Isotopic contrasts within the Internal Liguride ophiolite (N. Italy): the lack of a genetic mantle–crust link

Rampone, Elisabetta; Hofmann, Albrecht W.; Raczek, Ingrid

doi:10.1016/s0012-821x(98)00185-x

Cited by 129 publications

(101 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The infiltrated mantle rocks are intruded by gabbros (Lanzo: 161 ± 2 to 158 ± 2 Ma; Kaczmarek et al 2008;Platta: 161 ± 1 Ma, Schaltegger et al 2002) demonstrating that melt infiltration pre-dates their emplacement. On the other hand, the observation that the infiltrated rocks are overprinting previously depleted mantle rocks (depletion dated as Permian; Rampone et al 1998;Müntener et al 2004 or Proterozoic;Bodinier et al 1991), support the interpretation of Müntener and Piccardo (2004) that infiltration post-dates Permian magmatism and pre-dates mantle exhumation in late middle Jurassic time.…”

Section: Discussionmentioning

confidence: 80%

“…The formation of these rocks corresponds with Sm-Nd model ages of depleted mantle rocks that were interpreted to represent upper Carboniferous-Lower Permian partial melting residues, predating Mesozoic rifting (e.g. Rampone et al 1998;. The granulite to amphibolite facies contact metamorphic aureoles characteristically recorded long-lived isobaric cooling (IBC) following magma emplacement in Permian time, suggesting the attainment of thermal re-equilibration of the crustal section prior to the onset of Jurassic rifting and the onset of exhumation in Jurassic time Braga et al 2003).…”

Section: Continental Crustmentioning

confidence: 72%

“…Chenaillet unit; Manatschal and Müntener 2009). As shown by Rampone et al (1998) and , the mantle rocks within the Alpine Tethys domain have undergone a complex pre-rift history. A key element recorded in mantle rocks is Permian depletion inferred from Sm/Nd model ages on mantle rocks (Rampone et al 1998) and Sm/Nd mineral isochrones on crustal rocks (Voshage et al 1988;Thöni andJagoutz 1992, 1993).…”

Section: Mantlementioning

confidence: 99%

“…As shown by Rampone et al (1998) and , the mantle rocks within the Alpine Tethys domain have undergone a complex pre-rift history. A key element recorded in mantle rocks is Permian depletion inferred from Sm/Nd model ages on mantle rocks (Rampone et al 1998) and Sm/Nd mineral isochrones on crustal rocks (Voshage et al 1988;Thöni andJagoutz 1992, 1993). Thus, some of the mantle rocks within the Alpine Tethys domain probably represent former asthenospheric mantle that underwent fractional melting during Permian time before they cooled and became accreted to the subcontinental mantle lithosphere.…”

Section: Mantlementioning

confidence: 99%

“…However, recent studies question the classical interpretation of a slow-spreading ridge origin for some of the mantle rocks exposed in the Alps (Rampone et al 1995;Manatschal and Müntener 2009). In addition to geochemical and petrological arguments (Rampone et al 1998;, the occurrence of mantle rocks underlying crustal rocks, either welded by Permian gabbros (e.g. Malenco; Müntener and Hermann 1996) or sealed by Lower Cretaceous sediments (e.g.…”

Section: Mantlementioning

confidence: 99%

See 4 more Smart Citations

Unravelling the interaction between tectonic and sedimentary processes during lithospheric thinning in the Alpine Tethys margins

Mohn

Manatschal

Müntener

et al. 2010

Int J Earth Sci (Geol Rundsch)

161

163

View full text Add to dashboard Cite

The discovery of exhumed continental mantle and hyper-extended crust in present-day magma-poor rifted margins is at the origin of a paradigm shift within the research field of deep-water rifted margins. It opened new questions about the strain history of rifted margins and the nature and composition of sedimentary, crustal and mantle rocks in rifted margins. Thanks to the benefit of more than one century of work in the Alps and access to world-class outcrops preserving the primary relationships between sediments and crustal and mantle rocks from the fossil Alpine Tethys margins, it is possible to link the subsidence history and syn-rift sedimentary evolution with the strain distribution observed in the crust and mantle rocks exposed in the distal rifted margins. In this paper, we will focus on the transition from early to late rifting that is associated with considerable crustal thinning and a reorganization of the rift system. Crustal thinning is at the origin of a major change in the style of deformation from high-angle to lowangle normal faulting which controls basin-architecture, sedimentary sources and processes and the nature of basement rocks exhumed along the detachment faults in the distal margin. Stratigraphic and isotopic ages indicate that this major change occurred in late Sinemurian time, involving a shift of the syn-rift sedimentation toward the distal domain associated with a major reorganization of the crustal structure with exhumation of lower and middle crust. These changes may be triggered by mantle processes, as indicated by the infiltration of MOR-type magmas in the lithospheric mantle, and the uplift of the Briançonnais domain. Thinning and exhumation of the crust and lithosphere also resulted in the creation of new paleogeographic domains, the Proto Valais and Liguria-Piemonte domains. These basins show a complex, 3D temporal and spatial evolution that might have evolved, at least in the case of the Liguria-Piemonte basin, in the formation of an embryonic oceanic crust. The re-interpretation of the rift evolution and the architecture of the distal rifted margins in the Alps have important implications for the understanding of rifted margins worldwide, but also for the paleogeographic reconstruction of the Alpine domain and its subsequent Alpine compressional overprint.

show abstract

Section: Discussionmentioning

confidence: 80%

Section: Continental Crustmentioning

confidence: 72%

Section: Mantlementioning

confidence: 99%

Section: Mantlementioning

confidence: 99%

Section: Mantlementioning

confidence: 99%

See 3 more Smart Citations

Unravelling the interaction between tectonic and sedimentary processes during lithospheric thinning in the Alpine Tethys margins

Mohn

Manatschal

Müntener

et al. 2010

Int J Earth Sci (Geol Rundsch)

161

163

View full text Add to dashboard Cite

show abstract

Tectonomagmatic evolution of the final stages of rifting along the deep conjugate Australian-Antarctic magma-poor rifted margins: Constraints from seismic observations

et al. 2015

View full text Add to dashboard Cite

The processes related to hyperextension, exhumed mantle domains, lithospheric breakup, and formation of first unequivocal oceanic crust at magma-poor rifted margins are yet poorly understood. In this paper, we try to bring new constraints and new ideas about these latest deformation stages by studying the most distal Australian-Antarctic rifted margins. We propose a new interpretation, linking the sedimentary architectures to the nature and type of basement units, including hyperextended crust, exhumed mantle, embryonic, and steady state oceanic crusts. One major implication of our study is that terms like prerift, synrift, and postrift cannot be used in such polyphase settings, which also invalidates the concept of breakup unconformity. Integration and correlation of all available data, particular seismic and potential field data, allows us to propose a new model to explain the evolution of magma-poor distal rifted margins involving multiple and complex detachment systems. We propose that lithospheric breakup occurs after a phase of proto-oceanic crust formation, associated with a substantial magma supply. First steady state oceanic crust may therefore not have been emplaced before~53.3 Ma corresponding to magnetic anomaly C24. Observations of magma amount and its distribution along the margins highlight a close magma-fault relationship during the development of these margins.

show abstract

Early Permian mafic dikes in the Nagqu area, central Tibet, China, associated with embryonic oceanic crust of the Meso‐Tethys Ocean

Chen

Shi

et al. 2017

JGR Solid Earth

View full text Add to dashboard Cite

During the latest Carboniferous to Early Permian, a possible mantle plume initiated continental rifting along the northern Gondwana margin, which subsequently developed into the Meso‐Tethys Ocean. However, the nature and timing of the embryonic oceanic crust of the Meso‐Tethys Ocean remain poorly understood. Here we present for the first time a combined analysis of petrological, geochronological, geochemical, and Sr‐Nd isotopic data for mafic rocks from the Nagqu area, central Tibet. Zircons from the mafic rocks yield a concordant age of ~277.8 ± 1.8 Ma, which is slightly younger than the age of mantle plume activity (~300–279 Ma), as represented by the large igneous province (LIP) on the northern Gondwana margin. Geochemical features suggest that the Nagqu mafic rocks, which display normal mid‐ocean ridge basalt affinities, are different from those of the LIP, which display oceanic island basalt‐type affinities. The Nagqu mafic rocks result from a relatively high degree of melting of depleted asthenospheric mantle. Combined with observations from previous studies, we suggest that the late Early Permian Nagqu magmatism fully records processes of early stage rifting and incipient formation of oceanic crust. Moreover, the patterns of magmatism are consistent with patterns of rift‐related sedimentation that records the transition from predominantly continental to marine deposition in the region during the Carboniferous‐Permian. We therefore suggest that rifting of the eastern Cimmerian and northern Gondwana continents started at ~277.8 Ma, and the rifting culminated in the opening of the Meso‐Tethys Ocean.

show abstract

Isotopic contrasts within the Internal Liguride ophiolite (N. Italy): the lack of a genetic mantle–crust link

Cited by 129 publications

References 37 publications

Unravelling the interaction between tectonic and sedimentary processes during lithospheric thinning in the Alpine Tethys margins

Unravelling the interaction between tectonic and sedimentary processes during lithospheric thinning in the Alpine Tethys margins

Tectonomagmatic evolution of the final stages of rifting along the deep conjugate Australian-Antarctic magma-poor rifted margins: Constraints from seismic observations

Early Permian mafic dikes in the Nagqu area, central Tibet, China, associated with embryonic oceanic crust of the Meso‐Tethys Ocean

Contact Info

Product

Resources

About