Based on new and published cosmic-ray exposure chronologies, we show that glacier extent in the tropical Andes and the north Atlantic regions (TANAR) varied in-phase on millennial timescales during the Holocene, distinct from other regions. Glaciers experienced an early Holocene maximum extent, followed by a strong mid-Holocene retreat and a re-advance in the late Holocene. We further explore the potential forcing of TANAR glacier variations using transient climate simulations. Since the Atlantic Meridional Overturning Circulation (AMOC) evolution is poorly represented in these transient simulations, we develop a semi-empirical model to estimate the “AMOC-corrected” temperature and precipitation footprint at regional scales. We show that variations in the AMOC strength during the Holocene are consistent with the observed glacier changes. Our findings highlight the need to better constrain past AMOC behavior, as it may be an important driver of TANAR glacier variations during the Holocene, superimposed on other forcing mechanisms.

The Clarion and Clipperton Fracture Zones in the Eastern Pacific are well known as a manganese nodule belt, which developed since the late Oligocene. The slow growth rate of these marine ferromanganese nodules implies that they have potentially recorded long‐term environmental changes. To produce environmental records from these nodules, their chronology needs to be established first. In order to achieve this objective, many dating methods have been applied; however, due to relatively low‐resolution temporal constraint, high‐resolution environmental signals recorded in marine ferromanganese nodules have not been well documented yet. In this paper, we present a geochronological study based jointly on magnetic scanning and analyses of the authigenic beryllium isotopes (authigenic 10Be/9Be) and the cobalt (Co) flux of a marine ferromanganese nodule. Results lead to the following observations: (1) The growth of the studied nodule resulted from a combination of hydrogenetic and diagenetic processes, and (2) a total of 24 magnetozones is recognized for the studied nodule. Correlation to the geomagnetic polarity timescale suggests that chrons from C3n.2r to C1n were recorded in the nodule, implying that the growth of this nodule initiated ~4.70 Ma, which agrees well with the authigenic 10Be/9Be and Co chronometers. Furthermore, a consistent pattern of broad paleomagnetic field variations was observed between the nodule's magnetic signal and the ocean‐floor magnetic fields of the South Atlantic, confirming the validity of our growth model. Overall, our study highlights the potential of marine ferromanganese nodules from the Eastern Pacific as recorders of changes in Earth's magnetic field.

We present new age constraints for the late Miocene Volkovce Formation of Slovakia, alluvial facies that accumulated adjacent to Lake Pannon. Facies analysis and authigenic Be-10/Be-9 dating was undertaken at the Bernolakovo and Triblavina localities while the latter outcrop also yielded additional small mammal and mollusk assemblages as well as remains of flora. The results of seven radiometric dating ages yielded a weighted mean age of 9.65 +/- 0.61 Ma for the Triblavina outcrop and 8.85 +/- 0.32 Ma for the Bernolakovo outcrop. The small mammal assemblage at the Triblavina outcrop is indicative of the lowermost MN11 zone, which in the Western European standard definition suggests an age of <8.9 Ma. The similar to 0.1 Ma inconsistency between absolute dating and biostratigraphic dating at the Triblavina outcrop might be explained either by the variation of initial Be-10/Be-9 ratio in the depositional environment or/and by diachronous development of the mammal faunas across the Europe. The mollusk assemblage at this outcrop indicates the paleoenvironment of freshwater lakes affected by rivers with evidence for a nearby riparian forests; it may be roughly correlated with Papp's lithostratigraphic units G and H defined for the Pannonian stage in the Vienna Basin. Our results provide a detailed insight to the late Miocene stratigraphy and terrestrial environments alongside the Lake Pannon shoreline.

High-mountain environments in an active tectonic setting are prone to landsliding. The triggering mechanisms can vary, as these areas are influenced by several pre-conditioning factors coupled with active seismicity and climatic forcings. Understanding the intrinsic and external mechanisms by which these events are influenced would help to establish better constraints onto their timing and periodicity and, eventually, hazard assessment and prediction. Glacially eroded valleys are especially prone as they deeply incise mountain ranges leaving unstable slopes once they retreat. Establishing the timing of such events enables better understanding of the triggering and pre-conditioning factors of landslides. To this aim, 10Be and 26Al cosmogenic age determinations were performed in three landslide deposits in a poorly studied area of San Juan province, all of which are novel to the area. Coupled with remote sensing techniques, field observations and detailed stratigraphic and sedimentological studies, these new large landslides represent a first approach to understand this dynamic environment. The three landslides were categorized as rock avalanches found in the middle and lower reaches of the Blanco River, sourced from the Choiyoi Group with evidence of hydrothermal alteration and including/deforming moraine deposits during their fall. Ages are 20.9 ± 1.4, 10.8 ± 0.7 and 12.8 ± 0.9 ka from the lowermost deposit to the highest, respectively. Even though one sample per deposit is not enough to have statistically significant exposure ages, these values, along with the established chronostratigraphy, allow first order interpretations regarding the links between deglaciation processes and readjustment of the slopes via large landslide events.

The 400-km-long Talas-Fergana Fault is one of a series of major right-lateral strike-slip faults that cross the Tien Shan Range. This fault has been recognized as active in the late Holocene and accommodates part of the deformation induced by the ongoing Indo-Asian collision. The kinematics and the role of this strike-slip fault are poorly understood with no large earthquakes reported in the instrumental or historical catalogs, and no well-constrained geological slip-rate estimates. Here we used high-resolution satellite imagery to present a first detailed analysis of the fault segmentation. We identified nine geometric segments based on strike variations for the Talas-Fergana Fault. Along the Kyldau segment, through morphological analyses of an offset alluvial fan and the application of multiple dating methods (Be-10, Al-26, Cl-36, luminescence, and radiocarbon), we calculated a late Quaternary slip rate ranging from 2.2 to 6.3 mm/year. This rate is higher than the geodetic measurements, but the discrepancy can be partly explained if the Talas-Fergana Fault accommodates shortening by counterclockwise rotation around a vertical axis. Paleoearthquakes identified by trenching indicate that at least two primary surface ruptures (and possibly a third) occurred in the past 3,800 years, and that no large earthquake has ruptured the Kyldau segment since at least 420 years B.P. (possibly within the last 2,700 years), making this fault segment a potential candidate to generate an earthquake with M > 7 in the near future.

30 The ~400 km-long Talas-Fergana fault (TFF) is one of a series of major right-lateral 31 strike-slip faults that cross the Tien Shan Range. This fault has been recognized as active in 32 the late-Holocene and accommodates part of the deformation induced by the ongoing Indo33 Asian collision. The kinematics and the role of this strike-slip fault are poorly understood 34 with no large earthquakes reported in the instrumental or historical catalogs, and no well35 constrained geological slip-rate estimates. Here we used high-resolution satellite imagery to 36 present a first detailed analysis of the fault segmentation. We identified nine geometric 37 segments based on strike variations for the TFF. Along the Kyldau segment, through 38 morphological analyses of an offset alluvial fan and the application of multiple dating 39 methods (Be, Al, Cl, luminescence and radiocarbon), we calculated a late Quaternary 40 slip rate ranging from 2.2 to 6.3 mm/yr. This rate is higher than the geodetic measurements, 41 but the discrepancy can be partly explained if the TFF accommodates shortening by 42 counterclockwise rotation around a vertical axis. Paleo-earthquakes identified by trenching 43 indicate that at least two primary surface ruptures (and possibly a third) occurred in the past 44 3800 years, and that no large earthquake has ruptured the Kyldau segment since at least 420 45 years BP (possibly within the last 2700 years), making this fault segment a potential candidate 46 to generate an earthquake with M>7 in the near future. 47

T. M. Smith, S. Li, P. M. Ranjith, F. Su, J. Gattacceca, ASTER Team, and H. He State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China, Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China, Centre Européen de Recherche et d’Enseignement de Géosciences de l’Environnement (CEREGE), UM 34 CNRS-IRD, Aix-Marseille Université, Technopôle de l’Environnement Arbois-Méditerranée, 13545 Aix-enProvence, France, G. Aumaître, D. L. Bourlès, and K. Keddadouche.

Abstract A multidisciplinary study was conducted in a newly discovered Paleolithic locality, named ‘Evron Landfill. This locality is a part of the Lower Paleolithic complex of ‘Evron located at the western Galilee, Israel. Examination of artifacts has enabled the cultural attribution of ‘Evron Landfill to the Early Acheulian, while detailed paleomagnetic stratigraphy places the hominin occupations near the Brunhes–Matuyama transition ~0.77 Ma. This age is constrained by cosmogenic isotope burial dating of the sediments overlying the Paleolithic finds, providing a minimum age of ~0.66±0.11 Ma for hominin activity at the site. These results are further supported by the biochronological information derived from the faunal assemblage. Comparative analyses of faunal remains and lithic artifacts from ‘Evron Landfill demonstrate similarities to the assemblages from the Early Acheulian site of Evron Quarry, located ~300 m to the south. Pedo-sedimentological analyses indicate that hominin activity took place in a marsh environment in proximity to the Mediterranean coast, which probably fluctuated in both space and time with a fluvial environment. In addition, this study provides important data about ancient coastal activity during the early to middle Pleistocene.

There is growing interest in geochronological applications of terrestrial in situ-produced cosmogenic nuclides, with the most commonly measured being Be-10 and Al-26 in quartz. To extract and then separate these radio-nuclides from quartz and prepare them in the oxide form suitable for accelerator mass spectrometry (AMS) requires extensive and careful laboratory processing. Here we discuss the suitability of a crushed, sieved and etched, sub-aerially exposed vein quartz specimen (CoQtz-N) to act as a reference material for chemical laboratory preparation and AMS measurements. Splits of CoQtz-N were distributed to eleven target preparation laboratories. The CoQtz-N Be-10 targets were then measured at seven different AMS facilities and five of the preparation laboratories had their Al-26 targets measured at four different AMS facilities. We show that CoQtz-N splits are sufficiently homogeneous with regard to nuclide concentrations, that it has been cleaned of any atmospheric derived (i.e. meteoric) Be-10 and that it has low concentrations of the major elements that can interfere with Be and Al extraction chemistry and AMS measurements. We derive preliminary concentrations for Be-10 and Al-26 in CoQtz-N as 2.53 +/- 0.09 x 10(6) at/g and 15.6 +/- 1.6 x 10(6) at/g, respectively, at the 95% confidence limit.

High Be-10 contents in tektites reported in literature are taken as evidence of a source material, melted at the impact site, enriched in atmospheric Be-10; i.e., a soil or sediment. In 0.8 Ma Australasian tektites, Be-10 content increases with distance from the putative impact location in Indochina, with geographic averages from 69 x 10(6) atoms/g (Indochina) to 136 x 10(6) atoms/g (Australia). Here we report, for the first time, Be-10 contents in microtektites collected from Antarctica and the South China Sea. We show that microtektites are similar to 30 x 10(6) atoms/g richer in Be-10 than tektites from the same geographic areas. Antarctic microtektites, with an average Be-10 content of 184 x 10(6) atoms/g after correction for in situ production, are the richest impact glass ever measured. The simplest explanation for such systematic size and geographic trends is that the source depth of the melt within the target surface decreases with ejection velocity. Indeed, higher initial kinetic energy implies higher launch distances and higher fragmentation of the ejecta. Antarctic microtektite source depth may tentatively be restricted to the upper tens of centimeters at the impact site. Alternative models invoking a marine or loessic sediment source, or a secondary enrichment in the microtektite (either by atmospheric scavenging, selective fractionation by volatilization, or post-depositional contamination) fail to reproduce the observed relationships.

The formation of the Baikal rift system basins is controlled by active faults separating each basin from the adjacent horsts. The kinematics of these faults is mainly explored through investigation of complex sequences of the fault-intersecting river terraces that record both tectonic and climatic events. This study focuses on the northern margin of the major Tunka basin that develops south-west of Lake Baikal. The development of the basin is controlled by the segmented Tunka fault. We performed a detailed mapping of the Kyngarga river terraces, the best preserved terraces staircase in Baikal rift system, at their intersection with the Tunka fault. In order to decipher the chronology of seismic events and the slip rates along that segment of the fault, key terraces were dated using in situ produced cosmogenic 10Be. We demonstrate that the formation of the terrace staircase occurred entirely during MIS1–MIS2. The obtained data allowed us to estimate the rate of incision at different stages of the terrace staircase formation and the relationship between the vertical and horizontal slip rates along this sub-latitudinal segment of the Tunka fault making respectively 0.8 and 1.12mmyr−1 over the past ~12.5ka. Analysis of the paleoseismology and paleoclimate data together with terrace dating provided the possibility to estimate the influence of tectonic and climatic factors on the terrace formation. Our proposed model of the Kyngarga river terrace development shows that the incisions into terraces T3 and T6 were induced by the abrupt climatic warming episodes GI-1 and GI-2, respectively, whereas terraces T5, T4 and T2 were abandoned due to the vertical tectonic displacement along the Tunka fault caused by coseismic ruptures.

After 6 years of Cl-36 routine operation, more than 6000 unknown samples have been measured at the 5MV French accelerator mass spectrometry (AMS) national facility ASTER (CEREGE, Aix en Provence). This paper presents the long term behavior of ASTER through the analysis of the measurements of the most used chlorine standards and reference materials, KNSTD1600, SM-Cl-12 and SM-CL-13 over a 46 months' time period. Comparison of measured chlorine concentrations (both Cl-35 and Cl-36) from ice samples on two AMS facilities operating at 5MV (ASTER) and 6MV (DREAMS, Helmholtz-Zentrum Dresden-Rossendorf) and normalizing to two different reference materials agree within uncertainties making both reference materials (SM-Cl-12 and KNSTD1600) suitable for Cl-36 measurement at

Morphological and geological observations reveal that most Apenninic faults are highly segmented and that the majority of the fault segments are less than 10km long. Although these faults have undergone numerous paleoseismological investigations, quantitative data remain crucially lacking for a large number of fault segments. Because such data are essential to understanding how these faults have ruptured and interacted in the past and how they might behave in the future, we investigated the Holocene seismic history of the Pizzalto normal fault, a 13km long fault segment belonging to the Pizzalto-Rotella-Aremogna fault system in the Apennines. We collected 44 samples from the Pizzalto fault plane exhumed during the Holocene and analyzed the Cl-36 and rare earth element (REE) contents. Together, the Cl-36 and REE concentrations show that at least six events have exhumed 4.4m of the fault scarp between 3 and 1ka, with slip per event values ranging from 0.3 to 1.2m. No major events have been detected over the last 1kyr. The Rotella-Aremogna-Pizzalto fault system has a clustered earthquake behavior with a mean recurrence time of 1.2kyr and a low to moderate probability (ranging from 4% to 26%) of earthquake occurrence over the next 50years.

Although agriculturally accelerated soil erosion is implicated in the unsustainable environmental degradation of mountain environments, such as in the Himalaya, the effects of land use can be challenging to quantify in many mountain settings because of the high and variable natural background rates of erosion. In this study, we present new long-term denudation rates, derived from cosmogenic 10Be analysis of quartz in river sediment from the Likhu Khola, a small agricultural river basin in the Middle Hills of central Nepal. Calculated long-term denudation rates, which reflect background natural erosion processes over 1000+ years prior to agricultural intensification, are similar to present-day sediment yields and to soil loss rates from terraces that are well maintained. Similarity in short- and long-term catchment-wide erosion rates for the Likhu is consistent with data from elsewhere in the Nepal Middle Hills but contrasts with the very large increases in short-term erosion rates seen in agricultural catchments in other steep mountain settings. Our results suggest that the large sediment fluxes exported from the Likhu and other Middle Hills rivers in the Himalaya are derived in large part from natural processes, rather than from soil erosion as a result of agricultural activity. Catchment-scale erosional fluxes may be similar over short and long timescales if both are dominated by mass wasting sources such as gullies, landslides, and debris flows (e.g., as is evident in the landslide-dominated Khudi Khola of the Nepal High Himalaya, based on compiled data). As a consequence, simple comparison of catchment-scale fluxes will not necessarily pinpoint land use effects on soils where these are only a small part of the total erosion budget, unless rates of mass wasting are also considered. Estimates of the mass wasting contribution to erosion in the Likhu imply catchment-averaged soil production rates on the order of ~ 0.25–0.35 mm yr−1, though rates of mass wasting are poorly constrained. The deficit between our best estimates for soil production rates and measurements of soil loss rates supports conclusions from previous studies that terraced agriculture in the Likhu may not be associated with a large systematic soil deficit, at least when terraces are well maintained, but that poorly managed terraces, forest, and scrubland may lead to rapid depletion of soil resources.

Since its commissioning in 2006, the commercially available certificated National Institute of Standards and Technology standard reference material NIST SRM 4325 is used at the French national facility ASTER (CEREGE, Aix-en-Provence) to normalize Be-10 measurements. This standard solution being no longer disposable, we thus decided to produce in-house standards. As a first attempt, a STD-12 standard (Be-10/Be-9 = (4.939 +/- 0.053) x 10(-12)) has been prepared from 2.5 kg of marine sediments with an adapted chemical protocol. Then, a Be-10 enriched solution of known concentration being available, a STD-11 standard (Be-10/Be-9 = (1.191 +/- 0.013) x 10(-11)) that will be used at ASTER in the near future to calibrate Be-10 measurements and its dilution to the 10(-14) level (STD-14 (Be-10/Be-9 = (5.468 +/- 0.064) x 10(-14))) have been prepared from it. (C) 2015 Elsevier B.V. All rights reserved.

Since its commissioning in 2006, the commercially available certificated National Institute of Standards and Technology standard reference material NIST SRM 4325 is used at the French national facility ASTER (CEREGE, Aix-en-Provence) to normalize 10Be measurements. This standard solution being no longer disposable, we thus decided to produce in-house standards. As a first attempt, a STD-12 standard (10Be/9Be=(4.939±0.053)×10−12) has been prepared from 2.5kg of marine sediments with an adapted chemical protocol. Then, a 10Be enriched solution of known concentration being available, a STD-11 standard (10Be/9Be=(1.191±0.013)×10−11) that will be used at ASTER in the near future to calibrate 10Be measurements and its dilution to the 10−14 level (STD-14 (10Be/9Be=(5.468±0.064)×10−14)) have been prepared from it.

The Main Himalayan Thrust (MHT) is the source of great earthquakes that have been documented along the range. Its geometry is a key parameter that influences accommodation of tectonic loading and earthquake magnitudes along the Himalayan Arc. Although seismic images are available for both the western and the central part of the range, this geometry remains poorly constrained for the Bhutanese Himalayas. Here we address this issue using a Be-10 cosmogenic nuclides denudation transect across western Bhutan. We observe a wide low denudation rate domain between 50km and 110km from the front followed by a strong northward increase. Using a joint inversion of denudation rates, GPS data, and Holocene uplift rates, we interpret this pattern as a consequence of a flat-ramp transition along the MHT. Compared to central Nepal and Sikkim, this location of the ramp suggests a wider decollement, with implications for greater seismogenic potential of the MHT in western Bhutan.

Extensive fields of large boulders are common around the base of hills in the Atacama Desert. How these boulders are transported from nearby hillslopes is unclear given the lack of rainfall of the region. Here we document the central role of seismicity, not runoff, in transporting and smoothing >1 ton boulders all across the hyperarid core of the Atacama Desert. The generally granitoid boulders emerge as corestones on hillslopes at an erosion rate of 0.1–1mMa−1. Thereafter, physical and cosmogenic isotopic evidence suggests that boulders slide and bounce rather than roll down hills and onto adjacent flats. In the transport process, the largest boulders are split and the smaller ones are weathered to grus, narrowing average boulder mass to ~2tons (<1m3). At the base of hills, the boulders bunch together and rub during the frequent earthquakes in the region, producing distinctive smoothing around boulder mid-sections, and silt moats around the boulder bases. Our measurements show a strong correlation between boulder field density and rubbing, and only when the density exceeds 60–70% does rubbing become common. Except for slow removal by rubbing, the boulders seem to undergo no further erosion while in the flats. Exposure times for some boulders are >12Ma, making them among the oldest continuously exposed features on the Earth. Boulder rubbing is just one geologic feature among many in the Atacama that underscore the role that seismicity probably plays in shaping landscapes of the waterless worlds of the solar system.

The 290 km long Nayband right‐lateral fault cuts across a region seismically quiescent during the last few millennia. Chlorine‐36 and optically stimulated luminescence (OSL) dating of cumulative geomorphic offsets between 9 ± 1 m and 195 ± 15 m with ages from 6.8 ± 0.6 ka to ∼ 100 ka allow deriving a slip rate of 1.8 ± 0.7 mm yr‐1. The paleoseismic record retrieved from the first trench excavated across the fault combined with 18 OSL ages demonstrates the occurrence of at least four large (Mw ∼ 7) earthquakes during the last 17.4 ± 1.3 ka and two older earthquakes (before ∼ 23 ka and 70 ± 5 ka). Sediments from the last ∼ 7 ka contain evidence of the three younger earthquakes. Penultimate and antepenultimate events occurred between 6.5 ± 0.4 ka and 6.7 ± 0.4 ka within at most 1 ka whereas the most recent earthquake occurred within the last millennium. Such an irregular earthquake occurrence may suggest seismic clustering. Therefore, the imminence of an earthquake along the fault cannot be discarded even if the most recent earthquake occurred within the last 800 years. This event went unnoticed in the historical records demonstrating the incompleteness of the historical seismic catalogs in Central Iran, challenging any assessment of seismic hazard without geologic information. Infrequent large earthquakes typify the slow‐slipping strike‐slip faults slicing Central and Eastern Iran. Also, the slip rates summed from the Iran Plateau up to the Afghan lowlands appear in fairly good agreement with the most recent GPS data.