Israel Carmi

The Holocene climatic record of the salt caves of Mount Sedom Israel

Mount Sedom is a salt diapir, on the southwestern shore of the Dead Sea, which has been rising above the local base level throughout the Holocene. Karst development within the salt body has kept pace with the rise forming subhorizontal cave passages with vertical shafts. Wood fragments found embedded in flood sediments that were deposited in the cave passages yielded 14C ages ranging from c. 7100 to 200 BP. A palaeoclimatic sequence was constructed, based on parameters that include: relative abundance of plant types or floral communities, the elevations of the corresponding cave passages and the ratio of their width to present passage width. The results were correlated to the Holocene sedimentary sequence of the Dead Sea Basin, and other features associated with shifting lake levels. Moister climatic stages are indicated by relatively abundant wood remains, by wide cave passages and by elevated outlets indicating high Dead Sea level. Arid periods are marked by a scarcity of wood remains, by narrow cave passages and by low-level outlets. The Holocene sequence of Mount Sedom is subdivided into 10 climatic stages: A moist stage in the early Holocene, older than 7000 BP, and nine subsequent stages of drier climate, fluctuating between conditions that are somewhat drier, up to somewhat moister than those of today. The Dead Sea level dropped from c. -300 MSL during the early moist period to -400 MSL or lower during the subsequent arid periods.

Dating of cremated bones

When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a remarkable success rate for this method.

Radiocarbon dating of Ohalo II: Archaeological and methodological implications

Abstract Charcoal samples from the Early Epipalaeolithic submerged fisher-hunter-gatherers site of Ohalo II have been dated by three laboratories. The samples derive from huts, hearths, a grave and a stone installation. Twenty-five date range between 17,500-21,050 bp and average c. 19,400 bp . The thickness of deposits, the perishable building material (of the huts), the spatial organization of the camp and its rapid cover by sand and water suggest several occupational episodes, lasting not more than tens of years together. The discrepancy between the range of 14 C dates and the real length of occupation are due to the statistical limitations of the dating method.

A Holocene millennial-scale climatic cycle from a speleothem in Nahal Qanah Cave, Israel

Nahal Qanah Cave, located in the east Mediterranean region, has been inhabited by humans during several periods of the Holocene. These well-dated cultures are used here to establish the age of a speleothem growing over archaeological remains. d18O and d13C from a stalagmite through the last 6000 years display a 1000–2000-year cycle. Depleted d18O and d13C value correlate well with high Dead Sea levels and increased arboreal pollen, suggesting common climatic control affecting the entire region.

Radiocarbon Dating of Fourteen Dead Sea Scrolls

The name Dead Sea Scrolls refers to some 1200 manuscripts found in caves in the hills on the western shore of the Dead Sea during the last 45 years. They range in size from small fragments to complete books from the holy scriptures (the Old Testament). The manuscripts also include uncanonized sectarian books, letters and commercial documents, written on papyrus and parchment. In only a few cases, direct information on the date of writing was found in the scrolls. In all other cases, the dating is based on indirect archaeological and paleographical evidence. To check this evidence, radiocarbon ages of 14 selected scrolls were determined using accelerator mass spectrometry. The calibrated radiocarbon ages agree well, except in one case, with the paleographic estimates or the specific dates noted on the scrolls.

Water transport through Lake Kinneret sediments traced by tritium

The transport of water through the sediments of Lake Kinneret was estimated using tritium of fallout origin as a tracer. The calculation model takes into account the diffusion of the tracer and its decay, and allows for the advective flux through the sediment pores as a free parameter. The dependence of the interstitial diffusion constant on the porosity was assumed identical to that for chloride ions. Tritium profiles in nine cores were used for estimating the advective fluxes and velocities, by finding the best fit between data and model. Water advective fluxes of 3.4 g cm−2 yr−1 into the lake were found. This water flux is negligible in the hydrological balance of Lake Kinneret; but it carries along 7% of the unaccounted-for chloride input to the lake.

Calibration of Lacustrine Sediment Ages Using the Relationship Between 14C Levels in Lake Waters and in the Atmosphere: The Case of Lake Kinneret

The source of endogenic organic and inorganic carbon in lacustrine sediments is the dissolved inorganic carbon (DIC) in the lake water. The relation between the radiocarbon levels of DIC in Lake Kinneret and of CO (sub 2) in the atmosphere has been investigated. The ratio of the former to the latter was found to be 0.814+ or -0.013. This ratio is used for calibrating the age of the sediment according to the natural fluctuations in the atmospheric levels of (super 14) C that occurred during the past 10,000 years.

Hammat Gader (Israel): Geochemistry of a mixed thermal spring complex

Abstract A complex of four spring groups has been studied at Hammat Gader, northern Israel. The temperature and concentrations of dissolved ions reveal the springs to be mixtures of two types of water whose characteristics were deduced by extrapolation. The hot end member is enriched in 4 He, 226 Ra and nitrogen, flushed from the hot aquifer rocks. The Ne, Ar, Kr and Xe have atmospheric isotopic compositions and occur in relative elemental abundances similar to those dissolved in air-saturated water. This indicates that both water end members originated from rain water that equilibrated with air and infiltrated into the ground. The Ar, Kr and Xe concentrations revealed that both water types were formed from rains that entered the ground at “paleotemperatures” of 19 ± 3°C. The δD and δ 18 O values of the hot end member are lighter than for the cold one. The tritium and 14 C values indicate the true hot end member to have an age older than 11,7000 years whereas the true cold end member has an age of 12,000 ± 1,500 years. The cold spring D is mixed with about 3% post-nuclear-tests rain water.

The hydrology of the Jordan tributaries (Israel): Hydrographic and isotopic investigation

Abstract Nahal Dan, Nahal Snir and Nahal Hermon are the three principal tributaries of the Jordan River. All three are spring-fed and appear to derive their discharges from the same regional groundwater aquifer. The behaviour of this aquifer is examined by hydrograph separation and multivariate time-series analysis of discharge and rainfall records, and by investigation of 18 O and tritium records. Hydrograph separation gives base-flow recession constants of 11–20 months and in addition N. Snir and N. Hermon show an interflow recession of ∼ 1 month. The dual reservoir system for these two tributaries is confirmed by time-series analysis. 18 O data distinguish the different catchments for the springs and support the idea that interflow occurs in the near-surface part of the regional groundwater reservoir. Tritium data illustrate the inhomogeneity of the karstic reservoir. Assuming well-mixed conditions, the difference in behaviour between tritium records for rainfall and the tributaries is used to estimate the age distribution of water in the reservoir. At any time 50% of the storage is less than 1 yr. old and 90% is less than 3 yr. old.

Tritium in the Dead Sea

Abstract Tritium data in the Dead Sea for the period 1960–1979 are given. Tritium levels have increased until 1965 in the upper layers of the Dead Sea reaching a level of 170 TU, in response to the atmospheric buildup of tritium from thermonuclear testing. The levels have been decreasing ever since, both because of rapidly declining atmospheric concentrations of tritium and because of mixing of the surface layers with tritium deficient, deeper water masses. The depth of penetration of the tracer delineated the depth of meromictic stratification and successfully monitored the deepening of the pycnocline, until the overturn in 1979 homogenised the entire tritium profile. Modelling the changing tritium inventory over this period showed the predominance of the direct exchange across the air/sea interface, both in the buildup of tritium in the lake and also in its subsequent removal from it. The good fit between calculated and measured tritium inventories confirmed the evaporation estimate of 1.46 m/yr (the mean value for the period) with a precision unattained by other methods.