The steep, high‐relief eastern margin of the Tibetan Plateau has undergone rapid Cenozoic cooling and denudation yet shows little evidence for large‐magnitude shortening or accommodation generation in the foreland basin. We address this paradox by using a variety of geomorphic observations to place constraints on the kinematics and slip rates of several large faults that parallel the plateau margin. The Beichuan and Pengguan faults are active, dominantly dextral‐slip structures that can be traced continuously for up to 200 km along the plateau margin. Both faults offset fluvial fill terraces that yield inheritance‐corrected, cosmogenic 10Be exposure ages of <15 kyr, indicating latest Pleistocene activity. The Pengguan fault appears to have been active in the Holocene at two sites along strike. Latest Quaternary apparent throw rates on both faults are variable along strike but are typically <1 mm yr−1. Rates of strike‐slip displacement are likely to be several times higher, probably ∼1–10 mm yr−1 but remain poorly constrained. Late Quaternary folding and dextral strike‐slip has also occurred along the western margin of the Sichuan Basin, particularly associated with the present‐day mountain front. These observations support models for the formation and maintenance of the eastern plateau margin that do not involve major upper crustal shortening. They also suggest that activity on the margin‐parallel faults in eastern Tibet may represent a significant seismic hazard to the densely populated Sichuan Basin.

. (2011) Publisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

[1] The eastern margin of the Tibetan Plateau combines very high relief with almost no Tertiary foreland sedimentation and little evidence of Cenozoic tectonic shortening. While river incision and landscape development at the plateau margin have received significant attention over the last decade, little is known about the Cenozoic development of the adjacent Sichuan Basin. Here we assess the Cenozoic thermal history of this basin using detrital apatite fission track (AFT) and (U-Th)/He techniques and establish the presence of an exhumed AFT paleopartial annealing zone across much of the basin. This observation, combined with stratigraphic and borehole sections and inverse modeling of confined apatite fission tracks, indicates that the strata within the basin have undergone accelerated cooling after $40 Ma, consistent with the widespread erosion of $1 to 4 km of overlying sedimentary material. This regional-scale erosion is most likely a response to changes in the Yangtze River system draining and removing sediment from the basin. The base-level fall associated with this erosion contributed to a relative increase in relief across the Longmen Shan and may have helped drive Miocene-Recent incision and unloading of the plateau margin.

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Nitrous oxide (N 2 O) is primarily produced by the microbially-mediated nitrification and denitrification processes in soils. It is influenced by a suite of climate (i.e. temperature and rainfall) and soil (physical and chemical) variables, interacting soil and plant nitrogen (N) transformations (either competing or supplying substrates) as well as land management practices. It is not surprising that N 2 O emissions are highly variable both spatially and temporally. Computer simulation models, which can integrate all of these variables, are required for the complex task of providing quantitative determinations of N 2 O emissions. Numerous simulation models have been developed to predict N 2 O production. Each model has its own philosophy in constructing simulation components as well as performance strengths. The models range from those that attempt to comprehensively simulate all soil processes to more empirical approaches requiring minimal input data. These N 2 O simulation models can be classified into three categories: laboratory, field and regional/global levels. Process-based field-scale N 2 O simulation models, which simulate whole agroecosystems and can be used to develop N 2 O mitigation measures, are the most widely used. The current challenge is how to scale up the relatively more robust field-scale model to catchment, regional and national scales. This paper reviews the development history, main construction components, strengths, limitations and applications of N 2 O emissions models, which have been published in the literature. The three scale levels are considered and the current knowledge gaps and challenges in modelling N 2 O emissions from soils are discussed.

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Like the other large river systems that drain the India-Asia collision, the Yangtze River was 17 assembled through a series of Cenozoic capture events. These events are important for 18 orogenic erosion and sediment delivery, but their timing remains largely unknown. Here we 19 identify enhanced cooling in the Three Gorges region in central China, a key capture site 20 during basin development, beginning at 40-45 Ma. This event is not visible in regional 21 thermochronological data but is near-contemporaneous with the onset of widespread 22 denudation in the Sichuan Basin, just upstream of the Three Gorges. While we cannot rule out 23 alternative explanations, the simplest mechanism that links these events is progressive capture 24

The Longmen Shan Foreland Basin developed as a flexural foredeep during the Late Triassic Indosinian orogeny, spanning the time period c. 227±206 Ma. The basin fill can be divided into three tectonostratigraphic units overlying a basal megasequence boundary, and is superimposed on the Palaeozoic±Middle Triassic (Anisian) carbonate-dominated margin of the South China Block. The remains of the load system responsible for flexure of the South China foreland can be seen in the Songpan-Ganzi Fold Belt and Longmen Shan Thrust Belt. Early in its history the Longmen Shan Foreland Basin extended well beyond its present northwestern boundary along the trace of the Pengguan Fault, to at least the palinspastically restored position of the Beichuan Fault.The basal boundary of the foreland basin megasequence is a good candidate for a flexural forebulge unconformity, passing from conformity close to the present trace of the Beichuan Fault to a karstified surface towards the southeast. The overlying tectonostratigraphic unit shows establishment and drowning of a distal margin carbonate ramp and sponge build-up, deepening into offshore marine muds, followed by progradation of marginal marine siliciclastics, collectively reminiscent of the Alpine underfilled trinity of Sinclair (1997). Tectonostratigraphic unit 2 is marked by the severing of the basin's oceanic connection, a major lake flooding and the gradual establishment of major deltaic-paralic systems that prograded from the eroding Longmen Shan orogen. The third tectonostratigraphic unit is typified by coarse, proximal conglomerates, commonly truncating underlying rocks, which fine upwards into lacustrine shales.The foreland basin stratigraphy has been further investigated using a simple analytical model based on the deflection by supracrustal loads of a continuous elastic plate overlying a fluid substratum. Load configurations have been partly informed by field geology and constrained by maximum elevations and topographic profiles of present-day mountain belts. The closest match between model predictions and stratigraphic observations is for a relatively rigid plate with flexural rigidity on the order of 5 Â 10 23 to 5 Â 10 24 N m (equivalent elastic thickness of c. 43±54 km). The orogenic load system initially (c. 227±220 Ma) advanced rapidly (>15 mm yr À1 ) towards the South China Block in the Carnian, associated with the rapid closure of the Songpan-Ganzi ocean, before slowing to < 5 mm yr À1 during the sedimentation of the upper two tectonostratigraphic units (c. 220±206 Ma).

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