Paleoclimatology

Spatio-temporal patterns of Holocene environmental change in southern Sicily

by Paul Henne

Palaeogeography, Palaeoclimatology, Palaeoecology, In Press
Authors: Camilla Calò, Paul D. Henne, B. Brandon Curry, Michel Magny, Elisa Vescovi, Tommaso La Mantia, Salvatore Pasta, Boris Vannière, Willy Tinner

Few examples of natural forest remain near the Mediterranean coast. Therefore, it is difficult to study how coastal... more Few examples of natural forest remain near the Mediterranean coast. Therefore, it is difficult to study how coastal forests respond to climatic change or their resilience to human impact. We developed new sedimentary record of Holocene vegetation and fire history at Lago Preola, a coastal lake in southwestern Sicily (Italy). In order to verify the existence of forest at large scale on the coast, we compare pollen from Lago Preola, a medium-sized lake (33 ha), to Gorgo Basso, a small lake (3 ha) located nearby with the aim of separating local from extra-local vegetation dynamics through time using pollen percentages and influx. We then compare Lago Preola pollen to the record from Biviere di Gela, a large lagoon (120 ha) situated 160 km to the east in southern Sicily, to examine differences in vegetation dynamics between the two coastal areas during the Holocene. Lake-level reconstructions and ostracode analyses from Lago Preola provide vegetation-independent evidence of climate change, and help to disentangle human and climatic impacts on vegetation. Pollen data indicate Pistacia-dominated shrublands replaced open grasslands in the region surrounding Lago Preola by 9500 cal yr BP. This change coincided with rising lake levels and the development of an ostracode fauna typical of fresh waters. Evergreen forest dominated by Quercus ilex and Olea europaea started to expand by 7000 cal BP and consolidated at 6500 cal yr BP, when lake levels were near their Holocene high. Similarities between pollen from Lago Preola and Gorgo Basso demonstrate that forest was the dominant vegetation type in coastal Sicily during the middle Holocene at both regional and local scales, and even developed in the drier climatic setting around Biviere di Gela. Lake levels fell at Lago Preola after 7000 cal yr BP, with a strong decline accompanied by increasing salinity after 4500 cal yr BP. However, no transition in vegetation matched these inferred hydrological changes. Instead, forests persisted in the surrounding region until 2200 cal BP when human disturbance intensified. We propose that different climatic factors control lake levels and vegetation in coastal Mediterranean ecosystems. Whereas lake levels are most sensitive to the abundance of winter precipitation, coastal forests depend on spring precipitation and are limited by the length of summer drought. Moisture availability remained suitable for evergreen forests in coastal Sicily during the late Holocene, and humans, not a drier climate drove the regional forest decline.

The El'gygytgyn Scientific Drilling Project – conquering Arctic challenges through continental drilling.

by Maaret Kukkonen

Co-authored with Melles M., Brigham-Grette J., Minyuk P., Koeberl C., Andreev A., Cook, T., Fedorov G., Gebhardt C., Haltia-Hovi E., Kukkonen M., Nowaczyk N., Schwamborn G., Wennrich V. & El'gygytgyn Scientific Party (2011).

Between October 2008 and May 2009, the International Continental Scientific Drilling Program (ICDP) co-sponsored a... more Between October 2008 and May 2009, the International Continental Scientific Drilling Program (ICDP) co-sponsored a campaign at Lake El ́gygytgyn, located in a 3.6-Ma-old meteorite impact crater in northeastern Siberia. Drilling targets included three holes in the center of the 170-m-deep lake, utilizing the lake ice cover as a drilling platform, plus one hole close to the shore in the western lake catchment. At the lake’s center. the entire 315-m-thick lake sediment succession was penetrated. The sediments lack any hiatuses (i.e., no evidence of basin glaciation or desicca- tion), and their composition reflects the regional climatic and environmental history with great sensitivity. Hence, the record provides the first comprehensive and widely time- continuous insights into the evolution of the terrestrial Arctic since mid-Pliocene times. This is particularly true for the lowermost 40 meters and uppermost 150 meters of the sequence, which were drilled with almost 100% recovery and likely reflect the initial lake stage during the Pliocene and the last ~2.9 Ma, respectively. Nearly 200 meters of under- lying rock were also recovered; these cores consist of an almost complete section of the various types of impact brec- cias including broken and fractured volcanic basement rocks and associated melt clasts. The investigation of this core sequence promises new information concerning the El ́gygytgyn impact event, including the composition and nature of the meteorite, the energy released, and the shock behavior of the volcanic basement rocks. Complementary information on the regional environmental history, including the permafrost history and lake-level fluctuations, is being developed from a 142-m-long drill core recovered from the permafrost deposits in the lake catchment. This core con- sists of gravelly and sandy alluvial fan deposits in ice-rich permafrost, presumably comprising a discontinuous record of both Quaternary and Pliocene deposits.

Quantitative reconstruction of Early Pleistocene climate in southeastern Australia and implications for atmospheric circulation

by Kale Sniderman

Palaeosol stratigraphy across the Permian-Triassic boundary, Bodga Mountains, NW China: Implications for palaeoenvironmental transition through Earth's largest mass extinction

by Timothy Myers

Thomas, S.G., Tabor, N.J., Yang, W., Myers, T.S., Yang, Y., and Wang, D. (2011) Palaeogeography, Palaeoclimatology, Palaeoecology 308: 41-64

Upper Permian and Lower Triassic palaeosols from northeastern Tethyan localities exposed within the Bogda Mountains,... more Upper Permian and Lower Triassic palaeosols from northeastern Tethyan localities exposed within the Bogda Mountains, NW China, provide a wealth of information regarding long-term palaeoclimatic and palaeoenvironmental variations. Wuchiapingian palaeosols are characterized by intense redoximorphy, accumulation of vascular plant matter, accumulation of clay minerals and Fe-oxides, slickensides, and clastic dikes, suggesting a soil moisture regime that ranged from perennially wet to distinctly seasonal in soil moisture budget. Changsinghian to early Induan palaeosols include subsurface accumulations of clay and carbonate as well as surficial accumulations of organic matter, indicative of sub-humid to sub-arid soil moisture and variable soil moisture regimes. Induan to Olenekian palaeosols contain pedogenic CaCO3 accumulations and gypsum pseudomorphs, indicating a drier environment characterized by net soil moisture deficiency. Elemental composition of palaeosol matrix was used to estimate palaeoprecipitation through the chemical index of alteration minus Potassium (CIA-K) proxy. Estimates from various Wuchiapingian strata indicate relatively stable palaeoprecipitation. During the late Changsinghian and early Induan, palaeoprecipitation appears to have decreased from 1100 to 230 (±180)mm/year over less than 100 m of vertical stratigraphic section. In the Induan and Olenekian, palaeoprecipitation appears much less stable than in Wuchiapingian, with values vacillating from 290 to 1014 mm/year. The transition to a relatively unstable precipitation state coincides generally with the Permian–Triassic boundary, and may reflect climatic disturbances associated with the end-Permian extinction event in addition to altered atmospheric circulation patterns resulting from regional tectonics, moisture availability, and expansion of the subtropical high pressure belt.

Hallazgo de mamíferos pleistocénicos en el Arroyo La Barranquita (provincia de San Luis). Implicancias paloeambientales.

by José Luis Prado

Tognelli, G., E. Straser, J. Chiesa, G. Almandoz y J. L. Prado. 1993. Hallazgo de mamíferos pleistocénicos en el Arroyo La Barranquita (provincia de San Luis). Implicancias paloeambientales. Actas del XII Congreso Geológico Argentino y II Congreso de exploración de Hidrocarburos, II: 207-212. Mendoza. Argentina

Paleoclimatic and paleobiological correlation by mammal faunas from Southern America and SW Europe

by José Luis Prado

Alberdi, M.T., F.P. Bonadonna, E. Cerdeño, G. Leone, A. Longinelli, J.L. Prado, B. Sanchez and E.P. Tonni. 1993. Paleoclimatic and paleobiological correlation by mammal faunas from Southern America and SW Europe. Ciências da Terra (UNL), 12: 139-145. Portugal.

Dust flux estimates for the Last Glacial Period in East Central Europe based on terrestrial records of loess deposits: a review

by György Varga

A Late Messinian Palynoflora with a Distinct Taphonomy

by Fridgeir Grimsson

2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 9

A Lakeland Area in the Late Miocene

by Fridgeir Grimsson

2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 8

The Middle Late Miocene Floras - A Window into the Regional Vegetation Surrounding a Large Caldera

by Fridgeir Grimsson

2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 7

The Early Late Miocene Floras–First Evidence of Cool Temperate and Herbaceous Taxa

by Fridgeir Grimsson

2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 6

The Classic Surtarbrandur Floras

by Fridgeir Grimsson

2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 5

Climate Evolution in the Northern North Atlantic - 15 Ma to Present

by Fridgeir Grimsson

2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 13

The Miocene floras of Iceland and their significance for late Cainozoic North Atlantic biogeography

by Fridgeir Grimsson

2005
Thomas Denk, Fridgeir Grimsson, Zlatko Kvacek
Botanical Journal of the Linnean Society

Lythrum and Peplis from the Late Cretaceous and Cenozoic of North America and Eurasia: New evidence suggesting early diversification within the Lythraceae

by Fridgeir Grimsson

2011
Fridgeir Grimsson, Reinhard Zetter, Christa-Charlotte Hofmann
American Journal of Botany

Confirmation of Romer's Gap as a low oxygen interval constraining the timing of initial arthropod and vertebrate terrestrialization

by Michel Laurin

Íslands fornu skógar

by Fridgeir Grimsson

2008
Fridgeir Grimsson, Leifur A Símonarson
Skograektarritid

Upper Tertiary non-marine environments and climate changes in Iceland

by Fridgeir Grimsson

2008
Fridgeir Grimsson, Leifur A Simonarson
Jökull

Elstu flórur Íslands / Late Langhian to early Serravallian floras of Iceland

by Fridgeir Grimsson

2007
Fridgeir Grimsson, Leifur A Simonarson, Thomas Denk
Natturufraedingurinn

Kynlega stór aldin úr síðtertíerum setlögum á Íslandi / Unusually large samaras from Late Miocene sediments in Iceland

by Fridgeir Grimsson

2005
Fridgeir Grimsson, Leifur A Simonarson, Walter L Friedrich
Natturufraedingurinn