Abstract Testing models that link climate and solid Earth tectonics in mountain belts requires independent erosional, structural and climatic histories. Two well‐preserved stratigraphic sections of the Himalayan foreland basin are exposed in NW India. The Jawalamukhi (13–5 Ma) and Joginder Nagar sections (21–13 Ma) are dated by magnetostratigraphy and span a period of significant climate change and tectonic evolution. We combine sediment geochemistry, detrital zircon U–Pb dating and apatite fission track analyses to reconstruct changes in the patterns of erosion and exhumation in this area from the Early Miocene to Pliocene. The provenance of the foreland sediments reflects a mixture of Tethyan and Greater Himalayan sources from 21 to 11 Ma, with influx from the Inner Lesser Himalaya starting after 11 Ma, and a strong increase in Crystalline Inner Lesser Himalayan erosion after 8 Ma. This distinct shift in provenance most likely reflects exhumation of the Kullu‐Rampur Window, as well as the northward motion of the Jawalamukhi section towards the Himalayas, drainage reorganization in the foreland, and/or tectonically driven drainage capture in the mountains. Prior to 10.5 Ma sediment came from a large river whose sources were Greater Himalaya and Haimanta dominated, likely a palaeo‐Sutlej, while after 8 Ma the source river was dominated by a more local drainage. Our work is consistent with Nd isotope and mica Ar‐Ar constraints from the same sections that demonstrate initial Inner Lesser Himalayan unroofing in this region from 11 Ma, earlier than the 2 Ma implied from the marine record and during a period of summer monsoon weakening when fission track data indicate very rapid cooling and erosion of the Lesser Himalaya sources from no later than 10 Ma. Tectonically driven rock uplift coupled with southerly migration of the maximum rainfall belt during a time of drying, may have focused erosion over the Lesser Himalayan Duplex and created the Kullu‐Rampur Window.

Abstract Tectonic and paleo‐environmental reconstructions of rift evolution typically rely on the interpretation of sedimentary sequences, but this is rarely possible in early‐stage rifts where sediment volumes are low. To overcome this challenge, we use geomorphology to investigate landscape evolution and the role of different forcing mechanisms during basin development. Here, we focus on the humid Middle Shire River basin, located within the zone of progressive interaction and linkage between the southern Malawi Rift and Shire Rift Zone, East Africa. We used a digital elevation model to map knickpoints and knickpoint morphologies in the Middle Shire River basin and examined the relationships with pre‐rift and syn‐rift structures within the rift interaction zone. The main axial stream, Shire River, descends steeply, 372 m over a 50 km distance, across exposed metamorphic basement along the rift floor, exhibiting a strongly disequilibrated longitudinal elevation profile with both ‘mobile’ and ‘fixed’ knickpoints. In particular, we identify two clusters of mobile knickpoints, which we interpret as associated with baselevel fall events at the downstream end of the exposed basement that triggered knickpoint migration through the fluvial network since at least the Mid. Pleistocene. We infer that after the integration of the axial stream across the Middle Shire Basin, the knickpoints migrate upstream in response to fault‐related subsidence in the Shire Rift Zone. Conversely, the fixed knickpoints are interpreted to reflect local differential bedrock erodibility at lithologic contacts or basement‐hosted fault scarps along the basin floor. The results suggest that Middle Shire basin opening, associated with rift linkage, is likely a recent event (at least Mid. Pleistocene) relative to the Late Oligocene activation of Cenozoic rifting in the East African Rift's Western Branch. These findings support the hypothesis that the Western Branch developed from the gradual propagation, linkage and coalescence of initially nucleated distinct rift basins.

Abstract The Rukwa Rift Basin, Tanzania is regarded as a modern example of a cratonic rift zone despite complex polyphase extensional and episodic inversion structures. We interpret 2D seismic reflection data tied to wells to identify and describe structures controlling stratigraphic sequences (Late Carboniferous to Pleistocene) in two main segmented Rukwa Rift domains, A and B, which are controlled by the Chisi and Saza shear zones. Fault geometry and stratal patterns are illustrated in relation to their kinematic interaction with folds. Fold structures reflect both extensional and compressional deformation and were mapped with a particular interest for their helium potential. We illustrate fault bend folds, fault propagation folds and fault propagation monoclines that are related to extension events. Folds related to compression exhibit various structural styles reflecting at least two phases of episodic and widespread inversion. First, Early Jurassic inversion phase which involved multi‐faulted anticlines in the Karoo strata. Second, a mild and widespread inversion structures during the Pleistocene which are characterised by both symmetrical and asymmetrical anticlines styles. Taken together, the extensional and compressional fold structures, stratal juxtapositions and unconformities define stratigraphic packages that are widely distributed in the Rukwa Rift Basin, and form potential subsurface traps for helium‐nitrogen–rich gases, from which some seep to the surface, evidently documented in thermal springs across the region.

Abstract Source‐to‐sink studies and calculating sediment budgets of ancient systems are important approaches for basin analysis. Because of the enormous scale of basins, most existing studies depend on subsurface datasets. As drilling campaigns focus on structural highs or specific trap types, well datasets cover only limited subareas of entire sedimentary basins. Outcrop studies are almost always based on even more spatially limited datasets. The ramifications for basin analysis are considerable: (1) actual sediment budgets are underestimated; (2) catchment denudation rates and sizes are miscalculated; (3) predicted net:gross ratios in sink areas bear high uncertainties. This paper outlines a new workflow‐defined approach to reconstruct regional grain size profiles to better estimate sediment budgets across an entire sedimentary basin, even when datasets have spatial limited coverage. The workflow includes compilation of grain size data, transformation to mass balance frameworks, and lateral matching of local to regional grain size profiles. The approach was tested on two representative continental‐to‐marine delta systems which are covered by four spatially limited datasets while the entire sedimentary basin (sink area) is much larger. The original estimates account for only maximum 40% of the actual total sediment volume as analysed with the new approach. The new method provides significantly improved constraints for catchment (source) models as well as input parameters (sediment budget, input locations, fractions) for process‐based depositional modelling for predictions of net:gross and detailed facies proximal to distal relationships. General benefits include lower uncertainties in clastic reservoir quality prediction (hydrocarbon exploration) and provenance analysis (fundamental research).

Abstract Sediment transport through the Mississippi River affects the lives and economies of millions of people along its course, so that understanding the controls on this process is of scientific and societal importance. Detrital U‐Pb geochronology, supported by grain size and major element data, can be a robust tool for constraining sediment provenance in clastic sedimentary systems that has been applied to the Mississippi. However, sediment storage and reworking can complicate interpretation, and this can be further exacerbated by anthropogenic alteration via the construction of levees, dams, locks and river diversion projects. In this study, we date zircons from the modern Mississippi River and compare them to previously acquired data to illustrate the difference between samples taken from the same catchment in order to better understand the downstream propagation of the modern detrital zircon signal. The modern Mississippi River and tributary systems show distinct similarities and are comparable between studies when samples are not too far separated (<100 km). We estimate that the Arkansas River is more important than previously proposed, at least in terms of sand supply, supplying 7%–11% of the total load. The largest supplier of sediment to the Mississippi is the Missouri River (33%–43%), which derives much of its sediment from sedimentary rocks in the foredeep deposited during the Sevier and Laramide events. Anthropogenic alteration of the modern river system can be seen in the downstream propagation of a Red River cut‐off signal following construction of the “River Control Structure”, implying slow zircon transport rates (<2.8 km/year). Differences in the degree of recycling caused by sampling locations and low numbers of grains introduce significant uncertainties to mixing calculations.

Abstract Arguments for recognizing autogenic vs. allogenic signals in the stratigraphic record are still far from settled, as is the decoding of unsteady allogenic responses to climate vs. tectonic forcing. We offer the case of late Mesozoic Xuanhua basin in the western Yanshan fold‐and‐thrust belt of North China to make these points. The study area is an intramontane basin that has allowed detailed structural, sedimentological, and provenance analyses in a kilometre‐thick succession (the Tuchengzi Formation) of alluvial fan, fluvial, lake‐delta and lacustrine deposits. Extensive geological mapping provided confidence of near‐basinwide later correlation of strata, revealing two large‐scale upward‐coarsening (CU) successions each 80–240 m thick, with prominent vertical changes from lacustrine through deltaic and fluvial to alluvial fan deposits. Two intervals of thrust‐related growth strata identified in the Tuchengzi Fm suggest that the CU successions were the signals of tectonic uplift and accommodation change related to Likouquan and the Mapu thrusting. In the lower CU succession, there is a stacking (30+) of small‐scale (3–16 m thick) upward‐fining cyclothems that are argued to have been generated by alternating wet‐dry climate cycles. The wet half‐cycle is argued to have initiated with high sediment and water discharge of flood‐generated mass flows into the lake and ended with accumulation of lacustrine mudstones as lake level rose. The lake deposits include the maximum flooding during the wet half‐cycle. The dry half‐cycle was characterized by continued lacustrine deposits, but increased evidence of subaerial exposure (rooting, paleosols, and mudcracks) argued to result from falling of the lake level under dry conditions.

Abstract The exhumation record of a fold‐thrust belt is preserved by thermochronologic minerals, such as zircon and apatite, both in exposed bedrock and in synorogenic sedimentary rocks in the foreland basin. Treating these as separate records can lead to potentially contrasting interpretations of a single exhumation history. Integrating the bedrock and detrital records with thermokinematic models of sequential deformation of a fold‐thrust belt can identify viable exhumation pathways of the bedrock and elucidate both how bedrock exhumation varies in space and time and how accurately the basin records exhumation changes in the source region. Predicted bedrock cooling ages and modelled basin thickness are used to estimate the amount and source of sediments supplied to the foreland basin during each increment of deformation to predict the detrital cooling signal over time. Applying this integrated bedrock‐detrital model to a cross‐section in Arunachal Pradesh, NE India demonstrates spatial and temporal variability in exhumation, with a background exhumation rate of <2 mm/yr, periods of rapid exhumation at rates of 3–7 mm/yr, and short pulses of 10–12 mm/yr rates during out‐of‐sequence thrusting. Our results predict that the detrital apatite fission track (DAFT) system records a constant lag time of 0.5–1 Myr. Although the response of the detrital zircon fission track (DZFT) system is more complex, the system records changes in lag time (1–5 Myr) as a function of the kinematics, deformation rates and thermal profile of the crust in the hinterland. However, the DZFT cooling signal is delayed by 1–2 Myr relative to the age of marked shifts in location, magnitude and rate of exhumation in the source region. Our models also highlight the importance of recycled foreland deposits in matching the ca. 20 Ma static peak in the DZFT record and ca. 14 Ma static peak in the DAFT record.

Abstract The recognition of linear trails of fluid escape pipes that have been deformed by salt flow have recently been suggested to offer a novel approach to reconstructing the internal kinematics of thick salt sequences deforming under gravity. These deformed pipes constrain a number of key parameters for salt tectonic analysis including the salt flow direction, translation distance of the top salt and overburden, the internal flow profile and from the flow velocity, the bulk viscosity of the salt. Here we interpret and characterise two previously unrecognised large‐scale strain markers within a salt sequence that may be equally as valuable as the deformed pipes for constraining salt flow. This study is based on the interpretation of a ca. 4,600 km2 3D seismic survey from the outer slope of the Nile Cone, offshore Egypt, located at the boundary between the extensional and translational domains of the deformed marginal region of the Messinian salt basin. We mapped five deformed pipe trails that allow us to constrain the average flow velocity of the top salt, at ca. 2 mm/yr over the past 2–3 Myrs. The salt flowed in a basinward NW/NNW direction away from the basin margin. In addition, we mapped two large (ca. 2 km diameter) salt dissolution depressions formed by subjacent dissolution of the evaporites. These are presently located down the salt flow direction of a large remnant erosional high at the base of the salt, and in the general alignment of one of the pipe trails. We therefore argue that this dissolution structure most likely formed by fluid venting from the base salt high, and as such can be used to measure translation direction, distance and average velocity. The second of the two novel kinematic indicators requires mapping of genetically connected mud volcanoes and their depletion zones. The study area contains over 400 individual mud volcanoes that are sourced from beneath the salt and erupted from the Early Pliocene to Recent. A subset of these, extruded at or near to the present day seafloor, have well imaged pre‐salt depletion zones vertically beneath the erupted volcanic cones. A smaller subset, typically buried Early Pliocene extrusions, is found to have volcanic cones that are systematically offset laterally from their corresponding depletion zones, with an offset direction and distances closely matched with other kinematic markers. Hence we suggest that mud volcanic plumbing systems can provide another independent kinematic marker from which to infer salt flow regime.