John C Hellstrom

Biographic Data

ID3074118
NAMEJohn C Hellstrom
GIVEN NAMESJohn C
FAMILY NAMEHellstrom
SIGNATUREHELLSTROM J C
AFFILIATIONSThe University of Melbourne
VERIFIEDNo
TOTAL WORKS8
TOTAL CITATIONS21
AUTHOR COUNT8
EDITOR COUNT0
FIRST PUBLICATION YEAR2010
LATEST PUBLICATION YEAR2024
H-INDEX2

  • Tropical vegetation productivity and atmospheric methane over the last 40,000 years from model simulations and stalagmites in Sulawesi, Indonesia

    Open AccessClaire E Krause, Alena K Kimbrough et al.ARTICLEQuaternary Research2024

    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…

  • High-resolution reconstruction of infiltration in the Southern Cook Islands based on trace elements in speleothems

    Open AccessMohammadali Faraji, Andrea Borsato et al.ARTICLEQuaternary Research2024

    This study utilizes speleothem trace elements as climate proxies to reconstruct hydroclimate variability over approximately 350 years in the Southern Cook Islands. Stalagmites Pu17 and Pu4 from Pouatea cave were analyzed using high-resolution LA-ICP-MS for trace elements (Mg, Na, Sr, P, U, Y). By monitoring cave dripwater and conducting regression analysis, we found that Mg, Sr, and Na in Pouatea dripwater mostly originated from marine aerosols, …

  • Holocene hydroclimate changes in continental Croatia recorded in speleothem δ 13 C and δ 18 O from Nova Grgosova Cave

    Open AccessMaša Surić, Andrea Columbu et al.ARTICLEThe Holocene2021Cited by: 1References: 29

    We present the first stable isotope (δ 13 C and δ 18 O) speleothem record from continental Croatia retrieved from two coeval stalagmites from Nova Grgosova Cave. U-Th dates constrain the stalagmite growth history from 10 ka to the present, revealing coeval growth between 7.8 and 5.6 ka. We interpret δ 18 O as an autumn/winter hydrological proxy related to changes of vapor source, precipitation amount, and/or seasonal rainfall distribution, while …

  • Late-Holocene environmental change on the Nullarbor Plain, southwest Australia, based on speleothem pollen records

    Open AccessKia A Matley, Kale Sniderman et al.ARTICLEThe Holocene2020References: 12

    Fossil pollen from two stalagmites is examined to reconstruct a c. 2400-year history of vegetation change on the Nullarbor Plain. Environmental changes are reflected by variation in chenopod species abundance, and by a peak in woody taxa between 1000 and 800 years ago which is interpreted as evidence of increased moisture conditions associated with a positive phase of the Southern Annular Mode. While no strong palynological signal is observed at …

  • The Neanderthal in the karst

    Open AccessMartina Lari, Fabio Di Vincenzo et al.ARTICLEJournal of Human Evolution2015Cited by: 13References: 21

  • A continuous stable isotope record from the penultimate glacial maximum to the Last Interglacial (159–121 ka) from Tana Che Urla Cave (Apuan Alps, central Italy)

    Open AccessEleonora Regattieri, Giovanni Zanchetta et al.ARTICLEQuaternary Research2014

    Relatively few radiometrically dated records are available for the central Mediterranean spanning the marine oxygen isotope stage 6–5 (MIS 6–5) transition and the first part of the Last Interglacial. Two flowstone cores from Tana che Urla Cave (TCU, central Italy), constrained by 19 U/Th ages, preserve an interval of continuous speleothem deposition between ca. 159 and 121 ka. A multiproxy record (δ 18 O, δ 13 C, growth rate and petrographic chan…

  • Australopithecus sediba at 1.977 Ma and Implications for the Origins of the Genus Homo

    Open AccessRobert Pickering, Paul H G M Dirks et al.ARTICLEScience2011

    Further U-series dating and the magnetic stratigraphy of the hosting cave deposits show that Australopithecus sediba lived just under 2 million years ago, near or just before the emergence of Homo .

  • Holocene climate change in arid Australia from speleothem and alluvial records

    Open AccessMark Quigley, Mark C Quigley et al.ARTICLEThe Holocene2010Cited by: 7References: 6

    New high-resolution MC-ICPMS U/Th ages and C and O isotopic analyses from a Holocene speleothem in arid south-central Australia provide evidence for increased effective precipitation (EP) relative to present at c. 11.5 ka and c. 8—5 ka, peak moisture at 7—6 ka, and onset of an arid climate similar to present by c. 5 ka. δ 18 O and δ 13 C time-series data exhibit marked (>+1‰) contemporaneous excursions over base-line values of −5.3‰ and −11.0‰, r…