Guano-related weathering in caves received notable attention in several studies over the last decades. This study investigates the influence of bat guano on the development of Chariton Cave, the largest known hypogenic cave in Israel. We examine the cave morphology, sediments, and moisture sources to understand post-speleogenetic processes in a vadose environment. Apatite deposits along cave passages with keyhole cross-sections suggest secondary enlargement by guano-induced weathering. Estimation of the guano-related weathering suggests it accounts for at least 30 % of the entire cave volume. This significant weathering occurs in semi-arid conditions, with limited infiltration of meteoric water from the surface. However, condensation-evaporation cycles within the cave provide the moisture required for weathering associated with guano. U-Pb dating of calcite, which was deposited on secondary apatite, indicates bat activity in the cave since at least 5.19 +/- 0.85 Ma. This age enables calculation of maximum guano-related weathering rate of similar to 0.05 to similar to 0.07 mm/ka and maximum incision rate in Chariton canyon of 19.2 mm/ky. Furthermore, C-14 dating of guano shows bat activity and guano accumulation 3360-3620 years ago, which continues to the present. This research highlights the importance of biogenic processes in reshaping hypogenic caves after their disconnection from formative environments, contributing to our understanding of karst evolution.

This study demonstrates the feasibility of speleothem magnetism as a paleo-hydrology proxy in speleothems growing in semi-arid conditions. Soil-derived magnetic particles in speleothems retain valuable information on the physicochemical conditions of the overlying soil, and changes in bedrock hydrology. Yet, the link between magnetic and isotopic proxies of speleothems has been only partly established. We reveal strong coupling between the inflow of magnetic particles (quantified using the magnetic flux index, IRMflux) and delta C-13 in two Holocene speleothems from Soreq Cave (Israel). The stalagmite record spans from ca. 9.7 to ca. 5.4 ka, capturing the warm-humid conditions associated with the early Holocene and the transition to mid-Holocene wet-dry cycles. Extremely low IRMflux during the early Holocene, indicating minimal contribution from the overlying soil, is accompanied by anomalously high delta C-13 (approaching bedrock values) hypothesized to be caused by high rainfall and soil erosion. By contrast, IRMflux during the mid-Holocene covaries with the saw-tooth cyclicity of delta C-13 and delta O-18, interpreted as rapid fluctuations in rainfall amount. The peaks in IRMflux precede the negative (wet) delta C-13 peaks by similar to 60-120 yr. The apparent lag is explained as a rapid physical translocation of overlying soil particles via groundwater (high IRMflux) as a response to increasing rainfall, compared with slower soil organic matter turnover rates (10-10(2) yr).

The Lower Paleolithic Late Acheulian in the Levant marks a fascinating chapter in human cultural and biological evolution. Nevertheless, many aspects of the Late Acheulian are still undeciphered, hindered by the complex nature of each site on the one hand, a scarcity of wide, multidisciplinary studies on the other, and by difficulties in obtaining absolute chronology for this timeframe. Therefore, subjects such as human subsistence strategies and modes of adaptation, regional diversity, and the possible existence and nature of interactions between hominin groups are largely understudied. The discovery and study of Jaljulia, a large-scale Late Acheulian site at the central Coastal Plain, Israel, add valuable insights to the research of this chapter in human history. Considered to represent recurrent occupations at a favored, water and flint-rich setting, the site has provided extensive lithic assemblages obtained from several localities. Absolute chronology places the human activity on-site at roughly 500–300 ky (and possibly even later), which is suggested to be divided into several main occupation phases. Geomorphological and sedimentological analyses show a change in environmental conditions, from aeolian sand deposition and overlying Hamra soil during the Middle Pleistocene to high energy fluvial regime which transported large gravels in a north-south paleo-channel. Wetland environments, correlating to the human activity on site, developed later due to higher sea levels and a coastline shifts to the eastward, which caused a blockage of the Yarkon stream corridor to the sea by marine sand. In this paper we present results of the study of the site, including geomorphological formation and post-depositional processes, absolute chronology, lithic and faunal analyses. The site’s extensive lithic assemblages are currently under study and future investigations are expected to shed more light on the technological nature of Late Acheulian Jaljulia.

Soil-derived magnetic particles trapped in speleothems can retain valuable information on the physiochemical conditions of the overlying soil and changes in the hydrological system. However, a direct link between magnetic and isotopic properties of speleothems has been only qualitatively established and is known to vary regionally. Here we investigate two Holocene speleothems from Soreq Cave, Israel and provide evidence for strong coupling over centennial to millennial timescales between the inflow of magnetic particles (quantified using the magnetic flux index, IRMflux), δ13C, and rainfall amounts. The two stalagmites formed at separate intervals: one at ~9.5 ky BP capturing the transition from pluvial Eastern Mediterranean conditions associated with Sapropel 1 (S1) and a second at 5.4 ky BP recording mid-Holocene wet-dry cycles. The late-Holocene speleothem shows an anomalously high δ13C episode that is correlated with extremely low IRMflux, indicating minimal contribution from overlying soils due to either (1) recently denuded soils, or (2) high overland and vadose runoff. By contrast, the mid-Holocene sample shows saw-tooth cycles in both δ18O and δ13C, which are interpreted as rapid climate fluctuations associated with rainfall changes. IRMflux during this period varies in-phase with the δ13C cycles; however, the peaks in IRMflux values precede those of the isotope values. The apparent lag in isotopic values may be explained by the faster response of the IRMflux to increased rainfall resulting from the rapid physical translocation of overlying soil particles via groundwater, compared with slower soil organic matter turnover rates, which may vary on timescales of up to thousands of years. The separate palaeohydrological scenarios resolved from the two speleothems demonstrate how magnetic data can act as a powerful paleo-hydrology proxy, even in weakly-magnetized speleothems growing under semi-arid conditions.

Cave sediments pose dating challenges due to complex depositional and post-depositional processes that operate during their transport and accumulation. Here, we confront these challenges and investigate the stratified sedimentary sequence from Wonderwerk Cave, which is a key site for the Earlier Stone Age (ESA) in Southern Africa. The precise ages of the Wonderwerk sediments are crucial for our understanding of the timing of critical events in hominin biological and cultural evolution in the region, and its correlation with the global paleontological and archaeological records. We report new constraints for the Wonderwerk ESA chronology based on magnetostratigraphy, with 178 samples passing our rigorous selection criteria, and fourteen cosmogenic burial ages. We identify a previously unrecognized reversal within the Acheulean sequence attributed to the base of the Jaramillo (1.07 Ma) or Cobb Mtn. subchrons (1.22 Ma). This reversal sets an early age constraint for the onset of the Acheulean, and supports the assignment of the basal stratum to the Olduvai subchron (1.77-1.93 Ma). This temporal framework offers strong evidence for the early establishment of the Oldowan and associated hominins in Southern Africa. Notably, we found that cosmogenic burial ages of sediments older than 1 Ma are underestimated due to changes in the inherited Al-26/Be-10 ratio of the quartz particles entering the cave. Back calculation of the inherited Al-26/Be-10 ratios using magnetostratigraphic constraints reveals a decrease in the Al-26/Be-10 ratio of the Kalahari sands with time. These results imply rapid aeolian transport in the Kalahari during the early Pleistocene which slowed during the Middle Pleistocene and enabled prolonged and deeper burial of sand while transported across the Kalahari Basin. (C) 2021 Elsevier Ltd. All rights reserved.

Abstract Archeomagnetic data from the Levant revealed periods within the Holocene with fast and extreme changes in the geomagnetic field. Yet, the availability of the archeomagnetic data is sporadic and the correlation with the available sedimentary records from the region is rather poor. To further explore decadal variations in the directions of the field, we investigate three outcrops of the late Holocene Dead Sea that are exposed along the western retreating shores of the modern lake. The sediments were deposited under spatially varying limnological‐environmental conditions, influencing their magnetic properties. The southern section, located near Ein‐Gedi Spa (EG section) is dominated by detrital titanomagnetite whereas the northern sections, Nahal Og (Og section) and Ein‐Feshkha (EF section), are dominated by authigenic greigite. The chronology of the sections was established by radiocarbon dating of short lived organic debris. The magnetic data were obtained in a 2 cm resolution. The EF section, spanning the time interval from ca. 2,500 cal yr BP to ca. 1,000 cal yr BP, is dominated by greigite and thus providing the most robust geomagnetic record with precise paleomagnetic directions. Greigite forms very early in the sediment and the effects of smoothing and the inclination shallowing are negligible. The new data reveal a maximal deviation of 20° from the geocentric axial dipole field between 2,400 to 2,200 cal yr BP accompanied with a fast swing in inclination from 60° to 35° over about a century. This suggests high geomagnetic field activity associated with the Levantine Iron Age geomagnetic anomaly.

Abstract Diagenetic processes in anoxic sedimentary environments influence sediment magnetic properties mainly through dissolution of detrital magnetite and precipitation of authigenic greigite. Recently exposed late Holocene Dead Sea sediments provide an opportunity to study the processes governing greigite formation and preservation, and their relation to different hydrological settings. Magnetic data and pore‐fluid compositions were obtained from three Holocene sections along a N‐S transect on the western Dead Sea shore: Og, Ein‐Feshkha (EF), and Ein‐Gedi. The northern sections are closer to the major freshwater source to the Dead Sea‐the Jordan River. Detrital titanomagnetite is present at all sections, but greigite is the dominant magnetic phase at Og and EF. Bulk rock magnetic data vary between and within the sections by over 3 orders of magnitude, where higher values indicate higher greigite concentrations. At the three sites, pore fluids have similar or lower salinity than the modern and Holocene Dead Sea brine, with variable and dissolved iron (Fe2+) and sulfate (SO42−). Magnetic property changes are reflected by iron and/or sulfate microbial reduction that controlled sedimentary greigite formation. We propose that the N‐S greigite decrease suggests that anoxic microbial activity was controlled by labile organic matter and/or reactive iron brought by, or formed as a result of, freshwater influx from the Jordan River. Hence, greigite concentration changes depended on past freshwater input to the hypersaline lake and proximity to the freshwater source. The apparent relationship between hydrological conditions and magnetic properties provides a new method to trace past hydrological changes in the Dead Sea.

Abstract Archeomagnetic records are an important source of information on the past behavior of the geomagnetic field. Frequently, however, coeval archeomagnetic intensity (archeointensity) datasets from nearby locations display significant discrepancies, hampering precise reconstruction of high‐resolution secular variation curve. This is the case for the time interval between the later phase of the Early Bronze and the early phase of the Late Bronze Ages (23rd–15th centuries BCE) in the Levant and Mesopotamia. We address the problem by cross‐correlating archeointensity datasets from four major multilayered archeological sites in the southern Levant (Hazor and Megiddo), northern Levant (Ebla), and western Upper Mesopotamia (Mari). We report new archeointensity data, obtained using the Thellier‐IZZI‐MagIC and the Triaxe methods, from six strata at Hazor and four radiocarbon‐dated strata at Megiddo. From 39 pottery fragments, 199 specimens passed our selection criteria, from which we calculated the mean archeointensity for each stratum. To strengthen the comparison of these data with previously published data from Mari and Ebla, obtained using the Triaxe method, we conducted a blind test of the methods that resulted in indistinguishable results or a difference of less than 1 μT. The synchronized compilation, constrained by radiocarbon data from Megiddo, displays a V‐shaped pattern with a prominent minimum of at least 200 years centered around the 18th century BCE. The study highlights the importance of stacking archeomagnetic data obtained by different archeointensity methods only after cross‐testing the methods and ensuring that archeological samples were dated in a consistent manner.

Apart from magnetostratigraphy, archaeomagnetism is rarely used in Middle and Late Pleistocene sites. Here we present detailed palaeomagnetic analyses of cemented hearths and burnt chert items from Amud Cave, Israel (68-55 ka)-two types of materials common in Levantine Middle Palaeolithic cave sites. Both materials are shown to be recorders of the geomagnetic field and were used to reconstruct either the ancient field direction (for cemented hearths) or intensity (palaeointensity) (for chert) at the time of the last burning or shortly after. We test the utility of palaeomagnetic data to further our understanding of temporal aspects of occupations in the cave by comparing the dispersion of the palaeomagnetic data to the known characteristics of geomagnetic secular variation in the Holocene. We show that divergent palaeointensities can help identify diachronic burning events, suggesting different activity patterns in two areas of the cave. Additionally, we used palaeomagnetic directional vectors to distinguish between a well-preserved hearth and one that had been mixed prior to cementation. Using rock magnetic investigations, we demonstrate that magnetic methods can be used as a relatively fast and inexpensive method to identify burning of cherts in antiquity above 500 degrees C. The palaeomagnetic results are in agreement with results of previous studies at Amud Cave, obtained by other independent methods. This study shows that palaeomagnetic methods can serve as a powerful tool in the study of Palaeolithic sites.

Statistical analysis of geomagnetic paleosecular variation (PSV) and time‐averaged field has been largely based on global compilations of paleomagnetic data from lava flows. These show different trends in the averaged inclination anomaly (ΔI) between the two hemispheres, with small positive (<2°) anomalies in midsouthern latitudes and large negative (> −5°) anomalies in midnorthern latitudes. To inspect the large ΔI between 20°N and 40°N we augment the global data with a new paleomagnetic data set from the Golan‐Heights (GH), a Plio‐Pleistocene volcanic plateau in northeast Israel, located at 32–33°N. The GH data set consists of 91 lava flows sites: 40 sites obtained in the 1990s and 51 obtained in this study. The chronology of the flows is constrained by 57 40Ar/39Ar ages: 39 from previous studies and 18 from this study, which together cover most of the GH plateau. We show that the 1990s data set might be affected by block rotations and does not fully sample PSV. The Plio‐Pleistocene pole (86.3°N, 120.8°E, N = 44, k = 25, α95 = 4.4°), calculated after applying selection criteria with Fisher precision parameter (k) ≥ 100 and number of specimens per site (n) ≥ 5 is consistent with a geocentric axial dipole field and shows smaller inclination anomaly (ΔI = −0.4°) than predicted by global compilations and PSV models. Reexamination of the inclination anomaly in the global compilation using different calculation methods and selection criteria suggests that inclination anomaly values are affected by (1) inclusion of poor quality data, (2) averaging data by latitude bins, and (3) the way the inclination anomaly is calculated.

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.

Marine and lacustrine sediments represent an important source of global paleomagnetic data. Although it is usually assumed that detrital iron oxides record most of the magnetic signal in sediments, iron sulfides-which form during bacterial sulfate reduction-can also represent a significant source of sedimentary magnetism. Knowing how sulfate reduction impacts sedimentary magnetism is critical to the interpretation of paleomagnetic records. Here, we show that three distinct types of magnetic particles can be produced by bacterial sulfate reduction, each of which impacts the bulk sediment magnetism in a distinct way. We combined magnetic force microscopy and electron probe microanalysis to image magnetic mineral extracts from Dead Sea sediments from a glacial period and an interglacial period. In sediments from the dry interglacial period, during which bacterial sulfate reduction was suppressed, we found greigite framboids (Fe3S4) with strong intergrain magnetic interactions. Contrastingly, in sediments from the wet glacial period, which experienced extensive sulfate reduction, pyrite (FeS2) is the dominant sulfide phase. High-resolution magnetic imaging of glacial pyrite reveals that greigite is present as single-domain particles within the pyrite. We also found that as titanomagnetite grains undergo bacterially mediated alteration to form pyrite, the original magnetic grains become divided into smaller regions, which potentially facilitates acquisition of secondary magnetization by the reorganization of these magnetic domains. Our results provide a previously undocumented mechanism by which bacterially mediated alteration can overwrite primary detrital magnetic records.

Historical events are sometimes expressed in destruction layers. We present here a study in which aspects of construction, destruction, and chronostratigraphy of fired mud bricks were explored using archaeomagnetism, infrared spectroscopy, and micromorphology. We measured 88 oriented samples mostly collected from one stratum, dated ca. 1000 B.C.E., representing a destroyed late Canaanite (late Iron Age I) city in Tel Megiddo, Israel. Firing temperatures, evaluated from infrared spectroscopy, micromorphology, and high-temperature magnetic susceptibility cycles, range between 300 degrees C and 800 degrees C. Samples studied in one archaeomagnetic site yield a single stable magnetization vector in demagnetization experiments. Archaeomagnetic site means of three standing walls are grouped near the expected direction of the ancient geomagnetic field. We propose that walls in the destruction layer were constructed from sun-dried mud bricks that later burned during the destruction. Collapsed bricks and tilted walls show variable directions, diagnostic for the relative timing of collapse and cooling of bricks, during and following the destruction event. In addition, we attempt to assign stratigraphic affiliation based on archaeomagnetic considerations to standing walls, which are spatially disconnected from the studied destruction layer. Altogether, this study demonstrates the usefulness of archaeomagnetism to understanding site formation processes related to fire and destruction.