R Lawrence Edwards
Biographic Data
| ID | 220030 |
|---|---|
| NAME | R Lawrence Edwards |
| GIVEN NAMES | R Lawrence |
| FAMILY NAME | Edwards |
| SIGNATURE | EDWARDS R L |
| AFFILIATIONS | University of Minnesota |
| ORCID | 0000-0002-7027-5881 |
| VERIFIED | Yes |
| TOTAL WORKS | 75 |
| TOTAL CITATIONS | 4109 |
| AUTHOR COUNT | 75 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1965 |
| LATEST PUBLICATION YEAR | 2024 |
| H-INDEX | 10 |
Tropical vegetation productivity and atmospheric methane over the last 40,000 years from model simulations and stalagmites in Sulawesi, Indonesia
Recent research has shown the potential of speleothem δ 13 C to record a range of environmental processes. Here, we report on 230 Th-dated stalagmite δ 13 C records for southwest Sulawesi, Indonesia, over the last 40,000 yr to investigate the relationship between tropical vegetation productivity and atmospheric methane concentrations. We demonstrate that the Sulawesi stalagmite δ 13 C record is driven by changes in vegetation productivity and soi…
Climate variability in the northern Levant from the highly resolved Qadisha record (Lebanon) during the Holocene optimum
New stalagmites from Qadisha Cave (Lebanon) located at 1720 m above sea level provide a high-resolution and well-dated record for northern Mount Lebanon. The stalagmites grew discontinuously from 9.2 to 5.7 and at 3.5 ka, and they show a tendency to move from a more negative oxygen isotope signal at ~9.1 ka to a more positive signal at ~5.8 ka. Such a trend reflects a change from a wetter to a drier climate at high altitudes. The δ 13 C signal sh…
A new MIS 5 to MIS 2 speleothem record from Sandkraal Cave on the South African Cape south coast
We present new stable oxygen and carbon isotope composite records (δ 18 O, δ 13 C) of speleothems from Sandkraal Cave 1 (SK1) on the South African south coast for the time interval between 104 and 18 ka (with a hiatus between 48 and 41 ka). Statistical comparisons using kernel-based correlation analyses and semblance analyses based on continuous wavelet transforms inform the relationships of the new speleothem records to other proxies and their c…
Evolution of water extraction technology (spring tunnels) in the Southern Levant during the last three millennia
A spring tunnel is an ancient water installation used to artificially increase the water yield of a spring through a subterranean tunnel. We have developed a database of 216 spring tunnels documented in the central region of the Southern Levant (present‐day Israel), constructed between Iron Age II and the modern era. The study focuses on the evolution of this water installation over a period of 2500 years, examining these constructions from techn…
Development of the Intcal Database
The IntCal family of radiocarbon ( 14 C) calibration curves is based on research spanning more than three decades. The IntCal group have collated the 14 C and calendar age data (mostly derived from primary publications with other types of data and meta-data) and, since 2010, made them available for other sorts of analysis through an open-access database. This has ensured transparency in terms of the data used in the construction of the ratified c…
Geomorphological, chronological, and paleoenvironmental context of the Mousterian site at Roca San Miguel (Arén, Huesca, Spain) from the penultimate to the last glacial cycle
The Roca San Miguel (RSM) archaeological site was occupied during Mousterian times. Here we present a geoarchaeological and paleoenvironmental reconstruction of the site. Five stratigraphic units (A to E) formed by different archaeological levels are identified. Three optically stimulated luminescence (OSL) ages show that Unit A dates to between 169.6 ± 9.1 and 151.9 ± 11.1 ka, during the penultimate glacial period (PGP), and contains numerous si…
Hydroclimatic changes in south-central China during the 4.2 ka event and their potential impacts on the development of Neolithic culture
The 4.2 ka event is widely presumed to be a globally widespread aridity event and has been linked to several episodes of societal changes across the globe. Whether this climate event impacted the cultural development in south-central China remains uncertain due to a lack of regional paleorainfall records. We present here stalagmite stable carbon isotope and trace element–based reconstruction of hydroclimatic conditions from south-central China. O…
Climatic and anthropogenic influence on vegetation in southeastern China during the past 120 years inferred from speleothem
Oldest Dryas hydroclimate reorganization in the eastern Iberian Peninsula after the iceberg discharges of Heinrich Event 1
This study examines the first precisely dated and temporally highly resolved speleothem record from Iberia that reconstructs the Oldest Dryas (OD). The onset of cold conditions in the study area, contemporary with the beginning of Heinrich Stadial 1, is recorded at 18.13 ± 0.08 ka, with a pronounced drop of 6.1‰ in δ 13 C in 250 years. Henceforth, stadial conditions depict a period of instability in the Atlantic Meridional Overturning Circulation…
Addressing Kentucky’s Physician Shortage While Securing a Network for a Research-Intensive, Referral Academic Medical Center: Where Public Policy Meets Effective Clinical Strategic Planning
A critical shortage of physicians is looming in the United States. The situation in Kentucky is especially dire, especially in rural areas. Class size constraints have resulted in the University of Kentucky College of Medicine (UK COM) unable to admit over 100 qualified Kentuckians each year. This article describes how leadership at University of Kentucky committed to addressing the state physician shortage while simultaneously strengthening rela…
Timing and structure of early-Holocene climate anomalies inferred from north Chinese stalagmite records
In this paper, a new decadal resolution stalagmite δ 18 O record covering 10.4–6.5 ka BP from Kulishu cave in Beijing, north China is presented in combination with the published stalagmite δ 18 O record covering 10.4–14.0 ka BP in the same cave. Five significant monsoon collapses were identified around 11.5, 11.0, 10.0, 9.4, and 8.2 ka BP as well as three smaller ones around 10.3, 9.0, and 8.6 ka BP. The weak monsoon episodes around 8.6 and 8.2 k…
Th dating of flowstone from Ignatievskaya Cave, Russia: Age constraints of rock art and paleoclimate inferences
Paleolithic antiquity of parietal art in Ignatievskaya cave, Southern Ural, is supported by its subject (Late Pleistocene animals) as well as by paleontological and palynological data, and 14 C dates from cultural layers associated with artistic activity (17.8-16.3 cal ka BP; association is established by finds of ochre in these layers). However, three 14 C dates of charcoal motifs yielded younger, Holocene ages (7.4-6.0 cal ka BP). In this study…
Black carbon traces of human activities in stalagmites from Turkey
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
Radiocarbon ( 14 C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14 C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth syste…
East Asian summer monsoon climates and cave hydrological cycles over Dansgaard-Oeschger events 14 to 11 revealed by a new stalagmite record from Hulu Cave
A 230 Th/U-dated stalagmite from Hulu Cave was analyzed for δ 18 O, δ 13 C, and trace elements. A ~10-yr-resolution δ 18 O record, spanning 51.7–42.6 ka, revealed Dansgaard-Oeschger (DO) events 14 to 11. A similar rapid transition and synchronous timing of the onset of DO 12 is evident between the Greenland and Hulu Cave records, which suggests a common forcing mechanism of DO cycles in the North Atlantic and monsoonal region of Asia. Centennial-…
The Asian Summer Monsoon: Teleconnections and Forcing Mechanisms—A Review from Chinese Speleothem δ18O Records
Asian summer monsoon (ASM) variability significantly affects hydro-climate, and thus socio-economics, in the East Asian region, where nearly one-third of the global population resides. Over the last two decades, speleothem δ18O records from China have been utilized to reconstruct ASM variability and its underlying forcing mechanisms on orbital to seasonal timescales. Here, we use the Speleothem Isotopes Synthesis and Analysis database (SISAL_v1) …
Early-Holocene monsoon instability and climatic optimum recorded by Chinese stalagmites
The timing and duration of the Holocene East Asian summer monsoon (EASM) maximum and the interpretation of Chinese stalagmite δ 18 O records have long been disputed. Notably, interpretations of Holocene EASM variations are frequently based on a single record or study area and are often contradictory. In this study, we conducted stable isotope analyses of four Holocene stalagmites from Chongqing, southwest China. The results reveal differences in …
Integrating U-Th, 14 C, and 210 Pb methods to produce a chronologically reliable isotope record for the Belize River Valley Maya from a low-uranium stalagmite
Social and environmental changes had great spatiotemporal variability in the Maya Lowlands during the Classic and Postclassic Periods, and stalagmites promise high-resolution paleoclimate data that can refine our understanding of this complex time. Unfortunately, stalagmites in this region are often difficult to date by U-Th methods because of low initial uranium concentrations. Other dating techniques can be used on such stalagmites, and we pres…
The 7.2 ka climate event: Evidence from high-resolution stable isotopes and trace element records of stalagmite in Shuiming Cave, Chongqing, China
Speleothem records have radically changed our understanding of the paleo Asian monsoon (AM), but explanations for Asian summer monsoon (ASM) variations in the Holocene period are usually based on single proxy records, such as oxygen isotope (δ 18 O). The application of multi-proxy records to the study of the forcing mechanism and internal structure of climate events is more comprehensive and accurate in the analysis of paleoclimates than using si…
Climate dynamics during the penultimate glacial period recorded in a speleothem from Kanaan Cave, Lebanon (central Levant)
Little is known about terrestrial climate dynamics in the Levant during the penultimate interglacial-glacial period. To decipher the palaeoclimatic history of the Marine Oxygen Isotope Stage (MIS) 6 glacial period, a well-dated stalagmite (~194 to ~154 ka) from Kanaan Cave on the Mediterranean coast in Lebanon was analyzed for its petrography, growth history, and stable isotope geochemistry. A resolved climate record has been recovered from this …
Timing and duration of the East Asian summer monsoon maximum during the Holocene based on stalagmite data from North China
We present a continuous C-O isotope series that shows the detailed variability of East Asian summer monsoon (EASM) since 11.0 ka BP. The series is based on two stalagmites, namely, DSY1 and LM2, which were, respectively, obtained from Dongshiya and Laomu caves. The δ 18 O profiles of stalagmite excurse negatively in early Holocene and gradually become positive after around 6.9 ka BP, tracking the change in Northern Hemisphere summer insolation. M…
Evolution of the Asian summer monsoon during Dansgaard/Oeschger events 13–17 recorded in a stalagmite constrained by high-precision chronology from southwest China
A stalagmite with high 238 U content from Yangkou Cave, China, revealed the evolution of the Asian summer monsoon (ASM) between 49.1 and 59.5 ka, and the δ 18 O values recorded Dansgaard/Oeschger (D/O) events 13–17. The Yangkou record shows a relatively gradual transition into the D/O 14 and 16 events. The discrepancy between the abrupt and gradual transitions of D/O 14 in the records from northern and southern China, respectively, suggests diffe…
New speleothem data from Molinos and Ejulve caves reveal Holocene hydrological variability in northeast Iberia
New speleothem records from northeastern Iberian caves provide data to explore the climatic patterns during the Holocene. We present δ 13 C and Mg/Ca from three speleothems from two different caves located in the Iberian Range allowing replication of the climatic signal for several millennia. Through the integration of those stalagmites covering since the Holocene onset to 2 ka, the early Holocene (11.7–8.5 ka) appears as the wettest interval. A …
Strong coupling of centennial-scale changes of Asian monsoon and soil processes derived from stalagmite δ 18 O and δ 13 C records, southern China
The paleoclimate application of speleothem δ 13 C is influenced by site-specific processes. Here we present four stalagmite δ 13 C records from two caves in southern China, covering early and late Marine Isotope Stage (MIS) 3 and the Holocene, to investigate the spatio-temporal pattern of calcite δ 13 C changes and the relationship with Asian monsoon (AM) variability. In each growth period, precessional- to millennial-scale changes are clear in t…
Earliest direct evidence of monument building at the archaeological site of Nan Madol (Pohnpei, Micronesia) identified using 230 Th/U coral dating and geochemical sourcing of megalithic architectural …
Archaeologists commonly use the onset of the construction of large burial monuments as a material indicator of a fundamental shift in authority in prehistoric human societies during the Holocene. High-quality direct evidence of this transition is rare. We report new interdisciplinary research at the archaeological site of Nan Madol that allows us to specify where and when people began to construct monumental architecture in the remote islands of …
IntCal09 and Marine09 Radiocarbon Age Calibration Curves, 0-50,000 Years cal BP
The IntCal04 and Marine04 radiocarbon calibration curves have been updated from 12 cal kBP (cal kBP is here defined as thousands of calibrated years before AD 1950), and extended to 50 cal kBP, utilizing newly available data sets that meet the IntCal Working Group criteria for pristine corals and other carbonates and for quantification of uncertainty in both the 14 C and calendar timescales as established in 2002. No change was made to the curves…
IntCal13 and Marine13 Radiocarbon Age Calibration Curves 0–50,000 Years cal BP
The IntCal09 and Marine09 radiocarbon calibration curves have been revised utilizing newly available and updated data sets from 14 C measurements on tree rings, plant macrofossils, speleothems, corals, and foraminifera. The calibration curves were derived from the data using the random walk model (RWM) used to generate IntCal09 and Marine09, which has been revised to account for additional uncertainties and error structures. The new curves were r…
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
Radiocarbon ( 14 C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14 C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth syste…
High-precision U-series dating of Locality 1 at Zhoukoudian, China
Selection and Treatment of Data for Radiocarbon Calibration: An Update to the International Calibration (IntCal) Criteria
High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind 14 C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, and uncertainties involved in determining atmospheric and surface ocean 14 C/ 12 C in these archives, i…
A High-Resolution Radiocarbon Calibration Between 11,700 and 12,400 Calendar Years Bp Derived from 230 Th Ages of Corals from Espiritu Santo Island, Vanuatu
This paper presents radiocarbon results from a single Diploastrea heliopora coral from Vanuatu that lived during the Younger Dryas climatic episode, between ca. 11,700 and 12,400 calendar yr bp. The specimen has been independently dated with multiple 230 Th measurements to permit calibration of the 14 C time scale. Growth bands in the coral were used to identify individual years of growth. 14 C measurements were made on each year. These values we…
Emanuel Cave (Israel): The Site and its Bearing on Early Middle Paleolithic Technological Variability
A series of short successive occupations were revealed at the new Middle Paleolithic site of Emanuel Cave. A date of 191± 1 Ka (U/ Th) is suggested as a terminus post quem for the archaeological deposits. Despite the ephemeral nature of the site, the lithic assemblage displays two distinct facies ; the lower layers with a predominantly laminar nature and the upper layers, reflecting more use of the Levallois technology. Techno-typological compari…
A high-resolution stalagmite record of the Holocene East Asian monsoon from Mt Shennongjia, central China
High-resolution oxygen isotope (δ 18 O) profiles of six stalagmites from Sanbao Cave in Hubei province, central China, established with 1413 oxygen isotope data and 65 230 Th ages, provide a continuous history of East Asian Summer Monsoon (EASM) intensity for the period from 13—0.2 thousand years before present (ky BP, relative to AD 1950). The δ 18 O record includes four distinct stages in the evolution of the EASM: (1) an abrupt transition (~11…
Radiocarbon Calibration/Comparison Records Based on Marine Sediments from the Pakistan and Iberian Margins
We present a new record of radiocarbon ages measured by accelerator mass spectrometry (AMS) on a deep-sea core collected off the Pakistan Margin. The 14 C ages measured on the planktonic foraminifera Globigerinoides ruber from core MD04-2876 define a high and stable sedimentation rate on the order of 50 cm/kyr over the last 50 kyr. The site is distant from the main upwelling zone of the western Arabian Sea where 14 C reservoir age is large and ma…
Mass spectrometric U-series dating of Laibin hominid site in Guangxi, southern China
Centennial- to decadal-scale monsoon precipitation variability in the semi-humid region, northern China during the last 1860 years: Records from stalagmites in Huangye Cave
We developed a composite oxygen isotopic record of cave calcite for the last 1860 years based on three stalagmites from the Huangye Cave in eastern Gansu Province, northern China. The δ 18 O values reflect monsoon precipitation changes, with lower δ 18 O values representing higher precipitation and vice versa. Three intervals of high precipitation were identified at AD 138—450, AD 730—1200, and AD 1860—1960. Two intervals of low precipitation occ…
Radiocarbon Results from a 13-Kyr BP Coral from the Huon Peninsula, Papua New Guinea
This paper presents radiocarbon results from a single Goniastrea favulus coral from Papua New Guinea which lived continuously between 13.0 and 13.1 kyr BP. The specimen was collected from a drill core on the Huon Peninsula and has been independently dated with 230 Th. A site-specific reservoir correction has been applied to the results, and coral growth bands were used to calibrate individual growth years. Alternating density bands, which are the…
Mass spectrometric U-series dating of New Cave at Zhoukoudian, China
Archaeological Potential of the Atlantic Continental Shelf
Early man lived in eastern United States 11,000 years ago when most of the now-submerged continental shelf was exposed. The shelf almost certainly was ranged by nomadic hunters and possibly by marine fish- and mollusk- eaters. As the sea level rose at the end of the latest glacial epoch, the advancing water disrupted and submerged any habitation sites.The oldest radiocarbon dates for kitchen middens of marine refuse along the present shore appear…
The Hekla 3 volcanic eruption recorded in a Scottish speleothem
Recent research has demonstrated the presence of annual luminescent growth banding in a stalagmite from Sutherland, N.W. Scotland (Baker, Smart, Edwards and Richards, 1993). The banding record of this sample contains a short duration increase in annual band width, indicating a doubling of growth rate for a period of four years. Predicted growth rates derived from calcite precipitation kinetics are compared with observed growth-rate variability to…
Radiocarbon Dating of Deep-Sea Corals
Deep-sea corals are a promising new archive of paleoclimate. Coupled radiocarbon and U-series dates allow 14 C to be used as a tracer of ocean circulation rate in the same manner as it is used in the modern ocean. Diagenetic alteration of coral skeletons on the seafloor requires a thorough cleaning of contaminating phases of carbon. In addition, 10% of the coral must be chemically leached prior to dissolution to remove adsorbed modern CO 2 . A su…
Th dating of flowstone from Ignatievskaya Cave, Russia: Age constraints of rock art and paleoclimate inferences
Paleolithic antiquity of parietal art in Ignatievskaya cave, Southern Ural, is supported by its subject (Late Pleistocene animals) as well as by paleontological and palynological data, and 14 C dates from cultural layers associated with artistic activity (17.8-16.3 cal ka BP; association is established by finds of ochre in these layers). However, three 14 C dates of charcoal motifs yielded younger, Holocene ages (7.4-6.0 cal ka BP). In this study…
Black carbon traces of human activities in stalagmites from Turkey
The 7.2 ka climate event: Evidence from high-resolution stable isotopes and trace element records of stalagmite in Shuiming Cave, Chongqing, China
Speleothem records have radically changed our understanding of the paleo Asian monsoon (AM), but explanations for Asian summer monsoon (ASM) variations in the Holocene period are usually based on single proxy records, such as oxygen isotope (δ 18 O). The application of multi-proxy records to the study of the forcing mechanism and internal structure of climate events is more comprehensive and accurate in the analysis of paleoclimates than using si…
Timing and duration of the East Asian summer monsoon maximum during the Holocene based on stalagmite data from North China
We present a continuous C-O isotope series that shows the detailed variability of East Asian summer monsoon (EASM) since 11.0 ka BP. The series is based on two stalagmites, namely, DSY1 and LM2, which were, respectively, obtained from Dongshiya and Laomu caves. The δ 18 O profiles of stalagmite excurse negatively in early Holocene and gradually become positive after around 6.9 ka BP, tracking the change in Northern Hemisphere summer insolation. M…
Geochronology, sediment provenance, and fossil emplacement at Sumidouro Cave, a classic late Pleistocene/early Holocene Paleoanthropological site in eastern Brazil
Peter Wilhelm Lund's (1845a) heavily debated suggestion of a contemporaneity between Paleo‐Indians and extinct Pleistocene fauna at Sumidouro Cave was re‐examined through detailed sedimentological and geochronological analyses of sediment and both human and faunal remains. Sources of the cave's sediment include both entrances as well as ceiling fissures. Non‐human fossils, on the other hand, were probably carried by floodwater through the once mo…
A 6000-year high-resolution climatic record from a stalagmite in Xiangshui Cave, Guilin, China
Middle-to late-Holocene palaeoclimate change has been reconstructed at high resolution by the analysis of the carbon and oxygen isotopes from a thermal ionization mass spectrometric (TIMS) U/Th dated stalagmite from Xiangshui Cave, near Guilin, Guangxi Province, China. The carbon and oxygen isotopic records from the stalagmite suggest that changes in the Asian monsoon since the middle Holocene (6000 BP) can be divided into two periods: (1) an int…
Evolution of water extraction technology (spring tunnels) in the Southern Levant during the last three millennia
A spring tunnel is an ancient water installation used to artificially increase the water yield of a spring through a subterranean tunnel. We have developed a database of 216 spring tunnels documented in the central region of the Southern Levant (present‐day Israel), constructed between Iron Age II and the modern era. The study focuses on the evolution of this water installation over a period of 2500 years, examining these constructions from techn…
Integrating U-Th, 14 C, and 210 Pb methods to produce a chronologically reliable isotope record for the Belize River Valley Maya from a low-uranium stalagmite
Social and environmental changes had great spatiotemporal variability in the Maya Lowlands during the Classic and Postclassic Periods, and stalagmites promise high-resolution paleoclimate data that can refine our understanding of this complex time. Unfortunately, stalagmites in this region are often difficult to date by U-Th methods because of low initial uranium concentrations. Other dating techniques can be used on such stalagmites, and we pres…
Multiproxy evidence from caves of Native Americans altering the overlying landscape during the late Holocene of east-central North America
We compare environmental changes recorded in stalagmites and alluvium from the mountainous Buckeye Creek basin of West Virginia, USA to a nearby, independent archaeological record of Native American presences in the forested watershed. A climatic record constructed from stable isotopic (δ 18 O calc and δ 13 C calc ) and trace metal (Sr/Ca) ratios in stalagmitic calcite is consistent with regional palynology during much of the Holocene. The stalag…
The Autumn Colors on the Ch'iao and Hua Mountains, a Landscape by Chao Meng-fu
Archaeological Potential of the Atlantic Continental Shelf
Early man lived in eastern United States 11,000 years ago when most of the now-submerged continental shelf was exposed. The shelf almost certainly was ranged by nomadic hunters and possibly by marine fish- and mollusk- eaters. As the sea level rose at the end of the latest glacial epoch, the advancing water disrupted and submerged any habitation sites.The oldest radiocarbon dates for kitchen middens of marine refuse along the present shore appear…
Archaeological Use of the Universal Transverse Mercator Grid
The Universal Transverse Mercator Grid is a rectangular grid system now used on all standard military maps. Archaeologists could use this system for site location, which would prove especially beneficial in areas where townships and range grids have not been drawn. The use of the series of numbers in the system would help eliminate duplication in state or regional site files
U234U230Th232Th systematics and the precise measurement of time over the past 500,000 years
A Large Drop in Atmospheric 14 C/ 12 C and Reduced Melting in the Younger Dryas, Documented with 230 Th Ages of Corals
Paired carbon-14 ( 14 C) and thorium-230( 230 Th) ages were determined on fossil corals from the Huon Peninsula, Papua New Guinea. The ages were used to calibrate part of the 14 C time scale and to estimate rates of sea-level rise during the last deglaciation. An abrupt offset between the 14 C and 230 Th ages suggests that the atmospheric 14 C/ 12 C ratio dropped by 15 percent during the latter part of and after the Younger Dryas (YD). This promi…
The Hekla 3 volcanic eruption recorded in a Scottish speleothem
Recent research has demonstrated the presence of annual luminescent growth banding in a stalagmite from Sutherland, N.W. Scotland (Baker, Smart, Edwards and Richards, 1993). The banding record of this sample contains a short duration increase in annual band width, indicating a doubling of growth rate for a period of four years. Predicted growth rates derived from calcite precipitation kinetics are compared with observed growth-rate variability to…
A High-Resolution Radiocarbon Calibration Between 11,700 and 12,400 Calendar Years Bp Derived from 230 Th Ages of Corals from Espiritu Santo Island, Vanuatu
This paper presents radiocarbon results from a single Diploastrea heliopora coral from Vanuatu that lived during the Younger Dryas climatic episode, between ca. 11,700 and 12,400 calendar yr bp. The specimen has been independently dated with multiple 230 Th measurements to permit calibration of the 14 C time scale. Growth bands in the coral were used to identify individual years of growth. 14 C measurements were made on each year. These values we…
Speleothem evidence for Holocene fluctuations of the prairie-forest ecotone, north-central USA
Carbon and oxygen isotopic trends from seven Midwestern speleothems record significant offsets in the timing of middle-Holocene vegetation change. Interactions of dry Pacific and moist Gulf of Mexico air masses maintained a sharp moisture gradient across Iowa, Minnesota, and Wisconsin such that the arrival of prairie was offset by 2000 years between caves and pollen sites located only 50 km apart. Oxygen isotopes shift concomitantly with carbon i…
The half-lives of uranium-234 and thorium-230
A High-Resolution Absolute-Dated Late Pleistocene Monsoon Record from Hulu Cave, China
Oxygen isotope records of five stalagmites from Hulu Cave near Nanjing bear a remarkable resemblance to oxygen isotope records from Greenland ice cores, suggesting that East Asian Monsoon intensity changed in concert with Greenland temperature between 11,000 and 75,000 years before the present (yr. B.P.). Between 11,000 and 30,000 yr. B.P., the timing of changes in the monsoon, as established with 230 Th dates, generally agrees with the timing of…
High-precision U-series dating of Locality 1 at Zhoukoudian, China
Radiocarbon Dating of Deep-Sea Corals
Deep-sea corals are a promising new archive of paleoclimate. Coupled radiocarbon and U-series dates allow 14 C to be used as a tracer of ocean circulation rate in the same manner as it is used in the modern ocean. Diagenetic alteration of coral skeletons on the seafloor requires a thorough cleaning of contaminating phases of carbon. In addition, 10% of the coral must be chemically leached prior to dissolution to remove adsorbed modern CO 2 . A su…
Ma family
El Niño/Southern Oscillation and tropical Pacific climate during the last millennium
Mass spectrometric U-series dating of New Cave at Zhoukoudian, China
Timing, Duration, and Transitions of the Last Interglacial Asian Monsoon
Thorium-230 ages and oxygen isotope ratios of stalagmites from Dongge Cave, China, characterize the Asian Monsoon and low-latitude precipitation over the past 160,000 years. Numerous abrupt changes in 18 O/ 16 O values result from changes in tropical and subtropical precipitation driven by insolation and millennial-scale circulation shifts. The Last Interglacial Monsoon lasted 9.7 ± 1.1 thousand years, beginning with an abrupt (less than 200 year…
Uranium-series coral ages from the US Atlantic Coastal Plain–the “80ka problem” revisited
A 6000-year high-resolution climatic record from a stalagmite in Xiangshui Cave, Guilin, China
Middle-to late-Holocene palaeoclimate change has been reconstructed at high resolution by the analysis of the carbon and oxygen isotopes from a thermal ionization mass spectrometric (TIMS) U/Th dated stalagmite from Xiangshui Cave, near Guilin, Guangxi Province, China. The carbon and oxygen isotopic records from the stalagmite suggest that changes in the Asian monsoon since the middle Holocene (6000 BP) can be divided into two periods: (1) an int…
Radiocarbon Results from a 13-Kyr BP Coral from the Huon Peninsula, Papua New Guinea
This paper presents radiocarbon results from a single Goniastrea favulus coral from Papua New Guinea which lived continuously between 13.0 and 13.1 kyr BP. The specimen was collected from a drill core on the Huon Peninsula and has been independently dated with 230 Th. A site-specific reservoir correction has been applied to the results, and coral growth bands were used to calibrate individual growth years. Alternating density bands, which are the…
A Speleothem Record of Younger Dryas Cooling, Klamath Mountains, Oregon, USA
A well-dated δ 18 O record in a stalagmite from a cave in the Klamath Mountains, Oregon, with a sampling interval of 50 yr, indicates that the climate of this region cooled essentially synchronously with Younger Dryas climate change elsewhere in the Northern Hemisphere. The δ 18 O record also indicates significant century-scale temperature variability during the early Holocene. The δ 13 C record suggests increasing biomass over the cave through t…
The Holocene Asian Monsoon: Links to Solar Changes and North Atlantic Climate
A 5-year-resolution absolute-dated oxygen isotope record from Dongge Cave, southern China, provides a continuous history of the Asian monsoon over the past 9000 years. Although the record broadly follows summer insolation, it is punctuated by eight weak monsoon events lasting ∼1 to 5 centuries. One correlates with the “8200-year” event, another with the collapse of the Chinese Neolithic culture, and most with North Atlantic ice-rafting events. Cr…
Geochronology, sediment provenance, and fossil emplacement at Sumidouro Cave, a classic late Pleistocene/early Holocene Paleoanthropological site in eastern Brazil
Peter Wilhelm Lund's (1845a) heavily debated suggestion of a contemporaneity between Paleo‐Indians and extinct Pleistocene fauna at Sumidouro Cave was re‐examined through detailed sedimentological and geochronological analyses of sediment and both human and faunal remains. Sources of the cave's sediment include both entrances as well as ceiling fissures. Non‐human fossils, on the other hand, were probably carried by floodwater through the once mo…
Quaternary glaciation and hydrologic variation in the South American tropics as reconstructed from the Lake Titicaca drilling project
A 136-m-long drill core of sediments was recovered from tropical high-altitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Perio…
A 900‐year (600 to 1500 A.D.) record of the Indian summer monsoon precipitation from the core monsoon zone of India
We present a near‐annually resolved record of the Indian summer monsoon (ISM) rainfall variations for the core monsoon region of India that spans from 600 to 1500 A.D. from a 230 Th‐dated stalagmite oxygen isotope record from Dandak Cave. Our rainfall reconstruction, which spans the Medieval Warm Period (MWP) and the earliest portion of the Little Ice Age (LIA), indicates that the short instrumental record of ISM underestimates the magnitude of m…
Mass spectrometric U-series dating of Laibin hominid site in Guangxi, southern China
Geology and Paleoclimatology Research (63 works) · Geography (62 works) · Archaeology (47 works) · Cave (41 works) · Holocene (41 works) · Stalagmite (41 works) · Climatology (40 works) · Geology (37 works) · Geology (34 works) · Physical geography (34 works)