The eastern flank of the tropical Northern Andes (0.5–3.5°N) is characterized by variations in tectonic style due to strain partitioning, and thus an ideal setting to explore how along‐strike differences in rock uplift rate scale with relief and elevation. Here we quantify erosion and topography and their relationship along the Eastern Cordillera using new cosmogenic nuclide data, previously published thermochronology data, and topographic metrics. We found higher median cosmogenic nuclide‐derived erosion rates along the southern and northern sections of the study area (∼600 m/Myr) compared to the central part (∼140 m/Myr). The same trend is observed in erosion rates derived from thermochronology data, with values of 360 m/Myr in the south and north, and 160 m/Myr in the central zone, indicating that erosion patterns have remained constant since at least Pliocene times. Spatial variations in erosion rate correspond to changes in structural style due to strain partitioning; high erosion rates in the north and south are associated with dominant reverse faulting, while lower erosion rates in the central region coincide with dominant strike‐slip deformation. Cosmogenic nuclide erosion rates and channel steepness follow a power law relationship with a slope exponent n = 2.2—corresponding to a high sensitivity of erosion to channel steepness. This nonlinear‐scaling between erosion and topography derived from local erosion data is consistent with along‐orogen differences in channel steepness index, fluvial relief, and maximum elevation. Erosion rates in the northern and southern zones are ∼4.3 times higher than those in the central zone, but topographic metrics such as channel steepness, maximum elevation and fluvial relief are only ∼1.2–1.8x greater. This suggests that high sensitivity of erosion to channel steepness, likely caused by incision thresholds combined with steady river discharge, limits along‐orogen differences in relief along the Northern Andes.

Erosion rates are widely used to assess tectonic uplift and sediment export from mountain ranges. However, the scarcity of erosion rate measurements often hinders detailed tectonic interpretations. Here, we present 25 new cosmogenic nuclide-derived erosion rates from the Northern Andes of Colombia to study spatio-temporal patterns of uplift along the Central and Eastern Cordillera. Specifically, we combine our new and published erosion rate data with precipitation-corrected normalized channel steepness measurements for building high-resolution erosion rate maps. We find that erosion rates in the southern Central Cordillera are relatively uniform and average ~0.3 mm/a, whereas rapidly eroding canyons dissect slowly eroding, low-relief surfaces in the northern Central Cordillera. We interpret that long-term, steep slab subduction has led to an erosional steady-state in the southern Cordillera Central, whereas in the northern Cordillera Central, Late Miocene slab flattening caused an acceleration in uplift, to which the landscape has not yet equilibrated. The Eastern Cordillera also displays pronounced erosional disequilibrium, with a slowly eroding central plateau rimmed by faster eroding western and eastern flanks. Our maps suggest recent topographic growth of the Eastern Cordillera, with deformation focused along the eastern flank, which is also supported by balanced cross-sections and thermochronologic data. Spatial gradients in predicted erosion rates along the eastern flank of the Eastern Cordillera suggest transient basin-ward migration of thrusts. Finally, using our erosion maps to infer millennial-scale sediment fluxes, we find that the Eastern Cordillera exports nearly four times more sediment than the Central Cordillera. Our analysis shows that accounting for spatial variations in erosion parameters and climate gradients reveals important variations in tectonic forcing that would otherwise be obscured in traditional river profile analyses. Moreover, given relationships between tectonic, and topographic evolution, we hypothesize that the dynamic landscape evolution of the Northern Andes revealed by our erosion maps is mostly linked to spatio-temporal variations in slab dip with potentially superposed effects from inherited Mesozoic rift structures.

The stable isotopic composition of pedogenic carbonates is central to many studies of past climate and topography, providing a basis for our understanding of Earth's terrestrial history. A core assumption of many applications of oxygen isotope values (δ18O) of pedogenic carbonate is that they reflect the δ18O value of precipitation (rain/snow). This assumption is violated if soil carbonates form in evaporated soil waters. In this work, we develop a means to identify evaporation in ancient soils using the triple oxygen isotope composition (16O-17O-18O) of pedogenic carbonates. Both theoretical predictions of isotope kinetics during evaporation and studies of triple oxygen isotopes in other geological materials show that the deviation in the relationship between δ17O and δ18O from a reference line, evaluated using the parameter Δ′17O, is sensitive to evaporation. As a first step in developing the use of Δ′17O in ancient pedogenic carbonates, we report Δ′17O values from 47 near-modern pedogenic carbonate samples from globally distributed environments that vary in aridity (hyper-arid to humid). The Δ′17O values of pedogenic carbonate range from −154 to −60 per meg (as CaCO3, measured via O2, VSMOW-SLAP), corresponding to calculated soil water values of −66 to +27 per meg (VSMOW-SLAP) (using a carbonate-water triple oxygen isotope fractionation exponent of 0.5250 and clumped isotope-derived carbonate growth temperatures). The Δ′17O values indicate that evaporative modification of soil water from which pedogenic carbonate forms is common, especially in arid environments. Arid environments host pedogenic carbonates formed from soil waters ranging from highly to minimally evaporated, while humid environments host pedogenic carbonates formed from waters that are only minimally evaporated. The variability in Δ′17O within environments classified by the same aridity may relate to the fact that pedogenic carbonates record soil conditions only during times of carbonate mineralization, which may deviate from annual conditions. Thus, Δ′17O may be useful in understanding the specific circumstances of pedogenic carbonate formation but may not provide incontrovertible evidence of the magnitude of environmental aridity. Evaporative modification of δ18O values of pedogenic carbonates can be detected with Δ′17O, thereby improving estimates of δ18O of unevaporated waters. Our data show that evaporation must be (re)considered for all paleoclimate inferences based on the δ18O of pedogenic carbonate. The addition of Δ′17O will re-energize paleoclimate studies that use (or have avoided using) δ18O of pedogenic carbonate.

Uplift of the Tian Shan range modified regional climate during Cenozoic aridification in Central Asia. This study presents facies analyses and Neogene oxygen and carbon isotopic records from magnetostratigraphically dated terrestrial sedimentary sections on the southern side of the intermontane Issyk‐Kul basin in the Kyrgyz Tian Shan and 26 Al/ 10 Be isochron burial ages from the southern and eastern sides of the basin. The δ 18 O and δ 13 C data show a positive ca. 2‰ shift in values between ca. 8 and 7 Ma and a change from a negative to a positive trend. This change is attributed to the upwind growth of the Kyrgyz, Kungey and Trans Ili (Zaili) ranges, which diverted the westerlies, thereby changing the Issyk‐Kul basin from a windward to a leeward position, enhancing aridification and establishing the modern‐day spring and summer precipitation regime within the basin. Two 4 to 5 Ma 26 Al/ 10 Be isochron burial ages constrain the onset of Sharpyl Dak deposition on the eastern side of the basin; southward paleocurrent directions there suggest the eastward growth of the Kungey range in the Pliocene. Increased subsidence on the southern side of the basin and local tectonically induced river system reorganization led to the commencement of lake formation at ca. 5 Ma, followed by a ca. 2 Ma local depositional hiatus. The transition from sandstones of the Chu sedimentary group to conglomerates of the Sharpyl Dak group, marking a change from fluvial‐alluvial deposits to a proximal alluvial fan, is dated at 2.6–2.8 Ma by 26 Al/ 10 Be isochron burial dating on the southern side of the basin, driven either by tectonics or Northern Hemisphere glaciation. This study concludes that the late Miocene–Pliocene northward growth of Tian Shan significantly altered environmental conditions within the range, preventing the moisture‐bearing westerlies from reaching the intermontane Issyk‐Kul basin and promoting lake formation and expansion.

The fluvial network in active mountain ranges is considered to evolve from longitudinal to transverse-dominated drainage systems. This hypothesis links to the forelandward migration of the orogen, while crustal thickening modifies the range's flank slopes, enhancing erosional efficiency. We probe such a proposition with new empirical observations from the Colombian Andes by studying the recent capture of the longitudinal Su ' arez and Chicamocha Rivers by the transverse Sogamoso River. Firstly, by integrating published low-temperature ther-mochronology and quantitative topographic metrics like chi, we found that rejuvenated rock uplift in the Cocuy and Yariguies ranges delays the transition from longitudinal to transverse-dominated drainage systems by compensating the across-divide contrasts in erosion. To further constrain the spatiotemporal response of the Su ' arez and Chicamocha Rivers after the discrete capture, we computed sediment-gauge erosion rates in conjunction with rainfall-normalized channel steepness and Gilbert metrics. We observe stark contrasts in erosion rates between the Chicamocha (maximum of 148.22 +/- 44.86 m/Myr) and Su ' arez Rivers (maximum of 71.9 +/- 21.5 m/Myr). Higher erosion rates in the former are expressed with widely distributed slope-break knickpoints that migrated further upstream with catchment expansion at the expense of the less efficiently erosive Su ' arez River basin. We interpret these erosional differences as a lithological control on the pace of topographic response to an external perturbation (discrete capture), given low-lying sedimentary rocks delay the erosional response of the Su ' arez River basin. Our research therefore emphasizes the role that lithology poses in keeping the landscape in an unsteady topographic condition.

Paired in situ cosmogenic nuclides 14 C and 10 Be present an opportunity to explore erosion rate disequilibria over Holocene to latest Pleistocene timescales and are a new avenue in surface processes research. 14 C and 10 Be concentrations in quartz from river sand collected at the outlets of five mountainous catchments in the Argentine Andes are compared in this study. River gauge and 10 Be‐derived erosion rates are in good agreement; however, 14 C concentrations are approximately 2.7–4 times lower than expected relative to 10 Be under steady‐state erosion. Low 14 C to 10 Be ratios imply that sediment eroded from the high mountains was shielded for at least 7–15 ky. Neoglacial advances and storage in terraces may account for some of the reduced 14 C concentrations but are insufficient alone. Transient storage in dynamic talus slopes in the steep topography of the High Andes provides the best explanation for the observed 14 C concentrations.

Regulatory agencies routinely assess the presence of stray gas release from unconventional gas wells by sampling for methane in nearby groundwater after the well is drilled or if citizens complain about methane in their water. We studied whether methane concentrations in groundwater naturally vary through time in a shale gas basin where unconventional development and hydraulic fracturing has not yet occurred, to test the assumption that pre-drilling observations of well water quality can be reliable measures for assessing impacts of later gas drilling. We collected groundwater samples from 11 domestic wells in New York monthly for 13 months for methane and ion concentrations in a highly gas productive part of the Appalachian basin where fracking has been banned. Changing methane concentrations correlated with changes in chloride and bromide, indicating changing mixtures of shallow freshwater and deeper formation brine extracted by the wells through time. The hydrogeologic setting of a water well can cause variability in methane concentrations that may mimic stray gas but cannot be attributable to gas drilling. For this reason, before and after testing has limited utility to distinguish impacts of gas drilling from other causes of changing methane concentrations unless that testing includes sampling a comprehensive set of ions multiple times prior to drilling.

Las interacciones -clima-tectónica pueden dar lugar a cambios topográficos significativos tanto por aumentos en la elevación como por el incremento de pendientes. Estos cambios, en conjunción con la acción de la gravedad suscitan a su vez diferencias en la energía potencial de materiales geológicos (rocas, agua, etc.) desencadenando procesos geomórficos importantes tales como la erosión por agua, tanto laminar como concentrada, y los movimientos en masa En la vía Bogotá-Villavicencio en el kilómetro 58 del municipio de Guayabetal, se han presentado numerosos fenómenos de remoción en masa. La presente investigación explora como operan las interacciones entre el clima y la tectónica como procesos controladores del relieve actual a corto y largo plazo sobre la zona de estudio. Con esta finalidad se compilaron edades termocronológicas existentes en la zona, y se generó un modelo directo termocinemático 3D para estimar los pulsos y las tasas de exhumación. Los resultados de este último sugieren 3 pulsos de exhumación: el primero entre 40 Ma - 25 Ma a una tasa de exhumación de 0,5 km/Ma, seguido de un pulso entre 25 Ma - 15 Ma con una tasa de 0,1 km/Ma, y finalmente, desde 15 Ma al presente tasas de ~2 km/Ma. Adicionalmente, datos de precipitación fueron utilizados para estimar atributos primarios y secundarios del terreno, mientras que los datos de sismicidad instrumental fueron empleados para calcular la deformación sísmica, energía sísmica y levantamiento vertical por deformación sísmica. Las distintas variables fueron comparadas estadísticamente. Se concluye que el paisaje actual de la zona no es afectado uniformemente por la tectónica y las precipitaciones. En el noroccidente del área existen bajas tasas de erosión y actividad tectónica, así la evolución del paisaje es más pasiva, y el relieve es controlado por el patrón de precipitaciones. En contraste, hacia el suroriente específicamente entre macizo de Quetame y el piedemonte llanero, el relieve es controlado por la tectónica presente en el área. El efecto antrópico con las modificaciones al paisaje introducidas por la creación de una vía nacional, aunque es importante no fue analizado en la presente investigación.

We present two carbonate oxygen and carbon isotope records from late Miocene – early Pleistocene stratigraphic sections from the southern flank of the Issyk Kul basin, Kyrgyz Tien Shan. The two sections are 700 and 500 m thick and composed of fluvial and lacustrine sediments. They were dated using magnetostratigraphy (Roud et al., G-Cubed, in review) and 26Al/10Be isochron burial dating (presented here). Carbonate stable isotope data is useful for reconstruction of climate in Asia over the Cenozoic. Oxygen isotopes are commonly used to detect moisture sources and their interaction with topography. Pedogenic carbon isotopes are used to reconstruct past atmospheric CO2 levels or the spread of C4 vegetation. The environment of Central Asia is primarily affected by the northern mid-latitude westerlies − winds transporting moisture eastward across Eurasia. Issyk Kul basin is situated on the windward side of the northern Tien Shan. Published data suggest that the Tien Shan mountain ranges interacted with the westerlies since late Oligocene and reorganized Central Asian climate during Neogene (Caves et al., 2017; Charreau et al., 2012; Macaulay et al., 2016; Wang, et al., 2020). The amount of existing published paleoclimate data from northern Central Asia is scarce compared to interior China, and therefore the influence of the Tien Shan uplift on climate in Asia during the Cenozoic is poorly reconstructed. Our data provide new insight into the role of the range and its interaction with the westerlies in forming climate on the windward side of the northern Tien Shan in the late Neogene. We combine our data with published stratigraphically-older sections nearby (Macaulay et al., 2016) to complete the Neogene stable isotope record of the Issyk Kul basin and study how the evolution of the basin influenced regional climate. Our d18O and d13C values show slightly positive trends, unlike stratigraphically-older data from the Issyk Kul basin. The preliminary interpretation suggests that the circulation pattern within the range was changed in late Miocene possibly reflecting active tectonic uplift northward of the basin and an increase in aridification.

The tropical Northern Andes of Colombia are one the world's most biodiverse places, offering an ideal location for unraveling the linkages between the geodynamic forces that build topography and the evolution of the biota that inhabit it. In this study, we utilize a geomorphic analysis to characterize the topography of the Western and Central Cordilleras of the Northern Andes. We supplement our topographic analysis with erosion rate estimates based on gauged suspended sediment loads and river incision rates from volcanic sequences. In the northern segment of the Central Cordillera, an elevated low-relief surface (2,500m in elevation, ~40x110 km in size) with uniform lithology and surrounded by knickpoints, indicates a recent increase in rock and surface uplift rate. Whereas, the southern segment of the Central Cordillera shows substantially higher local relief and mostly well graded river profiles consistent with longer term uplift stability. These changes in the topography fit with the proposed location of a slab tear and flat slab subduction under the northern Central Cordillera, as well as with a major transition in the channel slope of the Cauca River. We identify several areas of major drainage reorganization, including captures and divide migrations that are supported by our erosion and incision rate estimates. We identify slab flattening as the most likely cause of strong and recent uplift in the Northern Andes leading to ~2 km of surface uplift since 8–4 Ma. Large scale drainage reorganization of major rivers is probably mainly driven by changes in upper plate deformation in relation to development of the flat slab subduction geometry; however, other factors such as climate and emplacement of volcanic rocks likely play secondary roles in this process. Several isolated biologic observations above the area of slab flattening suggest that surface uplift isolated former lowland species on the high elevation plateaus, and drainage reorganization may have driven diversification of aquatic species.

The tropical Northern Andes of Colombia are one the world's most biodiverse places, offering an ideal location for unraveling the linkages between the geodynamic forces that build topography and the evolution of the biota that inhabit it. In this study, we utilize geomorphic analysis to characterize the topography of the Western and Central Cordilleras of the Northern Andes. We supplement our topographic analysis with erosion rate estimates based on gauged suspended sediment loads and river incision rates from volcanic sequences. In the northern Central Cordillera, an elevated low-relief surface (2,500m in elevation, ~40x110 km in size) with quasi-uniform lithology and surrounded by knickpoints, indicates a recent increase in rock and surface uplift rate. Whereas the southern segment of the Central Cordillera shows substantially higher local relief and mostly well graded river profiles consistent with longer term uplift-rate stability. We also identify several areas of major drainage reorganization, including captures and divide migrations that are supported by our erosion and incision rate estimates. These changes in the topography coincide with the proposed location of a slab tear and flat slab subduction under the northern Central Cordillera, as well as with a major transition in the channel slope of the Cauca River. We identify slab flattening as the most likely cause of strong and recent uplift in the Northern Andes leading to ~2 km of surface uplift since 8-4 Ma. Large scale drainage reorganization of major rivers is probably mainly driven by changes in upper plate deformation in relation to development of the flat slab subduction geometry; however, other factors such as climate and emplacement of volcanic rocks likely play secondary roles in this process. Several isolated biologic observations above the area of slab flattening suggest that surface uplift isolated former lowland species on the high elevation plateaus, and drainage reorganization may have influenced the distribution of aquatic species.

In coupled “source-to-sink” systems, spatial differences in hydrology and geomorphology influence how processes in the source are recorded in the sink. The catchment of the tropical Cauca River (source) in the northern (Colombian) Andes, and its associated Mojana lowland sedimentary basin (sink), are a model system in which to explore the relationship between climate processes that control runoff and erosion in the upper catchment, and sediment deposition in the lower basin that occurs through avulsion events and seasonal wetland flooding. This study employed historical climate and hydrologic data from the Cauca River watershed and its associated sedimentary basin, along with topographic data and satellite imagery. We discovered that the Cauca River catchment and its associated Mojana Basin are governed by different patterns of intra- and inter-annual climate variability. Biannual passage of the Intertropical Convergence Zone (ITCZ) over the watershed, annual incursion of the Choco Jet, and sub-decadal variability of the El Niño Southern Oscillation (ENSO) all modulate runoff and sediment fluxes that ultimately become fluvial deposits (e.g., crevasse splays, channel and floodplain sediments). Fluctuations in wetland water levels and area, preserved as lacustrine and marsh deposits, are influenced primarily by annual variations in rainfall that are controlled by the yearly northernmost extent of the ITCZ. Long-term erosion in the Cauca River catchment is controlled largely by active tectonism in the northern Central Cordillera. Avulsion events on the Cauca River in 2010 and 2011 occurred as a consequence of levee failure during a period of high runoff associated with the negative phase of the El Niño Southern Oscillation (ENSO) along with higher cross-floodplain than down-valley slopes in the basin.

The Tatra mountains, the northernmost portion of the Central Western Carpathians, host a stunning alpine landscape despite an average elevation that rises 1.4 km above the surrounding lowlands. Regional geomorphology studies on both sides of the range correlate various landforms interpreted to be glacial in origin with all each of the eight major Alpine glacial events based largely landscape position, and in some cases geochronologic constraints. This regional relative chronology assumes that wet-based mountain glaciers are efficient agents of erosion and each successive glaciation lowered the valleys within the Tatra. While the tendency of subsequent glaciations to obscure evidence of previous events makes it difficult to study the work done by past glacial episodes, the cave networks on the northern side of the Tatra offer a way to evaluate the amount and timing of valley lowering with U-series dating of speleothems. Epiphreatic and paleophreatic caves that developed near the water table and dried out as valley deepening occurred can serve as excellent recorders of the valley incision history. Speleothems were collected from a number of cave levels present throughout the northern Tatra, of which only a subset were suitable for U-series geochronology. The oldest speleothems collected in active epiphreatic passages on the valley bottom level from each valley are consistently between 284-325 ka (MIS 8-9). This shows that the modern karst drainage system of the Tatra was established prior to the late Middle Pleistocene, and the cave conduits changed to epiphreatic or vadose conditions between 280 and 330 ka. Since the lowest cave level is at or below the modern valley floor, we can conclude that no valley incision occurred after ~330 ka, which includes both the penultimate and last glaciations periods. Clearly, the regional glacial chronologies in the Tatra must be reassessed. The implications of our findings demonstrate that the assumption of successive valley lowering should not be assumed and that even the extensive MIS2 glaciation did not result in valley lowering despite its size.

At the Guayabetal Municipality, on the eastern flank of Colombia's Eastern Cordillera, there have been significant mass removals affecting communication routes (km 58 Bogota-Villavicencio road). In this zone, significant rates of precipitation and exhumation are observed, which could trigger these phenomena. In the present investigation, the feedbacks between precipitation and tectonics are investigated as controlling processes of the current relief. Existing thermochronological ages were compiled, and a direct 3D thermokinematic model was generated to estimate pulses and exhumation rates. The results of this last one suggests 3 exhumation pulses: the first one between 40 Ma - 25 Ma at an exhumation rate of 0.5 km/Ma, followed by a pulse between 25 Ma - 15 Ma with a rate of 0.1 km/Ma, and finally, from 15 Ma to the present rates of similar to 2 km/Ma. Additionally, rainfall and seismological data were used to estimate primary and secondary attributes of the terrain, as well as: seismic deformation, seismic energy and seismic uplift. The different variables were statistically compared. It is concluded that the current landscape of the area is not uniformly affected by tectonics and rainfall patterns. In the northwest of the area there are low rates of erosion and tectonic activity, so the evolution of the landscape is more passive, and the relief is controlled by the pattern of precipitation. In contrast, to the southeast, specifically between the Quetame massif and the piedmont plains, the relief is controlled by the tectonics present in the area. The anthropic effect on modifications to the landscape introduced by the creation of a national road, although it is important, was not analyzed in the present research.

En el Municipio Guayabetal, flanco oriental de la Cordillera Oriental de Colombia se han presentado importantes fenómenos de remoción en masa que afectan las vías de comunicación (km 58 vía Bogotá-Villavicencio). En esta zona, significativas tasas de precipitación y de exhumación son observadas, las cuales pudieron desencadenar estos procesos. En la presente investigación, se analizan las interacciones entre precipitación y tectónica como procesos controladores del relieve actual. Se compilaron edades termocronológicas existentes, y se generó un modelo termocinemático directo 3D para estimar los pulsos y las tasas de exhumación. Los resultados de este último sugieren 3 pulsos de exhumación: el primero entre 40 Ma - 25 Ma a una tasa de exhumación de 0.5 km/Ma, seguido de un pulso entre 25 Ma - 15 Ma con una tasa de 0.1 km/Ma, y finalmente, desde 15 Ma al presente tasas de ~2 km/Ma. Adicionalmente, modelos de elevación digital, datos de precipitación y sismológicos fueron utilizados para estimar atributos primarios y secundarios del terreno, así como: deformación sísmica, energía sísmica y levantamiento vertical por deformación sísmica. Las distintas variables fueron comparadas estadísticamente. Se concluye que el paisaje actual de la zona no es afectado uniformemente por la tectónica y las precipitaciones. En el noroccidente del área existen bajas tasas de erosión y actividad tectónica, así la evolución del paisaje es más pasiva, y el relieve es controlado por el patrón de precipitaciones. En contraste, hacia el suroriente específicamente entre el macizo de Quetame y el piedemonte llanero, el relieve es controlado por la tectónica presente en el área. El efecto antrópico con las modificaciones al paisaje introducidas por la creación de una vía nacional, aunque es importante, no fue analizado en la presente investigación.

Mechanisms driving the tectonic evolution of the southeast (SE) margin of Tibet include the Paleogene extrusion of the coherent Indochina lithospheric block and the continuous deformation caused by lower crustal flow since the middle Miocene. The timing and style of regional deformations are keys to determining the role of each mechanism. Fault‐bounded and fault‐controlled Cenozoic basins within the SE margin of Tibet record regional deformation, surface uplift, and variations in paleoclimate but often are poorly dated. New magnetostratigraphy and 40Ar/39Ar dating of volcanic ashes constrain precisely the timing of sedimentation within the Lühe Basin to between ~35 and 26.5 Ma. The basin is located in the Chuandian terrane along the Chuxiong fault, which lies ~70 km north of, and parallel to, the Ailao Shan‐Red River fault. The asymmetric syncline of the Lühe Basin suggests syncontractional sedimentation, and the basal age of the basin represents the initiation of the Chuxiong fault and crustal shortening at ~35 Ma. This is coincident with the onset of the Ailao Shan‐Red River fault and supports a kinematic link between them. Our study suggests that, like the Ailao Shan‐Red River fault, the Chuxiong fault is a Paleogene transpressional structure that developed during the extrusion and clockwise rotation of Indochina around the Eastern Himalayan Syntaxis, which caused the late Paleogene deformation and surface uplift of the Chuandian terrane and Indochina. Our revised chronostratigraphy of the Lühe Basin provides further evidence that many of the “Neogene” sedimentary basins in the SE margin of Tibet may be much older than previously thought.

The relative controls of rock uplift (tectonics) and precipitation (climate) on the exhumation of earth’s rocks in tectonically active mountain ranges are still debated. In low latitude tropical regions where rates of precipitation and the amount of vegetation cover are higher, more data is required to test the relative contribution of these factors to the evolution of orogenic topography. To contribute to this debate, cooling ages were derived for 25 bedrock and four detrital samples using the apatite (U-Th-Sm)/He (AHe) low temperature thermochronometer. AHe ages are reported along a ~450-km-wide swath on the eastern flank of the Northern Andes in Colombia (South America). The AHe cooling ages, that range from 2.5 Ma to 17 Ma, are compared to precipitation rates and geomorphic parameters in order to discern the relative importance of climate and/or tectonics on exhumation. Along the transect, AHe cooling ages are poorly correlated with the rates of precipitation but show a good correlation with landscape parameters such as average hillslope and average channel steepness. Moreover, young AHe cooling ages coincide with areas where deformation is mainly compressional; older AHe cooling ages are found in the middle part of the study area where strike-slip deformation dominates. The spatial distribution of the new AHe cooling ages suggests that in mountainous regions, in this case with high precipitation rates (> 1500 mm/yr), denudation is mainly controlled by the rate of vertical advection of material via tectonic processes. The spatial variations in precipitation may only have a second-order role in modulating exhumation rates.

The geomorphic processes that control temporal and spatial patterns of erosion, sediment storage and evacuation in an active mountain range (source) have a direct impact on how the signal of tectonics and climate, are recorded in the adjacent sedimentary basins (sinks). Stream power based numerical models of landscape evolution predict strong time lags between rock uplift and waves of erosion in the foreland, but this is difficult to test without proper resolution between source and sink signals.. Confirmation of model results is typically gleaned through observations that are either snapshots of processes in modern systems, or inversion of the stratigraphic record to decipher what occurred in the uplands. While cosmogenic nuclide derived, catchment wide erosion rates in the modern rivers provide a snapshot of processes happening in the last thousands of years, thermochronmeters average over the ≥ millions of years it takes a rock to ascend from the closure isotherm to the Earth’s surface,making it difficult, if not impossible to capture a minimally time averaged signal of the geomorphic system in the stratigraphic record. Paleoerosion rates from the residual cosmogenic nuclide concentration of buried sediments offer a means to bridge the gap in resolution. This study combines numerical modeling and cosmogenic nuclide paleoerosion rates in the Argentine Precordillera to build a rich picture of how this foreland basin system, from the hinterland through the foreland basin evolves in time and space. Our modeling shows that the dynamics of wedge-top basin formation behind a rising, and then subsequently inactive range have profound and systematic effects on the geomorphic signals both upstream and downstream of the wedge-top basin. Downstream, it is clear that there are strong, million year time lags in the uplift-triggered erosive pulse and spatial controls on where the sediment delivered to the foreland is sourced. Upstream, aggradation in the wedge top leads to the development of a wave of low erosion into the hinterland that results in the creation of perched surfaces coeval to erosive pulses downstream. In the Argentine Precordillera at 30°S an 8 Ma record of paleoerosion rates from the wedge top and foreland basin deposits along with detrital zircons provenance in the foreland largely verifies the predictions of the numerical modeling. Similarly, upstream of the wedge-top basin, there are concordant knickpoints and large, broad planation surfaces perched some 1500 m above the floor of wedge top as predicted by the low erosion wave pulse. Our combination of numerical modeling and paleoerosion rates capture the dynamic evolution of mountain range at million to thousand year timescales.