Regional thermochronology provides an important record of crustal exhumation through deep time. However, untangling the myriad of geodynamic, tectonic, climatic and surface processes responsible for long-term upper crustal cooling is often hindered by thermochronology data being conventionally interpreted in a static geographic framework. Here, we present a workflow for interpreting thermochronology data and thermal history models via integration with numerical plate tectonic, mantle convection, and paleoclimate reconstructions. Using a compilation of inverse thermal history models from Central Asia, based on fission-track and (U-Th)/He data, we demonstrate the power of placing thermochronology data in their paleogeographic context to untangle the geodynamic, tectonic and climate drivers of exhumation. This shows that the diachronous Mesozoic-to-recent (230-0 Ma) exhumation history of Central Asia was primarily controlled by reactivation of pre-Mesozoic crustal-scale shear zones in response to plate kinematics and Tethyan subduction dynamics, while dynamic topography and changes in paleoprecipitation played relatively insignificant roles.
Low-temperature thermochronology provides a powerful tool for constraining the thermal evolution of upper crustal materials over geological time. These radiometric dating methods are widely used to determine the timing and rate of geological processes that influence crustal thermal states. In some cases, thermal histories recorded by thermochronology can reflect conductive processes, such as geothermal gradient changes due to deep-seated batholith emplacement, localised heating from intrusions, or small-scale perturbations from lava flows and wildfires. In other rare cases, they record convective hydrothermal fluid or groundwater flow. However, in most cases, thermochronology data primarily document advective heat and mass transport driven by exhumation and burial from tectonic and surface processes.
In active deformation zones where geological context is well preserved, spatiotemporal patterns in thermal histories can be interpreted more readily. Jumps in apparent cooling ages across faults and along-strike trends in thermal histories can provide 4D exhumation chronologies diagnostic of different strain regimes and fault system evolutions. However, in older, highly deformed regions where the geological record is fragmented, determining exhumation drivers is challenging. In these cases, interpretations often rely on speculative links to broader-scale processes, including far-field tectonic stresses, dynamic topography, and climate-driven erosion.
In reality, long-term denudational cooling histories recorded by thermochronology data likely often reflect a combination of concurrently operating short wavelength tectonism (i.e., fault driven exhumation) and long wavelength geological processes (e.g., plate kinematics, dynamic topography, paleoclimate). To separate out the potential influence of long wavelength exhumation drivers, therefore, requires regional-scale spatiotemporal analysis to assess whether the distribution of detected periods of denudational cooling match what would be expected of these broad scale mechanisms.
The recent expansion of open-source geoscience modeling tools, notably the GPlates plate tectonic software, offers new opportunities to integrate thermochronology with global Earth system models. Numerical plate tectonic reconstructions capture the time-dependent evolution of lithospheric plates and their boundaries, in a global context, and can be tied to mantle flow, paleoclimate, paleogeography and landscape evolution models to simulate the dynamic Earth system. Yet, besides some rare exceptions, low-temperature thermochronology data are still routinely interpreted at the sub-regional scale in a static, present-day plate configuration. A key limitation has been the absence of open access thermochronology databases and integrated modeling workflows.
With the advent of the first geospatial relational thermochronology database, a shift toward global-scale thermochronology modeling is now feasible. Here, we introduce an integrated workflow combining regional thermochronology with plate reconstructions, mantle convection models, and paleoclimate simulations, using the EarthBank platform (previously AusGeochem) and GPlates. This methodology enables thermochronology datasets to be analysed in their tectonic, geodynamic, and climatic contexts through deep time, and can be extended to incorporate additional datasets such as fault databases and paleotopography models.
To demonstrate this approach, we analyse a compiled dataset of 381 published thermal history models from Central Asia, based on apatite, zircon and titanite fission-track analyses and (U-Th)/He dating of apatite and zircon (Fig. 1). We define the Central Asia study area by the density of published thermochronology data and thermal history models north of the Pamirs, stretching from Central Uzbekistan, Siberia and Mongolia to the west, north and east. There, at the heart of Central Asia, the Tian Shan and Altai mountains formed diachronously through multi-stage tectonism since the Mesozoic, yet debate persists over the precise timing and geodynamic drivers of their evolution. While exhumation has been linked to distant Eurasian margin collisions, culminating in India-Eurasia convergence, other factors such as tectonic inheritance, subduction dynamics, dynamic topography, and paleoclimate variations have also been proposed. However, isolating these superimposed processes remains a challenge.
The tectonic framework of Central Asia was established in the Late Paleozoic with the formation of the Central Asian Orogenic Belt, which subsequently influenced Meso-Cenozoic deformation and topographic evolution (Fig. 2). By the Early Permian, northward subduction of the Paleo-Tethys Ocean began along the southern Eurasian margin as the Cimmerian blocks (e.g., Qiangtang, Lhasa) rifted off Gondwana and migrated northwards, opening the Meso-Tethys Ocean. The Late Triassic-Early Jurassic Cimmerian Orogeny marked the accretion of these blocks and the closure of the Paleo-Tethys (Fig. 2c), reactivating Paleozoic structures and driving Central Asian crustal exhumation, particularly in the Tian Shan. A prolonged tectonic quiescence followed from the Early-Middle Jurassic into the Cretaceous, characterised by widespread erosion and planation, though the precise timing remains uncertain.
In the Early Cretaceous, the Meso-Tethys Ocean was closed with the accretion of the Lhasa Block (Fig. 2d), though this had minimal impact on the nearby Tian Shan, where deformation was subdued. Meanwhile, the Mongol-Okhotsk Ocean separating Siberia and Mongolia was gradually closing, with paleomagnetic and sedimentary evidence suggesting final closure in the Late Jurassic-Early Cretaceous (Fig. 2e). This was followed by localised Late Cretaceous denudational cooling, interpreted as the onset of extension in the proto-Baikal Rift. While orogenic collapse of the Mongol-Okhotsk Orogen has been proposed as a driver, the lack of Jurassic-Cretaceous metamorphism and coarse clastic sediments suggests minimal deformation and uplift associated with ocean closure. Alternative mechanisms include slab rollback of the Paleo-Pacific plate, Mongol-Okhotsk slab break-off, and mantle upwelling. Major Baikal Rift development did not begin until the Oligocene-Miocene, with a subsequent rapid rifting phase and relief building in the Late Pliocene.
During the Cretaceous (~80-70 Ma), Neo-Tethys subduction along the southern Eurasian margin led to the accretion of the Karakoram Block to the Pamir region (Fig. 2). The Neo-Tethys ultimately closed in the Paleogene with India-Eurasia collision, though its exact timing remains debated. Some propose an early-mid Paleogene onset or 'soft' collision, citing a sudden convergence slowdown (Fig. S1) linked to the accretion of intra-oceanic arc systems (Fig. 2f). Others argue for a later ~35-34 Ma 'hard' collision based on the age of the youngest marine sediments, cessation of subduction-related magmatism, and thrust development (Fig. 2g).
Low-temperature thermochronology has been widely used to reconstruct Central Asia's complex Mesozoic-to-Recent geodynamic and exhumation history. These temperature-sensitive radiometric techniques rely on the retention of radiogenic daughter products as a function of time, temperature, cooling rate, and crystal chemistry. The most commonly applied thermochronometers -- apatite fission-track and (U-Th)/He systems -- are sensitive to temperatures of ~120-60 °C and ~80-40 °C, respectively, typically recording exhumation through the upper 1-5 km of the crust. The time-temperature histories these data record are then often quantified via thermal history modeling.
However, interpreting Central Asian exhumation histories remains challenging due to the spatial variability of cooling rates (Fig. 1) and the limited sensitivity of thermochronology to short-wavelength topographic relief. Thermal history models capturing rapid cooling (>0.5 °C/Ma, see Methods; Fig. S2) over the last 230 Ma show no clear spatial trends (Figs. S3, Videos S1-S4) and are highly localised (Fig. 1), interspersed with slower-cooling samples. The wide range in AFT ages (3-360 Ma) suggests some areas have undergone less than ~4 km of exhumation since the Late Paleozoic, with Tertiary exhumation concentrated near major faults.
Consequently, various processes have been proposed to explain Central Asia's diachronous exhumation since the Triassic, including prolonged subduction and collision along the Eurasian margin, back-arc extension, mantle dynamics, shear zone reactivation, and paleoclimate-driven denudation.
In this study, we integrate thermochronology-derived cooling histories with global plate reconstructions, mantle convection models, and paleoclimate simulations, to disentangle the geodynamic and climatic drivers of key Mesozoic-Cenozoic exhumation events in Central Asia, providing new insights into the long-term evolution of continental interiors.