PRESERVATION OF TRACE FOSSILS AND MOLDS OF TERRESTRIAL BIOTA BY INTENSE STORMS IN MID-LAST INTERGLACIAL (MIS 5c) DUNES ON BERMUDA, WITH A MODEL FOR DEVELOPMENT OF HYDROLOGICAL CONDUITS

Hearty, Paul J.; Olson, Storrs L.

doi:10.2110/palo.2010.p10-132r

Cited by 19 publications

(9 citation statements)

References 43 publications

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“…On Bermuda, where the term "aeolianite" was first applied, Sayles (1931) also considered the deposits to have formed primarily during glacial periods, when sea level was lower and an exposed insular shelf provided bioclastic sands to generate dunes. Bretz (1960) and Land et al (1967) rejected this view and proposed that Bermudan aeolianites are strictly interglacial features, a concept for that island that has persisted into even relatively recent studies (e.g., see Hearty and Olson 2011). However, on Bermuda, although Vacher (1973) accepted the general model of Bretz (1960) and Land et al (1967) of aeolianite formation during interglacial periods, he pointed out (p. 374) that sea level had to be at least slightly below its present level at the time of dune formation.…”

Section: Introductionmentioning

confidence: 99%

Quaternary sea-level history and the origin of the northernmost coastal aeolianites in the Americas: Channel Islands National Park, California, USA

Muhs

Pigati

Schumann

et al. 2018

Palaeogeography, Palaeoclimatology, Palaeoecology

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Along most of the Pacific Coast of North America, sand dunes are dominantly silicate-rich. On the California Channel Islands, however, dunes are carbonate-rich, due to high productivity offshore and a lack of dilution by silicate minerals. Older sands on the Channel Islands contain enough carbonate to be cemented into aeolianite. Several generations of carbonate aeolianites are present on the California Channel Islands and represent the northernmost Quaternary coastal aeolianites on the Pacific Coast of North America. The oldest aeolianites on the islands may date to the early Pleistocene and thus far have only been found on Santa Cruz Island. Aeolianites with well-developed soils are found on both San Miguel Island and Santa Rosa Island and likely date to the middle Pleistocene. The youngest and best-dated aeolianites are located on San Miguel Island and Santa Rosa Island. These sediments were deposited during the late Pleistocene following the emergence of marine terraces that date to the last interglacial complex (~120,000 yr to~80,000 yr). Based on radiocarbon and luminescence dating, the ages of these units correspond in time with marine isotope stages [MIS] 4, 3, and 2. Sea level was significantly lower than present during all three time periods. Reconstruction of insular paleogeography indicates that large areas to the north and northwest of the islands would have been exposed at these times, providing a ready source of carbonate-rich skeletal sands. These findings differ from a previously held concept that carbonate aeolianites are dominantly an interglacial phenomenon forming during high stands of sea. In contrast, our results are consistent with the findings of other investigators of the past decade who have reported evidence of glacial-age and interstadial-age aeolianites on coastlines of Australia and South Africa. They are also consistent with observations made by Darwin regarding the origin of aeolianites on the island of St. Helena, in the South Atlantic Ocean, more than a century and a half ago.

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Section: Introductionmentioning

confidence: 99%

Quaternary sea-level history and the origin of the northernmost coastal aeolianites in the Americas: Channel Islands National Park, California, USA

Muhs

Pigati

Schumann

et al. 2018

Palaeogeography, Palaeoclimatology, Palaeoecology

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“…The zonal temperature gradient, warmer tropics and cooler high latitudes, was enhanced by low obliquity of Earth's spin axis in the late Eemian. Empirical evidence for intense Eemian storms includes standing forests of 8-10 m trees that were rapidly buried in shelf sand and preserved on Bermuda at elevations several meters above sea level (Hearty and Olson, 2011), as well as other evidence discussed in Sec. 2.2.…”

Section: Impact Of Ice Melt On Stormsmentioning

confidence: 90%

Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming is highly dangerous

Hansen¹,

Sato²,

Hearty³

et al. 2015

Preprint

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Abstract. There is evidence of ice melt, sea level rise to +5–9 m, and extreme storms in the prior interglacial period that was less than 1 °C warmer than today. Human-made climate forcing is stronger and more rapid than paleo forcings, but much can be learned by combining insights from paleoclimate, climate modeling, and on-going observations. We argue that ice sheets in contact with the ocean are vulnerable to non-linear disintegration in response to ocean warming, and we posit that ice sheet mass loss can be approximated by a doubling time up to sea level rise of at least several meters. Doubling times of 10, 20 or 40 years yield sea level rise of several meters in 50, 100 or 200 years. Paleoclimate data reveal that subsurface ocean warming causes ice shelf melt and ice sheet discharge. Our climate model exposes amplifying feedbacks in the Southern Ocean that slow Antarctic bottom water formation and increase ocean temperature near ice shelf grounding lines, while cooling the surface ocean and increasing sea ice cover and water column stability. Ocean surface cooling, in the North Atlantic as well as the Southern Ocean, increases tropospheric horizontal temperature gradients, eddy kinetic energy and baroclinicity, which drive more powerful storms. We focus attention on the Southern Ocean's role in affecting atmospheric CO2 amount, which in turn is a tight control knob on global climate. The millennial (500–2000 year) time scale of deep ocean ventilation affects the time scale for natural CO2 change, thus the time scale for paleo global climate, ice sheet and sea level changes. This millennial carbon cycle time scale should not be misinterpreted as the ice sheet time scale for response to a rapid human-made climate forcing. Recent ice sheet melt rates have a doubling time near the lower end of the 10–40 year range. We conclude that 2 °C global warming above the preindustrial level, which would spur more ice shelf melt, is highly dangerous. Earth's energy imbalance, which must be eliminated to stabilize climate, provides a crucial metric.

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“…Boutakoff (1963) proposed that the solution pipes at Cape Bridgewater are buried tree trunks (hence the name of "Petrified Forest"). Tree trunk casts can create conduits for groundwater, so that they are filled by precipitation of calcrete or by subsidence of overlying soil (Neumann and Hearty, 1996;Hearty and O'Leary, 2008;Hearty and Olson, 2011). Rapidly buried vertical tree trunks entombed by blown sand have been found in parts of the Bahamas (Neumann and Hearty, 1996;Hearty and Olson, 2011).…”

Section: Vegetationmentioning

confidence: 99%

“…Tree trunk casts can create conduits for groundwater, so that they are filled by precipitation of calcrete or by subsidence of overlying soil (Neumann and Hearty, 1996;Hearty and O'Leary, 2008;Hearty and Olson, 2011). Rapidly buried vertical tree trunks entombed by blown sand have been found in parts of the Bahamas (Neumann and Hearty, 1996;Hearty and Olson, 2011). However, at Cape Bridgewater the solution pipes are clearly not buried trees, as Grimes (2004) pointed out, because they never expand into roots at the base (Fig.…”

Section: Vegetationmentioning

confidence: 99%

The genesis of solution pipes: Evidence from the Middle–Late Pleistocene Bridgewater Formation calcarenite, southeastern Australia

et al. 2015

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PRESERVATION OF TRACE FOSSILS AND MOLDS OF TERRESTRIAL BIOTA BY INTENSE STORMS IN MID-LAST INTERGLACIAL (MIS 5c) DUNES ON BERMUDA, WITH A MODEL FOR DEVELOPMENT OF HYDROLOGICAL CONDUITS

Cited by 19 publications

References 43 publications

Quaternary sea-level history and the origin of the northernmost coastal aeolianites in the Americas: Channel Islands National Park, California, USA

Quaternary sea-level history and the origin of the northernmost coastal aeolianites in the Americas: Channel Islands National Park, California, USA

Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming is highly dangerous

The genesis of solution pipes: Evidence from the Middle–Late Pleistocene Bridgewater Formation calcarenite, southeastern Australia

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