Craw (2001), Allibone and Wysoczanski (2002), Mellish et al. (2002), Read et al. (2002), Vogel et al. (2002), Stump et al. (2004Stump et al. ( , 2006, Wysoczanski and Allibone (2004), Cooper (2006a, 2006b), Read (2010), Cooper et al. (2011), Paulsen et al. (2013Paulsen et al. ( , 2016c, Hagen-Peter et al. (2015), Martin et al. (2015), and Hagen-Peter and . tified within the Ross orogen and therefore provides important new evidence for Cambrian (Furongian) or younger deformation in this sector of the range. ...
We present new zircon U-Pb isotopic data for volcanic rocks from deformed metavolcanic-sedimentary successions of the widespread Ross Supergroup in the Queen Maud Mountains, Antarctica. Zircon U-Pb analyses of Liv Group volcanic rocks thought to be Neoproterozoic in age instead have early Paleozoic ages. Zircon U-Pb analyses of five samples assigned to the Fairweather Formation have yielded 524±9 to 514±9 Ma (2σ) crystallization ages, whereas six samples assigned to the Taylor Formation have yielded 510±12 to 490±6 Ma (2σ) crystallization ages. Although these ages imply that the Fairweather Formation is generally older than the Taylor Formation, the age uncertainties show a 17-My overlap that is consistent with previous suggestions for temporal correlation of these formations. On a regional scale, Liv Group volcanism overlapped with the emplacement of ∼535–490 Ma plutonic rocks associated with the early Paleozoic Queen Maud batholith as well as igneous rocks found elsewhere along the early Paleozoic Pacific-Gondwana margin. Collectively, these igneous rocks provide plausible zircon sources for similar age detrital zircon populations found in outboard siliciclastic rocks belonging to the Leverett, Taylor, Fairweather, Greenlee, and Starshot Formations of the Queen Maud Mountains. The youngest crystallization age yielded by the deformed Taylor Formation (∼490 Ma) assumes regional significance because it represents the youngest volcanic rock yet identified within the Ross orogen in Antarctica and provides important new evidence for latest Cambrian or younger deformation, possibly associated with orogenic collapse during slab rollback at the terminal stages of the Ross orogeny.
... The northern extent of the basin may have been limited by the Muloorina Ridge, a gravity anomaly known only from the subsurface that likely represents Proterozoic basement (Von der Borch 1980). The ultimate southern extent of the basin and surrounding provinces is unknown; potentially correlative sediments of Adelaidean age are found in Antarctica, but the exact relationships are unclear (Wysoczanski and Allibone 2004). The basin was deformed through compression and shortening in the Cambrian Delamerian Orogeny, which exaggerated existing salt-tectonic deformation and resulted in the upturned, folded and faulted sediments seen today. ...
The Adelaide Rift Complex, a sedimentary basin in South Australia, has a long history
spanning over 300 million years from the Neoproterozoic to the Cambrian. Over 100
individual formations make up the basin fill, documenting its geologic evolution from
incipient rift to passive margin and recording a wide range of depositional environments.
The basin is significantly affected by syndepositional salt tectonics and later structural
deformation, creating a well-exposed natural laboratory in which to examine sedimentary
systems that are rarely exposed elsewhere. This publication briefly summarises the basin’s
geology (focusing on sedimentology), and provides a starting point for further research
through reviews of both recent and older literature. The deposits discussed here may serve
as analogues for similar depositional systems in the subsurface during petroleum
exploration and development; some relevant analogues are also discussed, focusing on
those that also have a component of salt-sediment interaction.
... Neoproterozoic-early Paleozoic metasedimentary rocks of the Ross-Delamerian orogenic belt are typically dominated by 1200-900 Ma and 700-500 Ma zircon age populations (Goodge et al., 2004;Wysoczanski and Allibone, 2004;Stump et al., 2007;Cooper et al., 2011;Paulsen et al., 2015;Paulsen et al., 2016), and these rocks serve as the country rocks to ca. (Barrett, 1991;Bradshaw, 2013 Data were collected in runs of 30 samples bracketed before and after by three analyses of the primary zircon reference material GJ-1 (Jackson et al., 2004) as well as secondary reference zircons 91500 (Wiedenbeck et al., 1995), Plesovice (Sláma et al., 2008) and Temora (Black et al., 2004). Data handling and reduction were performed with Iolite v2.5 (Paton et al., 2010) and ...
... Detrital zircon ages are compiled from Goodge et al. (2004), Stump et al. (2007), Cooper et al. (2011), and Paulsen et al. (2015). Volcanic and plutonic U-Pb crystallization ages are compiled fromRowell et al. (1993),Hall et al. (1995),Encarnación and Grunow (1996),Cooper et al. (1997),Cox et al. 2000),Cook and Craw (2001),Allibone and Wysoczanski (2002),Read et al. (2002),Mellish et al. (2002),Wysoczanski and Allibone (2004),Cottle and Cooper (2006a),Cottle and Cooper (2006b),Stump et al. (2006), Read (2010), Cooper et al. (2011), Martin et al. (2015), Hagen-Peter et al. (2015), Hagen-Peter and Cottle (2016). ...
