Southern high latitude climate variability in the Late Cretaceous greenhouse world (original) (raw)
Related papers
Terminal Cretaceous climate change and biotic response in Antarctica
Latest Cretaceous to early Palaeogene climates in Antarctica are being investigated from an exceptional sedimentary sequence on Seymour Island (James Ross Basin, Antarctic Peninsula) to determine the nature of climate change at the end of the Cretaceous. It has been suggested that, following peak mid Cretaceous warmth, cooling during the Maastrichtian (~71-65 Ma) may have been severe enough for short-term glaciations at high latitudes, challenging the current view of an ice-free, Cretaceous greenhouse world. High resolution records of palaeontological, sedimentological, and geochemical signals are being obtained to investigate the climate and environmental context at the Antarctic margin prior to the Cretaceous/Tertiary extinctions, the biotic response in the marine and terrestrial realm, and to test the hypothesis of the presence of ice in conjunction with climate/ice sheet model simulations.
Cretaceous Phytogeography and Climate Signals [and Discussion]
Philosophical Transactions of the Royal Society B: Biological Sciences, 1993
We address two aspects of Cretaceous plants and climate. Firstly, we briefly characterize Cretaceous global phytogeography and review some quantitative temperature estimates derived from plants. Secondly, by adopting a multivariate statistical approach to palaeophytogeographic mapping, we examine the effect of the rise in diversity and ecological radiation of angiosperms on the climate signal offered by non-angiosperms.
2018
By the use of general circulation models (GCM), Moore et al. (1992), Valdes et al. (1995) and Sellwood et al. (2000) simulated significant amounts of sea-ice in Antarctica during the late Jurassic (Kimmeridgian-Tithonian) as a result of Milankovitch (eccentricity-forced) orbital perturbations. In their simulations, the sea-ice front extended to 45° north and 50° south. Price and Nunn (2010) also suggest cool polar temperatures during the Cretaceous by simulation with a GCM. In their interpretation, episodes with ice-covered poles correspond to phases with aridity in Europe, which would support the idea of cool or glacial events (Price, 1999). Prentice and Matthews (1991) suggest that high sea surface temperatures enhanced vapour transport to the centre of Antarctica, where temperatures remained low and led to the formation of an ice cap. Changes in the Mesozoic faunal and floral assemblages in both the marine and terrestrial realms are associated to temperature variations (e.g. Vakhrameyev, 1982; Kemper, 1987; Price, 1999; Zakharov & Rogov, 2003). The potential existence of Boreal and Austral realms during parts of the Mesozoic supports the idea of cold or even sub-freezing high-latitude conditions. These regions are generally low in diversity, but temperature is an important controlling factor of the faunal distribution (Middlemiss, 1984; Rawson, 1973; Stevens, 1973). At the end of the Jurassic, provinciality amongst faunas became most remarkable (Casey & Rawson, 1973). A distinct bipolarity exists in the distribution of Pliensbachian and Tithonian (Early and Late Jurassic) and Aptian-Albian (Early Cretaceous) bivalves (Crame, 1986, 1993) and thus corresponds to episodes from which glacial sediments and glendonites have been reported (Price, 1999 and references therein). A tendency towards bipolar taxa occurs when the Earth's pole-equator temperature profile increases, leading to the expulsion of taxon from equatorial regions (Crame, 1993). Extensive floral evidence (Parrish et al., 1998; Philippe & Thevenard, 1996; Spicer & Parrish, 1986) also implies that permanent ice at high latitudes may have repeatedly existed during the Jurassic and Cretaceous (Price, 1999 and references therein). Several authors report on significant perturbations of the Early Cretaceous northern hemisphere climate, with repeated cool excursions punctuating otherwise warm conditions (e.g.
Cretaceous Phytogeography and Climate Signals: Discussion
1993
We address two aspects of Cretaceous plants and climate. Firstly, we briefly characterize Cretaceous global phytogeography and review some quantitative temperature estimates derived from plants. Secondly, by adopting a multivariate statistical approach to palaeophytogeographic mapping, we examine the effect of the rise in diversity and ecological radiation of angiosperms on the climate signal offered by non-angiosperms.
Geological Magazine, 1992
From the unique perspective of the geological record, it appears that the ' Greenhouse Earth' was a feature of climate for up to 80 % of the last 500 Ma, and that therefore our present glacially dominated climate is an anomaly. The Cretaceous in particular was a time of global warmth, an extreme greenhouse world apparently warmer than our current Earth. The geological record provides perspective and constraints against which the success of climate models can be evaluated. At present there are no ways of evaluating model predictions for the future of our ' Greenhouse Earth' until after the event. Retrodicting the past is therefore a very useful way of testing model sensitivity and robustness. The geological record tells us that the characteristics of the Cretaceous greenhouse world were a shallower equator-to-pole temperature gradient, shallow, well-stratified epicontinental seas with a tendency towards periodic dysaerobism, and a well-developed terrestrial flora extending to the high latitudes. Both marine and non-marine data show a global cooling trend throughout Late Cretaceous time, a trend that seems to correlate with declining atmospheric carbon dioxide.
Terrestrial cooling record through the Eocene-Oligocene transition of Australia
Global and Planetary Change, 2019
A new mid-latitude terrestrial climate proxy record is presented for southeastern Australia. The Middle Eocene to Middle Miocene palynofloral and δ 13 C record of the Latrobe Group, Gippsland Basin, details that the climate of southeastern Australia, paleolatitude 60-50 °S , supported the growth of highly diverse subtropical to cool-temperate rainforests. These forests are characterized by mesothermal to microthermal floral elements that are here interpreted as subtropical (Malvacipollis subtilis and Cupanieidites orthoteichus dominated palynofloras), warm-temperate (Beaupreadites elegansiformis and Phyllocladus mawsonii dominated palynofloras) and cool-temperate (Nothofagus spp. and Dacrycarpidites australiensis dominated palynofloras) rainforests. The palynofloral record of the Latrobe Group indicates that mean annual temperatures were between 20 and 24°C during the Middle Eocene resulting in subtropical rainforests, between 14 and 20°C for the late Middle Eocene to earliest (i.e. pre-Oi1) Oligocene resulting in warm-temperate rainforests, between 10 and 14°C for the late Early Oligocene to Early Miocene resulting in cool-temperate rainforests and between 14 and 20°C in the Middle Miocene, facilitating the resurgence of warm-temperate rainforest floras. Rainfall was also likely in excess of 1500 mm throughout the Middle Eocene to the Middle Miocene in southeastern Australia. The climatic trends preserved within this mid-latitude terrestrial record relate to global Cenozoic cooling, the exception being the Middle Miocene records, which instead relate to the Middle Miocene Climatic Optimum. In the mid-latitude Gippsland Basin, cooling appears to have begun in the Middle Eocene. Correlation of our palynoflora with records from Antarctica and New Zealand, in addition to benthic δ 18 O records, reaffirms that the Latrobe Group coals provide a long-term, largely authochthonous mid-latitude floral record that directly relates to global climatic evolution through the Cenozoic. The presentation of a new mid-latitude terrestrial record provides critical insight into the validation of Eocene-Oligocene transition climate models and improves our understanding of mid-latitude terrestrial ecosystem responses to increased carbon dioxide forcing. The correlation between the δ 13 C values of the Yallourn and Morwell coal seams to benthic δ 13 C records also highlights that a relationship exists between the terrestrial and marine benthic δ 13 C record .
Revista Chilena de Historia Natural, 2012
Forest environments have continuously existed in Antarctica since the late Paleozoic and only disappeared from this continent since the Neogene. Nevertheless, the structure of these forests underwent substantial evolutionary changes. During the late Cretaceous, forests dominated by conifers and pteridophytes were gradually replaced by angiospermdominated forests. Elements common to these Antarctic forests are important constituents of the recent Valdivian Forest. During the Turonian stage of the Late Cretaceous, the Antarctic Peninsula and Patagonia were reconnected by a land bridge after a separation since the end of the Jurassic. Using biogeographic tools applied to the palynological and leaf imprint record, outcrops of Campanian-Maastrichtian age were studied from the Snow Hill, James Ross and Seymour (Marambio) Islands in the James Ross basin, Antarctica; Skua Bay, Half Three Point, Price Point and Zamek Hill on King George Island, Antarctica, and Rocallosa Point, Cerro Guido, Las Chinas, Dorotea Hill, Cazador Hill and La Irene in Chilean-Argentinian Patagonia, comparing the current distribution and the paleogeography, as well as the influence of potential areas of endemism and vicariants events. The analysis indicates that vegetation evolved under environmental conditions subject to intense volcanic and climatic disturbances, with changes from a period with extreme greenhouse climate (Turonian-Campanian) to strong cooling during the Maastrichtian. We suggest that a continuous forest existed in southern South America and Antarctica, which was shaped during the Latest Cretaceous by the presence of marine basins and and intermittent connection and disconnection of the flora.