Hydrology and denudation rates of halite karst, 1994, Frumkin A,

Salt karst terrains exist mainly in arid climates where rock salt outcrops may escape complete destruction by dissolution. Such is the case with Mount Sedom, on the SW shore of the Dead Sea, one of the most arid parts of Israel. Many small catchments developed over the relatively insoluble cap rock which overlies the highly soluble rock salt. The catchments were surveyed and classified. Some 57% of the surface area is drained by an underground karst system. Water samples from various points in the system were analysed, and water development was inferred. Waters in cave conduits do not reach saturation during flood flow, unless the water is ponded for at least several hours. Based on the available evidence, regional karst denudation is tentatively estimated to be about 0.5-0.75 mm year-1, occurring mainly within the rock salt

Middle Holocene environmental change determined from the salt caves of Mount Sedom, Israel, 1994, Frumkin, A. , Carmi, I. , Zak, I. And Magaritz, M. , 1994

Paleoclimatic sequence for the Middle Holocene was constructed, based on Mount Sedom salt caves, and other evidence. 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. Allogenic karst development has kept pace with the rising, forming vadose caves. Wood fragments found embedded in flood sediments that were deposited in sub-horizontal cave passages yielded 14C ages from 7090 to 200 YBP. The paleoclimatic sequence is based on parameters that include: relative abundance of plant types or floral communities, the elevations of the corresponding relict cave passages and the ratio of their width to present passage width. Moister climatic stages are indicated by relatively abundant wood remains, by wide cave passages and by higher-level outlets, indicating high Dead Sea levels. Arid periods are marked by a scarcity of wood remains, by narrow cave passages and by low-level outlets. The results were correlated to other middle-Holocene evidence and temporal settlement changes. The Early Bronze period in Israel was the moistest period during the last 6000 years and as such it encouraged cultural development. It was followed by a considerable desiccation that caused a cultural deterioration.

RAPID ENTRENCHMENT OF STREAM PROFILES IN THE SALT CAVES OF MOUNT SEDOM, ISRAEL, 1995, Frumkin A, Ford Dc,

Rock salt is approximately 1000 times more soluble than limestone and thus displays high rates of geomorphic evolution. Cave stream channel profiles and downcutting rates were studied in the Mount Sedom salt diapir, Dead Sea rift valley, Israel. Although the area is very arid (mean annual rainfall approximate to 50 mm), the diapir contains extensive karst systems of Holocene age. In the standard cave profile a vertical shaft at the upstream end diverts water from a surface channel in anhydrite or elastic cap rocks into the subsurface route in the salt. Mass balance calculations in a sample cave passage yielded downcutting rates of 0.2 mm s(-1) during peak flood conditions, or about eight orders of magnitude higher than reported rates in any limestone cave streams. However, in the arid climate of Mount Sedom floods have a low recurrence interval with the consequence that long-term mean downcutting rates are lower: an average rate of 8.8 mm a(-1) was measured for the period 1986-1991 in the same sample passage. Quite independently, long-term mean rates of 6.2 mm a(-1) are deduced from C-14 ages of driftwood found in upper levels of 12 cave passages. These are at least three orders of magnitude higher than rates established for limestone caves. Salt cave passages develop in two main stages: (1) an early stage characterized by high downcutting rates into the rock salt bed, and steep passage gradients; (2) a mature stage characterized by lower downcutting rates, with establishment of a subhorizontal stream bed armoured with alluvial detritus. In this mature stage downcutting rates are controlled by the uplift rate of the Mount Sedom diapir and changes of the level of the Dead Sea. Passages may also aggrade. These fast-developing salt stream channels may serve as full-scale models for slower developing systems such as limestone canyons

Uplift rate relative to base-levels of a salt diapir (Dead Sea Basin, Israel) as indicated by cave levels, 1996, Frumkin A,

Rapid downcutting rates in the extremely soluble salt of the Sedom diapir, Dead Sea basin, Israel, allow cave channels to become rapidly graded with respect to base level. Diapir uplift leaves the older passages high and dry above present base level. Dating these passages by 14C allows us to estimate diapir uplift rates, taking into account previous Dead Sea levels. Maximum mean Holocene uplift rates are 6-7 mm a-1 along the eastern fault of Mount Sedom

Structure of northern Mount Sedom salt diapir (Israel) from cave evidence and surface morphology, 1996, Frumkin, A.

Mount Sedom salt diapir, at the south-western edge of the Dead Sea, is covered by a residual caprock, concealing its internal structure. Internal structure observed within karstic caves is correlated here to surface lineaments on top of the caprock. The structural evidence suggests that the northern part of the diapir consists of two salt walls rising from the east and the west. The border between the two walls is observed in caves along the northwestern part of the mountain. The layers are highly deformed along this border, while on both limbs the beds are relatively undeformed, dipping in different directions. The eastern limb comprises most of the width of the elongated northern part of the diapir.

Uplift rate relative to base level of a salt diapir (Dead Sea, Israel), as indicated by cave levels, 1996, Frumkin A.

Geomorphology of the eastern coast of the Dead Sea, Jordan, 1997, Salameh Hassan Ramadan,

Salt cave cross sections and their paleoenvironmental implications, 1998, Frumkin, A.

Salt caves respond rapidly to environmental changes. Direct measurement and 14C dating show that complex cross sections may develop in a few hundred years. Two basic forms are discussed: (1) ingrowing vadose canyons where changing width may correspond to changing discharge; (2) wide low passages with flat ceiling, developed by upward dissolution, which may indicate rising base level. Some cross sections are deformed by Holocene tectonics.

Landscape evolution and the preservation of tectonic landforms along the northern Yammouneh Fault, Lebanon, 1999, Butler Rwh, Spencer S,

The Yammouneh Fault is commonly considered to be the principal active strand of the Dead Sea Transform in Lebanon -- an inference reached primarily from interpretations of the geomorphological expression of the fault on satellite images. However, new geological field observations show the Yammouneh Fault to be sealed stratigraphically by the Homs Basalt, dated using new K-Ar ages at 5.2-6.5 Ma. Drainage systems which link to the pre-Homs Basalt palaeosurface show evidence of fault disruption. Those valleys incised into the basalt show no evidence for transcurrent offsets. The inferred left-lateral displacement of c. 45 km on the Dead Sea Transform that post-dates the Homs Basalt is presumed to have bypassed to the west of Mount Lebanon. These linked geological and geomorphological studies indicate that landscape evolution can be exceptionally slow in northern Lebanon. Faceted spurs, poljes and offset drainage along the Yammouneh Fault across Mount Lebanon, evident on satellite images, are interpreted as being of Miocene age and are not indicative of Plio-Quaternary displacements on the fault. Much of the Lebanese tectonic landscape has thus remained stable for many millions of years, although locally incised during large-scale uplift of the Mount Lebanon range. Presumably landscape insensitivity reflects the arid climatic conditions together with inhibited run-off due to the regional karst system

A Holocene millennial-scale climatic cycle from a speleothem in Nahal Qanah Cave, Israel, 1999, Frumkin A, Carmi I, Gopher A, Ford Dc, Schwarcz Hp, Tsuk T,

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

Holocene millenial-scale climatic cycle from Nahal Qanah Cave speleothem, Israel, 1999, Frumkin, A. , Carmi, I. , Gopher, A. , Tsuk, T. , Ford, D. C. And Schwarcz, H. P.

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 of a stalagmite through the last 6000 years display a 1-2 thousand years cycle. Depleted d18O and d13C values correlate well with high Dead Sea levels and increased arboreal pollen, suggesting common climatic control affecting the entire region.

Collapse and subsidence associated with salt karstification along the dead sea, 2001, Frumkin A, Raz E,

Two types of sinkholes are observed along the Dead Seashore, Israel. The first is associated with vadose dissolution in Mount Sedom salt diapir. The second is associated with dissolution under the watertable along the retreating Dead Sea shore. The Dead Sea level is falling dramatically, mainly because of human activity. Simultaneously, the take shores suffer tremendous impact since the late 1980s: The ground is collapsing and subsiding in hundreds of points along the take, with people, roads and property being swallowed in the more catastrophic events. The collapse is believed to result from dissolution of salt by aggressive groundwater, following the retreat of Dead Sea level and the groundwater halocline. Geological evidence suggests that a previous major lake level fall occurred naturallysimilar to2000 BCE. This may provide a new explanation for a curious historical-geological phrase in the book of Genesis, suggested to record formation of collapse sinkholes which occurred in response to the historic falling take level, associated with climatic desiccation

The Cave of the Letters Sediments ? Indication of an Early Phase of the Dead Sea Depression?, 2001, Frumkin, A.

The highest aquatic sediments along the shoulders of the Dead Sea depression have been found in the Cave of the Letters, Nahal Hever, Israel. The cave has acted as a sediment trap, preserving autogenic dolomite and detritic deposits. The dolomitic sediment may correlate with late Miocene dolomites within the rift valley. The morphostratigraphic setting of the sediment implies deposition within an early topographic low which existed in the Dead Sea region since ~10 to 7 Ma ago.

Radiocarbon chronology of the Holocene Dead Sea: Attempting a regional correlation, 2001, Frumkin, A. , Kadan, G. , Enzel, Y. , And Eyal, Y.

Sedimentary and geomorphic sequences from the Dead Sea region, Israel, are compared by correlation of more than 50 radiocarbon ages which provide the chronology of the region during the Holocene. The chronology allows us to detect basin-scale events which are hard to detect in single-site records. We show the possible use of such correlations for paleoclimate reconstruction, indicated by the Dead Sea level. The Holocene Dead Sea apparently reached a relatively high level at the mid-Holocene around 4400 BP and 3000 cal BCE. Around 4000 BP and 2500 cal BCE it fell sharply and later fluctuated close to early 20th century levels. The radiocarbon-based correlation is also used to estimate the rising rates of Mount Sedom salt diapir. The most probable average diapir rising rate is from 5 to 7 mm/yr.

The Cave of the Letters sediments - indication of an early phase of the Dead Sea depression?, 2001, Frumkin A.