Uranium Series Dating and Stable Isotope Studies of Speleothems: Part I - Theory and Techniques, 1978, Gascoyne M. , Schwarcz H. P. , Ford D. C.

Sea-Level Lowering During the Illinoian Glaciation: Evidence from a Bahama 'Blue Hole', 1979, Gascoyne M, Benjamin Gj, Schwarcz Hp, Ford Dc,

Stalagmites have been recovered from 45 meters below sea level in an underwater karstic cave ('blue hole') near Andros Island in the Bahamas. Uranium series ages, corrected for contamination of the sample by young marine carbonate replacements, show that the speleothem was deposited between 160,000 and 139,000 years before the present. This period corresponds to the Illinoian glacial event and demonstrates that sea level must have been lowered by at least 42 meters (allowing for subsidence) from its present position during this time

Uranium Series ages of Speleothems from Bahaman Blue Holes and their significance, 1984, Gascoyne M.

Uranium series Dating of Speleothems: Part II - Results from the Yorkshire Dales and Implications for Cave Development and Quaternary Climates, 1984, Gascoyne M. , Ford D. C.

Measurements of uranium series disequilibrium in the case-hardened Aymamon limestone in Puerto Rico., 1984, Ivanovich M. , Ireland P.

Uranium Series Dating of Cave Deposits at Creswell Crags Gorge, England, 1989, Rowe P. J. , Atkinson T. C. , Jenkinson R. D. S.

DENUDATION CHRONOLOGY FROM CAVE AND RIVER TERRACE LEVELS - THE CASE OF THE BUCHAN KARST, SOUTHEASTERN AUSTRALIA, 1992, Webb J. A. , Fabel D. , Finlayson B. L. , Ellaway M. , Li S. , Spiertz H. P. ,

Detailed mapping of surface and underground karst features at Buchan, in eastern Victoria, has shown that the three river terraces along the Buchan River can be correlated with three levels of epiphreatic development in the nearby caves. Each level represents a stillstand in the denudational history of the area. Uranium series dating of speleothems and palaeomagnetic studies of cave sediments indicate that all three stillstands are more than 730 ka old. The periods of incision separating the stillstands were probably the result of active tectonic uplift. This contrasts with some northern parts of the Southeastern Highlands, which have been stable since the Eocene. The overall amount of incision and uplift at Buchan is small, indicating that the majority of scarp retreat in this section of the highlands must have occurred earlier. The denudation history of the Buchan area over the last 730 ka has seen only 2-3 m of incision, despite the major climatic and sea-level changes that have occurred in that time. Whereas most karst landscapes in the Northern Hemisphere have been extensively modified during the late Pleistocene, the Buchan karst was little affected, and its geomorphology has an older origin

Late Pleistocene microtine rodents from Snake Creek Burial Cave, White Pine County, Nevada, 1998, Bell Cj, Mead Ji,

A total of 395 microtine rodent specimens recovered from Snake Creek Burial Cave (SCBC) are referred to Microtus SP. and Lemmiscus curtatus. Radiocarbon and Uranium series dates indicate an ae for these fossils of between 9460 160) yr. B.P. and 15,1000 700 yr, B.P. The sample of lower first molars of Lemmiscus includes 4-, 5-, and B-closed triangle morphotypes. Earlier reports of the 4-closed triangle morphotype are from Irvingtonian deposits in Colorado, Nevada, and New Mexico and from early Rancholabrean deposits in Washington. The morphotype is not known in living populations of Lemmiscus. SCBC specimens constitute the youngest record of the 4-closed triangle morphotype and are the only-specimens reported item the late Rancholabrean. Thc time of disappearance of Lemmiscus with this molar morphology is unknown, but populations with this morphotype possibly became extinct at or near the end of the Pleistocene

Palaeoclimatic interpretation of stable isotope data from Holocene speleothems of the Waitomo district, North Island, New Zealand, 1999, Williams P. W. , Marshall A. , Ford D. C. , Jenkinson A. V. ,

One straw stalactite and three stalagmites from the Waitomo district of North Island, New Zealand, were examined for stable isotopes of oxygen and carbon with a view to interpreting their palaeoclimate signal. Dating was by uranium series and AMS 14C for the stalagmites and by gamma-ray spectrometry for the straw. Records were thus established for about 100 years for the straw and 3.9, 10.1 and 10.2 ka for the stalagmites. The range of variability in d18Oc and d13Cc this century is about two-thirds of that experienced over the entire Holocene, and is most simply explained in terms of the oceanic source area of rain. Stable isotope variations in three stalagmites show some general similarities, but have significant differences in detail, which underlines the necessity to base palaeoclimatic interpretations on more than one speleothem record. The d18Oc of each stalagmite varies positively with temperature, indicating the dominance of the ocean source of evaporation in determining the isotopic composition of precipitation and hence speleothem calcite in the Holocene. This conclusion is contrary to that of other authors working in New Zealand, who identified a negative relationship between d18Oc and temperature, while examining time periods extending across the Last Glacial Maximum. It is concluded here that, whereas the ice volume effect dominates the large climatic shifts of glacial-interglacial amplitude, the oceanic source effect becomes more important during the period of relatively stable sea level during the Holocene. Results also indicate a late-Holocene altitudinal effect of 0.2{per thousand} d18Oc per 100 m and an associated temperature relationship of about 0.26{per thousand} per{degrees}C. The average of two records identifies the postglacial climatic optimum to lie in the interval from prior to 10 ka BP to 7.5 ka BP, when d18Oc values were up to 0.6{per thousand} less negative than present, implying an average annual mean temperature that was up to 2.3{degrees}C warmer. The average of three speleothem records for the last 3900 years reveals the coldest period of the Holocene to have occurred about 3 to 2 ka BP, when d18Oc values were typically 0.4{per thousand} more negative than present and average temperatures may have been 1.5{degrees}C cooler. Mean annual temperature variability of about 2{degrees}C was sometimes experienced in little more than 100 years

A Uranium series date from Malham Cove Rising, North Yorkshire, 2001, Murphy P. J. , Latham A. G.

Forum: 'A Uranium series date from Malham Cove Rising, North Yorkshire' [Correction], 2002, Murphy P. J. , Latham A. G.

A late Pleistocene ceiling collapse in Bogus Cave, Jones County, Iowa: A potential relationship to coeval accelerated mass wasting events across the central Midwest, 2002, Josephs, R. L.

A thick accumulation of boulder-size dolostone blocks, the result of one or more episodes of ceiling collapse, was encountered during geoarchaeological excavations in the front room of Bogus Cave, east-central Iowa. The rockfall layer was buried by a veneer of Holocene sediments that contained prehistoric artifacts dating to the Woodland Period (2500 - 1000 yr BP). An AMS 14C age of 17,260 ±120 yr BP, obtained from a caribou (Rangifer tarandus) mandible found wedged among the boulders, dates the collapse near the close of the last glacial maximum, a time when the projected mean annual temperature for this area was at least 14°C lower than at present. Paleoenvironmental evidence based on ?13C values from select vertebrate remains and their encompassing sediment, together with a uranium series age of 16,900 ±4800 yr BP from a stalagmite formed atop one of the boulders, strongly support a late Wisconsinan age for the collapse. The episode (or episodes) of collapse appears to be the result of cryoclastic processes associated with late glacial conditions and the onset of accelerated mass wasting that has been previously documented across the central Midwest

Uranium series dates from Qesem Cave, Israel, and the end of the Lower Palaeolithic, 2003, Barkai, R. , Gopher, A. , Lauritzen, S. E. , And Frumkin, A.

Israel is part of a geographical ?out of Africa? corridor for human dispersals. An important event in these dispersals was the possible arrival of anatomically modern humans in the Levant during the late Middle Pleistocene1,2,3. In the Levant the Lower Paleolithic ends with the Acheulo-Yabrudian complex, characterized by striking technological developments4,5 including the introduction of advanced technological innovations such as systematic blade production and the disappearance of hand-axes . These reflect new human perceptions and capabilities in lithic technology and tool function, as well as innovative human adaptation6. Qesem Cave, discovered in 2000, has a rich, well-preserved Acheulo-Yabrudian sequence holding great promise for providing new insights into the period. Here we report the dates of this cave obtained by U-series of speleothems and their implications. The results shed light on the temporal range of the Acheulo-Yabrudian and the end of the Lower Paleolithic, suggesting a long and unique cultural phase between the Lower Paleolithic Acheulian and the Middle Paleolithic Mousterian, starting well before 350 kyr and ending at ca. 200 kyr.

A uranium series date from Keld Head, Kingsdale, North Yorkshire, 2004, Murphy P. J. , Lundberg J. , Cordingley J. N.

The Great Barrier Reef: The Chronological Record from a New Borehole, 2004, Braithwaite Cjr, Dalmasso H, Gilmour M, Harkness Dd, Henderson Gm, Kay Rl, Kroon D, Montaggioni Lf, Wilson Pa,

A new borehole, 210 mbsf (meters below sea floor) deep, drilled in Ribbon Reef 5 on the Great Barrier Reef off Cooktown, NE Australia, reveals a shallowing-upwards succession, the younger part of which is punctuated by a series of erosion surfaces. Nine depositional units have been defined by lithological changes and are numbered sequentially from the base of the hole upwards. Aminostratigraphy, magnetostratigraphy, radiocarbon dating, uranium series dating, and modeling together with strontium ratios have been applied in an attempt to establish a chronology of accumulation. Carbonate deposition began about 770 ka ago in a relatively deep-water slope environment and is represented by a series of debris flows. Lithoclasts within these rocks, indicate that older limestones already existed in the area. Subsequent accretion involved the downslope accumulation of grainstones and wackestones, sometimes cross-laminated, characterized by intervals with abundant rhodoliths and scattered, probably reworked, corals. Four units at the base of the hole reflect deposition that probably began during isotope stage 16 and continued through stage 15 from about 770 to about 564 ka. Unit 5 probably extended to stage 11 (about 400 ka), and unit 6 to stage 9 ([~] 330 ka). Typical reefal associations of corals and calcareous algae were established in this area only above depths of about 100 m in the borehole, units 5-4. The succession is apparently unbroken to an erosion surface at 36 mbsf indicating subaerial emergence. The lack of evidence of emergence below this surface reflects progressive accretion or progradation or both. Two younger erosion surfaces define further periods of lowered sea level. Unit 7 is attributed to deposition during isotope stage 7, but erosion during stage 8 resulted in the preservation of only 8 m of unit 7 limestones. Unit 8 is correlated with stage 5 ([~]125 ka), and unit 9 is interpreted as Holocene (post 7,700 ka). The limited thicknesses of units 7, 8, and 9 are considered to reflect erosion. The progressive shallowing brought the depositional surface within the zone exposed during lowstands, and there is no sedimentological evidence that aggradation was restricted by a lack of accommodation