Burial Ages Research Articles

Speculation on an early Pleistocene origin of the Parker dunes of southwest Arizona, USA

The Parker Dunes in western Arizona, USA represent the largest dune system in the Sonoran Desert. This study presents a simple 10Be-26Al cosmogenic burial age of 1.90 ± 0.20 Ma, obtained from well cuttings 240–270 m deep in Butler Valley, just east of the dune field. Given the large errors associated with burial dating, we can only speculate that this oldest known aeolian sediment within the Parker Dunes is roughly concurrent with the Bat Cave flood event ca. 2.1 Ma of the nearby Colorado River, as well as regional climatic aridity during the early Pleistocene. Since older dune deposits may be present at other locations in the Parker Dunes, its origin dates back to at least the early Pleistocene. The more important, broader implication rests in highlighting the underutilized potential of well cuttings as a sediment source for cosmogenic burial dating in aeolian research.

Continental rift evolution and drainage reorganization along the Dead Sea rift since the Miocene

The Dead Sea fault is a section of the Arabian-African plate boundary. Widespread field relations indicate that three major drainage systems (stages) occupied the landscape west of the Dead Sea fault since its initiation at ca. 20 Ma. Specifically, (1) an early to middle Miocene drainage system, only minorly reconfigured by the fault (all sediments of this system belong to the Hazeva Formation); (2) a late Miocene to early Pleistocene fault-parallel drainage system named Paran-Neqarot (all sediments of this system belong to the Arava and Zehiha Formations; and (3) the early Pleistocene to present drainage configuration. The temporal and spatial frameworks of drainage stage 1 are generally constrained by radiometric dating of interfingering volcanic units, and the onset and temporal and spatial frameworks of drainage stage 3 are well constrained by cosmogenic 10Be surface exposure ages. The timing and longevity of the rift-parallel drainage (stage 2) have until now been evasive to direct dating. The overall time gap between stages 1 and 3 is ∼12−13 million years. Thus, an early age (within this time gap) of stage 2 would imply an immediate response of drainage reorganization to rift tectonics, while a later age of this drainage system would imply a delayed response. We present 11 10Be-26Al cosmogenic burial ages of alluvial and colluvial units related to the fault-parallel drainage system (stage 2), which collectively constrain the time of deposition of the Arava Formation sediments in the central Negev to ca. 8 Ma. The general lack of stratigraphic order, together with the large dispersion of ages both across and within the sampling sites, attests to significant recycling of sediments from drainage stage 1 into the Arava Formation deposits. The termination of Arava and Zehiha Formation sediment deposition at ca. 1.8 Ma was determined previously using cosmogenic exposure ages of desert pavements that cover the formations. Combining the previously published data with our new data, we established the longevity and character of the Paran-Neqarot drainage system. This framework highlights the temporal aspect of drainage system build-up and collapse as it responded to transform and extensional plate boundary tectonics during the Neogene.

Incision rate of the Manas River, northern Tian Shan: Insight from luminescence dating of terrace cobbles

Fluvial deposits in piedmont environments are usually enriched by cobbles, which can be used for luminescence dating, as an alternative to the conventionally employed sand-sized minerals. In this study, a modified multi-elevated-temperature post-infrared infrared stimulated luminescence (MET-pIRIR) procedure was employed to establish luminescence-depth profiles of upper and lower sides of fluvial cobbles and obtain the burial ages of cobbles from high terrace of the Manas River in northern Chinese Tian Shan. The age-stimulation temperature (A-T) plateau was combined with the conventional age-depth (A-D) plateau in luminescence-depth profile to evaluate the reliability of burial ages of cobble luminescence dating from the aspects of fading and bleaching of signals. When the signal was only bleached to a limited depth given rise to no A-D plateau, the A-T plateau could serve as an internal-check to evaluate the degree of bleaching of the luminescence signal just through a single rock slice. Our results showed that self-evidenced and reliable buried ages of fluvial cobbles could be determined by only using first sub-surface rock slice in the presence of A-T plateau. Thereafter, the deposition age of cobble from top of T6 terrace and bottom of T5 terrace were ∼23.6–24.0 ka and ∼22.7 ka, respectively, inferring a very fast incision rate of ∼20 mm/a. The observed variability in bleaching depth between upper and lower sides across different cobble samples suggested complex transport dynamics.

Constraining the evolutionary stages of a hypogene karst system by combining morphological, geochemical and geochronological data - the example of carbonate breccia-hosted Melnička Peštera

A combination of morphological observations, geochemical data from calcite minerals and geochronology by burial age dating and U-series is used to constrain the geological and geomorphological setting and the evolutionary stages of a hypogene karst system. This methodological suit is applied to Melnička Peštera, a horizontal cave developed in carbonate breccia overlying dolomite marble in Melnica locality (N. Macedonia), where hydrothermal karst development occurred in both dolomite and calcite marble. The passage morphology of the cave, having a reverse triangle, Laughöhle cross-sections, suggests development near the water table by slowly moving waters. Calcite crusts are found throughout the cave, and based on their relationship to passage morphology, appear to pre-date main horizontal passage formation. Their carbonate stable and clumped isotope and fluid inclusion noble gas compositions indicate cooling of the hydrothermal system with an increased contribution of shallower groundwater. U-series data suggests Early Pleistocene deposition of the calcite crusts. Water table notches and convectional features carved into breccia bedrock and calcite crusts point to subsequent development at and above the water table by condensation corrosion. The solutional aggressiveness near the water table was likely related to CO2, that previously degassed from the deeper parts of the system where calcite was depositing, and redissolved in the cooler, shallower waters. Due to poor connection with the surface, the cave air above the water table likely had high pCO2, that further helped to maintain aggressiveness of the groundwater at the water-air contact, and boosted condensation corrosion above it, preventing deposition of related secondary calcite minerals. The cave-hosting carbonate breccia deposited as an alluvial fan filling up a paleovalley cut into Upper Miocene sediments. Cosmogenic nuclide burial age dating of quartz fragments confirms Early Pliocene age for the breccia, and constrains the paleovalley incision to Late Miocene, likely related to base level lowering caused by the Messinian Salinity Crisis.

Feasibility of rock surface luminescence dating technique for measuring the burial ages of unheated flints

While flint and similar materials are some of the most often preserved finds from the pre-historic archaeological records, trapped charge techniques can currently only be used on heated flint pieces. Here, we investigate if rock surface luminescence dating using the light-sensitive OSL signal is applicable to unheated flint nodules and cobbles by measuring OSL signal-depth profiles in flint samples collected from eastern Zealand and Møn, Denmark. We demonstrate that a detectable, natural OSL signal is present in the centre in eight out of the nine investigated flint samples. Additionally, the OSL signal had been bleached to various depths at the flint surfaces, which were exposed to daylight at the time of sampling. The field-saturated OSL is 50% or lower compared to the laboratory OSL after a 6 kGy dose was administered to field-saturated flint slices; this discrepancy could be related to signal loss occurring over geological time scales, but the exact nature of the mechanism of signal loss remains unclear. The presence of a natural OSL signal that bleaches into the flint when exposed to daylight suggests that rock surface dating of unheated flints is feasible, and the method should be further tested on known-age samples.

Determination of the long-term slip rate of a fault in a slowly deforming region based on a reconstruction of the landform and provenance

Determining slip rates is essential for assessing earthquake hazards and understanding their recurrence intervals. However, in regions characterized by slow deformation, the long intervals between seismic events present challenges in understanding the long-term seismic behavior. This study focused on the Yangsan Fault (YF) on the Korean Peninsula, which is a major active fault in a slowly deforming area. We identified paleo-surface ruptures and validated stratigraphic evidence of paleo-earthquakes by geomorphological analyses and trench surveys along the YF. Landform restoration analyses indicate a lateral offset of ~320 m, which is supported by downstream changes in gravel composition in channels that cross the YF. Our investigation into the notable changes in gravel composition within channels forming in the alluvial fan revealed sediments with compositions unlikely to originate from the current topography. Observations of the sediment composition in channels within the alluvial fan, flowing from east to west, suggest a dextral slip sense focused around the YF. The minimum slip rate for the lateral offset was calculated to be 0.38–0.57 mm/yr using a burial age of ca. 698 ka for a gravel deposit exposed in a trench wall. The results show the importance of using diverse approaches to mitigate methodological uncertainties in measuring fault displacements and ages, particularly when determining the long-term slip rate in intraplate settings.

Chronology of late Holocene sediments related to the Qicheng ruins in central China

The Qicheng city wall is located in Puyang, Henan Province, China, and it is an important archaeological site from the Neolithic period in the North China Plain region. A trench across the northwest corner of the city wall revealed an 11 m thick sediment sequence, closely associated with human activities, which provides valuable records for the dating and environmental evolution of the site. In this study, we have applied field geological investigation, grain size analysis, optically stimulated luminescence (OSL) dating, and radiocarbon (14C) dating to reveal the history and changes in the site. The ancient city wall was built on the sedimentary sequence (U1) of the high terrace of the Ancient Yellow River. The upper 11 m thick sedimentary sequence (U2) recorded early moat sedimentation (U2L) and was followed by three cycles of paleosol-flooding deposits (U2U). The quartz OSL signals of the U2 silts are extremely bright, indicating high sensitivity. Partial bleaching was observed as well. The quartz OSL single-grain SAR dating results are consistent with that of charcoal 14C dating and are closer to the ‘true’ burial ages of the sediments than those obtained with multiple grains. By using a Bayesian statistical model, a chronological framework for the U2 sedimentary sequence was established. The earliest construction date of the Qicheng city wall is dating to 2100–1300 BC, during the late Longshan period, which is consistent with archaeological evidence (Li et al., 2015). The Qicheng city was not significantly affected by paleo-flooding prior to 870–960 AD, but experiences frequent flooding thereafter.

Probing sediment burial age, provenance and geomorphic processes in dryland dunes and lake shorelines using portable luminescence data

Luminescence signals from portable optically-stimulated luminescence readers (POSL or port-OSL) can provide expedient insights into sample relative age, and under certain conditions can be simplistically calibrated against existing luminescence chronologies to provide first-order estimates of burial age. This is most straightforward in simple sedimentary systems where samples share a common provenance and geomorphic process history. The spatially extensive southern African dune and palaeolake shoreline luminescence database, for which hundreds of non-light exposed bulk sediments are available, offers a valuable test case to examine the conditions under which POSL-bulk sediment calibration approaches are feasible. To do this we combine measurements of inherent luminescence sensitivity of bulk sediment (BSS) with analysis of sedimentary composition (petrology and presence of calcium carbonate) and texture. We show that BSS, along with POSL IRSL:BSL ratios and petrological data, account for region-to-region variations, whilst internal variability (scatter) within the lake shorelines dataset relates to variations in BSS and sediment texture. At the scale of southern African subcontinent drylands, we see that provenance and geomorphological process history influence sample mineralogical composition and POSL signal characteristic, including BSS.

Cosmogenic nuclide-derived downcutting rates of canyons within large limestone plateaus of southern Massif Central (France) reveal a different regional speleogenesis of karst networks

Abstract. We present 35 new burial ages (27 sites) based on 26Al / 10Be ratios of terrestrial cosmogenic radionuclides measured in clasts and sediments deep within 12 caves in the southern Massif Central, France. Our results, together with previously published burial ages, verify that cave morphogenesis has been continuously active in this region for at least the past ∼ 6 Myr. Combining sample burial ages with their associated cave elevation above the modern stream bed gives a mean regional incision rate of 88 ± 5 m Ma−1 for the Grands Causses area. South of the Cevennes Fault Zone bordering the Grands Causses, the incision rate is 43 ± 5 m Ma−1, suggesting that this difference might be accommodated by the fault zone. Sediment burial ages from caves which are not located on river valley flanks or cliff walls are surprisingly too young compared to their expected ages when calculated using this regional average river incision rate. This suggests that the classical epigenic speleogenesis model that presumes a direct correlation between cave level development and regional base level lowering does not apply for the study area. Therefore, we propose that regional speleogenesis is mainly controlled by the removal of ghost rocks by headward erosion from river canyons to central parts of the plateaus, emptying incipient primokarst passages to create cave systems. Our results suggest a continuum process from hypogene primokarst composed of passages filled with ghost rock to one of epigene karst dynamics emptying these passages and creating cave networks. We propose that these processes are the major mechanism in the southern Massif Central that initiates speleogenesis and controls the geometry of the networks. In this region, tiered karst cannot be associated with the pace of incision of the major rivers but must be explained by former ghost rock (or hypogene) processes.

Mammal-bearing Pleistocene deposits, Vranić, southwestern Pannonian Basin System

Vranić site is a sand quarry that is located on the southern foothills of Papuk Mountain. From bottom to top of the succession, three sedimentary units have been recognized as: Unit 1 containing massive sand with scattered gravel-sized clasts, marl cobbles and boulders, and abundant marine mammal and fish fossils; Unit 2 consisting of sand intercalated with silt, clay and gravel, which may be horizontally bedded; and Unit 3, which is an erosionally-based lenticular matrix to clast-supported structureless gravel. The basal part of Unit 1 shows numerous reworked skeletal remains of Miocene marine mammals. Cosmogenic radionuclides constrain the age of burial of Unit 1 to 895 ± 211 ka, while the source area of Unit 1 had a quick denudation.The massive sands deposited on the slopes of Papuk Mountain were vulnerable to erosion due to the absence of clay. Heavy rainfall or water from snow melting created flash floods that infiltrated the sands, thereby causing slope destabilization and deformation. This process led to slumps that were transformed into a sandy debris flow. This sediment was probably deposited during the interglacial marine isotope age (MIS) 21 period when the scarce vegetation and a warmer climate favored the melting of permafrost ice and consequently triggered slope movements during MIS 22. The reworked skeletal material sampled at the Vranić site comprises fossilized fish along with mammal bones and teeth. Thus, the Vranić site represents an important site for cetacean fossil remains and serves as an important data source for marine life in the Central Paratethys.

A new OSL dose model to account for post-depositional mixing of sediments

In applications of optically stimulated luminescence (OSL) dating to unconsolidated sediments, the burial age of a sample of grains is estimated using statistical models of the distribution of the experimentally determined equivalent doses of the grains, together with estimates of the environmental dose rate. For grains that have been vertically mixed after deposition (e.g., due to bioturbation), existing dose models may fail to appropriately account for the complexity of the mixing process, thus producing inaccurate age estimates of the original time of deposition of the ‘native’ grains in any particular sample (usually the quantity of most interest). Here we introduce a new dose model, the asymmetric Laplacian mixture model (ALMM), developed for vertically mixed samples with single-grain dose distributions. The approach is based on a continuous statistical mixture that models the displacement of grains in both upward and downward directions. The central dose of the native grains in each sediment sample is estimated by the ALMM, as well as the parameters associated with overdispersion of single-grain dose distributions and the (modelled) mixing process. Using Bayesian methodology, we apply the model to two series of vertically contiguous samples collected at the site of Nawarla Gabarnmang in northern Australia. Independent age estimates obtained from radiocarbon dating of charcoal fragments support the OSL ages for the native grains estimated by the ALMM. Moreover, our study includes sensitivity analyses that show the model is robust to variation in the experimental error of the OSL data, as well as a simulation study that demonstrates the model’s good ability to recover the simulated central dose and its excellent coverage properties. The ALMM is introduced in the context of compound Gaussian distributions, a broadly encompassing statistical framework that includes many of the most commonly used dose models. This unifying and accessible perspective on the statistical modelling of dose distributions will support practitioners in selecting an appropriate model for samples affected by post-depositional mixing, and hopefully stimulate further theoretical developments. A new R package rstanosl is provided that fits the ALMM and other commonly used dose models using Hamiltonian Monte Carlo methods via the Stan programming language.

Insight into the dynamics of a long-runout mass movement using single-grain feldspar luminescence in the Pokhara Valley, Nepal

Abstract. Mass movements play an important role in landscape evolution of high mountain areas such as the Himalayas. Yet, establishing numerical age control and reconstructing transport dynamics of past events is challenging. To fill this research gap, we bring luminescence dating to the test in an extremely challenging environment: the Pokhara Valley in Nepal. This is challenging for two reasons: (i) the optically stimulated luminescence (OSL) sensitivity of quartz, typically the mineral of choice for dating sediments younger than 100 ka, is poor, and (ii) highly rapid and turbid conditions during mass movement transport hamper sufficient OSL signal resetting prior to deposition, which eventually results in age overestimation. Here, we first assess the applicability of single-grain feldspar dating of medieval mass movement deposits catastrophically emplaced in the Pokhara Valley. Second, we exploit the poor bleaching mechanisms to get insight into the sediment dynamics of this paleo-mass movement through bleaching proxies. The Pokhara Valley is a unique setting for our case study, considering the availability of an extensive independent radiocarbon dataset as a geochronological benchmark. Single-grain infrared stimulated luminescence (IRSL) signals were measured at 50 ∘C (IRSL-50) and post-infrared infrared stimulated luminescence signals at 150 ∘C (pIRIR-150). Our results show that the IRSL-50 signal is better bleached than the pIRIR-150 signal. A bootstrapped minimum age model (bMAM) is applied to retrieve the youngest subpopulation to estimate the paleodose. However, burial ages calculated with this paleodose overestimate the radiocarbon ages by an average factor of ∼23 (IRSL-50) and ∼72 (pIRIR-150), showing that dating of the Pokhara Formation with a single-grain approach was not successful for most samples. Some samples, however, only slightly overestimate the true emplacement age and thus could be used for a rough age estimation. Large inheritances in combination with the scatter in the single-grain dose distributions show that the sediments have been transported under extremely limited light exposure prior to deposition, which is consistent with the highly turbid nature of the sediment-laden flood and debris flows depositing the Pokhara gravels. To investigate the sediment transport dynamics in more detail, we studied three bleaching proxies: the percentage of grains in saturation 2D0 criteria, the percentage of best-bleached grains (2σ range of bMAM-De) and the overdispersion (OD). None of the three bleaching proxies indicate a spatial relationship with runout distance of the mass movement deposits. We interpret this as evidence for the lack of bleaching during transport, which reflects the catastrophic nature of the event. While not providing reliable burial ages of the Pokhara mass movement deposits, single-grain feldspar dating can potentially be used as an age range finder method. Our approach shows the potential of luminescence techniques to provide insights in sediment transport dynamics of extreme and rare mass movement events in mountainous regions.

In situ U-Pb dating of Jurassic dinosaur bones from Sichuan Basin, South China

Abstract Direct dating of vertebrate fossils is difficult due to complex postburial diagenetic processes and the often low and heterogeneous concentration of radioisotopes (e.g., U) in fossilized bone material. Here, we demonstrate a novel approach to dating vertebrate fossils via laser ablation–inductively coupled plasma–mass spectrometry U-Pb dating of early diagenetic calcite cements precipitated within bone cavities of a Jurassic sauropod from the Sichuan Basin, South China. Early diagenetic calcite yielded a U-Pb age of 165.3 ± 3.6/5.6 Ma, in agreement with a maximum depositional age of 165.8 ± 1.0 Ma from detrital zircon ages of the surrounding rocks, suggesting that diagenesis occurred shortly after the death of the sauropod. This new age demonstrates that the best-known Jurassic large sauropod faunas in South China are much older than those in North America and Africa, suggesting the geographical isolation of South China. Authigenic apatite U-Pb dating on the fibrolamellar bones from the same sauropod gave a distinctly younger age, indicating more complex U-Pb system behavior, possibly due to U uptake by residual organic matter and recrystallization of apatite after early diagenesis. Our findings demonstrate that U-Pb dating of calcite cements within bone cavities has significant potential for constraining the burial age of vertebrate fossils, which could aid in constructing a more robust temporal framework for the radiation and evolution of vertebrates.

New perspectives on organic carbon storage in lake sediments based on classified mineralization

The burial amount of organic carbon (OC) in lake sediments is constantly changing owing to mineralization. Statically measured OC does not entirely reflect the dynamic OC processes in lake sediments. This study proposes a dynamic deposition and mineralization model for sedimentary OC (DMSOC) and applies it to eight sedimentary cores from two lakes to invert the history of OC in sediments. The results showed that the trophic level and temperature of the lake predominantly affected the amount of deposited OC (De-OC). The amount of mineralized OC in the sediments is adversely affected by the end sources, burial time, and trophic level of the lake. The OC end source mainly determined the mineralization rate in the following order: algae > aquatic > terrestrial sources. Burial time primarily affected the compositional characteristics of the remaining OC, owing to the asynchronous mineralization of OC from different sources. The De-OC of Dianchi Lake, a eutrophic lake, increased more than twice compared to that of the scenario 100 years ago. The De-OC content of Fuxian Lake, an oligotrophic lake, decreased by approximately 25 %. The greenhouse effect may further reduce the carbon sequestration capacity of lakes, particularly oligotrophic lakes. With a set burial age, the model results show that the increase in OC storage in lake sediments may be much lower than expected. Therefore, the roles of different types of lakes in the carbon cycle must be reassessed.

Northward propagation of the Gulf of Elat-Aqaba constrained by cosmogenic burial ages and magnetostratigraphy of onshore sediments

The Gulf of Elat-Aqaba (GEA), located in the southern part of the Dead Sea Transform (DST), is one of the most active segments of the Dead Sea fault system. Yet, some fundamental details concerning its evolution in space and time are still not fully understood. To better constrain the tectonic history of this region, we study a succession of alluvial, lacustrine, and fluvial deposits in the north-western edge of the GEA, which belong to the Quaternary Eilot and Garof Fms. The Eilot Fm. represents low-energy shallow freshwater bodies and sabkhas, which predate the development of the deep part of the basin. Later, in response to the subsidence of the basin, the Garof Fm. was deposited in alluvial fans that built up following the increase in the depositional energy. Cosmogenic burial ages combined with magnetostratigraphy show that these Fms. were deposited as early as 3.03 Ma and as late as 1.65 Ma, depending on the applied age model. Considering the present depth of the northern GEA, this age indicates a maximum subsidence rate of the head of the GEA of ∼1.98mm/yr. We suggest that faults along the onshore margin of the deep basin were active during the deposition of the Garof Fm. and subsequently became inactive, while the faulting activity migrated toward the center of the basin. Closed Holocene basins north of the present seashore, such as the Elat and Evrona playas, which may represent a modern analogue to the Plio-Pleistocene morphology, raise the possibility that the GEA head is still propagating northward.

Ground-penetrating radar (GPR) survey and spatial analysis of the George and Addie Giddens Cemetery, Opelika, Alabama

ABSTRACT Interest in locating and preserving the cemeteries of enslaved African Americans has increased the need for new methodologies coupled with efficient, noninvasive geophysical techniques, such as ground-penetrating radar (GPR). The southeast United States, where many of such sites are located, provides many challenges to using GPR due to its humid climate and abundant vegetation, which deteriorates burial remains, disguises burial shafts, and forms physical obstacles to GPR surveys. These challenges make it difficult for GPR alone to locate caskets or burial shafts. To address these issues, this study uses GPR combined with an innovative spatial and observational methodology to locate burials in a humid climate and determine their burial conditions. These mixed methods led to the location of 129 potential graves. Knowing the spatial distribution of burial features provides a context for analyzing the relative burial ages and decay rates within the cemetery site.

Pleistocene valley incision, landscape evolution and inferred tectonic uplift in the central parts of the Balkan Peninsula – Insights from the geochronology of cave deposits in the lower part of Crna Reka basin (N. Macedonia)

Although the general geomorphology is reasonably well understood, not much information is available on the incision rates of rivers and related tectonic uplift in the central parts of the Balkan Peninsula. Caves in the lower part of Crna Reka drainage (N. Macedonia) provide the possibility to reconstruct the Neogene-Quaternary evolution of this area, as previous research has identified two major cave development phases: one related to Pliocene-Early Pleistocene basin infilling and establishment of lacustrine environments, and a subsequent cave development phase related to valley incision due to draining of the lacustrine systems and tectonic uplift.Here, we present new geochronological data obtained by U-Th dating on speleothems and cosmogenic nuclide burial age determination of clastic cave sediments, that provide time constraints on the Pleistocene karst and valley evolution, and an insight into the related tectonic uplift. The obtained cosmogenic nuclide burial age (2.1 ± 0.5 Ma) of the clastic cave sediments from Temna Peštera – Dragožel, further supports previous results on placing the onset of the draining of the Pliocene lakes in Macedonia in the Early Pleistocene. The similar timing obtained for the downstream and upstream parts of Crna Reka drainage suggests that the draining was more likely initiated by regional uplift, rather than headward erosion related to subsidence in the Aegean Sea. The Middle to Late Pleistocene age of the dated speleothems agrees well with the existing conceptual model for karst and landscape evolution in the area. The cumulative valley incision rates based on these radiometric data show an increase towards the present, with values of <0.1 m/ka in Early Pleistocene, increasing to ∼0.2–0.5 m/ka in Middle Pleistocene, and up to 1 m/ka in Late Pleistocene. They are lower than the measured uplift rates in the area (1.1–1.2 m/ka), and mostly overlap with the range of GPS-based vertical deformation rates in the Hellenides. Higher Middle to Late Pleistocene uplift rate is inferred in the downstream part of Crna Reka, an area in the Vardar zone bounded by seismogenic faults, than in the upstream part, at the easternmost edge of the Pelagonian massif.

Luminescence Chronology of Reticulated Laterites in the Humid Subtropical Mountains of South China

AbstractLaterite is a red weathering crust developed with various rocks and Quaternary loose sediments as its parent material in the tropics and subtropics regions of the world. Since the 1930s, researchers have believed that the fluvial reticulated laterite in southern China was influenced by the warm and humid climate of the Middle Pleistocene. In recent years, the remains of Paleolithic human activities are often found in the reticulated laterite of southern China. However, the study of laterite chronology is sporadic or there is no critical chronological analysis, which causes uncertainty in the identification and discussion of the ages of reticulated laterite and Paleolithic sites. In this study, a Paleolithic site found in fluvial reticulated laterite in South China was systematically tested by quartz optical luminescence dating and geomorphic process analysis. The results show that, (a) The T3 terrace, an archive of hominin activity in the study area, primarily formed between 56 and 11 ka. (b) Reticulated laterite cannot be used simply to determine the ages of the Paleolithic sites found in this stratum, and typical reticulated laterite cannot be used as a marker for climatic stratigraphy and chronostratigraphy. The fluvial reticulated laterite in the southern tropics, under suitable hydrothermal conditions, can form within tens of thousands of years or even within 10 ka. (c) Human activities can affect the burial age of reticulated laterite, and the stratigraphic diachronism of riverine terraces can also lead to an inversion in the age of reticulated laterite.

Timing of gully development in a structurally controlled badland landscape, western Turkey

The development of badlands at a global scale has become an increasingly relevant research topic in various earth science disciplines with respect to climate change and extensive erosion over the past few decades. Not only understanding badland forming processes but also investigating the potential causes and timing of badlands at a spatio-temporal scale is of great importance to unravel the genesis of badlands. To address these key aspects, this work focuses on a multi-method study in a Mediterranean badland landscape, Kula Badlands, western Turkey, exposed in two tributary catchments of the Gediz river. The Kula Badlands is recognised with its dense gully network deeply incised into fine grain and weakly consolidated Miocene and Quaternary sediments. These badlands are known to have developed within the extensional tectonic regime of a mini-graben system. However, the genesis, timing and incision history of the gully and badland development of the Kula Badlands require further investigation. In this work, timing and behaviour of gully erosion and sedimentation are studied with age control using appropriate luminescence and radiocarbon dating methods combined with geological and geomorphological observations. Sedimentation pattern and age results demonstrate a staircase-like form resembling river terraces in badland gullies. Sediment burial ages of badland deposits show an estimated age range of 140 ka to 0.5 ka. An accelerated incision is observed during the mid-Holocene with alternating erosion and sedimentation waves in response to upstream erosion. This period coincides with increased human activity in the area. Although, an apparent link between the timing of the preserved deposition and climate change could not be observed. A volcanic damming and subsequent breaching, and an interplay between tectonics and climate are likely to have triggered and accelerated the badland erosion and sedimentation activity within the spatial gully network pattern along the fault lines.

The moa footprints from the Pliocene – early Pleistocene of Kyeburn, Otago, New Zealand

ABSTRACT In March, 2019, a trackway of seven footprints was found at a riverbank outcrop of Maniototo Conglomerate Formation in the Kyeburn River, Central Otago, South Island, New Zealand. In this study, we describe this first known occurrence of moa (Dinornithiformes) footprints to be found and recovered in Te Waipounamu/South Island. Footprints of the trackway were ∼46 mm deep, 272–300 mm wide and 260–294 mm in length. An associated separate footprint was 448 mm wide and 285 mm long. Cosmogenic nuclide dating of adjacent overlying beds from the same formation establishes a mean minimum age of burial age for the tracks of 3.57 Ma (+1.62/−1.18 Ma) with a mode of 2.9 Ma, which we interpret to be Late Pliocene, with a conservative age range of Pliocene to Early Pleistocene. The trackway maker is identified as a moa from the Emeidae family, probably from the genus Pachyornis, with a mean mass of 84.61 kg that was travelling at a speed of 2.61 kmh−1. The single adjacent footprint was made by an individual from the family Dinornithidae, most likely from the genus Dinornis with an estimated mass of 158 kg. These moa footprints represent the second earliest fossil record of moa.