https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30179 18O and δ¹³C minima. Periods of lowered recharge are indicated by ¹⁸O and δ¹³ enrichment, primarily affecting δ¹⁸O, argued to be driven by evaporation of shallow soil/epikarst water in this water-limited environment. A hydrological driver is supported by calcite fabric changes. These include the presence of laminae, visible organic colloids, and occasional dissolution features, related to recharge, as well as the presence of sediment bands representing cave floor flooding. A shift to slower-growing, more compact calcite and an absence of lamination is interpreted to represent reduced recharge. The Mairs Cave record indicates that the Flinders Ranges were relatively wet during the LGM and early deglaciation, particularly over the interval 18.9–15.8 ka. This wetter phase ended abruptly with a shift to drier conditions at 15.8 ka. These findings are in agreement with the geomorphic archives for this region, as well as the timing of events in records from the broader Australasian region. The recharge phases identified in the Mairs Cave record are correlated with, but antiphase to, the position of the westerly winds interpreted from marine core MD03-2611, located 550 km south of Mairs Cave in the Murray Canyons region. The implication is that the mid-latitude westerlies are located further south during the period of enhanced recharge in the Mairs Cave record (18.9–16 ka) and conversely are located further north when greater aridity is interpreted in the speleothem record. A further comparison with speleothem records from the northern Australasian region reveals that the availability of tropical moisture is the most likely explanation driving enhanced recharge, with further amplification of recharge occurring during the early half of Heinrich Stadial 1 (HS1), possibly influenced by a more southerly displaced Intertropical Convergence Zone (ITCZ). A rapid transition to aridity at 15.8 ka is consistent with a retraction of this tropical moisture source.]]> Wed 21 Aug 2019 09:48:28 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30180 2 drawdown during the last glacial period were linked to iron (Fe) fertilization of subantarctic surface waters. The principal source of this Fe is thought to be dust transported from southern mid-latitude deserts. However, uncertainty exists over contributions to CO₂ sequestration from complementary Fe sources, such as the Antarctic ice sheet, due to the difficulty of locating and interrogating suitable archives that have the potential to preserve such information. Here we present petrographic, geochemical and microbial DNA evidence preserved in precisely dated subglacial calcites from close to the East Antarctic Ice-Sheet margin, which together suggest that volcanically-induced drainage of Fe-rich waters during the Last Glacial Maximum could have reached the Southern Ocean. Our results support a significant contribution of Antarctic volcanism to subglacial transport and delivery of nutrients with implications on ocean productivity at peak glacial conditions.]]> Wed 11 Apr 2018 17:19:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:17747 DIC and drip rate depend on the local structural setting and water path length. The data presented show that Galleria delle Stalattiti (the focus of the paleoclimate research) has the most stable conditions in terms of temperature, and the dripwaters show constant pH, electrical conductivity, alkalinity, calcium and magnesium content and δ¹⁸O. Drip rate is not affected by rain events and displays long-term trends that require a longer period of monitoring for elucidating their nature. The preliminary data presented here corroborate the hypotheses suggesting Galleria delle Stalattiti as a good example of a “deep” hypogean system of Fairchild et al. (2007).]]> Wed 11 Apr 2018 13:25:52 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47316 Tue 30 Apr 2024 09:51:07 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46693 Tue 29 Nov 2022 09:42:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:9608 Sat 24 Mar 2018 08:39:39 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:1524 Sat 24 Mar 2018 08:30:48 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:1701 0 °C at a time when MIS 6 ice volumes were close to their maximum. High stable carbon isotope (δ¹³C) values (−2.8‰ to +3.1‰) throughout the stalagmite's growth reflect a persistently low input of biogenic CO², indicating that the steep, barren and alpine-like recharge area of today has been in existence for at least the last ∼380 kyr. During MIS 9, the lowest δ¹³C values occur well after maximum interglacial conditions, suggesting a lag in the development of post-glacial soils in this high-altitude karst. The stable oxygen isotope (δ¹⁸O) trends match the main structural features of the major climate proxy records (SPECMAP, Vostok and Devils Hole), suggesting that the δ¹⁸O of CC1 has responded to global-scale climate changes, whilst remarkable similarity exists between CC1 δ¹⁸O and regional sea-surface temperature reconstructions from North Atlantic core ODP980 and southwest Pacific marine core MD97-2120 through the most detailed part of the CC1 record, MIS 9–8. The results suggest that CC1 and other stalagmites from the cave have the potential to capture a long record of regional temperature trends, particularly in regards to the relative severity of Pleistocene glacial stages.]]> Sat 24 Mar 2018 08:27:20 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:9790 Sat 24 Mar 2018 08:11:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:9792 Sat 24 Mar 2018 08:11:03 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:5532 100 ka), can be recovered at temporal resolutions of < 10 yr, and show meaningful changes through time. This approach is therefore of considerable potential value to Quaternary science.]]> Sat 24 Mar 2018 07:46:41 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3323 Sat 24 Mar 2018 07:23:19 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3321 Sat 24 Mar 2018 07:23:18 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3183 Sat 24 Mar 2018 07:18:09 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3184 Sat 24 Mar 2018 07:18:08 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52766 Mon 29 Jan 2024 18:40:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50776 Mon 22 Apr 2024 11:47:11 AEST ]]>