@article {winkler_more_2023,
	title = {More Frequent Hurricane Passage Across the Bahamian Archipelago During the Little Ice Age},
	journal = {Paleoceanography and Paleoclimatology},
	volume = {38},
	number = {11},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023PA004623},
	month = {11/2023},
	pages = {e2023PA004623},
	abstract = {The year 2020 Common Era (CE) experienced the highest number of named tropical cyclones in the Atlantic Ocean since 1850 CE, but the short instrumental record makes it challenging to assess if this level of activity is statistically meaningful. Here, we present two near-annually resolved hurricane reconstructions from sediment archived in two blue holes located only 300 m apart on the northern margin of Grand Bahama. These two blue holes provide a replicated signal of hurricanes passing within a 50{\textendash}100 km radius over the last 1,800 years, and the long-term reconstructions document multiple 50-to-150-year intervals when hurricane frequency was significantly higher than it has been over the last 100 years. These two records were first merged into a single stack, and then compiled with five other high-resolution reconstructions from across the Bahamian Archipelago to form a single 1500-year record of Bahamian hurricane frequency. This new Bahamian Compilation documents more hurricanes passing \~{}75{\textdegree}W from 21{\textdegree}N to 26{\textdegree}N during the Little Ice Age (LIA; 1300{\textendash}1850 CE) relative to the prior millennium and the last 170 years. The US Eastern Seaboard also experienced heightened hurricane activity during the LIA, whereas the Gulf of Mexico and Southern Caribbean were inactive. This suggests that despite a globally cooler climate, regional climate conditions during the LIA remained favorable for cyclogenesis and intensification along certain Atlantic hurricane pathways. Perhaps heightened Sahel rainfall during the LIA indicates an increase in African Easterly waves, which in turn possibly seeded more tropical cyclones in the Atlantic Main Development Region.},
	keywords = {Bahamas, Carbonate, common era, hurricanes, Paleoclimate, sedimentology},
	issn = {2572-4525},
	doi = {10.1029/2023PA004623},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023PA004623},
	author = {Winkler, T. S. and van Hengstum, P. J. and Donnelly, J. P. and Wallace, E. J. and Albury, N. A. and D{\textquoteright}Entremont, N. and Hawkes, A. D. and Maio, C. V. and Roberts, J. and Sullivan, R. M. and Woodruff, J. D.}
}
@article {longworth_radiocarbon_2022,
	title = {Radiocarbon measurement of CO2 from carbonate minerals using a hybrid gas ion source with an open split interface},
	journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
	volume = {531},
	year = {2022},
	month = {11/2022},
	pages = {49{\textendash}55},
	abstract = {We have developed a method for measuring radiocarbon in carbonate minerals as CO2 gas via a NEC MCSNICS hybrid sputter gas ion source (HGIS). The method uses helium as a carrier gas to displace CO2 from sample vials to an open split, where a glass capillary samples the mixture for delivery directly to the HGIS. This method skips the gas transfer and quantification steps used in a closed inlet HGIS system, simplifying sample measurement. Samples larger than 8 mg carbonate can be measured. Results from measurements of consensus standards (TIRI I, IAEA C2, and an internal modern shell standard), and samples from a marine core (F14C = 0.4{\textendash}1.15) show that the method agrees well with traditional AMS measurement of the same samples as graphite, and that the 1σ uncertainty is about 1\%. We discuss advantages and disadvantages of continuous flow sample introduction, and the effect of reduced precision on calibrated age-depth models produced using gas-source data.},
	keywords = {Carbonate, Hybrid gas ion source, radiocarbon},
	issn = {0168-583X},
	doi = {10.1016/j.nimb.2022.08.013},
	url = {https://www.sciencedirect.com/science/article/pii/S0168583X2200218X},
	author = {Longworth, Brett E. and Burton, Joshua R. and Pendleton, Simon L. and Moser, Sydney D. and Roberts, Mark L. and Kurz, Mark D.}
}
@article {Falk20161,
	title = {Controls on the stable isotope compositions of travertine from hyperalkaline springs in Oman: Insights from clumped isotope measurements},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {192},
	year = {2016},
	pages = {1 - 28},
	abstract = {Abstract Carbonate formation at hyperalkaline springs is typical of serpentinization in peridotite massifs worldwide. These travertines have long been known to exhibit large variations in their carbon and oxygen isotope compositions, extending from apparent equilibrium values to highly depleted values. However, the exact causes of these variations are not well constrained. We analyzed a suite of well-characterized fresh carbonate precipitates and travertines associated with hyperalkaline springs in the peridotite section of the Samail ophiolite, Sultanate of Oman, and found their clumped isotope compositions vary systematically with formation environments. Based on these findings, we identified four main processes controlling the stable isotope compositions of these carbonates. These include hydroxylation of CO2, partial isotope equilibration of dissolved inorganic carbon, mixing between isotopically distinct carbonate end-members, and post-depositional recrystallization. Most notably, in fresh crystalline films on the surface of hyperalkaline springs and in some fresh carbonate precipitates from the bottom of hyperalkaline pools, we observed large enrichments in Δ47 (up to \~{}0.2{\textperthousand} above expected equilibrium values) which accompany depletions in δ18O and δ13C, yielding about 0.01{\textperthousand} increase in Δ47 and 1.1{\textperthousand} decrease in δ13C for every 1{\textperthousand} decrease in δ18O, relative to expected equilibrium values. This disequilibrium trend, also reflected in preserved travertines ranging in age from modern to \~{}40,000 years old, is interpreted to arise mainly from the isotope effects associated with the hydroxylation of \{CO2\} in high-pH fluids and agrees with our first-order theoretical estimation. In addition, in some fresh carbonate precipitates from the bottom of hyperalkaline pools and in subsamples of one preserved travertine terrace, we observed additional enrichments in Δ47 at intermediate δ13C and δ18O, consistent with mixing between isotopically distinct carbonate end-members. Our results suggest that carbonate clumped isotope analysis can be a valuable tool for identifying and distinguishing processes not readily apparent from the carbonate bulk stable isotope compositions alone, e.g., kinetic effects or mixing of different carbonate end-members, which can significantly alter both the apparent formation temperatures and apparent radiocarbon ages. The isotope trends observed in these travertine samples could be applied more broadly to identify extinct hyperalkaline springs in terrestrial and extraterrestrial environments, to better constrain the formation conditions and post-depositional alteration of hyperalkaline spring carbonates, and to extract potential paleoclimate information.},
	keywords = {Carbonate},
	issn = {0016-7037},
	doi = {http://doi.org/10.1016/j.gca.2016.06.026},
	url = {http://www.sciencedirect.com/science/article/pii/S0016703716303568},
	author = {E.S. Falk and W. Guo and A.N. Paukert and J.M. Matter and E.M. Mervine and P.B. Kelemen}
}
@article {2237,
	title = {Radiocarbon age anomalies in land snail shells from Texas: Ontogenetic, individual, and geographic patterns of variation},
	journal = {Radiocarbon},
	volume = {41},
	year = {1999},
	note = {228qgTimes Cited:28
Cited References Count:18
},
	month = {1999},
	pages = {149-156},
	abstract = {Accelerator mass spectrometric (AMS) radiocarbon analyses of live-collected, prebomb samples of shell carbonates of the land snails Rabdotus dealbatus and R. alternatus from Texas were carried out to quantify the characteristic age anomalies of land snails from limestone areas. Age anomalies are similar for the two species; they average +700 yr and vary by +/-180 yr (1 sigma) among samples. Serial analysis of I shell reveals a significant ontogenetic trend in C-14 age anomalies, with older apparent ages (up to 1200 yr) in the apical part of the shell and younger and uniform ages in the last whorl. No trend in age anomalies was found across a broad range of rainfall conditions (from 300 to 1000 mm mean annual rainfall).},
	keywords = {Carbonate},
	isbn = {0033-8222},
	author = {Goodfriend, G. A. and Ellis, G. L. and Toolin, L. J.}
}
