Tracking lithospheric delamination and surface processes across the Messinian salinity crisis

doi:10.21203/rs.3.rs-3576407/v1

Download PDF

Article

Tracking lithospheric delamination and surface processes across the Messinian salinity crisis

https://doi.org/10.21203/rs.3.rs-3576407/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Lithospheric delamination involves short-lived crustal and surface responses, alkaline magmatism, high heat flow and extension. In the Western Mediterranean, delamination is thought to have triggered uplift at the origin of the Messinian Salinity Crisis (MSC). This scenario is questioned by the insufficient temporal resolution relative to other proposed mechanisms that include crustal shortening and slab detachment. Here, we report new U-Pb ages and clumped isotope analyses from calcite veins formed in an intramontane basin of the eastern Betics. They reveal a short-lived fluid event from 8.5 to 5 Ma linked to extension and retreating delamination. The end of extension coincides with the onset of shortening and uplift at 4.5-3 Ma across the boundary between the Cabo de Gata arc basement and the Iberia margin. Our results reveal that the MSC was established before the onset of shortening while delamination was underway. The MSC is therefore the product of long-lived lithospheric thinning and evolution from calc-alkaline to high-alkaline magmatism during delamination. After the MSC, around 5 Ma, slab detachment triggered the formation of a new plate boundary fault and tectonic escape between Africa and Iberia.

Earth and environmental sciences/Solid Earth sciences

Earth and environmental sciences/Solid Earth sciences/Geodynamics

Earth and environmental sciences/Solid Earth sciences/Sedimentology

Delamination is a process by which the lithospheric mantle or/and lower crust are detached and lost in the asthenosphere ^1,2. It provides an efficient mechanism to recycle crust and mantle into the convective mantle ^3,4, it also explains the differentiation of the continental crust in arc setting ^5,6 and in early Earth without involving two-plate subduction processes ^7,8. In late-/post-collision settings, continental delamination reflects the sinking of a negatively buoyant thickened or inherently dense lithosphere ^9–11 or accompanies slab rollback by decoupling the mantle lithosphere from the overlying orogen as illustrated in the Western Mediterranean, e.g. in the Apennines ^12,13 and the Betic-Rif arc ^14–17. Eventually, the delaminated slab detaches (lithospheric tearing or break-off) leading to the development of new plate boundary faults, tectonic escape and uplift, e.g. Anatolian Plateau uplift and the formation of North and East Anatolian Faults ^18–21. As delamination involves the replacement of the lithosphere by asthenosphere, it leads to complex and short-lived crustal and surface responses, including uplift, alkaline magmatism, high heat flow and extension. The rapid succession in time of these processes is a major difficulty in distinguishing between the causes and effects of delamination.

In the Betic-Rif arc (Fig. 1), it has been suggested that delamination, witnessed in the eastern Betics by the post-collisional mantle-derived magmas at 6.3 Ma, caused uplift of the Alboran continental margin ¹⁵. This triggered the Messinian Salinity Crisis (MSC, 5.97–5.33 Ma) by closing the marine gateways between the Atlantic and the Mediterranean ^15,22. Delamination is however a unique mechanism invoked for pre-MSC uplift of the Betics, as it is allegedly synchronous with the onset of shortening often presented as the major driver of the pre-MSC late Tortonian (< 7.8–7.3 Ma) emersion ²³. Alternatively, both mechanisms can be at play. For instance, numerical models have suggested that the westward propagation of slab tearing and detachment following delamination stalled by around 8 Ma, resulting in resisting forces in the mantle that can explain uplift and the current tectonic activity ²⁴, notably the formation of a new convergent plate boundary between Iberia and Africa ²⁵. Other numerical scenarios have linked the pre-MSC uplift to lithospheric rebound induced by lithospheric tearing modulated by the obliquity of the convergence relative to the Iberian paleomargin ²⁶. Additional processes like the emplacement of a thick buoyant arc in the Eastern Alboran Basin (EAB) contributed to emergence of the Alboran domain before the MSC from 10 to 6.2 Ma, and a land bridge may have persisted between Africa and Iberia during and after the MSC from 7 to 3 Ma ²⁷.

The exact relationships between uplift, onset of indentation and mantle-derived process have not yet reached sufficient temporal resolution to allow a clear distinction between delamination, detachment and shortening as the main drivers of the uplift and exhumation that led to the MSC. Here, we investigate the case of the eastern Betics where the continental basement of Alboran, now accreted to the southern Iberia paleomargin and intruded by mantle-derived magmas, is indented by the magmatic arc of the EAB, represented by the Cabo de Gata Volcanic Province (CGVP) and Águilas Arc (Figs. 1a&b). Geodetic data shows that indentation is accommodated by the extrusion of the Alboran block bounded to the north by a wide zone of East-West right-lateral transtensional shearing in the Betics, and to the south-east by the left-lateral movement of the Carboneras Fault (CF) and Palomares Fault (PF) ^28,29. These fault segments are part of the Trans-Alboran Shear Zone (TASZ), a 400 km-long left-lateral fault network crossing the whole Alboran basin (Fig. 1b). The current tectonic context is the result of a complex geodynamic evolution of the Betic-Rif arc that began by subduction in the Eocene. Details of plate kinematics is debated but a consensus exists on the fact that from around 20 Ma, the Betic orogenic belt collapsed leading to the opening of the Alboran basin controlled by the westward retreat of the Gibraltar slab and delamination ³⁰. The different motion between the retreating slab domain (Alboran) and the upper plate (Iberia) caused highly oblique crustal thinning in the continental basement of the Alboran Basin throughout the Langhian to Tortonian (16 − 8 Ma), which led to exhumation of E-W metamorphic domes and subsidence in intermontane basins of the Internal Betics ³¹. The Gibraltar slab is now imaged resting at 600 km below the Alboran Sea ²², and its northern edge, forming part of the Iberia continental lithosphere, is detached over of 400 km (Fig. 1b) below the Betics from the Lorca basin to the region of Malaga ³².

As a result of extension, the internal intramontane basins (Fortuna-Lorca, Guadix-Baza, Huercal-Overa, and Almanzora basins) and external basins (Tabernas, Sorbas, Vera, Alicante-Cartagena, Nijar-Carboneras basins) are distinguished according to their position on the margin, proximal and distal, respectively (Figs. 1a, b&c). Within the more distal margin, the external Tabernas basin represents an E-W-trending basin filled by Serravallian-Tortonian continental to late Tortonian deep marine deposits (Kleverlaan 1989; Riding et al. 1998; Haughton 2000) resting at ~ 400 m above sea-level between the metamorphic domes of Sierra de Alhamilla and Sierra de los Filábres (Figs. 1a,b, c,&d).

Critical unknowns are the duration of extension in the Tabernas basin and its relationship to transitions with uplift, mantle-derived magmatism, slab detachment and initiation of contraction in the eastern Betics, specifically the onset of the Carboneras plate boundary fault. To resolve these issues, we analyse new U-Pb dates tied to clumped-isotope temperatures of syn-extension calcite-filled fractures from the Tabernas basin, with a view to constrain the transition in intramontane basins from extension to compression and uplift, along with lithosphere thermal conditions. Results are compared to key transitions resolved by time-temperature paths obtained from apatite (U-Th-Sm)/He (AHe) thermochronology in the CGVP and continental basement. We examine the relationships between the lithosphere structure, thermal state in the mantle and analyse the isostatic/dynamic support of the topography. These are compared to existing age constraints on exhumation and short-lived phases of magmatism, and allow us to better constrain the mechanisms responsible for the Messinian Salinity Crisis.

Carbonate U-Pb dating of syn-extension fractures

Carbonate samples in syn-extension fractures (veins, faults) (Supplementary Data 1) were selected along a section comprising the metamorphic basement of the Tabernas basin, exposed on the flank of the Sierra de los Filábres, and Tortonian-Messinian sediments, in the centre of the basin, for in-situ Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LA-ICPMS) U-Pb geochronology. Basement samples comprise high-grade schists of the Nevado-Filábride (NF) complex (TA38, TA44) and Triassic marbles of the Alpujárride complex (TA41) that yield carbonate U-Pb ages of 7.22 ± 0.79 Ma (TA38, n = 51, 2σ), 5.05 ± 0.27 Ma (TA44, n = 112, 2σ) and 8.54 ± 0.21 Ma (TA41, n = 25, 2σ) (Fig. 1d and Fig. 2). Calcite from veins collected in lower Tortonian continental deposits (TA45, TA24) yield U/Pb ages of 5.37 ± 0.25 Ma (TA45, n = 124, 2σ) and 7.23 ± 0.60 Ma (TA24, n = 84, 2σ). Note that TA24 was sampled in lower Tortonian conglomerates exposed in the Tabernas topographic ridge, a structure interpreted as strike-slip fault (Fig. 1d). The carbonate U-Pb date in the upper Tortonian marine turbidites (TA36) is 5.47 ± 0.23 Ma (n = 75, 2σ).

Clumped-isotope temperatures of fluids

Among these U-Pb dated samples, five (TA24, TA36, TA38, TA41, TA45) were jointly analyzed for clumped isotope temperatures (T₄₇) and oxygen isotopic values of the mineralizing fluids (Fig. 3) (see also Supplementary Data 2). Samples from the Nevado-Filábride (TA38) and Alpujárride complexes (TA41) show similar precipitation temperatures T₄₇ of 66.9 ± 4.4°C (n = 3) and 63.7 ± 4.2°C (n = 3) (°C ± 95%), corresponding to equally close values of δ¹⁸O_water of 0.7 ± 0.7‰ VSMOW and − 0.9 ± 0.7‰ VSMOW, respectively. Lower Tortonian continental deposits (TA45, TA24) yield higher T₄₇ of 76.2 ± 4.8°C and 84.5 ± 5.0°C, and the fluid composition also show contrasted δ¹⁸O_water of -4.6 ± 0.7‰ VSMOW (TA45) and 3.1 ± 0.7‰ VSMOW (TA24). Upper Tortonian marine sediments (TA36) indicates a precipitation temperature of 76.7 ± 4.8°C and isotopic composition of fluids δ¹⁸O_water of 0.3 ± 0.7‰ VSMOW. The TA31 sample for which we have no U-Pb date was collected in the upper Tortonian channelized turbidites, south of the Tabernas topographic ridge, in a stratigraphic level only slightly younger than TA36. It yields a T₄₇ of 56.4 ± 3.9°C and δ¹⁸O_water of -5.2 ± 0.7‰ VSMOW.

Apatite (U-Th)/He dating of volcanic and metamorphic rocks

Five AHe ages from apatites with aliquots that replicate well were obtained in CGVP rhyolite (MOJ1.3, n = 4), dacite (MOJ.1.4, n = 4) and andesite (MOJ1.1, n = 4; MOJ1.2, n = 5; MOJ1.5, n = 3) (Supplementary Data 3). Results show single-grain alpha-ejection corrected AHe ages between 10.8 ± 0.9 Ma and 3.1 ± 0.2 Ma. Mean AHe ages are ranging in andesites from 4 ± 0.2 Ma (2σ) for MOJ1.1, 9.1 ± 0.3 Ma for MOJ1.2 and 6.1 ± 0.3 Ma for MOJ1.5, and consistent AHe ages of 7.0 ± 0.3 Ma for dacite MOJ1.4 (n = 4) and 5.9 ± 0.2 Ma for rhyolite MOJ1.3 (n = 4). West of the Carboneras fault, only one sample out of five originally collected in the NF metamorphic basement yielded a sufficient number of apatite grains suitable for AHe analyses. MOJ2.1 (n = 3) sampled at 520 m in NF micaschists east of the Sierra de los Filábres yielded the youngest mean AHe age of 2.6 ± 0.1 Ma. The scarcity of apatite in NF micaschists and their low Uranium content (0.5–1.4 ppm for MOJ2.1) has already early been noticed ³³. We note that in the region of the NF micashists (Sierra Alhamilla) where these previous apatite-fission track analyses have been successful, apatite yielded slightly older ages of 5.7 ± 1.1 Ma and 6.1 ± 1.2 Ma. An AHe age of 15.2 ± 0.8 Ma was obtained close to MOJ2.1 (elevation 2000 m) but it is more problematic considering it is similar than its apatite-fission track age of 15.6 ± 1.9 Ma ³⁴. The eU-age and (U-Th)/age relationships of our AHe-dated apatite samples show positive correlation that agrees with the expected increase of closure temperature as a function of radiation damage ³⁵.

Time-temperature histories

Time-temperature histories of CGVP have been reconstructed based on simple thermal inputs assuming that published ⁴⁰Ar/³⁹Ar ages ^16,36 faithfully represent the timing of magma cooling below 350 ± 50°C (Tc 350°C on biotite), and that the timing of cooling at surface temperature (20 ± 20°C) is indicated by the deposition of Tortonian-Messinian marine limestones on top of sampled CGVP lavas (Fig. 4). These deposits attest to emersion as early as 10 − 9 Ma (lower Tortonian) while other stratigraphic contact suggest later emersion until the Messinian ^37,38. As the sampled dacite, andesite, and rhyolite from CGVP were emplaced at the surface, cooling is expected to be instantaneous on the geological timescales. However, the large majority of AHe ages (closure temperature of 70 − 50°C) in CGVP are younger than the ⁴⁰Ar/³⁹Ar ages of their parental volcanic rocks (11 ± 1 Ma) by 7 to 2 myrs. The delay between magma crystallization of calc-alkaline suites and AHe cooling ages reveal a complex cooling history caused by subsequent punctual thermal events. This may represent the effect of pyroclastic eruptions or lava flow, doming or caldera collapse, circulation of hydrothermal fluids linked to Cu-Au mineralization well documented during the CGVP formation ³⁹ and burial heating by Tortonian-Messinian to Pliocene deposits. Modelling results show that all volcanic rocks cooled below 350 ± 50°C at different rates between 12 and 8 Ma, which marks the end of the volcanic phase. After 8 Ma, samples variably recorded the deposition of the upper Tortonian-lower Messinian carbonate platform. Samples from the southern half of CGVP MOJ1.2 to MOJ1.5 show no significant heating or cooling, or within the uncertainties of surface temperature, hence indicating no measurable exhumation (Fig. 4). By contrast, in the north, where lower Messinian and lower Pliocene marine deposits are preserved, MOJ1.1 thermal evolution shows burial heating below sediments followed by cooling at ca. 4.5 Ma. For thermal history modelling of the MOJ2.1 micaschist sample, we have used published AHe and AFT data from a sample collected nearby. Model shows that MOJ2.1 resided at 120 − 80°C (Tc AFT) and possibly 70 − 50°C (Tc AHe) at 15 ± 1 Ma, and cooled at ca. 3 Ma (Fig. 4). We infer that both CGVP volcanic rocks (MOJ1.1) and metamorphic basement (MOJ2.1) north of CF cooled between 4.5 and 3 Ma, clearly after the MSC, at a rate between 36°C/Myr (MOJ1.1) and 48°C/Myr (MOJ2.1).

Impact of mantle-derived processes on topography

The mean elevation of the Central-Eastern Betics (Fig. 5a) region is 868 m with a highest elevation of 3467 m in the Sierra Nevada. Receiver functions and reflection seismic data ⁴⁰ reveal a bimodal distribution of crustal thicknesses ranging from 35 km in the north to 25 km in the south and east (Figs. 1a and 5a), expressing crustal and lithosphere thinning south of Sierra Nevada, Sierra de los Filábres and Sierra de las Estancias, linked to the oblique opening of the Alboran basin ³¹. Crustal thinning onshore is reflected in the topographic decrease down to 176 m south of Sierra de los Filábres and in Cabo de Gata (Fig. 5a). The crustal thickness offshore reduces to 15 km in the EAB (Figure (1a). To compare current topography with predictions using isostatic calculations, the lithosphere thickness across the eastern Betics was inferred from various seismic tomography models SL2013sv ⁴¹, LITHO1.0 ⁴² and Mean model ⁴³ (Fig. 5a). From these models, upper and lower bounds for the lithosphere thickness fall between 65 km and 50 km. The value of 65 km fits both SL2013sv and Mean models. It is also consistent with maximum depths for the lithosphere of about 60 km (1.8 GPa) independently determined from thermobarometric calculations on Neogene mantle-derived K-rich basalts (MgO > 8 wt. %, SiO₂ > 45 wt. %) ⁴⁴. This value is within the range of thicknesses < 100 km for fertile and hot phanerozoic sub-continental lithosphere ⁴⁵, a feature characteristics of the European lithosphere ⁴⁶.

Elevation is calculated for a column of continental lithosphere with respect to the depth of a standard mid-ocean ridge, assuming pressure-temperature dependent densities and chemical depletion for the lithospheric mantle ⁴⁷ (Supplementary Discussion 1). Results show that for a lithosphere thickness of 65 km, the calculated elevation is negative (-250 m), assuming a crustal thickness of 25 km (Moho depth below Tabernas Basin), an average crustal density of 2.7 based on EPcrust model ⁴⁸, and a reference density for the lithospheric mantle of 3.3 (Fig. 5b); it is null for lithosphere thickness of 50 km and − 500 m for a 70 km-thick lithosphere (Fig. 5c). The lithosphere below the eastern Betics is therefore not in isostatic equilibrium, unless we assume a mantle density decrease of 80–100 kg/m^− 3. Studies of rifted margins show that the formation of light mineral phases such as plagioclase during extension and shallowing of the lithospheric mantle can produce a density decrease of mantle rocks down to 3.2 at 60 km for temperatures above 800°C ⁴⁹. This is likely to have occurred in the Betics during Mesozoic extension as the lithospheric mantle was re-fertilized by tholeiitic MORB-like melts ⁵⁰. Alternatively, elevation can also be well reproduced by the upwelling of hot asthenosphere, likely with a fraction of melt as indicated by low S-wave velocity domain of 4.2 km.s^− 1 around 100 km (Fig. 5a). Based on parametrization of shear wave velocity-temperature ⁵¹ we determine anomalously high sub-lithospheric temperatures of 1550°C. Such a low viscous channel could easily explain the observed mean topography of 500 m around Tabernas Basin (see Method section and Supplementary Discussion 1). We infer that compositional variations in the mantle lithosphere and asthenospheric upwelling likely acted together and contributed to the support of the eastern Betic topography.

Pre-MSC uplift and subsidence induced by mantle delamination

The timing of uplift in the eastern part of the Betics has been provided in recent research by the age of the marine-continental transition in the intermontane basins. In the internal basins of Fortuna-Lorca, Guadix-Baza Huercal-Overa, and Almanzora, the transition has been dated to the end of the Tortonian (8-7.5 Ma), indicating uplift before the MSC ^23,52–55. It has also been suggested that the onset of N-S/NW-SE shortening occurred around 8 − 7 Ma in the eastern Betics ^56–58 and in the Alboran sea ⁵⁹. This timing is in line with previous T-t paths inferred from apatite fission tracks (AFT) ages ranging from 2.5 Ma to 25 Ma (mode of 8 Ma ; Fig. 1a) ^{33,34,60–63} that support the interpretation that exhumation in the Internal Zone was progressive and associated with orogen-parallel stretching from the Sierra de los Filábres at 13 − 11 Ma (Serravallian-Tortonian) to the Sierra de Nevada at 8 − 6 Ma (Late Tortonian-Messinian). The late Tortonian uplift and exhumation documented in the internal basins therefore appear temporally closely related to a late Tortonian stage of extension. At lower elevation, in external basins that recorded the MSC, the marine-continental transition shows a younger uplift ranging from Pliocene, ca. 5.3 Ma in Sorbas Basin, to post-mid-late Pliocene (4-3.6 Ma) Ma for distal Vera, Alicante-Cartagena, Nijar-Carboneras basins ^52,55,64. Final uplift in the external basins occurred therefore after the Zanclean reconnection between Atlantic and Mediterranean.

New U-Pb ages, isotopic signatures and temperatures of carbonate fluids in veins from the Tabernas basin are representative of the thermal conditions and fluid pathways that prevailed during extension in external basins. The narrow U-Pb age range from 8.5 to 5 Ma argue for a short-lived fluid event, for which the cessation coincides with a change in the tectonic stress field. This scenario is further argued by the differential exhumation across the CF between the CGVP (MOJ1.1) that cooled from 4.5 Ma and the NF metamorphic complex (MOJ2.1) that cooled from 3 Ma. We interpret this difference as evidence for sequential deformation from south to north associated with the movement across the CF as the CGVP and Águilas Arc collided with the continental basement. The initiation of cooling across the CF is coincident with the termination of fluid circulation and uplift of the external basins. We infer that the end of fluid circulation marks the onset of compression across the CF at 4.5 Ma that regionally coincides with the onset of collision with the magmatic arc crust of EAB. The Pliocene compression is synchronous with the post-MSC uplift in external basins and is clearly distinct from the late Tortonian, pre-MSC uplift, documented in internal basins, which is associated with extension.

The different timing of uplift between internal (8-7.5 Ma) and external basins (post-5 Ma) is significant and has acted at different scales. For instance, the late Tortonian uplift is described as nearly synchronous across the whole of the Betics, even farther westward of the tip of the slab tear ^23,54. If this late Tortonian uplift in the internal basin is compared to the age and type of magmatism in eastern Betics, it appears to coincide with a transition from post-collisional calc-alkaline volcanism (basaltic andesite, andesite, dacite, rhyolite), older than 8 Ma in CGVP (mostly 11 ± 1 Ma) and Alboran Sea, to high-K calc-alkaline, shoshonitic and ultrapotassic volcanism (Si-K-rich lamproite) dated between 8 and 6 Ma, mean ages of 7.4 Ma ^16,65,66 (Fig. 6). These mantle-derived lavas are found preferentially north of CGVP and south of the slab edge (Fig. 6) where asthenosphere upwelling is imaged by low S-wave velocity anomaly (Fig. 5).

Control of mantle-driven processes on late Tortonian syn-extension fluids can be tested in the Tabernas basin based on clumped-isotope water composition and temperatures. Comparison of δ¹⁸O_water inferred from samples δ¹⁸O_calcite (Fig. 3) with the oxygen isotope composition of Tortonian and Messinian sea-water and freshwater supports an interpretation that the fluids originated from two distinct sources. Values of δ¹⁸O_water between − 0.9 ± 0.7‰ VSMOW and + 3.1 ± 0.7‰ VSMOW (T24, T36, T38, T41) reveals they precipitated in equilibrium with marine water or involved a component of formational water, indicating fluid-rock interactions. This contrasts with the negative δ¹⁸O_water (TA45, TA31) of about − 5‰ VSMOW pointing to a contribution of meteoric water. Given the temporal overlap of U-Pb-dated fluids, we infer that circulation of seawater and meteoric water alternated in time during the 3-Myr fluid-flow event. T₄₇ estimates indicate these fluids precipitated at around 75 ± 10°C (2σ of 5°C) or 72°C ± 15°C if the undated TA31 sample is included in the calculation. Assuming they are fluids emplaced prior to folding of host rocks, paleodepths of 1-1.5 km are inferred for fluids that precipitated during the Tortonian (TA24, TA38, TA41) and Pliocene (TA36, TA45) (Figs. 1d&5). It has been argued that the northern flank of the Tabernas syncline hosting NF and AJ basement samples (TA38, TA41) was folded before the Serravallian-Lower Tortonian ³¹. When associated with the lower Tortonian sample from the Tabernas ridge (TA24) characterized by identical T₄₇ and U-Pb age, we infer that these Tortonian fluids reflect a basin-scale thermal event consistent with regional gradients above 75°C/km. In summary, we conclude that these pre-5 Ma fluids precipitated in association with regional palaeogeothermal gradients of > 50°C/km, likely locally rising above 75°C/km on the flanks of the basins. Comparison with continental geotherms accounting for radiogenic crustal heat production, and transient cooling of the lithosphere, show that these shallow crustal gradients are consistent with steady-state temperature gradients of 55°C/km computed for a 65 km thick lithosphere, crustal thickness of 25 km, and thermal-tectonic age of the lithosphere of 20 Ma (Supplementary Discussion 2). We predict a surface heat flow of 118 mW/m², which agrees with the measured current heat flow of 124 mW/m² in the EAB ⁶⁷. Note that this value requires a high mantle heat flux of 48 mW/m2 that is 50% higher than the average European mantle heat flow ⁴⁶. The δ¹⁸O_water of the veins argue that fluids precipitated in equilibrium with the expected seawater and meteoric sources under a high regional continental geotherm established during lithosphere thinning and mantle upwelling.

These new results combined with previous data show that basin subsidence and lithospheric thinning has continued from 8.5 and 5 Ma in the external basins (Fig. 7), in contrast to the internal basins that recorded synchronous uplift. The right-lateral strike-slip tectonic regime observed today (Fig. 1b), found associated with lithospheric tearing and delamination, is likely to be the trigger of the contrasting vertical movements (Fig. 7b). Evidence for delamination are brought by geochemical and petrological data on the mantle sources of alkaline lavas. They demonstrate that the transition from calk-alkaline to high-K calc-alkaline, shoshonitic and ultrapotassic volcanism is the result of variable degrees of melting of a lithospheric mantle that was metasomatised by fluids prior to Paleogene collision in the Betics ⁶⁸. Delamination of the Iberian mantle, accompanied by upwelling of the asthenospheric mantle (Fig. 7a), provides the most reliable explanation for the observed magmatic evolution. Because of the differential motion between the retreating mantle delamination zone (Alboran) and the overriding plate (Iberia), propagating strike-slip faults resulted in lithospheric tearing in the sense of ⁶⁹. In the exposed crust, tectonic interpretation of E-W dextral transfer fault zones, vertical rotations across the Internal and External Betics ⁷⁰ and orogen-parallel extension supports this scenario. Recent research has established that tearing is distribute rather than localized, and that extension is oblique to the Betic trend, hence resulting in the formation of a highly oblique rifted margin ³¹.

We propose that the association of strike-slip tectonic regime with northward retreating delamination explains the contrast between uplift of internal basins that developed on the thick, proximal margin and the subsidence of external basins that underwent larger rift-related extension (Fig. 7b). Importantly, the mid-late Miocene stage of formation of the strike-slip transfer zone is temporally distinct from the onset of slab tearing, which is a localized lithospheric feature that does not extend over the whole Betics, as imaged by seismic data (Fig. 1b). According to our interpretation, this tectonic configuration lasted until 5 Ma when the delaminated slab detached and shortening initiated (Fig. 7). Extrusion of the Alboran block and onset of the CF developed at this time. It has been suggested that the transition from oceanic subduction to continental delamination was responsible for the change between the pre-MSC high-K calc-alkaline, shoshonitic and ultrapotassic volcanism and the emplacement of the most primitive magmatic rocks, comprising the isolated emission of post-MSC Na-alkaline basalts (hawaiite) (2.9–2.3 Ma) ⁷¹. In contrast, we argue that the 3 Myrs gap between pre-MSC and post-MSC magmatism observed in eastern Betics (Fig. 6) is the consequence of shortening. The MSC occurs during the latest stages of continental delamination retreat and extension initiated as early as the EAB magmatic arc formed around 11 ± 1 Ma (Fig. 7). We link the MSC to the topographic uplift caused by the combination of mantle lithosphere thinning, magmatism, and mantle upwelling producing dynamic topography. This model agrees with the occurrence of an Alboran volcanic archipelago that permitted faunal exchanges before and after the MSC ²⁷. The post-5 Ma formation of a new plate boundary fault between Africa and Iberia has so far produced limited regional effects on topography compared to deep mantle processes.

Samples

Calcite samples were collected in veins predominantly striking NW-SE and WNW-ESE opened perpendicular to the regional extension-oriented NE-SW determined from paleostress data ³¹ and in calcite steps on faults consistent with the same regional extension. Calcite veins are present in all the stratigraphic section both in the basement and the overlying sedimentary series (Fig. 1d). Most veins are predominantly vertical (TA31, TA36, TA45, TA38) and locally at moderate angle (TA44) with respect to bedding and their widths range from millimeter to centimeter (Figs. 2 and 3). The calcite crystals form generally elongated blocky syntaxial to fibrous textures (Supplementary Data 1). Fourteen slabs were prepared and polished thin sections were examined by conventional and cold cathodoluminescence microscopes to detect the different generations of crystallization/recrystallisation and select the in-situ rock sample for further analyses. In most veins, one continuous single calcite phase precipitation (TA31, TA24, TA45, TA38, TA44) is observed indicating coeval opening and mineralization (Supplementary Data 1). Samples TA36 and TA41 have two generations of calcite (consistent with U-Pb analyses showing secondary late U-Pb ages, Supplementary Data 1).

Sampling for (U-Th)/He analyses has focused on the most felsic lavas in CGMP (andesite, dacite, rhyolite) (MOJ1.1, MOJ1.2, MOJ1.3, MOJ1.4, MOJ1.5) and in NF metamorphic complex (MOJ2.1) for comparing cooling histories across the Carboneras fault zone (see sample information and analyses in Supplementary Data 3). An attempt was made to select CGVP samples near marine carbonates of Tortonian-Messinian and lower Pliocene ages that were deposited after magma emplacement to place thermal constraints for modelling the post-Tortonian uplift and exhumation.

Calcite LA-ICP-MS U-Pb geochronology

Calcite U-Pb analyses were performed at the Geochronology & Tracers Facility, British Geological Survey (Nottingham, UK) using a Nu Instruments Attom single collector inductively coupled plasma mass spectrometer coupled to a NWR193UC laser ablation system fitted with a TV2 cell, following protocols reported previously (Roberts et al., 2017). Laser parameters were 100 µm spots, ablated at 10 Hz for 30 s with a fluence of ~ 4 J cm² (see Supplementary Data 1 for full instrumental conditions). Normalisation used WC1 ⁷² as a primary reference material for Pb/U ratios and NIST614 for Pb/Pb ratios (Woodhead and Hergt, 2001); ASH15D (Nuriel et al., 2020) was run as a secondary reference material and the pooled result across the analytical sessions is within 2% accuracy of the accepted age. Data reduction uses the Time-Resolved-Analysis function in the Attolab software, followed by normalisation offline in excel. Age calculations and plotting use IsoplotR (Vermeesch, 2018). All ages are lower intercept ages derived from Tera-Wasserburg plots (see Fig. 2 and Supplementary Data 1), quoted at 2s and shown as ± α/β, where α and β are without and with systematic uncertainties, respectively (following Horstwood et al., 2016). Several samples were analysed but were not used in our study due to low U/Pb ratios hindering a robust age calculation, or to highly scattered analyses indicating age mixing and/or U mobility. All data are presented in Supplementary Data 1.

Clumped isotope analysis

All analyses were performed at the Laboratoire des Sciences du Climat et de l’Environnement (LSCE, Gif sur Yvette). Six samples (TA24, TA31, TA36, TA38, TA41, TA45) of homogenized carbonate powder were converted to CO2 by phosphoric acid reaction at 90°C in a common, stirred acid bath for 15 minutes. Initial phosphoric acid concentration was 103% (1.91 g/cm3) and each batch of acid was used for 7 days. After cryogenic removal of water, the evolved CO₂ was helium-flushed at 25 mL/mn through a purification column packed with Porapak Q (50/80 mesh, 1 m length, 2.1 mm ID) and held at − 20°C, then quantitatively recollected by cryogenic trapping and transferred into an Isoprime 100 dual-inlet mass spectrometer equipped with six Faraday collectors (m/z 44–49). Each analysis took about 2.5 hours, during which analyte gas and working reference gas were allowed to flow from matching, 10 mL reservoirs into the source through deactivated fused silica capillaries (65 cm length, 110 µm ID). Every 20 minutes, gas pressures were adjusted to achieve m/z = 44 current of 80 nA, with differences between analyte gas and working gas generally below 0.1 nA. Pressure-dependent background current corrections were measured 12 times for each analysis. All background measurements from a given session within ± 6 hours of any given analysis were used to determine a mass-specific relationship for that analysis, linking background intensity (Zm), total m/z = 44 intensity (I44 ), and time (t): Zm = aI44 + P(t), with P being a polynomial of degree 2 to 4. Background-corrected ion current ratios (δ45 to δ49) were converted to δ¹³C, δ¹⁸O, and “raw” Δ₄₇ values as described by ⁷³, using the IUPAC oxygen-17 correction parameters. The isotopic composition (δ13C, δ18O) of our working reference gas was computed based on the nominal isotopic composition of all ETH carbonate standards ⁷⁴ and an oxygen-18 acid fractionation factor of 1.00813 ⁷⁵. Raw Δ₄₇ values were then converted to the I-CDES reference frame ⁷⁶ using a pooled regression approach ⁷⁷ as implemented by the D47crunch Python library. Full analytical errors are derived from the external reproducibility of unknowns and standards (Nf = 39) and conservatively account for the uncertainties in raw Δ₄₇ measurements as well as those associated with the conversion to the I-CDES reference frame ⁷⁷. T₄₇ reconstructions are based on the OGLS23 calibration of ⁷⁸. Temperature confidence intervals account for analytical error in Δ₄₇ but not for calibration uncertainties, which remain below ± 1°C (95 % CL) in the ange 0–50°C. The δ¹⁸O values of the mineralizing fluids (δ¹⁸O_water) are derived from T₄₇ and the δ¹⁸O_CaCO3 of the mineral based on the fractionation equation of ⁷⁹. Analyses are summarized in Supplementary Data 2.

Apatite (U-Th)/He dating

Separation and selection of apatites were carried out at the GET laboratory. Each sample was crushed to obtain grains smaller than 500 µm. Two successive steps of dense liquor separation followed to recover grains with density between 2.97 and 3.38 (apatite density 3.2). This fraction was then magnetically sorted by Frantz. The remaining fraction, non-magnetic, was finally sorted by optical microscope (picking). Apatite crystals for (U-Th-Sm)/He dating were handpicked in order to select inclusion-free crystals with a minimum of three aliquots. Crystal dimension and geometry were measured along two axes, considering the apatite crystals as regular hexagonal prisms, grains had in general a minimum width of 60 µm to minimize the effect of alpha particles ejection. After this first step, (U-Th)/He analyses on apatite were performed at the Noble Gas Laboratory of the Geosciences Montpellier laboratory. Each grain, packed in Pt tubes, was placed under vacuum and heated for 5 minutes with a 1090 nm fiber laser operating at 4.0 W (900°C). After spiking (addition of a known amount to be able to quantify the real content in the minerals) with 3He, gas purification was performed by a cryogenic trap and two AP-10-N SAES getters, and the helium content was measured on a PrismaPlus QMG 220 quadrupole. The 4He content was determined by the peak height method which is 10 to 10,000 times higher than typical blank levels. A second heating cycle using the same analytical procedure was routinely performed to verify that more than 99% of the 4He was extracted in the first cycle. After helium extraction, the Pt tubes were retrieved from the sample chamber and transferred to a 2ml polypropylene conical tube. The samples were triple spiked (149Sm, 230Th and 233U) and dissolved following the procedures described by ⁸⁰. The resulting solutions were diluted and U (233U and 238U), Th (230Th and 232Th) and Sm (149Sm and 147 Sm) were measured using ICPMS isotope dilution. For the age calculation, it is necessary to perform the alpha (4He) particle ejection correction ⁸¹. This correction was calculated using Ft software taking into account the size, and shape of each apatite ^82,83. Analyses are presented in Supplementary Data 3.

QTQt thermal modelling

Thermal histories were retrieved from AHe data analyses using thermal inversion QTQt modelling software ⁸⁴. For AHe, QTQt incorporates kinetic models for helium diffusion in apatite crystals that account for radiation damage production and annealing ^85,86. These two diffusion models may produce different results, depending on the integrated thermal history of each grain. The inversion procedure uses a Bayesian “Markov chain Monte Carlo” algorithm to determine the best time-temperature path reproducing our data through a large number (between 100,000 and 200,000 on average) of randomly tested solutions. In our case, we have run nearly 170 000 models. Details of the modelling procedure are given by ⁸⁴. The final model is represented by a set of time-temperature histories for which we included the expected model (weighted mean model) and the maximum likelihood model (best data fitting model). A table summarizing the thermal history model input parameters and all thermal models are provided in Supplementary Data 3.

Isostatic calculation, Vs-temperature conversion and dynamic topography

The topography of continents reflects the combined effects of 1) isostasy that results from the variation of age-dependent lithosphere thickness and densities and 2) a non-isostatic (dynamic) component caused by plate strength, subduction dynamics, or more broadly mantle flow driven by anomalously hot asthenosphere. The elevation, e, of a buoyant lithospheric column in Airy isostatic equilibrium, with respect to the average mid-ocean ridge depth, is given by

$$e={h}_{c}\left(\frac{{\rho }_{a}-{\rho }_{c}}{{\rho }_{a}}\right)-{h}_{oc}\left(\frac{{\rho }_{a}-{\rho }_{oc}}{{\rho }_{a}}\right)-{h}_{w}\left(\frac{{\rho }_{a}-{\rho }_{w}}{{\rho }_{a}}\right)+\left({h}_{l}-{h}_{c}\right)\left(\frac{{\rho }_{a}-{\rho }_{m}}{{\rho }_{a}}\right)$$

where ρ_c, ρ_oc, ρ_w, ρ_m, and h_c, h_oc, h_w, h_l are the densities and thickness of the crust, oceanic crust, water column above mid-ocean ridge, and continental lithosphere, respectively. Calculation assumes the density of the asthenosphere ρ_a accounts for an adiabatic temperature gradient and for effect of compressibility. ρ_m varies with depth according to a linear geotherm and accounts for the effect of depletion and compressibility. Elevation is calculated for the case of thermal equilibration and for the case of the instantaneous removal of the lithospheric material by delamination, assuming no thermal equilibration at the base of the original lithosphere ⁴⁷. An original lithosphere thickness of 100 km consistent with average thickness of Phanerozoic lithosphere is assumed. Equations and parameters are presented in Supplementary Discussion 1.

S-wave velocities from model SL2013sv are then used to calculate temperatures in the mantle using the parametrization of ⁵¹. Vs (P, Θ, a) is dependent on pressure P (depth, z), temperature Θ in °C and a which is a variable describing the activation process. V_s is given by

$${V}_{s}=(1-{b}_{v}( z-50) \left(m{\Theta }+\text{c}+\text{A}\text{e}\text{x}\text{p}\left(\frac{-E-P{V}_{a}}{RT}\right)\right)$$

where empirical constants are b_v=3.84x10^− 4 km^− 1, m=-0.28 m.s^− 1 $\oint$C^− 1, c = 4720 m.s^− 1, A=-1.8x10¹⁶ m.s^− 1, E = 409x10³ J.mol^− 1, V_a=10x10^− 6 m³.mol^− 1 and R the gas constant is 8.3145 (see Supplementary Discussion 1). The highest temperature obtained is 1550°C at 100–125 km below the Tabernas basin and to the south where Vs decrease to 4.2 km.s^− 1.

Dynamic uplift U created by the temperature anomaly is then calculated assuming thermal expansivity from background temperature and Airy isostasy ⁸⁷ using the following equation :

$$\text{U}=\frac{H\alpha \stackrel{-}{T}}{1-\alpha {T}_{0}}$$

where H is the layer thickness, α is the thermal expansivity, ${T}_{0}$ is the background temperature, and $\stackrel{-}{T}$ is the average temperature in the low viscous asthenospheric channel produced by the excess in temperature (parameters are provided in the Supplementary Discussion 1). For an average thermal anomaly of 100 and 200 km the predicted uplift ranges between 500 m and 1 km. Considering the elevation of -250 m predicted by isostasy assuming pressure-temperature dependent densities and chemical depletion for the lithospheric mantle, the range of dynamic uplift can produce the elevation of 500 m observed around Tabernas Basin.

Temperature of continental lithosphere and heat flux estimates

The continental geotherms T_cont is given by

$${T}_{cont}\left(z, age, {H}_{s}\right)= {T}_{std}\left(z, {H}_{s}\right)+T \left(age\right)$$

It is calculated using the stationary part of the geotherm T_std and contribution due to the radiogenic heat production H_s in the crust, and correction T(age) due to transient cooling of the lithosphere that depends on the age of the last major plate-scale thermal event.

Temperature T_m at Moho depth, h_c, is used for calculation of temperature at depths below the Moho and is given by :

$${T}_{m}= {T}_{0}+\frac{{q}_{m}}{{k}_{c}}{h}_{c}{+T}_{r}$$

where T₀ and q_m correspond to the temperature at the surface and the mantle heat flux calculated at the Moho depth. T_r is the radiogenic contribution that is dependent on the thickness of the crust h_c, density ρ_c, radiogenic production H_s, radiogenic production decay depth h_r, and thermal conductivity coefficient k_c according to the following equation :

$${T}_{r}= \frac{{\rho }_{c}{H}_{s}{h}_{r}^{2}}{{k}_{c}}\left(1-{e}^{\frac{{h}_{c}}{{h}_{r}}}\right)$$

Details on the calculation are given in Supplementary Discussion 2.

Data availability

The authors declare that the data are provided in the article and in the supplementary material.

Acknowledgments

This project was funded in part by TotalEnergies and CNRS. Discussions with E. Masini from M&U, S. Calassou, C. Fillon and V. Miegebielle from TotalEnergies are duly acknowledged. We thank Guillermo Booth-Rea for sharing his expertise during field work in the eastern Betics.

Author contributions

F.M., L.B. and M.L. have conceived the project and developed the conceptual model. F.M., M.L., L.B. collected the samples. M.L, L.B., S.B., N.E.B., D.H., N.M.W.R. and M.D. analysed the samples. N.E.B. and D.H. interpreted the isotope data. N.M.W.R. and M.D. critically reviewed and interpreted the U-Pb and D₄₇ analyses, respectively. F.M. developed the model with L.B and F.M. wrote the manuscript with contributions from all the authors.

Competing interests

The authors declare no competing interests.

Additional information

Supplementary information. The online version contains supplementary material available at :

Bird, P. Continental delamination and the Colorado Plateau. Journal of Geophysical Research: Solid Earth (1978–2012) 84, 7561–7571 (1979).
Bird, P. Initiation of intracontinental subduction in the Himalaya. J. Geophys. Res.: Solid Earth 83, 4975–4987 (1978).
Clift, P. D., Vannucchi, P. & Morgan, J. P. Crustal redistribution, crust–mantle recycling and Phanerozoic evolution of the continental crust. Earth-sci Rev 97, 80–104 (2009).
Kay, R. W. & Kay, S. M. Delamination and delamination magmatism. Tectonophysics 219, 177–189 (1993).
Jagoutz, O. & Behn, M. D. Foundering of lower island-arc crust as an explanation for the origin of the continental Moho. Nature 504, 131–134 (2013).
Jagoutz, O. & Kelemen, P. B. Role of Arc Processes in the Formation of Continental Crust. Annual Review of Earth and Planetary Sciences 43, 363–404 (2015).
Chowdhury, P., Gerya, T. & Chakraborty, S. Emergence of silicic continents as the lower crust peels off on a hot plate-tectonic Earth. Nat. Geosci. 10, 698–703 (2017).
Chelle-Michou, C., McCarthy, A., Moyen, J.-F., Cawood, P. A. & Capitanio, F. A. Make subductions diverse again. Earth-sci Rev 226, 103966 (2022).
Pourhiet, L. L., Gurnis, M. & Saleeby, J. Mantle instability beneath the Sierra Nevada Mountains in California and Death Valley extension. Earth and Planetary Science Letters 251, 104–119 (2006).
Zandt, G. et al. Active foundering of a continental arc root beneath the southern Sierra Nevada in California. Nature 431, 41–46 (2004).
Platt, J. P. & England, P. C. Convective removal of lithosphere beneath mountain belts; thermal and mechanical consequences. Am. J. Sci. 294, 307–336 (1994).
Chiarabba, C. & Chiodini, G. Continental delamination and mantle dynamics drive topography, extension and fluid discharge in the Apennines. Geology 41, 715–718 (2013).
Serri, G., Innocenti, F. & Manetti, P. Geochemical and petrological evidence of the subduction of delaminated Adriatic continental lithosphere in the genesis of the Neogene-Quaternary magmatism of central Italy. Tectonophysics 223, 117–147 (1993).
Calvert, A. et al. Geodynamic evolution of the lithosphere and upper mantle beneath the Alboran region of the western Mediterranean: Constraints from travel time tomography. J. Geophys. Res.: Solid Earth 105, 10871–10898 (2000).
Duggen, S., Hoernle, K., Bogaard, P. van den, Rüpke, L. & Morgan, J. P. Deep roots of the Messinian salinity crisis. Nature 422, 602–606 (2003).
Duggen, S., Hoernle, K., Bogaard, P. van den & Harris, C. Magmatic evolution of the Alboran region: The role of subduction in forming the western Mediterranean and causing the Messinian Salinity Crisis. Earth Planet Sc Lett 218, 91–108 (2004).
Valera, J.-L., Negredo, A.-M. & Villaseñor, A. Asymmetric Delamination and Convective Removal Numerical Modeling: Comparison with Evolutionary Models for the Alboran Sea Region. Pure Appl. Geophys. 165, 1683–1706 (2008).
Whitney, D. L. et al. Breaking plates: Creation of the East Anatolian fault, the Anatolian plate, and a tectonic escape system. Geology 51, 673–677 (2023).
Keskin, M. Magma generation by slab steepening and breakoff beneath a subduction-accretion complex: An alternative model for collision-related volcanism in Eastern Anatolia, Turkey. Geophysical Research Letters 30, 8046 (2003).
Göğüş, O. H. & Pysklywec, R. N. Mantle lithosphere delamination driving plateau uplift and synconvergent extension in eastern Anatolia. Geology 36, 723–726 (2008).
Faccenna, C., Bellier, O., Martinod, J., Piromallo, C. & Regard, V. Slab detachment beneath eastern Anatolia: A possible cause for the formation of the North Anatolian fault. Earth Planet Sc Lett 242, 85–97 (2006).
Garcia-Castellanos, D. & Villaseñor, A. Messinian salinity crisis regulated by competing tectonics and erosion at the Gibraltar arc. Nature 480, 359–363 (2012).
Krijgsman, W. et al. The Gibraltar Corridor: Watergate of the Messinian Salinity Crisis. Mar Geol 403, 238–246 (2018).
Spakman, W., Chertova, M. V., Berg, A. van den & Hinsbergen, D. J. J. van. Puzzling features of western Mediterranean tectonics explained by slab dragging. Nat Geosci 11, (2018).
Peña, L. G. de la et al. Evidence for a developing plate boundary in the western Mediterranean. Nat Commun 13, 4786 (2022).
Boonma, K., García-Castellanos, D., Jiménez-Munt, I. & Gerya, T. Thermomechanical modelling of lithospheric slab tearing and its topographic response. Frontiers Earth Sci. 11, 1095229 (2023).
Booth-Rea, G., Ranero, C. R. & Grevemeyer, I. The Alboran volcanic-arc modulated the Messinian faunal exchange and salinity crisis. Scientific reports 8, 13015 (2018).
Borque, M. J. et al. How Much Nubia-Eurasia Convergence Is Accommodated by the NE End of the Eastern Betic Shear Zone (SE Spain)? Constraints From GPS Velocities. Tectonics 38, 271–1839 (2019).
Palano, M., González, P. J. & Fernández, J. The Diffuse Plate boundary of Nubia and Iberia in the Western Mediterranean: Crustal deformation evidence for viscous coupling and fragmented lithosphere. Earth and Planetary Science Letters 430, 439–447 (2015).
Platt, J. P., Whitehouse, M. J., Kelley, S. P., Carter, A. & Hollick, L. Simultaneous extensional exhumation across the Alboran Basin: Implications for the causes of late orogenic extension. Geology 31, 251–254 (2003).
Larrey, M. et al. Oblique rifting triggered by slab tearing and back-arc extension: the case of the Alboran rift in the eastern Betics. Egusphere 2022, 1–39 (2022).
Mancilla, F. de L. et al. Slab rupture and delamination under the Betics and Rif constrained from receiver functions. Tectonophysics (2015) doi:10.1016/j.tecto.2015.06.028.
Platt, J. P., Kelley, S. P., Carter, A. & Orozco, M. Timing of tectonic events in the Alpujárride Complex, Betic Cordillera, southern Spain. J Geol Soc London 162, 451–462 (2005).
Vázquez, M., Jabaloy, A., Barbero, L. & Stuart, F. M. Deciphering tectonic- and erosion-driven exhumation of the Nevado-Filábride Complex (Betic Cordillera, Southern Spain) by low temperature thermochronology: Deciphering tectonic- and erosion-driven exhumation. Terra Nova 23, 257–263 (2011).
Shuster, D. L., Flowers, R. M. & Farley, K. A. The influence of natural radiation damage on helium diffusion kinetics in apatite. Earth Planet. Sci. Lett. 249, 148–161 (2006).
ZECK, H. P., MALUSKI, H. & KRISTENSEN, A. B. Revised geochronology of the Neogene calc-alkaline volcanic suite in Sierra de Gata, Alborán volcanic province, SE Spain. J Geol Soc London 157, 75–81 (2000).
Martín, J. M., Braga, J. C. & Betzler, C. Late Neogene–Recent uplift of the Cabo de Gata volcanic province, Almería, SE Spain. Geomorphology 50, 27–42 (2003).
Braga, J. C., Martín, J. M. & Quesada, C. Patterns and average rates of late Neogene–Recent uplift of the Betic Cordillera, SE Spain. Geomorphology 50, 3–26 (2003).
Arribas, A. et al. Geology, geochronology, fluid inclusions, and isotope geochemistry of the Rodalquilar gold alunite deposit, Spain. Econ. Geol. 90, 795–822 (1995).
Diaz, J., Gallart, J. & Carbonell, R. Moho topography beneath the Iberian-Western Mediterranean region mapped from controlled-source and natural seismicity surveys. Tectonophysics 692, 74–85 (2016).
Schaeffer, A. J. & Lebedev, S. Global shear speed structure of the upper mantle and transition zone. Geophysical Journal International 194, ggt095-449 (2013).
Pasyanos, M. E., Masters, T. G., Laske, G. & Ma, Z. LITHO1.0: An updated crust and lithospheric model of the Earth. Journal of Geophysical Research: Solid Earth 119, 2153–2173 (2014).
Steinberger, B. & Becker, T. W. A comparison of lithospheric thickness models. Tectonophysics 746, 325–338 (2016).
Thurner, S., Palomeras, I., Levander, A., Carbonell, R. & Lee, C. Ongoing lithospheric removal in the western Mediterranean: Evidence from Ps receiver functions and thermobarometry of Neogene basalts (PICASSO project). Geochem. Geophys. Geosystems 15, 1113–1127 (2014).
O’Reilly, S. Y. & Griffin, W. L. Imaging global chemical and thermal heterogeneity in the subcontinental lithospheric mantle with garnets and xenoliths: Geophysical implications. Tectonophysics 416, 289–309 (2006).
Mouthereau, F. et al. Cenozoic mountain building and topographic evolution in Western Europe: impact of billions of years of lithosphere evolution and plate kinematics. Bsgf - Earth Sci Bulletin 192, 56 (2021).
McNab, F., Ball, P. W., Hoggard, M. J. & White, N. J. Neogene Uplift and Magmatism of Anatolia: Insights From Drainage Analysis and Basaltic Geochemistry. Geochem Geophys Geosystems 19, 175–213 (2018).
Molinari, I. & Morelli, A. EPcrust: a reference crustal model for the European Plate. Geophysical Journal International 185, 352–364 (2011).
Chenin, P. et al. Potential role of lithospheric mantle composition in the Wilson cycle: a North Atlantic perspective. Geological Soc Lond Special Publ 470, 157–172 (2018).
Bianchini, G., Beccaluva, L., Nowell, G. M., Pearson, D. G. & Siena, F. Mantle xenoliths from Tallante (Betic Cordillera): Insights into the multi-stage evolution of the south Iberian lithosphere. Mantle Dynamics and Crust-Mantle Interactions in Collisional Orogens Topical Session at the Geological Society of America Annual Meeting 2007 124, 308–318 (2011).
Priestley, K. & McKenzie, D. The thermal structure of the lithosphere from shear wave velocities. Earth Planet. Sci. Lett. 244, 285–301 (2006).
Iribarren, L., Vergés, J. & Fernàndez, M. Sediment supply from the Betic–Rif orogen to basins through Neogene. Tectonophysics 475, 68–84 (2009).
Garcés, M., Krijgsman, W. & Agustí, J. Chronology of the late Turolian deposits of the Fortuna basin (SE Spain): implications for the Messinian evolution of the eastern Betics. Earth Planet Sc Lett 163, 69–81 (1998).
Flecker, R. et al. Evolution of the Late Miocene Mediterranean–Atlantic gateways and their impact on regional and global environmental change. Earth-sci Rev 150, 365–392 (2015).
Clauzon, G. et al. New insights on the Sorbas Basin (SE Spain): The onshore reference of the Messinian Salinity Crisis. Mar Petrol Geol 66, 71–100 (2015).
Weijermars, R., Roep, Th. B., Eeckhout, B. V. den, Postma, G. & Kleverlaan, K. Uplift history of a Betic fold nappe inferred from Neogene-Quaternary sedimentation and tectonics (in the Sierra Alhamilla and Almeria, Sorbas and Tabernas Basins of the Betic Cordilleras, SE Spain). Geologie en Mijnbouw 397–411 (1985).
Couto, D. D. et al. Tectonic inversion of an asymmetric graben: Insights from a combined field and gravity survey in the Sorbas basin. Tectonics 33, 1360–1385 (2014).
Giaconia, F. et al. Compressional tectonic inversion of the Algero-Balearic basin: Latemost Miocene to present oblique convergence at the Palomares margin (Western Mediterranean): Tectonic Inversion of Palomares Margin. Tectonics 34, 1516–1543 (2015).
Martínez-García, P., Comas, M., Lonergan, L. & Watts, A. B. From Extension to Shortening: Tectonic Inversion Distributed in Time and Space in the Alboran Sea, Western Mediterranean. Tectonics 36, 2777–2805 (2017).
Clark, S. J. P. & Dempster, T. J. The record of tectonic denudation and erosion in an emerging orogen: an apatite fission-track study of the Sierra Nevada, southern Spain. Journal of the Geological Society 166, 87–100 (2009).
Reinhardt, L. J., Dempster, T. J., Shroder, J. F. & Persano, C. Tectonic denudation and topographic development in the Spanish Sierra Nevada. Tectonics 26, n/a-n/a (2007).
Janowski, M. et al. Neogene exhumation and relief evolution in the eastern Betics (SE Spain): Insights from the Sierra de Gador. Terra Nova 29, 91–97 (2017).
Johnson, C., Harbury, N. & Hurford, A. J. The role of extension in the Miocene denudation of the Nevado-Filábride Complex, Betic Cordillera (SE Spain). Tectonics 16, 189–204 (1997).
Sendra, J., Reolid, M. & Reolid, J. Palaeoenvironmental interpretation of the Pliocene fan-delta system of the Vera Basin (SE Spain): Fossil assemblages, ichnology and taphonomy. Palaeoworld 29, 769–788 (2020).
Turner, S. P. et al. Magmatism Associated with Orogenic Collapse of the Betic-Alboran Domain, SE Spain. Journal of Petrology 40, 1011–1036 (1999).
Duggen, S. et al. Geochemical zonation of the Miocene Alborán Basin volcanism (westernmost Mediterranean): geodynamic implications. Contrib Mineral Petr 156, 577 (2008).
Polyak, B. G. et al. Heat flow in the Alboran Sea, western Mediterranean. Tectonophysics 263, 191–218 (1996).
Conticelli, S. et al. Trace elements and Sr–Nd–Pb isotopes of K-rich, shoshonitic, and calc-alkaline magmatism of the Western Mediterranean Region: Genesis of ultrapotassic to calc-alkaline magmatic associations in a post-collisional geodynamic setting. Lithos 107, 68–92 (2009).
Govers, R. & Wortel, M. J. R. Lithosphere tearing at STEP faults: response to edges of subduction zones. Earth Planet Sc Lett 236, 505–523 (2005).
Crespo-Blanc, A., Comas, M. & Balanyá, J. C. Clues for a Tortonian reconstruction of the Gibraltar Arc: Structural pattern, deformation diachronism and block rotations. Tectonophysics 683, 308–324 (2016).
Duggen, S., Hoernle, K., BOGAARD, P. van den & GARBE-SCHÖNBERG, D. Post-Collisional Transition from Subduction- to Intraplate-type Magmatism in the Westernmost Mediterranean: Evidence for Continental-Edge Delamination of Subcontinental Lithosphere. Journal of Petrology 46, 1155–1201 (2005).
Roberts, N. M. W. et al. A calcite reference material for LA-ICP-MS U-Pb geochronology. Geochemistry, Geophysics, Geosystems 18, 2807–2814 (2017).
Daëron, M., Blamart, D., Peral, M. & Affek, H. P. Absolute isotopic abundance ratios and the accuracy of ∆47 measurements. Chem. Geol. 442, 83–96 (2016).
Bernasconi, S. M. et al. Reducing Uncertainties in Carbonate Clumped Isotope Analysis Through Consistent Carbonate-Based Standardization. Geochem., Geophys., Geosystems 19, 2895–2914 (2018).
Kim, S.-T., Mucci, A. & Taylor, B. E. Phosphoric acid fractionation factors for calcite and aragonite between 25 and 75°C: Revisited. Chem. Geol. 246, 135–146 (2007).
Bernasconi, S. M. et al. InterCarb: A Community Effort to Improve Interlaboratory Standardization of the Carbonate Clumped Isotope Thermometer Using Carbonate Standards. Geochem., Geophys., Geosystems: G(3) 22, e2020GC009588 (2021).
Daëron, M. Full Propagation of Analytical Uncertainties in ∆47 Measurements. Geochem., Geophys., Geosystems 22, (2021).
Daëron, M. & Vermeesch, P. Omnivariant Generalized Least Squares Regression: Theory, Geochronological Applications, and Making the Case for Reconciled ∆47 calibrations. (2023) doi:10.22541/essoar.169607909.95281327/v1.
Kim, S.-T. & O’Neil, J. R. Equilibrium and nonequilibrium oxygen isotope effects in synthetic carbonates. Geochim. Cosmochim. Acta 61, 3461–3475 (1997).
Wu, L. et al. Cenozoic exhumation history of Sulu terrane: Implications from (U–Th)/He thermochrology. Tectonophysics 672, 1–15 (2016).
Farley, K. A., Wolf, R. A. & Silver, L. T. The effects of long alpha-stopping distances on (U-Th)/He ages. Geochim. Cosmochim. Acta 60, 4223–4229 (1996).
Gautheron, C. & Tassan-Got, L. A Monte Carlo approach to diffusion applied to noble gas/helium thermochronology. Chem Geol 273, 212–224 (2010).
Ketcham, R. A., Gautheron, C. & Tassan-Got, L. Accounting for long alpha-particle stopping distances in (U–Th–Sm)/He geochronology: Refinement of the baseline case. Geochimica et Cosmochimica Acta 75, 7779–7791 (2011).
Gallagher, K. Transdimensional inverse thermal history modeling for quantitative thermochronology. J Geophys Res Solid Earth 1978 2012 117, n/a-n/a (2012).
Flowers, R. M., Ketcham, R. A., Shuster, D. L. & Farley, K. A. Apatite (U–Th)/He thermochronometry using a radiation damage accumulation and annealing model. Geochim Cosmochim Ac 73, 2347–2365 (2009).
Gautheron, C., Tassan-Got, L., Barbarand, J. & Pagel, M. Effect of alpha-damage annealing on apatite (U–Th)/He thermochronology. Chemical Geology 266, 157–170 (2009).
Rudge, J. F., Champion, M. E. S., White, N., McKenzie, D. & Lovell, B. A plume model of transient diachronous uplift at the Earth’s surface. Earth Planet. Sci. Lett. 267, 146–160 (2008).

There is NO Competing Interest.

SupplData1.xlsx
Dataset 1
SupplData2.pdf
Dataset 2
SupplData3.docx
Dataset 3
SupplDiscussion1.pdf
Supplementary Info 1
SupplDiscussion2.docx
Supplementary Info 2

Download PDF

Version 1

posted

You are reading this latest preprint version

Tracking lithospheric delamination and surface processes across the Messinian salinity crisis

Status:

Version 1

Abstract

Figures

Introduction

Results

Carbonate U-Pb dating of syn-extension fractures

Clumped-isotope temperatures of fluids

Apatite (U-Th)/He dating of volcanic and metamorphic rocks

Time-temperature histories

Impact of mantle-derived processes on topography

Discussion

Pre-MSC uplift and subsidence induced by mantle delamination

Method

Samples

Calcite LA-ICP-MS U-Pb geochronology

Clumped isotope analysis

Apatite (U-Th)/He dating

QTQt thermal modelling

Isostatic calculation, Vs-temperature conversion and dynamic topography

Temperature of continental lithosphere and heat flux estimates

Declarations

References

Additional Declarations

Supplementary Files

Status:

Version 1