Paleoclimate

The Influence of Climatic Change on the Late Bronze Age Collapse and the Greek Dark Ages

by Brandon Lee Drake

Between the 13th and 11th centuries BCE, most Greek Bronze-Age Palatial centers were destroyed and/or abandoned. The... more Between the 13th and 11th centuries BCE, most Greek Bronze-Age Palatial centers were destroyed and/or abandoned. The following centuries were typified by low population levels. Data from oxygen-isotope speleothems, stable carbon isotopes, alkenone-derived sea surface temperatures, and changes in warm species dinocysts and formanifera in the Mediterranean indicate that the Early Iron Age was more arid than the preceding Bronze Age. A sharp increase in Northern Hemisphere temperatures preceded the collapse of Palatial centers, a sharp decrease occurred during their abandonment. Mediterranean Sea surface temperatures cooled rapidly during the Late Bronze Age, limiting freshwater flux into the atmosphere and thus reducing precipitation over land. These climatic changes could have affected Palatial centers that were dependent upon high levels of agricultural productivity. Declines in agricultural production would have made higher-density populations in Palatial centers unsustainable. The ‘Greek Dark Ages’ that followed occurred during prolonged arid conditions that lasted until the Roman Warm Period.

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

by Kale Sniderman

Early Pleistocene vegetation change in upland south-eastern Australia

by Kale Sniderman

Progressive Cenozoic cooling and the demise of Antarctica's last refugium

by Alexandra Kirshner

The Antarctic Peninsula is considered to be the last region of
Antarctica to have been fully glaciated as a... more The Antarctic Peninsula is considered to be the last region of
Antarctica to have been fully glaciated as a result of Cenozoic
climatic cooling. As such, it was likely the last refugium for plants and animals that had inhabited the continent since it separated from the Gondwana supercontinent. Drill cores and seismic data acquired during two cruises (SHALDRIL I and II) in the northernmost Peninsula region yield a record that, when combined with existing data, indicates progressive cooling and associated changes in terrestrial vegetation over the course of the past 37 million years. Mountain glaciation began in the latest Eocene (approximately 37–34 Ma), contemporaneous with glaciation elsewhere on the continent and a reduction in atmospheric CO2 concentrations. This climate cooling was accompanied by a decrease in diversity of the angiosperm-dominated vegetation that inhabited the northern peninsula during the Eocene. A mosaic of southern beech and conifer-
dominated woodlands and tundra continued to occupy the
region during the Oligocene (approximately 34–23 Ma). By the middle Miocene (approximately 16–11.6 Ma), localized pockets of limited tundra still existed at least until 12.8 Ma. The transition from temperate, alpine glaciation to a dynamic, polythermal ice sheet took place during the middle Miocene. The northernmost Peninsula was overridden by an ice sheet in the early Pliocene (approximately 5.3–3.6 Ma). The long cooling history of the peninsula is consistent with the extended timescales of tectonic evolution of the Antarctic margin, involving the opening of ocean passageways and associated
establishment of circumpolar circulation.

Comparative study on the Late Cenozoic red clay deposits from China and Central Europe (Hungary)

by György Varga

Plio-Pleistocene red clay deposits in the Pannonian basin: 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

The Classic Surtarbrandur Floras

by Fridgeir Grimsson

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

The Archaic Floras

by Fridgeir Grimsson

2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 4

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

Diverse fossil Onagraceae pollen from a Miocene palynoflora of north-east China: early steps in resolving the phytogeographic history of the family

by Fridgeir Grimsson

2012
Fridgeir Grimsson, Reinhard Zetter, Qin Leng
Plant Systematics and Evolution

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

by Fridgeir Grimsson

2007
Fridgeir Grimsson, Leifur A Simonarson, Thomas Denk
Natturufraedingurinn

Combined LM and SEM study of the Middle Miocene (Sarmatian) palynoflora from the Lavanttal Basin: Part I. Bryophyta, Lycopodiophyta, Pteridophyta, Ginkgophyta, and Gnetophyta

by Fridgeir Grimsson

2011
Fridgeir Grimsson, Reinhard Zetter, Christian Baal
Grana

Strengthening of North American dust sources during the late Pliocene (2.7 Ma)

by David Naafs

Published in Earth and Planetary Science Letters

Here we present orbitally-resolved records of terrestrial higher plant leaf wax input to the North Atlantic over the... more Here we present orbitally-resolved records of terrestrial higher plant leaf wax input to the North Atlantic over the last 3.5 Ma, based on the accumulation of long-chain n-alkanes and n-alkanl-1-ols at IODP Site U1313. These lipids are a major component of dust, even in remote ocean areas, and have a predominantly aeolian origin in distal marine sediments. Our results demonstrate that around 2.7 million years ago (Ma), coinciding with the intensification of the Northern Hemisphere glaciation (NHG), the aeolian input of terrestrial material to the North Atlantic increased drastically. Since then, during every glacial the aeolian input of higher plant material was up to 30 times higher than during interglacials. The close correspondence between aeolian input to the North Atlantic and other dust records indicates a globally uniform response of dust
sources to Quaternary climate variability, although the amplitude of variation differs among areas. We argue that the increased aeolian input at Site U1313 during glacials is predominantly related to the episodic appearance of continental ice sheets in North America and the associated strengthening of glaciogenic dust sources. Evolutional spectral analyses of the n-alkane records were therefore used to determine the dominant
astronomical forcing in North American ice sheet advances. These results demonstrate that during the early Pleistocene North American ice sheet dynamics responded predominantly to variations in obliquity (41 ka), which argues against previous suggestions of precession-related variations in Northern Hemisphere ice sheets during the early Pleistocene.

Middle Palaeolithic human occupation of the high altitude region of Hovk-1, Armenia

by Roman Hovsepyan

Pinhasi R., Gasparian B., Nahapetyan S., Bar-Oz G., Weissbrod L., Bruch A.A., Hovsepyan R., Wilkinson K. 2011. Middle Palaeolithic human occupation of the high altitude region of Hovk-1, Armenia. Quaternary Science Reviews, Volume 30, Issue 27-28, December 2011, Pages 3846-3857.

Charting the timing of human occupation in the mountainous regions of the Caucasus during the Last... more Charting the timing of human occupation in the mountainous regions of the Caucasus during the Last Interglacial/Glacial periods is of particular interest to the understanding of past human adaptive and behavioural plasticity and capacity. In this paper we analyse palaeoenvironmental, faunal, and archaeological data gathered during 2006-2009 excavations of the Palaeolithic cave site of Hovk-1, Armenia, in order to address whether human presence in this cave correlates with episodes of mild climate and certain environmental and ecological conditions that were favourable to huminin occupation in such a region. In the second part of the paper we evaluate the implications of our results in understanding the nature of human presence in other mountainous regions such as the Alps and its potential implications for Palaeolithic research.
Our analysis demonstrates that hominins occupied Hovk-1 Cave during milder climatic phases of the Last Interglacial sensu lato (MIS 5d-c) and Last Glacial (late MIS 4/early MIS 3) periods when the area surrounding the cave was an open meadow environment. The stratigraphic Units with noticeable traces of hominin occupation (Units 4, 5 & 8) contrast with others in the lack of cave bear fauna and suggest an inverse correlation between human and cave bear occupational phases in Hovk-1. We speculate that human groups visited this region to hunt specific prey species that prevailed in this habitat (such as the bezoar goat). However, the assemblages of large mammals from Hovk-1 do not provide any clear anthropogenic signal and therefore highlight the difficulty of teasing apart natural and cultural formation processes.

Enregistrement des variations climatiques au cours des interglaciaires d'après l'étude des isotopes stables de la calcite de tufs pléistocène du nord de la France : exemple des séquences de Caours (SIM 5e; Somme) et La-Celle-sur-Seine (MIS 11 ; Seine-et-Marne)

by Julie Dabkowski

Co-authors with N. Limondin-Lozouet, P. Antoine, A. Marca-Bell and J. Andrews.
Published in Quaternaire, 22 (4), 2011

RECORD OF CLIMATIC CHANGES DURING INTERGLACIALS FROM STABLE ISOTOPES IN NORTHERN FRANCE PLEISTOCENE TUFA CALCITE:... more RECORD OF CLIMATIC CHANGES DURING INTERGLACIALS FROM STABLE ISOTOPES IN NORTHERN FRANCE PLEISTOCENE TUFA CALCITE: EXAMPLES OF CAOURS (MIS 5e; SOMME) AND LA CELLE (MIS 11; SEINE ET MARNE).
Tufas are mainly composed of calcite (CaCO3) which makes them suitable for geochemical investigation, especially oxygen and carbon stable isotopes (δ18O and δ13C). These isotopic parameters have already been shown to record temperature and humidity variations in the Holocene tufas, proving their suitability as climatic proxies. This study focuses on two French Pleistocene sites, Caours and La Celle. Results are compared to palaeoenvironmental, especially malacological, data. This comparison shows that δ18O and δ13C in tufas are important proxies of palaeoclimatic variation during Pleistocene interglacials, just as they are during the Holocene.


La composition minéralogique des tufs calcaires, essentiellement constitués de CaCO3, permet l’utilisation d’indicateurs climatiques géochimiques et en particulier l’étude des isotopes stables de l’oxygène et du carbone (δ18O et δ13C). Ces derniers sont déjà bien connus dans les tufs holocènes comme marqueurs des variations de température et d’humidité. L’analyse des isotopes stables a été réalisée ici sur les séquences de tuf pléistocènes de Caours (SIM 5e, Somme) et de La Celle (SIM 11, Seine et Marne). Les résultats de cette étude géochimique ont été comparés aux données paléoenvironnementales, notamment malacologiques. Ces premières analyses montrent que, comme dans le cas des tufs holocènes, les variations des isotopes stables du carbone et de l’oxygène dans les tufs pléistocènes constituent des indicateurs fiables des variations climatiques au cours des interglaciaires pléistocènes.

Ginkgo in Australia

by Stephen McLoughlin

Popular science article.
Reference:
McLoughlin, S. Dec 2010. Ginkgo in Australia. Australian Age of Dinosaurs 8, 42–47.

Frumkin, A., Bar-Yosef, O., and Schwarcz, H. P. 2011, Possible paleohydrologic and paleoclimatic effects on hominin migration and occupation of the Levantine Middle Paleolithic. Journal of Human Evolution 60:4 437-451.

by Amos Frumkin

Pliocene mammals and climatic reconstruction in the Western Mediterranean area

by Serge Legendre

AGUILAR, J.-P., LEGENDRE, S., MICHAUX, J. and MONTUIRE, S. 1999. Pliocene mammals and climatic reconstruction in the Western Mediterranean area. In J. H. Wrenn, J.-P. Suc and S. A. G. Leroy (eds). The Pliocene: Time of change. American Association of Stratigraphic Palynologists Foundation, Dallas, pp. 109-120.

The specffic diversity of extant mammalian faunas, the body weight distribution of component species (as expressed by... more The specffic diversity of extant mammalian faunas, the body weight distribution of component species (as expressed by cenograms), and the specific richness of some taxonomic groups change with the climate. Using these parameters, we attempt to estimate the climatic conditions of earlier times and to estimate past temperatures and precipitation.
Cenogram analysis shows that there is a contrast between rather closed and warm environments at the beginning of Pliocene times, and more open and cooler environments during the Pleistocene, and also that the Iberian Peninsula, as compared to southern France, was characterized by more open environments. The specific diversity of Murinae in Western Europe shows that the climate was warm with high precipitation (mean annual temperature = 21°C and mean annual rainfall = ca. 1100 mm) at the end of the Lower Pliocene (-4.0 to -3.5 My). The drop in diversity in Murinae that can be seen in Spain and in France is probably related to a deterioration of the climate towards coolness and dryness between -3.2 My and -2.0 My. About 1 My ago, the climate became dryer, with estimates of about 13°C and 700 mm. The first glacial phases are thus characterized by rather mild temperatures.

Rodents and climate: A new model for estimating past temperatures

by Serge Legendre

LEGENDRE, S., MONTUIRE, S., MARIDET, O. and ESCARGUEL, G. 2005. Rodents and climate: A new model for estimating past temperatures. Earth and Planetary Science Letters, 235, 408-420.

Based on the high correlation between species richness in sigmodontine rodents and temperatures, we propose a new... more Based on the high correlation between species richness in sigmodontine rodents and temperatures, we propose a new model in order to quantify past climates. Because of the close phylogenetic relationship and the tooth morphological similarity between extant New World cricetids (Sigmodontinae) and fossil European cricetids (Cricetinae s.l.), extant New World sigmodontines are taken as analogues for Old World fossil cricetines. Sigmodontine species richness has been compiled for 282 extant local faunas from North, Central and South America, with corresponding climatic data (temperatures and precipitations). There is almost no correlation between areas covered by local faunas (ranging from 1 km2 up to 46,000 km2) and numbers of sigmodontine species in localities (R2=0.027). Number of sigmodontine species in local faunas and mean annual daily temperatures are highly correlated (R2=0.88). The relationships of species richness and precipitation is low (R2=0.19 for mean annual precipitation).
The method is exemplified for Old World cricetines using well documented Miocene rodent faunas located in the Lyon area (France MN4-5 to MN10).