Uplift Dynamics of the Obducted Northeastern Continental Margin of the Arabian Peninsula, Sultanate of Oman

Eustatic sea level changes and vertical tectonic movements are producing uplifted paleoshorelines. Along subduction zones, uplifted terraces are used to study fault activities and, overall, allow to interpret the tectonic history of plate convergence. Northeastern Oman is experiencing plate convergence following the late Cretaceous obduction of the Semail Ophiolite. Post‐obduction shallow‐marine carbonates have been uplifted to different elevations from 133 to >2,000 m. The present study employs a multidisciplinary approach to elucidate the variability in relief and to introduce a geodynamic model that extends beyond the temporal constraints imposed by the late Quaternary age of the sediments found on the uplifted terraces. Stratigraphic and fault analyses produced a post‐obductional geodynamic model to advance the existing regional models in the framework of the subduction of the Arabian Plate in the Makran Zone. In addition, we rely on imaging geodesy, geomorphology and dating to explain the late Quaternary uplift scenario. Overall, analyses of geomorphology, stratigraphy, and fault patterns reveal spatially heterogeneous post‐late Cretaceous uplift in the region. Compartmentalization by major faults created individual blocks and relief variability. Within the timeframe of marine terrace formation (late Quaternary), we also observed spatially varied displacements. Ground displacements by Interferometric Synthetic Aperture Radar document an ongoing spatial heterogenous uplift at approximately 1.3 mm/a. Finally, temporal variability was evident during the late Quaternary by unusually high late Pleistocene (<40 ka) uplift rates averaging ≥2 mm/a in younger terraces, while for older terraces (>40 ka) the uplift rate is distinctly lower (<1 mm/a).

. The preservation of marine terraces on the coastal slopes of the Salma Plateau in northeastern Oman offers a record of uplift events due to continued convergence between the Arabian and Indian plates (Hoffmann et al., 2020;Kusky et al., 2005;Moraetis et al., 2018).
Lately, a major international and intensifying research effort indicates a substantial and growing interest to understand the uplift history of Oman, including the uplift mechanisms and timing of the Oman Mountains (Grobe et al., 2018;Hansman et al., 2017) and of the coastal terraces (Ermertz et al., 2019;Falkenroth et al., 2019;Hoffmann et al., 2013Hoffmann et al., , 2020;;Kusky et al., 2005;Mattern et al., 2018;Moraetis et al., 2018;Yuan et al., 2016).The present study is another main step in this exciting research effort.The uplift mechanisms and their timing as well as the topographic evolution of the Salma Plateau are still a matter of debate (e.g., Hoffmann et al., 2020;Kusky et al., 2005;Moraetis et al., 2018).Especially, the relief heterogeneity along the northeastern coast of Oman has not been interpreted.The current study seeks to fill these gaps by creating a new uplift model for northeastern Oman (Salma Plateau's marginal coastal area).We employ a multidisciplinary approach to shed light on the intricate geological landscape, encompassing not only the temporal framework derived from sedimentary age profiles that blanket the conserved marine terraces but also the temporal expanse after the emplacement of the ophiolite with stratigraphic and fault analyses.
Offshore, northeastern Oman exhibits a transition from continental to oceanic lithosphere which is currently moving to the Makran subduction zone (Hansman et al., 2017;Scharf et al., 2021a).Indeed, part of the Oman Sea and the Indian Ocean contain what is considered still analog segments of the Semail Ophiolite (see seismic profile D′D in Figure 7 of White (1984), and seismic profile DE in Figure 2 in White and Klitgord (1976), Ninkabou et al. (2021), and references therein).The continental part of this subducting plate, the northeastern Arabian continental margin, features a coastal-parallel 70-km-long and 20-km-wide system of "staircase-like" uplifted marine terraces between Quriyat and Sur (Figure 1b), similar to those along active margins (Mouslopoulou et al., 2016;Pedoja et al., 2011Pedoja et al., , 2014)).In Oman, Quaternary uplift rates, based on the 14 C method, range between 0.9 and 6.67 mm/a (Moraetis et al., 2018, recalculated in this study 0.7-4.4mm/a) in low elevation terraces where marine deposits are preserved.Distinctly lower uplift rates between 0.2 and 1.8 mm/a (recalculated in this study 0.2-1.7 mm/a) using the 36 Cl, 10 Be and Optically-Stimulated Luminescence (OSL) techniques have been reported by Hoffmann et al. (2020) in higher terraces where marine deposits are lacking.
Uplift of >2,000 m at the Salma Plateau (Figure 1) started after the mid-Eocene and is still active (e.g., Hoffmann et al., 2013Hoffmann et al., , 2020;;Moraetis et al., 2018;Searle, 2007;Wyns et al., 1992b).Reasons for the ongoing uplift are debated and are (a) possibly linked to bending/forebulge formation of the Arabian lithosphere related to the ongoing Arabia-Eurasia convergence (e.g., Kusky et al., 2005;Rodgers & Gunatilaka, 2002;Yuan et al., 2016), and/or (b) convergence between the Arabian and Indian plates since the Oligocene/Miocene (e.g., Corradetti et al., 2020;Fournier et al., 2006;Scharf et al., 2022), and/or (c) some uplift of marine terraces reflecting serpentinization and associated volume increase of ultramafic rocks (Ermertz et al., 2019;Hoffmann et al., 2020).In addition, the published chronologies pertaining to the uplifted terraces show incongruities and possible dating limitations for this particular geographical area which are yet to be constrained.
We characterize the associated geomorphology and tectonic controls along a ∼150-km-long coastal section of the northeastern Arabian Peninsula from Muscat to Sur (including the 70 km of uplifted terraces) (Figures 1  and 2).New absolute ages, uplift rates and remote sensing data are presented for uplifted marine terraces from the Quriyat-Sur area.We address the variability of ages among the "staircase-like" uplifted terraces and the dating constraints derived from the different dating techniques.Finally, we investigated whether faults controlled differential uplift.This study utilizes a variety of approaches including (a) stratigraphic analysis of key geomorphic features, (b) age constraints by OSL and Accelerator Mass Spectrometry 14 C of marine and terrestrial deposits, (c) Digital Surface Model (DSM) and detailed topographic profiles, (d) semi-automated geomorphological mapping, (e) sedimentary petrographic analyses, (f) structural/tectonic analyses and (g) calculations of current ground displacements by using high resolution Interferometric Synthetic Aperture Radar (InSAR) analyses.The acquired data in combination with published information provide a framework to reveal the Cenozoic uplift dynamics of the northeastern Oman coastal area.The large scale and varied methods of our investigation are a novelty for Oman and our results are of general significance for uplifted continental margins associated with subduction.

Tectonic/Geological Setting
During the Permian, Oman was situated near an r-r-r triple junction between Arabia, India and the Cimmerian blocks (e.g., Chauvet et al., 2009), and Arabia was thinned (Weidle et al., 2022).Following rifting, a passive margin formed in northeastern Oman and the Neo-Tethys Ocean was created along with the >450-km-wide deepsea Hawasina Basin adjacent to Oman (e.g., Béchennec et al., 1990).Throughout the Permo-Mesozoic, Arabia was a passive margin, amassing mostly shallow-marine carbonates on the shelf as well as continental slope sediments (e.g., Glennie et al., 1974).
Regarding the presence of potentially reactivated fault systems, it needs to be pointed out that Oman consists of probably ∼NNE-striking terrains in the subsurface, which had been accreted during the Pan-African Orogeny (e.g., Allen, 2007).Moreover, within the eastern Arabian lithosphere, major NNE-striking faults exist (Weidle, et al., 2022(Weidle, et al., , 2023)).These faults have been reactivated during much of their history, depending on the respective stress fields.One major fault is the NNE-striking Semail Gap Fault (Scharf et al., 2019; Figure 1a).The Ibra Fault is another major NE-striking crustal fault, as shown by seismic tomography.This fault extends from the SW of Ibra to Quriyat/Dibab (Figure 1a; Weidle et al., 2022).The NE-striking Dibab blind fault, which is probably a part of the Ibra Fault, was introduced by Moraetis et al. (2018).Other NE-striking blind faults are the Quriyat and Daghmar faults.The Qalhat Fault is a similarly oriented major fault in the eastern part of the study area (Figures 1 and 2; Wyns et al., 1992a).Other faults, striking NW/SE are the Ja'alan Fault, Issmaiya Fault Zone and Wadi Mansah Fault Zone (WMFZ; Callegari et al., 2022;Moraetis et al., 2018;Scharf et al., 2019Scharf et al., , 2022; Figure 2).These faults probably originated during the late Paleozoic breakup of Pangea (Blendinger et al., 1990;Chauvet et al., 2009;Moraetis et al., 2018;Scharf et al., 2019) and were eventually reactivated during the Cenozoic (Mattern, Bolhar, et al., 2021).
and 3).Details on the geology, tectonics and geomorphic analysis of these areas are provided in Section S1 in Supporting Information S1, and in Scharf et al. (2021aScharf et al. ( , 2021b)).

Fieldwork and Geomorphological Investigations
Geomorphological mapping of subaerial landforms was carried out using remote sensing and topographic data by a double precision real-time kinematic (RTK) GPS receiver (Figure S1 in Supporting Information S1).The RTK GPS receiver was used to record the elevation and location of the "staircase-like" relief of the study area (Daghmar-Qalhat) and associated samples.The x, y, and z coordinates were automatically corrected by using a static base station at Dibab (23.094091°N/59.035736°E,at 70.54 ± 0.14 m).Furthermore, we mapped the distribution and continuity of landforms such as marine terraces, escarpments, dolines, alluvial fans and hanging valleys.

Delineation of Planation Surfaces
Terrain analysis involved the semi-automatic delineation within a Geographic Information System of planation surfaces and other hydrological properties for the coastal zone.For this purpose, we used a Cartosat-1 Euro-Maps 3D DSM (Nadeem et al., 2007).Euro-Maps 3D is a homogeneous 5 m spaced DSM derived from CartoSat-1 (formerly IRS-P5) mission (Krishnaswamy & Kalyanaraman, 2002).Details of the terrain analysis are provided in Methods Section S2 of Supporting Information S1.In addition, the uplifted marine terraces were visualized using stacked swath profiles (Fernández-Blanco et al., 2020) with a python code (de Gelder et al., 2022).QGIS-3.30.3's-Hertogenbosch was used to depict geology maps and to produce some of the elevation profiles.

InSAR Processing and Relative Sea Level Changes
Archived Synthetic Aperture Radar data from the Copernicus Sentinel-1 mission was utilized, comprising 61 scenes acquired on ascending orbit 159 covering the period between August 2016 and September 2019.Interferometric processing (Papageorgiou et al., 2019;Strozzi et al., 2000) was undertaken using GAMMA software packages (Wegmüller et al., 2016) on a Virtual Machine having direct access to the Copernicus archives via the CREODIAS infrastructure (https://creodias.eu).The elaboration of the InSAR processing is provided in Methods Section S2 of Supporting Information S1.
Concerning relative sea-level changes, monthly observations from regional tide gauges were accessed via the Permanent Service for Mean Sea-Level, a global data bank for long-term sea-level change information (https:// www.psmsl.org).

Sediment Dating
A series of OSL and 14 C ages were obtained from appropriate samples for continental and marine sediments (Tables 1 and 2).The dated samples were collected from terraces T1, T2 and T3 (samples Dibab-1, Dcalc-1, Dcalc-2, DAG-8g, DT2B-3, DT2B OSL1, DT2B OSL2, and DCALC1_OSL, Figure S1b in Supporting Information S1).Acquisition and processing details of dated samples are provided in Section S2 of Supporting Information S1.Coordinates and the relative positions of all samples are indicated in Table 1.

Uplift Rate Calculation
For the calculation of uplift rates, it is necessary to know the present elevation of the terrace, the position of the eustatic sea-level during terrace formation, and the age of terrace formation.In our study, we used the global model of sea-level curves based on Spratt and Lisiecki (2016) for the ESL estimation (Figure 8a).
The calculation of the average displacement rate (R mean ) of terraces, as described by Lajoie (1986) and Gallen et al. (2014), is displacement (D), which corresponds to the difference between the present elevation of the terrace (TE) and the original elevation (ESL) ' of the eustatic sea-level estimation by the global models, divided by its age (A) as following: R mean = (TE − ESL)/A.The calculation of the sigma deviation for the uplift rate was based on the Gallen et al. (2014) formula (see Section 3.3 in Gallen et al. (2014)).For comparison, we recalculated all uplift rates from previous studies (Hoffmann et al., 2020;Moraetis et al., 2018).The terrace elevation was calculated using the average RTK topographic survey elevation at the seaward side of the terraces (outer break of slope).The standard deviation was also calculated from the topographic survey elevation measurements.

Petrographic Analysis
Seven samples (Dag 3, Dag 4, Dag 8d, Dag 8a, Dag 6, Calc-1, and Calc-2) were collected from terraces T1 and T2 for thin-section analysis under transmitted light (Figures S16 and S17 in Supporting Information S1).Calc-1 and Calc-2 are from the same sedimentary deposit as the 14 C samples Dcalc-1 and Dcalc-2.Sample Dag8a and Dag8d are from the same locality as the 14 C sample Dag-8g.Samples from terrace T3 were not analyzed under the microscope due to friable texture.Details of the petrographic analysis are given in Section S3 of Supporting Information S1.

Geomorphology From the Saih Hatat Dome to the Batain Area
Our geomorphological analysis determined five distinguished morphotectonic segments (Figures 1b and 3a-3c).This subdivision is based on the terrain analysis with a semi-automated method using a high-resolution DSM.We also analyzed distinct landforms such as cliffs, hanging valleys, planation surfaces, alluvial fans and canyons  2018).Uplift rates were calculated based on Eustatic Sea Level for each sample adopted from Spratt and Lisiecki (2016) (also in Figure 8a).Dating deviation, elevation deviation and uplift deviation have a 1-sigma error margin."-": Uplift rate is not calculated for soil sample as it is not a sea-level indicator.amsl, above mean sea level.).Topographic profiles from the Saih Hatat Dome (Segment 1) to the Jabal-Ja'alan-Batain area (Segment 5) show strata dipping subparallelly to the coastline (Figure 4).
The surface elevation of Segment 1 is ≤275 m in 1-km-distance from the coast in the Saih Hatat Dome and in elevation of ∼100-150 m in the coastal areas between the Quriyat and Sur corridors (Segments 2-4).
In the Batain area (Segment 5), the elevation is low at <20 m (Figure 3a).The topography changes significantly between 5 and 25 km inland (Figures 3b and 3c).The elevation of the Saih Hatat Dome (Segment 1) is ≤500 m in the northern part and rises to ∼1,500 m NW of Quriyat.
In contrast, the elevation is <200 m between Quriyat and Dibab (Segment 2), with a planation surface rising to the southeast to ∼2,000 m along the Salma Plateau (Segment 3).
The elevation is <200 m SE of Sur and in the Batain area (Segments 4-5), except for the Jabal Ja'alan region (Figures 3b and 3c).Profiles B and C in Figures 3b and 3c show deep wadi incisions.This down-cutting erosion across the planation surfaces of the Salma Plateau (Segment 3) yields a fragmented and denudated landscape.).The front of each terrace surface is characterized by steep cliffs and scree mixed with marine deposits at the base of the cliff (Figure 4).
The average elevations of terraces T1-T6 between Daghmar and Dibab (Quriyat Corridor, Segment 2) range between 4.9 ± 0.5 to 132 ± 2.6 m.Terrace T1 is identified from Daghmar to Tiwi, while it is absent from Daghmar to Dibab (Figures 5a-5e).Overall, terraces T4-T6 are at lower elevations at the Quriyat Corridor (Segment 2) compared to the Salma Plateau (Segment 3) (Figures 5a-5e and 5h-5l).However, in the areas between Dibab and Fins, terrace T6 shows some spikes in the elevation, which are considered outliers and possibly derived from poor correlation.In the places where T6 can clearly be traced, the elevation is ∼190-210 m in the Salma Plateau (Segment 3) and ∼133 m in the Quriyat Corridor (Segment 2) (Figures 5f and 5g).Terraces T2 and T3 are found at a higher elevation at Daghmar (Quriyat Corridor) compared to the Salma Plateau (Figures 5f, 5g, and 5i).A planation surface on the landward side of terrace T6 (Daghmar-Dibab; Segment 2) occurs at an elevation of ∼133 ± 1 m with characteristic karstic landforms such as dolines, ponors, and dry incised valleys (Figure 4).Terrace T3 of Segment 2 contains well-preserved alluvial fans with caliche-like soils (Figures S6 and S7 in Supporting Information S1).In some locations, underneath terrace T3, a remnant carbonate paleosol occurs (Figures S7 and S8 in Supporting Information S1).

Stratigraphic Correlation Across Northeastern Oman
Stratigraphic correlations between the Saih Hatat Dome and the Jabal Ja'alan-Batain area are based on the geologic maps of Ibra, Quriyat, Tiwi and Sur at a scale of 1:100,000 (Al Battashy et al., 2001;Peters et al., 2005;Wyns et al., 1992aWyns et al., , 1992b) ) and our field observations (Figures 2 and 6).Cenozoic shallow-marine sediments are positioned at an elevation of ∼2 km at the Salma Plateau (Segment 3), whereas the same formations occur mostly at <500 m of elevation within the Quriyat Corridor (Segment 2) and Jabal Ja'alan-Batain area (Segment 4) (Figure 6).Differences in elevation, over short distances, coincide with major faults, involved in differential uplift (Moraetis et al., 2018;Hoffmann et al., 2020 and references mentioned in Section 5.3).At the Salma Plateau, Cenozoic lithologies often cover allochthonous rocks, while in the Quriyat and Saih Hatat areas, Cenozoic deposits blanket (par)autochthonous rocks (Figure 6).The absence of the allochthonous units in the Quriyat and Saih Hatat areas is attributed to the latest Cretaceous major exhumation of the Saih Hatat Dome, resulting in denudation of allochthonous and some (par)autochthonous rocks prior to the deposition of the Maastrichtian Qahlah Formation (e.g., Searle, 2007).Late Cretaceous doming/exhumation in the future Salma Plateau area was less than that of the Saih Hatat area because allochthonous rocks are still preserved.

Imaging Geodesy-InSAR Displacement Field
The average Line-of-Sight (LoS) displacement rates indicate decreased uplift toward the SE (Figure 7a).Similarly, the quadratic InSAR signal (Figure 7b), indicating long wavelength displacements, shows a regional trend with uplift to the NW (6.7 mm/a at the broader southern Saih Hatat Dome-Quriyat Corridor; Segments 1 and 2) relative to the southeastern region −6.4 mm/a at Qalhat to Sur (Segment 4; Figure 7a).This regional trend is also reflected in the relative sea-level changes measured by surrounding tide gauge stations (Figures S12 and S13 in Supporting Information S1).The northeastern tide stations (close to Saih Hatat) show no sea-level rise compared to the southwestern gauge stations, which show sea level rise, implying no or limited land uplift.The residuals from LoS and quadratic InSAR subtraction verifies sound InSAR processing (Figure 7c).To further investigate the displacement pattern along the coastline, geologic cross-sections at 1, 5 and 10 km distances from the coastline were examined (Figures 7d-7f).
The variability in vertical displacement appears higher for the inner land section (5 ± 0.6 mm/a), whereas for the coastal zone, variations are limited to 2.5 ± 0.5 mm/a.This is compatible with the higher elevation of terraces T2 and T3 in the Quriyat Corridor compared to that of the Salma Plateau (CartoSat DSM analysis; Figures 5f and 5g).
The average InSAR ground displacement rates show distinctively higher uplift rates in the northern areas, Daghmar to Dibab (Segment 2) compared to those of the Salma Plateau and the southeastern areas (Segments 3 to 5) (Figures 7g-7k).The observed displacement field appears independently of local topography, denoting the successful relief compensation during InSAR processing (no residual topographic phases).The range of displacement rates along the coastal area (<5 km distances to the coastline) is between −2 mm/a in the Fins/Tiwi area (Segment 3) and 3 mm/a in the Quriyat Corridor (Segment 2; Figures 7g-7l).Overall, the coastal area appears to be uplifting at an average rate of 1.3 mm/a (average at a distance of <5 km from the coast) with low subsidence rates in isolated areas.
The obtained uncertainties (Figure S9 in Supporting Information S1), even for a marginal period of 3 years of SAR observations, remain for most of the locations lower than the estimated rates, signifying an overall robust solution.

Stratigraphic/Sedimentary Materials for 14 C and OSL Dating
Dated sediments from terrace T1 are grainstones with abundant limestone lithoclasts and shells (samples Calc-1 and Calc-2 in Figures S17c and S17f in Supporting Information S1).The lithoclasts and bioclasts are lined by microcrystalline cement and later equant calcite cement.Both cement generations are postdated by vuggy porosity.The 14 C-age range in three samples for terrace T1 in the Quriyat Corridor (Segment 2) is 19.73 (±0.50), 30.7 (±0.12) and 40.64 (±0.28) ka BP with an uplift rate of 2.06 (±0.14) to a maximum 6.16 (±0.53) mm/a (Table 1).The age of 19.73 (±0.50) ka BP is derived from a different locality in terrace T1 compared to the other two which were derived from the same location (Table 1, Figure S1b in Supporting Information S1, Figures 8a and 8b).
Sample Dag 8d from terrace T2 is a conglomerate with numerous shallow-marine shells as components (Figures S16f-S16h in Supporting Information S1, Figure 8b).We obtained a 14 C shell age of 43.9 (±0.59) ka BP (sample Dag 8g) and an uplift rate of 2.41 (±0.11) mm/a for terrace T2.Thin-section analyses of samples Dag 8a and Dag 8d from the same dated 14 C unit of terrace T2 show that marine shells are "floating" within brownish/reddish micrite (Figures S14c and S16h in Supporting Information S1).In addition, samples DAG 3, 4 from terrace T2 show a completely dolomitized bedrock with micrite rims and infilled porosity with brown-red micrite (Figures in Supporting Information S1).Circles are for samples analyzed using a petrographic microscope and triangles for samples that were dated.
Two terrestrial sediments from an alluvial fan of terrace T3 were dated using the OSL method.Both samples are from the same outcrop but display different lithologies.The stratigraphic lower sample (DT2B_OSL1) consists of unconsolidated sand to silt-sized clastic components, while the upper sample contains unconsolidated angular pebbles to cobble-sized clasts (DT2B_OSL2; Figure S7 in Supporting Information S1).These sediments unconformably overlie the terrace T3 bedrock (Eocene limestones).The OSL ages were 26.29 (±2.14) (DT2B_OSL2) and 142.34 (±11.80)ka BP (DT2B_OSL1; Table 2, Figures 8a and 8b).
Furthermore, we dated a caliche sample with the 14 C technique from the same alluvial fan as the two OSL samples.The caliche developed in a 30-cm-thick horizon, and it mainly contained spherical and a few elongated and lenticular calcite nodules (Figure S8 in Supporting Information S1).The caliche sample DT2B-3 (80 cm below the surface) yielded a 14 C age of 30.60 (±0.12) ka BP.All three samples are from an alluvial fan deposited on terrace T3 (Figure 8b).Therefore, we do not know the sea-level at the time of deposition and have not calculated the uplift rate except for the older age sample (DT2B_OSL1) as an indicative maximum rate (1.18 ± 0.11 mm/a).

Terrace T1
The three dated samples at terrace T1 provide an age range (19.73 ± 0.50-40.64± 0.28 ka BP) with no seaward younging trend.The age variance may reflect two different processes: (a) the common limitations of 14 C dating of shells (see Section 3.2 of Mouslopoulou et al. (2015)) since shells may contain recrystallized calcite of different ages (Amundson et al., 1989;Wang et al., 1994), (b) and/or the matrix of the sediment contains a mixture of reworked shells of different ages (Mouslopoulou et al., 2015).Mixing of reworked shells could be related to alluvial processes and/or multiple successive sea occupations of the terrace, creating polygenetic marine terraces with a range of 14 C ages (Malatesta et al., 2019;Regard et al., 2010).The fact that in these samples no extensive CaCO 3 alteration was observed (neomorphism, dolomitization etc.) makes the mixing of reworked sediments a possible explanation of the scatter ages.Similar to the previous petrographic observation, Falkenroth et al. (2020) mentioned that thin section analyses of the lower terrace's marine deposits in the nearby Sur area show marine deposits with little or no calcite alteration (Falkenroth et al., 2020), which likely excludes recrystallization and "contamination" of carbon in the lower terraces.
The isopachous rim in samples Calc-1 and Calc-2 (SI17C, E) is related to microbial micritization, which is very common in subtidal environments in low latitude areas (Tucker, 2001).The vuggy porosity postdates the cement deposition (SI17E), and its formation is explained by a later aerial exposure.Thus, we propose a subtidal deposition of the clastic sediment of these two samples.The uplift rate of terrace T1, based on OSL dating (DCALC1_ OSL; 45.72 ± 4.08 ka BP, Table 2), is similar to one of the three 14 C ages (40.64 ± 0.28 ka BP, Table 1).We conclude that the uplift rate of Terrace T1 most likely ranges between 1.77 and 2.06 ± 0.19 mm/a depending on the dating method OSL or 14 C, respectively (see Section 3.5 and Table 1 for details on the calculation).For the age range 35-50 ka, there is increasing evidence for an eustatic sea-level of approximately −40 m (Gowan, et al., 2022;Pico et al., 2016).Considering this eustatic sea-level and recalculating the uplift range in terrace T1 is 1.10-1.77mm/a.Thus, terrace T1 still shows an uplift rate range >1 mm/a.

Terrace T2
We dated one marine shell from terrace T2 with the 14 C method, which yielded an age of 43.9 ± 0.59 ka BP, corresponding to an uplift rate of 2.41 ± 0.11 mm/a (Table 1).This rate is comparable to that related to the 14 C age reported by Moraetis et al. (2018) (Table 1; 2.31 ± 0.13 mm/a) and also to other works in other locations of the Arabian plate (Gardner, 1988;Wood et al., 2012).The resemblance of the T2 shell age with the one from terrace T1 (DCalc-1: 40.64 ± 0.28 ka BP) indicates the transportation of shells from terrace T2 to terrace T1.
The uplift rate of terrace T2 (2.41 ± 0.11 mm/a) is distinctly higher than the uplift rates produced by Hoffmann et al. (2020), which are based on CR ( 36 Cl, 10 Be) and OSL techniques (0.19-0.85 ± 0.18 mm/a).Hoffmann et al. (2020) found that in several cases (compare samples TD13/5 TD13/6, TD13/7 in Table 1, Hoffmann et al., 2020) their OSL and CR ages were "noisy" due to reworking processes and the high chlorine content in the dated rocks.The lower uplift rates are due to older ages, derived from the CR ( 36 Cl, 10 Be) and OSL techniques (average of ∼239 ka BP).Overall, the reported differences in uplift rates caused by different dating techniques ( 14 C, OSL and/or CR) are not yet fully understood for the coast of northeastern Oman, at least for terrace T2.
Generally, age differences from the same terrace between 14 C and OSL ages have been reported by Argyilan et al. (2005) from strandplains close to Lake Michigan and Lake Superior.Age discrepancies could be related either to 14 C dating constraints as mentioned above or to incomplete sunlight resetting of OSL samples in fluvial and littoral deposits (Wallinga et al., 2001).For the 14 C and CR ( 36 Cl, 10 Be) discrepancies, other reasons, except 14 C dating drawbacks, such as high chlorine content of the rocks or inherited 10 Be due to reworked pebbles, could lead to ages that are too low or too high, respectively (Larsen et al., 2021;Owen et al., 2011).

Terrace T3
Alluvial fan deposits were dated at Terrace T3.OSL ages are ∼26 ± 2.14 and 142 ± 11.08 ka BP (samples DT2B_OSL2 and DT2B_OSL1, respectively; Figure S7 in Supporting Information S1).The samples are in stratigraphic order with the younger sample DT2B_OSL2 overlying the older sample DT2B_OSL1.These two ages are explained by two alluvial aggradation events.The older bed (DT2B_OSL1) contains caliche concretions (Figure S8 in Supporting Information S1) and demonstrates a later terrestrial pedogenic process.The caliche age (30.60 ± 0.12 ka BP with 14 C) slightly predates the deposition of sample DT2B_OSL2 (26 ± 2.14 ka BP).
The lack of marine sediments makes the estimation of the maximum uplift rate in this terrace tricky, since the ages correspond to terrestrial sedimentation events and not sea-level indicators.However, the uplift rate (1.18 ± 0.11 mm/a) from the older deposit (DT2B_OSL1: 142 ka) is lower than that of the terraces T1 and T2.

Other Terraces
Considering uplift rates for terraces T4 to T6 of ∼0.2-0.36 mm/a (except T13/8 which is considered an outlier by Hoffmann et al., 2020) and the one obtained from terrace T3, we suggest that the uplift rate decreased abruptly toward older terraces (≥T3).Uplift rates are between ∼0.2 and 1 mm/a for terraces ≥T3, while they are ∼1 to ≥2 mm/a for terraces T1 and T2.
In summary, the 14 C ages are variable.In combination with the OSL data, one reliable uplift rate for Terrace T1 was calculated (1.77-2.06± 0.19 mm/a).This uplift rate is comparable with reported rates (Gardner, 1988;Moraetis et al., 2018;Wood et al., 2012).Possible reworking induced chemical alteration and constraints on dating techniques leaving a speculative uplift rate for terrace T2.Our age results of Terrace T3 can be explained by different alluvial aggradation events.The obtained maximum uplift rate of 1.18 ± 0.11 mm/a is in agreement with the magnitude of uplift rates reported by cosmogenic and OSL dating (Hoffmann et al., 2020).Finally, we can confirm high uplift rates (>2 mm/a) of the late Pleistocene to Holocene (<50 ka) for Terrace T1 along with other published data (Gardner, 1988;Moraetis et al., 2018;Wood et al., 2012).

Post-Late Cretaceous to Recent Tectonic Evolution and Fault Delineation
The stratigraphic analysis showed that uplift in the study area was heterogeneous due to different tectonic events.Exhumation in the Saih Hatat Dome with convex morphology and a decreasing slope gradient toward the southeast occurred earlier compared to the uplift of the Salma Plateau where allochthonous rocks are preserved (Figure 6).The proto-Saih Hatat Dome was mainly uplifted during the late Cretaceous until the early Eocene (∼55 Ma) based on geochronology, thermochronology and stratigraphy data (e.g., Hansman et al., 2017Hansman et al., , 2021;;Saddiqi et al., 2006; see also Qahlah Formation of Maastrichtian age at Nolan et al., 1990).Second and gentler surface uplift of the Saih Hatat Dome occurred during the post-Mid-Eocene (Hansman et al., 2017).
There was little to no uplift in the Sur Corridor and Jabal Ja'alan-Batain region since the Late Cretaceous, and these areas were not overthrust by the Semail Ophiolite (Wyns et al., 1992a(Wyns et al., , 1992b)).Falkenroth et al. (2020) also indicated no tectonic uplift in the Sur Corridor, at least since the late Pleistocene in the Sur Corridor.
The entire northeastern coast of Oman, except for most of the Saih Hatat area, was covered by shallow-marine sedimentary rocks during the late Paleocene to mid-Eocene.Thus, there was subsidence and tectonic quiescence from the Quriyat Corridor to the Jabal Jaʼalan-Batain area.In the Salma Plateau and in the same time span (Paleocene to mid-Eocene), subsidence was significant, allowing for the accommodation of >2-km-thick shallow-marine rocks (Wyns et al., 1992a(Wyns et al., , 1992b)).Segmented post-mid-Eocene uplift resumed, and the Salma Plateau rose to its current elevation (Figure 6).Surface uplift was >2 km in the Salma Plateau but minor to none in the Quriyat and Sur corridors as well as the Batain region.Despite the absence of noticeable uplift after the mid-Eocene in the Quriyat Corridor, the area between Daghmar and Dibab preserved a karstified planation surface with deeply incised meandering wadis (Figures S10 and S11 in Supporting Information S1).This observation suggests a similar age of initial uplift for the Quriyat Corridor and Salma Plateau, but the overall relief in the Quriyat Corridor remained low.Thus, subsequent subsidence or low uplift rates created the Quriyat Corridor through the activation of blind faults (Quriyat, Daghmar and Dibab blind faults).
The Jabal Ja'alan-Batain area (Segment 5) and the Sur Corridor (Segment 4) were possibly positioned above the sea-level prior to the late Cretaceous since there is no exposure of Permian to Mesozoic autochthonous rocks (Wyns et al., 1992a).The Ja'alan-Batain area has never been bent significantly since it was overthrust only by a thin unit of deep-sea sedimentary rock (∼2 km in thickness) derived from the Batain area not associated with the Semail Ophiolite (e.g., Mount et al., 1998;Roger et al., 1991;Schreurs & Immenhauser, 1999).It is considered to be the northern continuation of the Huqf-Haushi Uplift (Figure 1) (Filbrandt et al., 1990).The Sur Corridor and Jabal Ja'alan-Batain area were submerged after the late Cretaceous with continuous sedimentation until the mid-Miocene.
All segments from the Saih Hatat Dome to Jabal Ja'alan-Batain were situated above sea-level during the late Miocene to Holocene.The landscape of the coastal area of northeastern Oman probably had similar relief through the late Cenozoic.Continued uplift of terraces T3-T6 at the Quriyat Corridor and Salma Plateau postdates the Miocene (Moraetis et al., 2018;Hoffmann et al., 2020;and present study).Terraces >T3 occur at higher elevations in the Salma Plateau compared to that of the Quriyat Corridor (Daghmar to Dibab; Figure 5f).This observation conforms to the differential uplift rates of the Salma Plateau and the Quriyat Corridor.However, this trend is not obvious to terraces T2 and T3 between the Salma Plateau and the Quriyat Corridor in the Dibab area (Figure 5g), indicating a possible temporal cessation of the differential uplift between the Quriyat Corridor and the Salma Plateau.Its age is constrained by the younger terrace T1 (late Pleistocene).Thus, an intervening fault or fault zone, which is not exposed at the surface, may exist between these two segments (Dibab blind fault in Figure 2; Hoffmann et al., 2020;Le Métour et al., 1986;Moraetis et al., 2018).The differential uplift is corroborated by the InSAR results presented in Section 4.3 (Figure 7).
The boundaries between the highly uplifted Saih Hatat Dome (Segment 1), Quriyat Corridor (segment 2), Salma Plateau (Segment 3), Sur Corridor (Segment 4) and the Jabal Ja'alan-Batain area (Segment 5) are delineated by several major exposed or blind faults.These faults have generated a distinct geomorphology with a "staircase-like" landscape between different segments (Figure 9).The Quriyat blind fault (suggested in this study) is possibly NE striking and located between segments 1 and 2, as revealed by the recent earthquake epicenters (Figure 9).This fault was probably active coevally with the Proto-Saih Hatat Dome uplift (late Cretaceous/early Cenozoic).The elevation profile between segments 1 and 2 (profile A-B) in Figure 9 has a steep topographic gradient across the blind fault.Other faults, such as the Daghmar and Dibab blind faults as part of the crustal-scale Ibra Fault (Figure 2; Weidle et al., 2022), were probably active after the mid-Eocene, separating the Segment 2 from the Segment 3.These faults are probably also active today as indicated by the low magnitude earthquake epicenters (Figure 9).The Daghmar elevation profile (C-D) across the blind fault shows a distinct "staircase-like" landscape, while in the Dibab area (E-F) this landscape is less discernible.However, in Figure 5, the Dibab fault and the derived landscape are obvious.The Qalhat Fault is the controlling factor of differential uplift between the Salma Plateau in the west (Segment 3) and the Sur Corridor (Segment 4) and Jabal Ja'alan-Batain area (Segment 5) in the east.The northwest-striking Ja'alan fault displays reverse kinematics, and its continuation marks the southwestern inland boundary of coastal uplift processes.The Ja'alan and Qalhat faults possibly regulated the tectonic activity even prior to the obduction of the Semail Ophiolite.However, today's geomorphology has been influenced by the reactivation of these faults during major Cenozoic tectonic events such as the Oligocene-Miocene (e.g., Corradetti et al., 2020;Fournier et al., 2006;Jacobs et al., 2015;Scharf et al., 2022).These major exposed faults are probably part of deep-seated fault sets striking NE/SW and NW/SE similar to other faults (Ibra Fault Zone and Frontal Range Fault Zone which strike NE/SW and Issmaiya Fault Zone and Wadi Mansah Fault Zone, which strike NW/SE).However, the above needs further investigation.These faults still show activity today as historically recorded earthquakes (Ermertz et al., 2019) and the recorded earthquake epicenters during the years 2000-2015 are revealing (Figure 9).They also exhibit a "staircase-like" landscape as it is shown in the elevation profiles I-J, G-H.Finally, the northeastern part of Segment 1 shows an accumulation of earthquake epicenters which were attributed to the Al Sifah fault, specifically identified by Moraetis et al. (2018).This is possibly the extension of the FRF fault (Mattern & Scharf, 2018) (Figure 9).
In summary, the uplift rates were higher from the late Pleistocene to Holocene (∼2 mm/a) compared to that of the pre-Pleistocene and are uniform in the Quriyat Corridor and Salma Plateau.However, the two areas reveal a striking difference in relief which is probably controlled by blind faults.The elevation contrast between the low-lying Quriyat Corridor and the raised Salma Plateau indicates that the uplift rate must have been largely heterogeneous prior to the late Pleistocene.This heterogeneity can also be observed today by InSAR uplift rates, demonstrating different uplift rates along the 150 km extent of the investigated area (Figures 7a-7l).The differentiation of uplift rates is related to the different fault (re)activations along the northeastern Oman coast.

Tectonic Model
The study area was already sheared by several major basement faults, such as the Qalhat, Ja'alan, and possibly the Quriyat, Daghmar and Dibab blind faults prior to the late Cretaceous obduction of the Semail Ophiolite (Figure 10a).The area from the Saih Hatat Dome (Segment 1), Quriyat Corridor (Segment 2) to Salma Plateau (Segment 3) has been affected by obduction with ∼16-km-thick allochthonous nappes (Peters et al., 2005; Figure 10b), which are still partly preserved west of the Salma Plateau.The dense and heavy load of the allochthonous nappes depressed the Arabian crust/mantle boundary, causing lateral and vertical displacement of the mantle.The Sur Corridor (Segment 4) and the Jabal Ja'alan-Batain area (Segment 5) were not affected by this obduction and possibly had an emerged landscape.The Qalhat Fault probably was a major fault, separating the undeformed/non-loaded ESE part of Oman from the deformed/loaded crust in the WNW.The Saih Hatat area, Quriyat Corridor and the future Salma Plateau (Figure 10c) were exhumed during and after the Semail obduction (e.g., Agard et al., 2010;Hansman et al., 2021;Searle et al., 2004).Rapid and major exhumation occurred during the latest Cretaceous to early Eocene and resulted in considerable removal of the allochthonous nappes from the Saih Hatat Dome and partly from the Quriyat Corridor and Salma Plateau (e.g., Hansman et al., 2017;Nolan et al., 1990; see also Figure 10c).The possible slab break-off at ∼80 to 55 Ma (e.g., Hansman et al., 2021;Rioux et al., 2016; see also Section 2) may have played an important role too.Thus, the load on the Arabian crust decreased rapidly from the late Cretaceous to early Cenozoic which led to a partial rebound of the viscoelastic mantle material and uplift of parts of the Oman Mountains, including the Saih Hatat Dome, Quriyat Corridor and Salma Plateau.Note that in the Saih Hatat area, exhumation also resulted in the return flow of subducted continental rocks within an exhumation channel (e.g., Hansman et al., 2021).
All areas between the Quriyat Corridor (Segment 2) and the Jabal Ja'alan-Batain area (Segment 5) showed distinct slow uplift and transgression during the Paleocene to mid-Eocene (Figure 10d).This led to the deposition of shallow-marine rocks at the margin of the Oman Mountains (Figure 10d; e.g., Mattern, Scharf, et al., 2021).Subsidence and deposition sheltered the allochthonous rocks from erosion.Crustal subsidence amounted to ∼2 km, mostly at the future Salma Plateau.
The whole of northeastern Oman (segments 1-5) was ultimately above sea level following the Oligocene-Miocene.
The presence of shallow-marine middle-late Miocene formations in the Quriyat Corridor and Sur Corridor suggests that the corridors were the last to be exhumed (Wyns et al., 1992a(Wyns et al., , 1992b)), which corroborates the idea of block-like uplift in northeastern Oman.Eastern Arabia was affected by deformation during the late Eocene to Miocene by two tectonic events (Corradetti et al., 2020;Fournier et al., 2006;Hansman et al., 2017;Scharf et al., 2019Scharf et al., , 2022)).Deformation triggered the reactivation of parts of the basement faults, which resulted in blocklike uplift of parts/segments of the Arabian crust, that is, the Salma Plateau (Figure 10e).

Uplift Mechanisms
The present results show that the exhumation of northeastern Oman was not terminated during Oligocene-Miocene tectonic events; it continued/resumed during the late Pleistocene.The Oligocene-Miocene tectonic events are well documented by thermochronology data and were due to convergence of the Arabian and Eurasian plates resulting in uplift of the Jabal Akhdar Dome (Corradetti et al., 2020;Grobe et al., 2018;Hansman et al., 2017;Jacobs et al., 2015) ∼30 Ma after completion of obduction.
Late Pleistocene uplift has also been observed in other areas of the Arabian Peninsula (Moraetis et al., 2018 and references therein).Ongoing uplift of the Salma Plateau is possibly linked to deformation with bending of the Arabian lithosphere related to the flexural forebulge formation during ongoing Arabia-Eurasia convergence (e.g., Rodgers & Gunatilaka, 2002;Yuan et al., 2016) and/or convergence between the Arabian and Indian plates since the Oligocene/Miocene (e.g., Fournier et al., 2006;Scharf et al., 2022).It has been discussed elsewhere (Kusky et al., 2005;Moraetis et al., 2018) that the uplift related to forebulge formation could have been as high as 500 m and possibly affected the Salma Plateau during the Pliocene.However, the forebulge cannot fully explain the 2,000 m uplift in the Salma Plateau and especially the observed uplifted terraces.Convergence may be responsible for the high uplift rates of the marine terraces.Alternatively, some uplift of marine terraces may reflect serpentinization and associated volume increase of ultramafic rocks (Ermertz et al., 2019;Hoffmann et al., 2020).However, this inferred weathering process is probably a minor factor on uplift rates because of the lack of ultramafic rocks subjacent in the northern Salma Plateau and the Quriyat Corridor, although there are There was no obduction of the Semail Ophiolite in the Batain area, which was a positive landscape.The major activity along the Qalhat Fault between the obducted and non-obducted margins.By the load of the allochthonous nappes, the Arabian lithosphere was depressed into the mantle.The mantle material flowed away from the depression.The subduction of continental rocks below the Saih Hatat area.(c) Oman as a passive margin, except for the Saih Hatat area.Immediately after obduction was completed, major denudation of allochthonous rocks took place, resulting in the elastic rebound of the lithosphere.Major uplift also ensued in the Saih Hatat area, related to return flow in a subduction channel, unrelated to the elastic rebound.(d) Paleocene to mid-Eocene tectonic quiescence and sea-level rise resulted in the deposition of shallow-marine rocks, mostly in the future Salma Plateau area, blanketing the allochthonous rocks, preventing their erosion and, thus, further uplift.The accumulation of shallow marine rocks in the Salma Plateau area may imply some subsidence during this period (slow, unspecified subsidence; Poupeau et al., 1998).(e) Late Eocene to present reactivation of some of the major faults lead to block-like uplift of the Salma Plateau and some uplift of the Saih Hatat area.Resumed erosion along the Salma Plateau (i.e., deep wadi incision during pluvial intervals) resulted in further and on-going uplift.
marine terraces exposed.Furthermore, magnetite (U-Th)/He dating within calcite veins yields an age of ∼15 Ma that crosscuts serpentinized peridotite from the Salma Plateau (Cooperdock et al., 2020).Thus, possible extensive serpentinization occurred prior to the Miocene.Moreover, there is no current evidence for serpentinization even at sites such as springs with high pH water, as is the case in other areas of Oman (Falk et al., 2016).The volume increase and concomitant uplift from serpentinization of the obducted oceanic lithosphere is unlikely to account for the recent uplift of the marine terraces.

Conclusions
We present the uplift history of a fault-segmented down-going margin of coastal eastern Oman.The relief evolution of the margin is evaluated through geological structures, age data and regional tectonic analysis.
Compartmentalization of eastern Oman is attributed to blind and major exhumed faults.These faults are deep-seated faults, which could be as old as the Pan-African continent formation and Pangea Rifting.In addition, the faults were active during and after the obduction of the Semail Ophiolite, accommodating loading and unloading of the Arabian crust by allochthonous rocks and facilitating differential uplift of the eastern Oman coastal region.The blind faults need further study.
The characteristic planation surface and marine terrace landscape in northeastern Oman are attributed to uplift of the down-going margin which postdates the late Eocene.The overall uniform uplift in the late Pleistocene (terraces 1-3) in the Quriyat Corridor and Salma Plateau may reflect a transient period which otherwise is heterogeneously distributed along the coastal area with a rate of ≥2 mm/a during the late Pleistocene and at a present-day average of 1.3 mm/a as calculated using InSAR measurements.The relief variability between the Quriyat Corridor and the Salma Plateau denotes the uplift rate of the Salma Plateau was higher compared to that of the Quriyat Corridor during the late Eocene to early Pleistocene.The ongoing subducting margin uplift is related to the reactivation of faults and the convergence of Arabia with the Eurasian and/or Indian plates.Euro-Maps 3D DSM-Level A data were generously provided by the European Space Agency within the CAT-1 research project ID 46575.We are truly grateful to the reviewers Dr. R. Hansman and the anonymous reviewer 2. We are also thankful to Dr. Gino de Gedler who accepted to be part of the authorship during the major review stage and who created the stacked swath profiles which significantly supported us in the identification of the uplifted marine terraces and uplift rates.We thankfully acknowledge Sarah Mattern who improved the English text.

Figure 3 .
Figure 3. Three topographic profiles from the Saih Hatat Dome to the Jabal Ja'alan-Batain area at different distances to the coast (a) 1 km, (b) 5 km, and (c) 25 km.Note the different scales.

Figure 4 .
Figure 4. Overview photograph of the study area between Daghmar and Dibab with terraces T3-T6.Salma Plateau (elevation >1,500 m) in the background.One doline is shown at the edge of terrace T6.

Figure 5 .
Figure 5. (a).Overview figure of marine terraces between Daghmar and Qalhat (Figure 1b) derived from the analysis of CartoSat Digital Surface Model.(b-e) Detailed maps as indicated in A. (f) Average elevation of the different terraces between Dagmar and Qalhat.(g) Average elevation of the different terraces from the NW to SE (zoom of F over the area between Daghmar and Bimma).The shaded region marks the approximate location of the Dibab blind fault.(h-l) The stacked swath terrace profiles (de Gelder et al., 2022) of the study area in A. Dashed lines denote that terrace is not clearly traced.

Figure 6 .
Figure 6.Schematic geological cross-section parallel to the northeastern coast of Oman from the Saih Hatat Dome to the Jabal Ja'alan-Batain Area.The vertical exaggeration in this cross-section is 23x.

Figure 7 .
Figure 7. Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) LoS displacement rates for the coastal area of Oman (08/2016-09/2019, ∼3 years), as adjusted based on geological uplift rate from in situ dating, the average uplift obtained by dating in the present study.(a) Initial motion rates.(b) Quadratic long-wavelength signal (regional trend).(c) Residual local motion determined by subtracting quadratic from initial estimates.The reference point (set at 2.3 mm/a) is marked by a black square.Displacement rates along profiles at (d) 1 km, (e) 5 km, and (f) 10 km parallel to the coastline.(g-k) Average InSAR ground displacement rates for the marine terraces from 2016 to 2019.(l) Changes in average displacement rates for each terrace (center of mass) by distance from Daghmar (considered as zero distance).Shaded regions correspond to the Dibab blind fault (Section 5.2).

Figure 8 .
Figure 8.Comparison of sample ages of the present study with other studies as well as sample locations of the present study.(a) Sample ages calibrated from the present study (green label), Moraetis et al. (2018; red label) and Hoffmann et al. (2020; blue label).Symbols refer to different dating methods.Different terraces are shown within different gray areas which also include the respective dated samples (Figures S14 and S15 in Supporting Information S1).Eustatic sea level was adopted following the Spratt and Lisiecki (2016) age calibration line.(b) Topographical survey of terraces T1-T6 with real-time kinematics from Daghmar to Dibab (Figure S1in Supporting Information S1).Circles are for samples analyzed using a petrographic microscope and triangles for samples that were dated.

Figure 9 .
Figure 9. Digital Elevation Model (30 m resolution) from open topography tool provided by QGIS-3.30.3-'s-Hertogenbosch.Major and blind faults are shown as depicted also on Figure 2. Black circles show the earthquake epicenters of 2000-2015 modified from Moraetis et al. (2018) (Richter scale magnitude 1-3).Elevation profiles A-B, C-D, E-F, G-H, I-J are across the Quriyat, Daghmar, Dibab blind fault, Qalhat and Ja'alan major exposed faults, respectively.Elevation profiles were generated using the profile tool in QGIS.

Figure 10 .
Figure10.Lithospheric-scale schematic depiction of the Cretaceous to present-day evolution of Oman's passive margin between the Saih Hatat Dome and the Batain area.(a) Oman as a passive margin with major pre-existing faults.(b) Oman as an active margin during obduction.There was no obduction of the Semail Ophiolite in the Batain area, which was a positive landscape.The major activity along the Qalhat Fault between the obducted and non-obducted margins.By the load of the allochthonous nappes, the Arabian lithosphere was depressed into the mantle.The mantle material flowed away from the depression.The subduction of continental rocks below the Saih Hatat area.(c) Oman as a passive margin, except for the Saih Hatat area.Immediately after obduction was completed, major denudation of allochthonous rocks took place, resulting in the elastic rebound of the lithosphere.Major uplift also ensued in the Saih Hatat area, related to return flow in a subduction channel, unrelated to the elastic rebound.(d) Paleocene to mid-Eocene tectonic quiescence and sea-level rise resulted in the deposition of shallow-marine rocks, mostly in the future Salma Plateau area, blanketing the allochthonous rocks, preventing their erosion and, thus, further uplift.The accumulation of shallow marine rocks in the Salma Plateau area may imply some subsidence during this period (slow, unspecified subsidence;Poupeau et al., 1998).(e) Late Eocene to present reactivation of some of the major faults lead to block-like uplift of the Salma Plateau and some uplift of the Saih Hatat area.Resumed erosion along the Salma Plateau (i.e., deep wadi incision during pluvial intervals) resulted in further and on-going uplift.

Table 2
Dating Results With Optical Stimulate Luminescence (OSL)