Radiocarbon chronology of Iron Age Jerusalem reveals calibration offsets and architectural developments.

Reconstructing the absolute chronology of Jerusalem during the time it served as the Judahite Kingdom's capital is challenging due to its dense, still inhabited urban nature and the plateau shape of the radiocarbon calibration curve during part of this period. We present 103 radiocarbon dates from reliable archaeological contexts in five excavation areas of Iron Age Jerusalem, which tie between archaeology and biblical history. We exploit Jerusalem's rich past, including textual evidence and vast archaeological remains, to overcome difficult problems in radiocarbon dating, including establishing a detailed chronology within the long-calibrated ranges of the Hallstatt Plateau and recognizing short-lived regional offsets in atmospheric 14C concentrations. The key to resolving these problems is to apply stringent field methodologies using microarchaeological methods, leading to densely radiocarbon-dated stratigraphic sequences. Using these sequences, we identify regional offsets in atmospheric 14C concentrations c. 720 BC, and in the historically secure stratigraphic horizon of the Babylonian destruction in 586 BC. The latter is verified by 100 single-ring measurements between 624 to 572 BC. This application of intense 14C dating sheds light on the reconstruction of Jerusalem in the Iron Age. It provides evidence for settlement in the 12th to 10th centuries BC and that westward expansion had already begun by the 9th century BC, with extensive architectural projects undertaken throughout the city in this period. This was followed by significant damage and rejuvenation of the city subsequent to the mid-eight century BC earthquake, after which the city was heavily fortified and continued to flourish until the Babylonian destruction.

Sub-annual bomb radiocarbon records from trees in northern Israel.

Spatial and temporal variations in the atmospheric bomb radiocarbon make it a very useful tracer and a dating tool. With the introduction of more atmospheric bomb radiocarbon records, the spatial and temporal changes in bomb radiocarbon are becoming clearer. Bomb radiocarbon record from a pine tree in the northern Israel region shows that the Δ14C level in the region is closer to the northern hemisphere zone (NH) 1 as compared to the northern hemisphere zone (NH) 2. A comparison of this pine's Δ14C record with a nearby olive tree's Δ14C values also highlights changes in the growing season of the olive wood from one year to the other. The observation suggests that olive wood 14C ages can show offset compared to the IntCal curve, and thus they should be interpreted cautiously.

Crystallinity assessment of anthropogenic calcites using Raman micro-spectroscopy.

Anthropogenic calcite is a form of calcium carbonate produced through pyrotechnological activities, and it is the main component of materials such as lime binders and wood ash. This type of calcite is characterized by a significantly lower degree of crystallinity compared with its geogenic counterparts, as a result of different formation processes. The crystallinity of calcite can be determined using infrared spectroscopy in transmission mode, which allows decoupling particle size effect from atomic order and thus effectively distinguish anthropogenic and geogenic calcites. On the contrary, Raman micro-spectroscopy is still in the process of developing a reference framework for the assessment of crystallinity in calcite. Band broadening has been identified as one of the proxies for crystallinity in the Raman spectra of geogenic and anthropogenic calcites. Here we analyze the full width at half maximum of calcite bands in various geogenic and anthropogenic materials, backed against an independent crystallinity reference based on infrared spectroscopy. Results are then used to assess the crystallinity of anthropogenic calcite in archaeological lime binders characterized by different states of preservation, including samples affected by the formation of secondary calcite, and tested on micromorphology thin sections in which lime binders are embedded in sediments.

Three dimensional structures of the inner and outer pig petrous bone using FIB-SEM: Implications for development and ancient DNA preservation.

We report on the 3D ultrastructure of the mineralized petrous bone of mature pig using focused ion beam - scanning electron microscopy (FIB-SEM). We divide the petrous bone into two zones based on the degree of mineralization; one zone close to the otic chamber has higher mineral density than the second zone further away from the otic chamber. The hypermineralization of the petrous bone results in the collagen D-banding being poorly revealed in the lower mineral density zone (LMD), and absent in the high mineral density zone (HMD). We therefore could not use D-banding to decipher the 3D structure of the collagen assembly. Instead we exploited the anisotropy option in the Dragonfly image processing software to visualize the less mineralized collagen fibrils and/or nanopores that surround the more mineralized zones known as tesselles. This approach therefore indirectly tracks the orientations of the collagen fibrils in the matrix itself. We show that the HMD bone has a structure similar to that of woven bone, and the LMD is composed of lamellar bone with a plywood-like structural motif. This agrees with the fact that the bone close to the otic chamber is fetal bone and is not remodeled. The lamellar structure of the bone further away from the otic chamber is consistent with modeling/remodeling. The absence of the less mineralized collagen fibrils and nanopores resulting from the confluence of the mineral tesselles may contribute to shielding DNA during diagenesis. We show that anisotropy evaluation of the less mineralized collagen fibrils could be a useful tool to analyze bone ultrastructures and in particular the directionality of collagen fibril bundles that make up the bone matrix.

Ancient DNA from a lost Negev Highlands desert grape reveals a Late Antiquity wine lineage.

Recent excavations of Late Antiquity settlements in the Negev Highlands of southern Israel uncovered a society that established commercial-scale viticulture in an arid environment [D. Fuks et al., Proc. Natl. Acad. Sci. U.S.A. 117, 19780-19791 (2020)]. We applied target-enriched genome-wide sequencing and radiocarbon dating to examine grapevine pips that were excavated at three of these sites. Our analyses revealed centuries long and continuous grape cultivation in the Southern Levant. The genetically diverse pips also provided clues to ancient cultivation strategies aimed at improving agricultural productivity and ensuring food security. Applying genomic prediction analysis, a pip dated to the eighth century CE was determined to likely be from a white grape, to date the oldest to be identified. In a kinship analysis, another pip was found to be descendant from a modern Greek cultivar and was thus linked with several popular historic wines that were once traded across the Byzantine Empire. These findings shed light on historical Byzantine trading networks and on the genetic contribution of Levantine varieties to the classic Aegean landscape.

Early Upper Paleolithic cultural variability in the Southern Levant: New evidence from Nahal Rahaf 2 Rockshelter, Judean Desert, Israel.

The Levantine Early Upper Paleolithic (ca. 45-30 ka) has been a focus of research because of its unique position as a conduit of human, flora, and fauna species between Africa and Eurasia. Studies have mainly focused on the Early Ahmarian and Levantine Aurignacian, two entities, the former endemic and the latter foreign, which are considered to have coinhabited the region during that period. However, other cultural entities, such as the Atlitian in the Mediterranean region and the Arkov-Divshon in the arid regions of the southern Levant received less attention, and accordingly, suffer from broad definitions and chronological insecurity. These cultures hold potential insights regarding nuanced adaptations, reciprocal influences, and diachronic assimilation processes. The recently discovered site of Nahal Rahaf 2 Rockshelter in the Judean Desert provides integral information on one of these entities-the Arkov-Divshon. Two excavation seasons revealed a sequence of archaeological layers, with lithic assemblages in which laterally carinated items were prominent. Alongside rich faunal assemblages, other components of the material culture include perforated marine shells and bone tools, marking the first association of these elements with Arkov-Divshon and implying some degree of contact with the Mediterranean regions of the Levant. Good preservation of organic materials allowed radiocarbon dating of the human occupation at the site to ca. 37.5-34.0 ka cal BP, indicating chronological overlap with the Levantine Aurignacian, and possibly also with the latest phases of the Early Ahmarian. Thus, challenging the validity of the widely accepted 'Two Tradition' Model of the Levantine Upper Paleolithic. Lithic analyses suggest the use of one main reduction sequence and the primary production of bladelets from carinated items. Faunal remains suggest targeted hunting of ibex and gazelle. Botanical remains and sedimentary analyses suggest roughly similar environmental conditions, with a possible woodier environment in the surroundings of the site.

The petrous bone contains high concentrations of osteocytes: One possible reason why ancient DNA is better preserved in this bone.

The characterization of ancient DNA in fossil bones is providing invaluable information on the genetics of past human and other animal populations. These studies have been aided enormously by the discovery that ancient DNA is relatively well preserved in the petrous bone compared to most other bones. The reasons for this better preservation are however not well understood. Here we examine the hypothesis that one reason for better DNA preservation in the petrous bone is that fresh petrous bone contains more DNA than other bones. We therefore determined the concentrations of osteocyte cells occluded inside lacunae within the petrous bone and compared these concentrations to other bones from the domestic pig using high resolution microCT. We show that the concentrations of osteocyte lacunae in the inner layer of the pig petrous bone adjacent to the otic chamber are about three times higher (around 95,000 lacunae per mm3) than in the mastoid of the temporal bone (around 28,000 lacunae per mm3), as well as the cortical bone of the femur (around 27,000 lacunae per mm3). The sizes and shapes of the lacuna in the inner layer of the petrous bone are similar to those in the femur. We also show that the pig petrous bone lacunae do contain osteocytes using a histological stain for DNA. We therefore confirm and significantly expand upon previous observations of osteocytic lacuna concentrations in the petrous bone, supporting the notion that one possible reason for better preservation of ancient DNA in the petrous bone is that this bone initially contains at least three times more DNA than other bones. Thus during diagenesis more DNA is likely to be preserved in the petrous bone compared to other bones.

Expansion of eastern Mediterranean Middle Paleolithic into the desert region in early marine isotopic stage 5.

Marine Isotopic Stage 5 is associated with wetter climatic conditions in the Saharo-Arabian deserts. This stage also corresponds to the establishment of Middle Paleolithic hominins and their associated material culture in two geographical provinces in southwest Asia-the Eastern Mediterranean woodland and the Arabian Peninsula desert. The lithic industry of the Eastern Mediterranean is characterized by the centripetal Levallois method, whereas the Nubian Levallois method characterizes the populations of the Arabian desert. The Negev Desert, situated between these regions is a key area to comprehend population movement in correlation to climatic zones. This investigation addresses the nature of the Middle Paleolithic settlement in the Negev Desert during MIS 5 by studying the site of Nahal Aqev. High resolution chronological results based on luminescence dating and cryptotephra show the site was occupied from MIS 5e to MIS 5d. The lithic industries at Nahal Aqev are dominated by centripetal Levallois core method. These data demonstrate that Nahal Aqev is much closer in its cultural attributes to the Eastern Mediterranean Middle Paleolithic than to the Arabian Desert entity. We conclude that Nahal Aqev represents an expansion of Middle Paleolithic groups from the Mediterranean woodland into the desert, triggered by better climatic conditions. These groups possibly interacted with hominin groups bearing the Nubian core tradition from the vast region of Arabia.

The absolute chronology of Boker Tachtit (Israel) and implications for the Middle to Upper Paleolithic transition in the Levant.

The Initial Upper Paleolithic (IUP) is a crucial lithic assemblage type in the archaeology of southwest Asia because it marks a dramatic shift in hominin populations accompanied by technological changes in material culture. This phase is conventionally divided into two chronocultural phases based on the Boker Tachtit site, central Negev, Israel. While lithic technologies at Boker Tachtit are well defined, showing continuity from one phase to another, the absolute chronology is poorly resolved because the radiocarbon method used had a large uncertainty. Nevertheless, Boker Tachtit is considered to be the origin of the succeeding Early Upper Paleolithic Ahmarian tradition that dates in the Negev to ∼42,000 y ago (42 ka). Here, we provide 14C and optically stimulated luminescence dates obtained from a recent excavation of Boker Tachtit. The new dates show that the early phase at Boker Tachtit, the Emirian, dates to 50 through 49 ka, while the late phase dates to 47.3 ka and ends by 44.3 ka. These results show that the IUP started in the Levant during the final stages of the Late Middle Paleolithic some 50,000 y ago. The later IUP phase in the Negev chronologically overlaps with the Early Upper Paleolithic Ahmarian of the Mediterranean woodland region between 47 and 44 ka. We conclude that Boker Tachtit is the earliest manifestation of the IUP in Eurasia. The study shows that distinguishing the chronology of the IUP from the Late Middle Paleolithic, as well as from the Early Upper Paleolithic, is much more complex than previously thought.

Discovery of annual growth in a modern olive branch based on carbon isotopes and implications for the Bronze Age volcanic eruption of Santorini.

The volcanic eruption of Santorini in the Bronze Age left detectable debris across the Mediterranean, serving as an anchor in time for the region, synchronizing chronologies of different sites. However, dating the eruption has been elusive for decades, as radiocarbon indicates a date about a century earlier than archaeological chronologies. The identification of annual rings by CT in a charred olive branch, buried alive beneath the tephra on Santorini, was key in radiocarbon dating the eruption. Here, we detect a verified annual growth in a modern olive branch for the first time, using stable isotope analysis and high-resolution radiocarbon dating, identifying down to the growing season in some years. The verified growth is largely visible by CT, both in the branch's fresh and charred forms. Although these results support the validity of the Santorini branch date, we observed some chronological anomalies in modern olive and simulated possible date range scenarios of the volcanic eruption of Santorini, given these observed phenomena. The results offer a way to reconcile this long-standing debate towards a mid-sixteenth century BCE date.

Climatic and environmental conditions in the Western Galilee, during Late Middle and Upper Paleolithic periods, based on speleothems from Manot Cave, Israel.

Early Ahmarian, Levantine Aurignacian and Post-Levantine Aurignacian archeological assemblages show that the karstic Manot Cave, located 5 km east of the Mediterranean coast in the Western Galilee region of Israel, was intensively occupied during the Early Upper Paleolithic. The coexistence of these rich archaeological layers with speleothems in Manot Cave provides a window of opportunity for determining the relationships between climatic conditions and the nature of human activity and mobility patterns in the Western Galilee region during the Early Upper Paleolithic period. This study, based on four stalagmites that grew almost continuously from ∼75 to 26.5 ka, covers most of the last glacial, and overlaps with the human occupation of the cave. The speleothems oxygen (δ18O) and carbon (δ13C) isotopic records indicate that climate and environmental conditions fluctuated during the last glacial, some of which correspond with Dansgaard-Oeschger (D-O) cycles 12, 10, 7 and Heinrich (H) events VI and V. Consistent with independent evidence from botanic and faunal remains, these climatic shifts brought about significant environmental changes in the region, ranging from dominant thick Mediterranean forest to more open landscape. A good correlation with less negative δ13C values is most pronounced during the Early Ahmarian time period, but there was also a change to less negative δ13C values during the Levantine Aurignacian and Post-Levantine Aurignacian industries in the Levant. These positive δ13C shifts suggest that environmental transformation towards a more open grassy landscape dominated by C4 vegetation might have played an important role in the development of these cultural entities (mainly the Early Ahmarian) in Manot Cave region.

Site formation processes at Manot Cave, Israel: Interplay between strata accumulation in the occupation area and the talus.

Manot Cave contains important human fossils and archaeological assemblages related to the origin and dispersal of anatomically modern humans and the Upper Paleolithic period. This record is divided between an elevated in situ occupation area and a connecting talus. We, thus, investigated the interplay between the accumulation of the sediments and their associated artifacts in the occupation areas and the translocation of part of these sediments and artifacts down the talus. We examined the lithostratigraphy of two excavation locations in the occupation area (areas E and I), and two in the talus (areas C and D). We also assessed the diagenetic processes that have affected all these areas. A linear array of stalagmites and stalactites separates the occupation area from the talus, demarcating a major topographic barrier between the two. We infer that during human occupation, sediment accumulation of soil, wood ash, and bone was rapid and that some sediments with their associated artifacts overflowed the barrier and translocated down the talus. During periods of nonoccupation, the ash in the occupation area partially dissolved owing to the release of acid from the degrading bat and bird guano, and the layer thicknesses decreased. The south side of the talus (area C) has a normally stratified archaeological record, with the older archaeological materials underlying the younger materials. This suggests that the barrier between the occupation area and area C was relatively shallow and allowed a fairly continuous sediment accumulation in the talus. In the central part of the talus (area D), the stratigraphy is complex and shows mixing, presumably owing to the steep underlying bedrock topography and the mixing that occurs when sediments move down a steep slope. Finally, the distribution of secondary phosphates is consistent with the location of a main cave entrance to the south of the Paleolithic occupation area.

The Marine Isotope Stage 3 landscape around Manot Cave (Israel) and the food habits of anatomically modern humans: New insights from the anthracological record and stable carbon isotope analysis of wild almond (Amygdalus sp.).

The excavation of Manot Cave (Israel) reveals intensive occupation during the Early Upper Paleolithic and provides the first continuous set of anthracological data available for the Ahmarian, Levantine Aurignacian and post-Levantine Aurignacian periods. The paper aims to study the vegetal landscape around Manot Cave in the context of climate changes that characterized the last part of the Marine Isotope Stage 3 (MIS 3) and to address the issue of firewood and food procurement among Paleolithic hunter-gatherers. Charcoal samples recovered from the archaeological layers at Manot Cave shed light on the fuel and food procurement strategies while radiocarbon dating and stable carbon isotope analysis (Δ13C) of selected charcoals provide information about the ancient climate. The results show that five woody taxa were exploited at the site; Amygdalus sp. was the most common species, whereas Quercus ithaburensis, Tamarix sp., Pomoideae indet., and Pistacia atlantica were relatively rare. The representations of the recovered wooden species suggest that an open forest of almonds and oaks existed in the area during MIS 3. Radiocarbon dating of Amygdalus sp. charcoals, coupled with stable carbon isotope analysis (Δ13C) of modern and archaeological Amygdalus sp. clearly indicate variations in rainfall that could have decreased the density of tree cover. These analyses provide high-resolution data on the climate changes affecting the surroundings of Manot Cave between ∼46 and 28 ka cal BP and indicate two drier phases corresponding to the Ahmarian and post-Levantine Aurignacian cultures while a more humid period identified during the Levantine Aurignacian.

Radiocarbon dating and microarchaeology untangle the history of Jerusalem's Temple Mount: A view from Wilson's Arch.

Radiocarbon dating is rarely applied in Classical and Post-Classical periods in the Eastern Mediterranean, as it is not considered precise enough to solve specific chronological questions, often causing the attribution of historic monuments to be based on circumstantial evidence. This research, applied in Jerusalem, presents a novel approach to solve this problem. Integrating fieldwork, stratigraphy, and microarchaeology analyses with intense radiocarbon dating of charred remains in building materials beneath Wilson's Arch, we absolutely dated monumental structures to very narrow windows of time-even to specific rulers. Wilson's Arch was initiated by Herod the Great and enlarged during the Roman Procurators, such as Pontius Pilatus, in a range of 70 years, rather than 700 years, as previously discussed by scholars. The theater-like structure is dated to the days of Emperor Hadrian and left unfinished before 132-136 AD. Through this approach, it is possible to solve archaeological riddles in intensely urban environments in the historical periods.

Precipitation variability differently affects radial growth, xylem traits and ring porosity of three Mediterranean oak species at xeric and mesic sites.

In the Mediterranean basin, diffuse-porous, semi-ring-porous and ring-porous tree species coexist in the same regions. Climate change might differently affect these types, but a mechanistic understanding of drought effects on their xylem structure is lacking. We investigated tree-ring width and xylem functional traits in ring-porous Quercus boissieri, semi-ring-porous Q. ithaburensis and diffuse-porous Q. calliprinos, at xeric (Galilee) and mesic (Golan) sites in the South-Eastern Mediterranean basin. We quantitatively assessed how dry and wet years affect growth and xylem traits in different porosity type oaks, and evaluated whether porosity type is preserved or altered during these years. We measured, counted or computed tree-ring width, vessel number, maximum lumen area, frequency, tree-ring and xylem theoretical hydraulic conductivity along 40-year ring series of 50 trees in total. We also quantified ring porosity in each year using two indices, the Gini coefficient and the porosity ratio of vessel area, and described vessel area intra-ring variations by distribution profiles. We then compared these parameters in the five driest and five wettest years of the 40-year period. Radial growth and functional trait variations were more similar between species in the same site (strong drought effects in Q. ithaburensis and Q. calliprinos in Galilee, moderate effects in Q. boissieri and Q. calliprinos in Golan) than between sites for the same species (Q. calliprinos was more affected in Galilee than in Golan). Ring porosity indices and distribution profiles showed that diffuse-porous xylem structure of Q. calliprinos was maintained even under dry conditions at both sites. However, Q. boissieri xylem shifted from ring-porous in wet and normal years to semi-ring-porous in dry years, i.e. the porous ring cannot be completely built under water constraint. This suggests that ring porous strategy, typical of temperate regions with strong seasonality, might not be realized under future drier conditions in the Mediterranean basin.

Ancient trash mounds unravel urban collapse a century before the end of Byzantine hegemony in the southern Levant.

The historic event of the Late Antique Little Ice Age (LALIA) was recently identified in dozens of natural and geological climate proxies of the northern hemisphere. Although this climatic downturn was proposed as a major cause for pandemic and extensive societal upheavals in the sixth-seventh centuries CE, archaeological evidence for the magnitude of societal response to this event is sparse. This study uses ancient trash mounds as a type of proxy for identifying societal crisis in the urban domain, and employs multidisciplinary investigations to establish the terminal date of organized trash collection and high-level municipal functioning on a city-wide scale. Survey, excavation, sediment analysis, and geographic information system assessment of mound volume were conducted on a series of mounds surrounding the Byzantine urban settlement of Elusa in the Negev Desert. These reveal the massive collection and dumping of domestic and construction waste over time on the city edges. Carbon dating of charred seeds and charcoal fragments combined with ceramic analysis establish the end date of orchestrated trash removal near the mid-sixth century, coinciding closely with the beginning of the LALIA event and outbreak of the Justinian Plague in the year 541. This evidence for societal decline during the sixth century ties with other arguments for urban dysfunction across the Byzantine Levant at this time. We demonstrate the utility of trash mounds as sensitive proxies of social response and unravel the time-space dynamics of urban collapse, suggesting diminished resilience to rapid climate change in the frontier Negev region of the empire.

Radiocarbon analysis of modern olive wood raises doubts concerning a crucial piece of evidence in dating the Santorini eruption.

Charred olive wood is abundant in the archaeological record, especially around the Mediterranean. As the outermost ring closest to the bark is assumed to represent the latest time that the tree was alive, the radiocarbon date obtained from the outermost rings of an olive branch buried during the Santorini volcanic eruption is regarded as crucial evidence for the date of this cataclysmic event. The date of this eruption has far reaching consequences in the archaeology of the Aegean, Egypt and the Levant, and the understanding of their interconnections. We analyzed the radiocarbon concentrations in cross-sections from a modern olive tree trunk as well as from a living branch, and obtained near-annual resolution dates using the radiocarbon "bomb peak". In both cases we show that radiocarbon dates of the last formed wood along the circumference are not chronologically homogenous, and can differ by up to a few decades. Thus the outermost wood layer does not necessarily represent the date of the last year of growth. These findings challenge the interpretation of the results obtained from dating the olive branch from the Santorini volcanic eruption, as it could predate the eruption by a few decades. In addition, our results are also significant for any future studies based on archaeologically preserved olive wood.

High Resolution AMS Dates from Shubayqa 1, northeast Jordan Reveal Complex Origins of Late Epipalaeolithic Natufian in the Levant.

The Late Epipalaeolithic Natufian (~14,600 - 11,500 cal BP) is a key period in the prehistory of southwest Asia. Often described as a complex hunting and gathering society with increased sedentism, intensive plant exploitation and associated with an increase in artistic and symbolic material culture, it is positioned between the earlier Upper- and Epi-Palaeolithic and the early Neolithic, when plant cultivation and subsequently animal domestication began. The Natufian has thus often been seen as a necessary pre-adaptation for the emergence of Neolithic economies in southwest Asia. Previous work has pointed to the Mediterranean woodland zone of the southern Levant as the 'core zone' of the Early Natufian. Here we present a new sequence of 27 AMS radiocarbon dates from the Natufian site Shubayqa 1 in northeast Jordan. The results suggest that the site was occupied intermittently between ~14,600 - 12,000 cal BP. The dates indicate the Natufian emerged just as early in eastern Jordan as it did in the Mediterranean woodland zone. This suggests that the origins and development of the Natufian were not tied to the ecological conditions of the Mediterranean woodlands, and that the evolution of this hunting and gathering society was more complex and heterogeneous than previously thought.

Radiocarbon chronology of Manot Cave, Israel and Upper Paleolithic dispersals.

The timing of archeological industries in the Levant is central for understanding the spread of modern humans with Upper Paleolithic traditions. We report a high-resolution radiocarbon chronology for Early Upper Paleolithic industries (Early Ahmarian and Levantine Aurignacian) from the newly excavated site of Manot Cave, Israel. The dates confirm that the Early Ahmarian industry was present by 46,000 calibrated years before the present (cal BP), and the Levantine Aurignacian occurred at least between 38,000 and 34,000 cal BP. This timing is consistent with proposed migrations or technological diffusions between the Near East and Europe. Specifically, the Ahmarian could have led to the development of the Protoaurignacian in Europe, and the Aurignacian in Europe could have spread back to the Near East as the Levantine Aurignacian.

Radiocarbon Dating of an Olive Tree Cross-Section: New Insights on Growth Patterns and Implications for Age Estimation of Olive Trees.

The age of living massive olive trees is often assumed to be between hundreds and even thousands of years. These estimations are usually based on the girth of the trunk and an extrapolation based on a theoretical annual growth rate. It is difficult to objectively verify these claims, as a monumental tree may not be cut down for analysis of its cross-section. In addition, the inner and oldest part of the trunk in olive trees usually rots, precluding the possibility of carting out radiocarbon analysis of material from the first years of life of the tree. In this work we present a cross-section of an olive tree, previously estimated to be hundreds of years old, which was cut down post-mortem in 2013. The cross-section was radiocarbon dated at numerous points following the natural growth pattern, which was made possible to observe by viewing the entire cross-section. Annual growth rate values were calculated and compared between different radii. The cross-section also revealed a nearly independent segment of growth, which would clearly offset any estimations based solely on girth calculations. Multiple piths were identified, indicating the beginning of branching within the trunk. Different radii were found to have comparable growth rates, resulting in similar estimates dating the piths to the 19th century. The estimated age of the piths represent a terminus ante quem for the age of the tree, as these are piths of separate branches. However, the tree is likely not many years older than the dated piths, and certainly not centuries older. The oldest radiocarbon-datable material in this cross-section was less than 200 years old, which is in agreement with most other radiocarbon dates of internal wood from living olive trees, rarely older than 300 years.