A database of detrital zircon U–Pb ages and Hf isotopes for the Middle East (Iranian and Arabian plates)

The detrital zircon records significant information in the ‘source‐sink’ system. With the application of in situ laser ablation technology, a large number of high‐quality detrital zircon data have been published since 2000. In this study, a total of 41,342 detrital zircon U–Pb ages and 6,129 Hf isotopes were compiled from the published literatures of the Middle East (Iranian and Arabian plates). Through data filtering and recalculation, valid data were employed for further analysis. The detrital zircons from the Middle East show a Cambrian–Precambrian age population of 500–1,000 Ma, with a major age peak of ~620 Ma and dispersed εHf(t) values of −35 to +20. The Alborz Mountains and central Iran terrane show a Permo–Triassic age range of 200–300 Ma. The Mesozoic–Cenozoic detrital zircons are mostly occurred in the Zagros orogenic belt and Makran accretionary complex, with three obvious age ranges of 145–180 Ma, 80–110 Ma and 15–65 Ma. The Mesozoic zircons yield positive εHf(t) values, while Cenozoic zircons have varied εHf(t) values. This database allows for the further exploration of the provenance analysis and application in constraining the timing of the major tectonic events in the Middle East, and may also help to explore the affinities of plates, thus guiding future palaeogeographic research efforts.


| INTRODUCTION
The Middle East (Iranian and Arabian plates), connected the Alpine and Himalayan-Tibetan orogenic belts, is fundamental to understand the breakup of the supercontinent and the tectonic evolution of the Tethys Ocean (Muttoni et al., 2009;Seber et al., 1997;Takin, 1972).With the breakup of the Gondwanaland in the southern hemisphere, a series of terranes has split and drift to amalgamation to the north (Sengör, 1987).Given the limited studies in the Middle East, some fundamental problems remain controversial (Agard et al., 2005(Agard et al., , 2011;;Alavi, 2004), concerning the timing of collision events, affinity and nature of the terranes and palaeogeographic reconstruction.
The detrital zircon, mostly from the clastic sedimentary rock, represents one of the most stable accessory mineral, which is well employed in the application of provenance analysis, palaeogeographic reconstruction and basin analysis.Based on the comparison of the age kernel density estimate (KDE; Vermeesch, 2012), or a cumulative age probability diagram (Gehrels, 2011) between the source and sink, the similar age patterns (age peaks and troughs) demonstrate the sedimentary records can be comparable with the corresponding magmatic records (Condie et al., 2009;Hawkesworth et al., 2010).Moreover, the diagram of multidimensional scaling (MDS) statistical analysis for a large number of detrital zircons helps to contrast the similarity of the age groups and further demonstrates the provenance (Vermeesch, 2013;Vermeesch & Garzanti, 2015).Besides of the zircon U-Pb ages, in situ zircon Hf isotopes provide additional information on the provenance discrimination (e.g., Chu et al., 2006;Wu et al., 2010).Recently, a large number of published detrital zircon U-Pb ages and Hf isotopes from the Middle East, especially the Zagros orogenic belt (Horton et al., 2008;Koshnaw et al., 2021), provide a valuable dataset for further study on the varied tectonic problems in the Middle East and surrounding regions.
In this paper, a total of 41,342 detrital zircon U-Pb ages and 6,129 Hf isotopes were compiled from 60 and 22 literatures respectively.The detrital zircon U-Pb ages were processed by data filtering and the Hf isotopes were recalculated with the decay constant value for 176 Lu (Scherer et al., 2001).The goal of this paper was to present the detrital zircon characteristics of the different terranes from the Iranian and Arabian plates.All these available data would be employed for the regional provenance analysis, palaeogeographic and tectonic reconstruction in the future.

| GEOLOGICAL SETTING
The Iranian plate can be roughly divided into four tectonic units according to the different evolutionary history and depositional records, including the Alborz Mountains, central Iran terrane, Makran accretionary complex and Zagros orogenic belt (Figures 1 and 2).

| Alborz Mountains
The Alborz Mountains extend over 1,200 km along the southern coast of the Caspian Sea from west to east (Figure 1).They are mostly composed of Late Neoproterozoic-Mesozoic sedimentary and volcanic successions with a few Paleozoic-Pleistocene intrusive plutons and dikes (Figure 2, Stöcklin, 1974;Axen et al., 2001).The sedimentary strata include late Neoproterozoic to Early Cambrian siliciclastic and carbonate-dominated sequences, Ordovician to Silurian siliciclastic rocks and voluminous mafic volcanic rocks, Devonian to Triassic thick carbonate and siliciclastic rocks and Late Triassic to Jurassic fluvial siliciclastic rocks (Berberian & King, 1981).

| Central Iran terrane
The central Iran terrane is bounded by the Alborz Mountains to the north and the Zagros orogenic belt to the south and west (Figure 1).It has a Precambrian basement with Gandwanan affinity.The overlying covers include the Cambrian-Ordovician sedimentary rocks and Devonian-Carboniferous intrusive plutons.These Palaeozoic units are covered by the Upper Palaeozoic-Neogene sedimentary successions (Azizi et al., 2011;Bea et al., 2011;Mohammadi et al., 2022;Saccani et al., 2013), which are composed of the Permo-Triassic shallow-water limestones, Jurassic siliciclastic sandstones and the Upper Cretaceous-Eocene wellbedded, carbonate-rich terrigenous sandstones and shales (Mohammadi et al., 2022).The Oligocene-Miocene sedimentary and volcanic rocks unconformably overlie these sequences (Figure 2, Mohammadi et al., 2022).

| Makran accretionary complex
The Makran accretionary complex in the southeast of Iran, accumulated mostly Cenozoic deposits with minor Mesozoic clastic sequence (Figure 2).It is subdivided into four major E-W extending zones from north to south: North Makran, Inner Makran, Outer Makran and Coastal Makran (Dolati, 2010).They are mainly composed of the Cenozoic clastic rocks (Dolati, 2010;Mohammadi et al., 2016).
The UDMA is a NW-SE extending linear magmatic belt along the south of central Iran terrane, and is mostly composed of the Eocene-Oligocene (ca.55-25 Ma of flare up) calc-alkaline magmatic rocks and volcano-sedimentary rocks (Berberian et al., 1982;Chiu et al., 2013).The SSZ, located to the south of the UDMA, consists mainly of metamorphosed and complexly deformed rocks, spatially associated with a number of Mesozoic to Cenozoic granitoid intrusions resulted from the northward subduction of Neo-Tethys oceanic crust (Berberian & King, 1981;Zhang et al., 2018).The ZFTB, including the High Zagros belt and Zagros simply folded belt (Figure 1, Berberian & King, 1981), is mostly composed of the radiolariteophiolite complexes, thrust sheets rooted from the SSZ F I G U R E 2 Upper Neoproterozoic-Cenozoic stratigraphy of the Iranian and Arabian plates (after Berberian & King, 1981;Ghorbani, 2019).The Formations are showing the compiled samples.

| Arabian plate
The Arabian plate is bounded by the Red Sea Rift to the southwest and the Zagros orogenic belt to the northeast (Figure 1).It was generated by the accretion of continental microcontinents and arc terranes during the Neoproterozoic (~600-900 Ma Pan-African orogeny, Stern, 1994;Meert, 2003).Above the Neoproterozoic basement, the Arabian plate was a stable passive margin, including the Cambrian to Permian terrestrial-marine deposits (Stern & Johnson, 2010).The Mesozoic and Cenozoic clastic and carbonate rocks were accumulated in the east and north margin of the Arabian plate (Garzanti et al., 2013;Nairn & Alsharhan, 1997).Besides, the active dune fields (~70, 000 km 2 ) cover nearly one-third of the Arabian Peninsula, represented by the Great Nafud in the north and the Rub' al-Khali in the south (Garzanti et al., 2013).

| Overview of the dataset
The detrital zircon U-Pb age and Hf isotopic data were compiled from the published literatures, the data of which are mainly derived from the Alborz Mountains, Central Iran terrane, Makran accretionary complex, Zagros orogenic belt and Arabian plate (Figure 1), geographically including Iran, Syria, Lebanon, Jordan, Israel, Iraq, Saudi Arabia, The United Arab Emirates, Yemen and Oman.
A total of 41,342 detrital zircon U-Pb ages of 444 samples have been compiled from 59 papers and one thesis for the dataset of this study.Among these publications, 44 literatures have been published since 2015, while the other 16 papers were between 2000 and 2014.A total of 6,129 Hf isotopes from 148 samples have been collected from 22 literatures.The strata where these samples were collected vary from the Precambrian to Quaternary (Figure 2).The major lithology of these samples is sandstones and modern sands, which account for nearly 80% of the total samples.Other lithologies also include conglomerate, mudstone and metasedimentary rocks (i.e.schist and metasandstone).Vermeesch, 2018).The KDE and MDS diagrams were employed for zircon U-Pb age displaying (Figures 3-5).

| Central Iran terrane
A total of 40 samples from Central Iran terrane are mostly from the Eocene-Oligocene continental deposits (e.g., Qom Formation), and secondly from the Cambrian and

| Makran accretionary complex
A total of 42 samples compiled from the Makran accretionary complex mostly belong to the Oligocene-Miocene sedimentary sequence, with five samples from the Triassic and Cretaceous strata (Figure 2).A total of 6,169 zircons yield concordant U-Pb ages based on 6,645 published zircons.~66% of zircon ages are less than 200 Ma and yield the age ranges of 30-110 Ma (peaking at ~45 Ma, and 85 Ma), and 150-180 Ma (peaking at ~170 Ma).The εHf(t) from these two age clusters yield different features, referring to the most positive values (+4.0 on average, ranging from −18.5 to +22.0) for ages of 30-110 Ma, while negative values (−6.2 on average, ranging from −27.0 to −2.2) for clusters of 150-180 Ma.The other ~34% zircons yield scattered age distributions, with small age peaks at ~510 and ~800 Ma (Figure 3).

| Arabian plate
A total of 150 samples of the Arabian plate are from the Precambiran basement, the Cambiran-Ordovician Saq, Sanamah, Dibsiyah, Qasim, and Zarqa, the Devonian Tawil, Jubah, and Khusayyayn, the Carboniferous-Permian Juwayl and Unayzah formations (Figure 2), which show similar age distributions with the ages more than 500 Ma.In detail, a total of 8,518 detrital zircons The multidimensional scaling (MDS) statistical analysis of detrital zircon U-Pb age spectra from the different tectonic divisions in the Middle East (Spencer & Kirkland, 2016).

| A summary of the results
The compiled detrital zircons of this study from Iran and Arabia show a similar Cambrian-Precambrian age range of 500-1,000 Ma, with a major age peak at ~620 Ma.The corresponding εHf(t) values disperse widely from −35 to +20 (Figure 3).The Permian-Triassic detrital zircons are common in the Alborz Mountains and central Iran terrane with the age probability of 200-300 Ma (peaking at ~250 Ma) (Figure 3).The Late Mesozoic-Cenozoic detrital zircons are widely distributed in the Zagros orogenic belt.The SSZ is characterized by the Jurassic zircons (age ranges of ~145-180 Ma), with mostly positive εHf(t) values, which also occurred in the deposits of the ZFTB and Makran accretionary complex.Another obvious ~80-110 Ma age cluster is locally appeared in the ZFTB and Makran accretionary complex (Figures 3 and 4).This group of detrital zircons is featured as the positive εHf(t) values feature, indicating the depleted mantle source.The Cenozoic zircons (age range of 15-65 Ma) are widely observed in the Zagros orogenic belt and Makran accretionary complex, and also sporadically appeared in the Alborz Mountains (Figures 3 and 4).

| POTENTIAL DATASET APPLICATION
A lot of studies have been conducted to constrain the tectonic evolution of the Tethyan Oceanin the Middle East by the detrital zircons (Barber et al., 2018;Cai et al., 2021;Horton et al., 2008;Koshnaw et al., 2019;Zhang et al., 2017).The detrital zircons from the Arabian plate distinctly yield the Pan-African zircon age features, showing age clusters of 500-850 Ma and 900-1,100 Ma, while lacking the Mesozoic-Cenozoic zircons.Instead, the detrital zircons from the Iranian plate (i.e.SSZ, UDMA, central Iran terrane) yield abundant Mesozoic-Cenozoic U-Pb ages, indicating the significant age ranges of 15-65 Ma and 80-150 Ma, which were formed during the subduction of the Neotethys oceanic crust and the subsequent Arabia-Iran collision (Chiu et al., 2013(Chiu et al., , 2017;;Zhang et al., 2018).The MDS diagrams for the different tectonic divisions of this study indicate that the Zagros orogenic belt, central Iran terrane and the Makran accretionary complex have comparable sources, while the Alborz Mountains and Arabia could share similar provenance (Figure 5).Based on these plenty of detrital zircon U-Pb ages and Hf isotopes published, this dataset can be potentially used in the provenance analysis in the basin deposits and the palaeogeographic reconstruction in the Middle East, and then further in constraining the timing of the major tectonic events, such as the affinities of plates, opening and closure of the Tethyan Ocean and the Arabia-Eurasia initial collision.
The statistics for numbers of detrital zircon data items from the Middle East in this study.
There are at least two ages ( 206 Pb/ 238 U or207Pb/ 206 Pb) reported for each zircon; however, the choice for the 'best age' is different from literature by literature.Based on the original published data we collected, a unified criterion of 'best age' is defined by assessing the concordance between 206 Pb/ 238 U and 207 Pb/ 206 Pb ages.The 206 Pb/ 238 U age for single zircon grain younger than 1,200 Ma and 207 Pb/ 206 Pb age older than 1,200 Ma are applied in the 'best age' picking.The concordance calculation of the age is applied by the formulas of ( 207 Pb/ 206 Pb age -206 Pb/ 238 U age)/ 207 Pb/ 206 Pb age for the zircons >1,200 Ma, and ( 206 Pb/ 238 U age -207 Pb/ 235 Pb age)/ 206 Pb/ 238 U age for the ages <1,200 Ma.The age with discordance <30% is included for further analysis and displaying.The εHf(t) values were recalculated on the original Hf isotopes by the initial 176 Hf/ 177 Hf ratio of 0.282772 and 176 Lu/ 177 Hf of 0.0332 (Blichert-Toft et al., 1997).The decay constant value of 1.865 × 10 −11 year −1 for 176 Lu reported by Scherer et al. (2001) was used.The results are displayed in the diagram with εHf(t) values versus corresponding U-Pb ages (Figures 3 and 4).All original and filtered data were uploaded at the Deep-time Digital Earth (DDE) Big Science Program (doi: 10.12297/dpr.dde.202211.4;https://repos itory.deep-time.org/detai l/15884 10678 03788 4930).The numbers of data items are listed in Table 1.The detrital zircon U-Pb ages of each group were input into the IsoplotR (online version, https://www.ucl.ac.uk/~ucfbp ve/isopl otr/home/,