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Quaternary Discussion Group (QDG): archive

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# Thursday 23rd February 2017, 5.30pm - Francis Wenban-Smith, Archaeology, University of Southampton
MIS 7, the "Ebbsfleet Interglacial": sub-stage structure and recognition in the UK record
Venue: Latimer Room (Old Court), Clare College, Trinity Lane

More than 20 UK Quaternary sites are reliably related to MIS 7 of the global marine isotope stage framework. This interglacial has a distinctive O18:O16 profile of an early warm peak (MIS 7e) followed by a well-defined cooler episode (MIS 7d), which is followed in turn by a double warm peak (MIS 7c and MIS 7a) divided by a minor cool episode (MIS 7b). Foremost among UK MIS 7 sites is the Ebbsfleet Valley, a minor tributary on the south side of the Thames estuary. Here, approximately half a dozen separate localities have provided evidence of sequences from MIS 7, ranging from localities first investigated in the 1930s to currently-unpublished localities investigated as part of the HS1 archaeological programme. When the disparate palaeo-environmental, litho-stratigraphic and dating evidence from these Ebbsfleet localities is considered as a whole, a picture emerges in which all three warm MIS 7 peaks can be recognised and distinguished from each other, and their distinctive palaeo-environmental and biostratigraphic characteristics can thus provide the framework within which other UK sites should be integrated.

# Thursday 9th February 2017, 5.30pm - Paul Valdes, School of Geographical Sciences, University of Bristol
Modelling the Last Glacial-Interglacial Cycle: How sensitive are past climates?
Venue: Latimer Room (Old Court), Clare College, Trinity Lane

Understanding the mechanisms involved in Late Quaternary glacial cycles is one of the ultimate challenges for palaeoclimate science. The driving cause of the variability is related to changes in the Earth’s orbit but there are numerous feedbacks between the atmosphere, ocean, ice sheets and carbon cycle. Earth System Modelling can play an important role in quantifying some of these feedbacks and helping us to determine the major components of change. Through a combined modelling and data approach, palaeoclimate studies improve our understanding of key processes and hence contribute to improved confidence in future predictions. However, palaeoclimate studies have also attempted to directly estimate past climate sensitivity to CO2, a key parameter for future climate change. A key assumption of such work is that climate sensitivity is unchanging, so that knowing climate sensitivity in the past is relevant for climate sensitivity in the future. The talk will describe a series of modelling simulations that help us understand the feedback processes important during the last glacial-interglacial cycle, and show that the model relatively well represents the changes observed in the proxy climate data. We further use the model to investigate climate sensitivity. The simulations show that the sensitivity varies throughout the last 120,000 years, indicating that there are serious limitations on direct estimates of future climate sensitivity from palaeo-data.

This talk is part of the Quaternary Discussion Group (QDG)

# Thursday 26th January 2017, 5.30pm - Christine Lane, Department of Geography, University of Cambridge
Late Quaternary tephrostratigraphies from East African lakes
Venue: Latimer Room (Old Court), Clare College, Trinity Lane

This talk is part of the Quaternary Discussion Group (QDG)

Understanding the spatial and temporal variability of climate forcing and palaeoenvironmental response across a continent as climatically diverse as Africa relies upon comparison of data from widespread palaeoenvironmental archives. Accurate, precise and independent chronologies for such records are essential; however this remains a challenge in many environments and often prevents the valid comparison of detailed palaeo-proxy records. Many studies have now shown that volcanic ash (tephra) can be detected in terrestrial and marine sediments thousands of kilometres from their source, often as microscopic or “cryptic” layers. As well as offering opportunities for both direct (e.g. by 40Ar/39Ar methods) and indirect (e.g. by associated 14C dates) dating of the sediment sequence, tephra layers can provide stratigraphic tie-lines between archives, facilitating precise correlations at single moments in time. Furthermore, where two or more tephra layers are co-located in multiple records, rates of change can be compared within a period of equivalent duration, even in the absence of absolute age estimates.
Investigations into the presence of visible and non-visible (crypto-) tephra layers within lacustrine palaeoenvironmental records of the last ~150 ka BP from across East Africa are revealing the potential for this approach to (i) correlate palaeoclimate archives from across and beyond tropical Africa within a regional tephrostratigraphic framework; (ii) provide age constraints for individual core chronologies, in particular beyond the limits of radiocarbon dating; and (iii) increase our knowledge of the history of Late Quaternary explosive volcanism in East Africa.

# Thursday 24th November 2016, 5.30pm - Mick Frogley and Alex Chepstow-Lusty, University of Sussex
From Cambridge to Cuzco and back again: 4000 years of environmental history from the heart of the Inca Empire
Venue: Latimer Room (Old Court), Clare College, Trinity Lane

A sediment core brought back to Cambridge in 1993 from the small infilled lake of Marcacocha located at 3300 m above sea level in Andean Peru has provided a 4000-year record that, even today, continues to shed new light on environmental changes and how humans managed their environment. Surrounded by pre-Inca and Inca terraces and ruins, Marcacocha is located next to a major trade route that connects the Inca settlement of Ollantaytambo with the rainforest. By combining the study of conventional proxies such as pollen, dung fungal spores, plant macrofossils and sediment geochemistry with those that are less orthodox (such as oribatid mites), we have shown that the record spans the early development of agriculture and pastoralism, the rise and fall of the Inca Empire (c. AD 1400–1533) and into the historic period. Besides providing a detailed palaeoenvironmental record, there are indications that, particularly from 1000 years ago, major efforts in agroforestry and landscape stabilisation were being practiced. Indeed, these historic strategies may yet prove important in helping to alleviate the impacts of Peru’s increasingly acute water shortage issues, as Andean glaciers disappear and ancient aquifers are stressed by unregulated abstraction. This talk presents a welcome opportunity to bring the results of the project back to Cambridge after more than two decades.

# Thursday 10th November 2016, 5.30pm - Lucy Farr, University of Cambridge
Archaeological insights into the 8.2 ka event
Venue: Latimer Room (Old Court), Clare College, Trinity Lane

Greenland ice cores show a sharp decrease in oxygen isotope ratios and ice accumulation rates at 8.2 ka BP which persisted for c. 150 years (Dansgard et al., 1993; Grootes et al., 1993; Alley et al., 1997). Marine, ice and terrestrial proxy records from the Atlantic high and mid-latitudes, appear to consistently record a sharp change to colder, drier and possibly windier climatic conditions at this time (Pross et al., 2009).

The 8.2 ka event is a significant marker in palaeoclimatic studies, being identifiable in so many northern hemispheric records and recently posited as an official boundary marker dividing the Early and Mid-Holocene periods (Walker et al. 2012). Officially dividing the Holocene at the 8.2 ka event may be useful for archaeologists. Many archaeological records in Europe and south-west Asia show very clear technological, cultural and subsistence changes dating to the Early to Mid-Holocene transition, approximately 8000 years ago (e.g. Horn et al., 2015) but resolution issues frequently prohibit the identification of human responses in direct relation to the 8.2ka event. Recent advances in radiocarbon dating are now enabling archaeologists to better evaluate the role of the 8.2 ka event in cultural evolution occurring at this time (e.g. Flohr et al., 2016).

# Thursday 27th October 2016, 5.30pm - Jenny Collier, Imperial College London
The separation of Britain from mainland Europe in the late Quaternary
Venue: Latimer Room (Old Court), Clare College, Trinity Lane

It has been previously suggested that the separation of Britain from mainland Europe in the late Quaternary was a consequence of a catastrophic flood caused by a spillover of a proglacial lake that occupied the present-day southern North Sea basin during the Elsterian glaciation. Such an event would have significant palaeogeographic, biological and archaeological implications, but it remains controversial. Ten years ago we discovered a drainage system carved into the floor of the English Channel that is consistent with the catastrophic flood model. In this talk I will present a new compilation of seabed bathymetry and sub-bottom profiler data that we have used to analyse key landform features both within the downstream region and at the proposed breach point at the Straits of Dover. Our observations support the hypothesis that the landforms were initially carved by high-water volume flows via a unique catastrophic drainage of a pro-glacial lake in the southern North Sea at the Dover Strait rather than by fluvial erosion throughout the Pleistocene. The system also shows evidence for modification by a second flood that may have been a consequence of spillover of younger ice-marginal lake systems to the east, either in the North Sea basin or mainland Europe.

# Thursday 13th October 2016, 5.30pm - Kate Hendry, University of Bristol
Silicon cycling and opal production in the Atlantic: lessons from the last deglaciation
Venue: Latimer Room (Old Court), Clare College, Trinity Lane

Major shifts in ocean circulation are thought to be responsible for abrupt shifts in temperature and atmospheric CO2 as the Earth warmed up after the last ice age, linked to changes in latitudinal heat transport and deep ocean carbon storage. There is also widespread evidence for shifts in biological production during these times of deglacial CO2 rise, including enhanced growth of silica-producing algae (diatoms) in regions such as the equatorial Atlantic. In this talk, I’ll show how we can use marine sediment geochemical archives to demonstrate that the supply of dissolved silicon – a key nutrient for diatoms – was enhanced in the NE Atlantic during the abrupt climate events of the deglaciation. However, despite an enriched supply of this critical nutrient at depth, diatoms could only proliferate during abrupt climate shifts in regions of the NE Atlantic where the deep supply of dissolved silicon could reach the surface. These regions were influenced by enhanced regional wind-driven upwelling and weakened stratification due to circulation changes during phases of weakened Atlantic meridional overturning. Globally near-synchronous pulses of diatom production and enhanced subsurface concentrations of dissolved silicon suggest that widespread deglacial surface-driven breakdown of stratification, linked to changes in atmospheric circulation, had major consequences for biological productivity and carbon cycling across the North Atlantic.

# Thursday 12th May 2016, 5.30pm - Benjamin Stocker. Department of Life Sciences, Imperial College London
Large CO2 emissions from pre-industrial land use change – Does the carbon budget add up?
Venue: Thirkill Room, Clare College

CO2 emissions from preindustrial land use change (LUC) are subject to large uncertainties with model-based estimates ranging from 60 to 360 GtC (Olofsson and
Hickler, 2008; Pongratz et al., 2009; Kaplan et al., 2011; Stocker et al., 2011). Thus, early anthropogenic impacts rose to significance between 7-3 kyr BP depending on reconstruction and may have altered the natural carbon © cycle and climate states to a degree that would lend support for the definition of a correspondingly
early onset of the Anthropocene. However, the reconstructed parallel evolution of atmospheric CO2 and its 13C-signature indicate only 36+/-37 Gt loss of terrestrial C during the last 5 millennia (Elsig et al., 2009). It has been argued that this is the result of compensating effects of large LUC emissions and C sequestration in northern peatlands, which is estimated to be on the same order as upper-end estimates of
preindustrial LUC (Ruddiman and Ellis, 2009).

Here, we combine updated observation-based and model-based reconstructions of peat C buildup (∆Cpeat) and model-based LUC emission estimates for a range of
recently published reconstructions (Kaplan et al., 2009; Klein Goldewijk and Verburg, 2013) and accounting for changing land management regimes over time and space.
Using the independent constraint on the total terrestrial C budget from ice core measurements of CO2 and d13C (∆Ctot), we assess the compatibility of different LUC
scenarios with ∆Ctot and ∆Cpeat.

This reveals that large LUC emissions required to explain the observed CO2 rise between 7 and 5 kyr BP cannot be reconciled with ∆Ctot and ∆Cpeat unless a large additional terrestrial sink is invoked. Furthermore, this analysis points to the importance of other, non-anthropogenic impacts for explaining the ~150 Gt terrestrial C source between 5 and 2 kyr BP, where scenarios suggest emissions of only 20-50 GtC. More highly resolved ice core (Bauska et al., 2015) and peat C balance data (Charman et al., 2013) covering the last millennium further reveals that only extreme assumptions on the extent of post-Columbian reforestation in the Americas can close the C budget between 1500 and 1650 CE and that upper-end scenarios of preindustrial LUC are incompatible with the C budget between 1760 and 1920 CE.

# Thursday 5th May 2016, 5.30pm - Mike Walker, School of Archaeology, History & Anthropology, Trinity Saint David, University of Wales, Lampeter, and Department of Geography and Earth Sciences, Aberystwyth University
A formal subdivision of the Holocene Series/Epoch
Venue: Thirkill Room, Clare College

This presentation considers the prospects for a formal subdivision of the Holocene Series/Epoch. Although previous attempts to subdivide the Holocene have proved inconclusive, recent developments in Quaternary stratigraphy, including the definition of the Pleistocene–Holocene boundary and subdivisions of the Pleistocene Series/Epoch, mean that it may be timely to revisit this matter. The Quaternary literature reveals a widespread, but variable, informal usage of a tripartite division of the Holocene (‘Early’, ‘Middle’ or ‘Mid’, and ‘Late’), and it is suggested that this de facto subdivision should now be formalized to ensure consistency in stratigraphic terminology. The proposal is for three stages and subseries/subepochs of the Holocene: the Greenlandian, Northgrippian and Meghalayan, each of which is underpinned by a Global Standard Stratotype Section and Point (GSSP). It is suggested that the Early–Middle Holocene boundary should be defined by the global cooling event at 8.2 ka BP, and the Middle–Late Holocene boundary by the widespread low-latitude aridity phase at 4.2 ka BP, Should the proposal find support from the Quaternary community, a submission for ratification will be made to the International Union of Geological Sciences (IUGS), via the Subcommission on Quaternary Stratigraphy (SQS) and the International Commission on Stratigraphy (ICS).

# Thursday 21st April 2016, 5.30pm - Maryline Vautravers (University of Cambridge)
1 million years of Pacific Ocean paleoceanography viewed from IODP Exp350 sites 1436C and 1437B foraminifers' records recovered near the IZU subduction Arc
Venue: Thirkill Room, Clare College

In 2014 I sailed for 2 months on IODP EXP350 on board JOIDES Resolution, South of Japan near the Izu-Arc formed by the subduction of the West Pacific plate under the Phillippine plate. The area investigated near 30° N is affected by the Kuroshio Current. The age models for 2 Sites; U1436C and U1437B are based on stable isotopes stratigraphy N. dutertrei. The quantitative micropaleontological (planktonic foraminifer) content for 460 samples includes the indices of calcium carbonate preservation, individual shell weight, percent planktonic foraminifer fragments, planktonic foraminifer concentrations, various faunal proxies, and benthic/planktonic ratio. Altogether evidencing qualitative surface temperatures changes traced by faunal polar/subpolar versus subtropical assemblages recording the changing influences in the Kuroshio/Oyashio currents over the last 1 My. The remarkable locations of the sites at intermediate water depth in the Pacific Ocean; but separated by the hydrographic divide created by the Izu rise provide a rare insight opportunity into the operation of intermediate circulations and the influence of Quaternary Northern Hemisphere glaciations on the operation of the intermediate water mass as can be traced by changes in carbonates preservation recorded by foraminifers. The study points to the so-called Pacific carbonate cycles pattern recorded in the NW Pacific at intermediate depth to be the result of climatological and/or geochemical changes originating in the North Atlantic affecting the NADW production during interglacials and the NAGW during glacials. In term of paleoceanographic/climatic evolution it also points at MIS17 as a remarkable interglacial within the Pacific Ocean realm.

# Thursday 10th March 2016, 5.30pm - James Scourse (Bangor University)
North Atlantic annually resolved temperatures for the last millennium: the Arctica islandica record.
Venue: Latimer Room, Clare College

Abstract not available

# Thursday 25th February 2016, 5.30pm - Michael Weber (Institute of Geology and Mineralogy, University of Cologne)
Ice sheet, atmosphere, and ocean dynamics in the Atlantic sector of Antarctica – past reconstruction and future course.
Venue: Latimer Room, Clare College

Abstract not available

# Thursday 11th February 2016, 5.30pm - Eric Galbraith (ICREA, Barcelona, Spain),
Orbital wobbles, ice sheets, CO2, and the deep sea: a model-informed perspective on the ocean’s role in Quaternary climate.
Venue: Cripps Meeting Room 5, Cripps Court Building, Chesterton Road, Magdalene College

Abstract not available

# Thursday 3rd December 2015, 5.30pm - Sebastian Breitenbacher (Earth Sciences Department, University of Cambridge)
Climate and Society: Examples of the climate impact on civilizations
Venue: Latimer Room, Clare College

Abstract not available

# Thursday 19th November 2015, 5.30pm - Mark Bateman (Department of Geography, University of Sheffield)
Using the Land-Ocean Transition to understand coastal landscapes
Venue: Latimer Room, Clare College

Abstract not available

# Thursday 5th November 2015, 5.30pm - Christopher Evans (Division of Archaeology, University of Cambridge)
Landscape Retreat and 'Jumping': Late Prehistoric Fenland Environmental Adaption/Response
Venue: Latimer Room, Clare College

Abstract not available

# Thursday 15th October 2015, 5.30pm - Anais Orsi, Laboratoire des Sciences du Climat et de l'Environnement, Gif-sur-Yvette (France)
The last 1000 years in East Antarctica: insights from a new temperature proxy.
Venue: Cripps Meeting Room 4, Cripps Court Building, Chesterton Road, Magdalene College

Abstract not available

# Thursday 28th May 2015, 5.30pm - Prof Dr. Dominik Fleitmann (University of Reading)
Stalagmites as excellent recorders of major volcanic eruptions
Venue: Cripps Meeting Room 3, Cripps Court Building, Chesterton Road, Magdalene College

Abstract not available

# Thursday 14th May 2015, 5.30pm - Dr. Sambuddha Misra (Godwin Laboratory for Palaeoclimate Research, Earth Sciences Department, University of Cambridge)
Boron isotopes as pH proxy: a critical evaluation
Venue: Cripps Meeting Room 3, Cripps Court Building, Chesterton Road, Magdalene College

Abstract not available

# Thursday 5th March 2015, 5.30pm - Prof Chris D. Clark, Department of Geography, University of Sheffield (UK)
Retreat of the last British-Irish Ice Sheet; landforms, sediments, dates and the BRITICE-CHRONO project
Venue: Thirkill Room, Clare College

Abstract not available

# Thursday 19th February 2015, 5.30pm - Prof Mary E. Edwards, Department of Geography and Environment, University of Southampton (UK)
New DNA approaches to understanding Late-Quaternary and recent biodiversity changes – potential and problems
Venue: Thirkill Room, Clare College

Major advances in the ability to sequence many DNA samples has led to a proliferation of Quaternary molecular studies. The Ecochange project developed a methodology that allows DNA of vascular plants and mammals to be extracted from Quaternary sediments and used as proxy data for the components of terrestrial ecosystems. It uses an approach called “metabarcoding”: for plants, this is based on short (10-200 BP) sequences of chloroplast or nuclear DNA. Taxonomic resolution is potentially better than that of pollen and matches that of macrofossils. Furthermore, DNA detects the presence of taxa at when biomass levels are relatively low. I will illustrate the current status of DNA-based palaeoecological reconstructions with a range of modern (calibration) and fossil studies from Siberian yedoma, northern lake sediments (from Svalbard and Scotland) and modern tundra landscapes. Key findings are that modern soil DNA matches the taxa present in modern vegetation with few false positives and roughly reflects biomass, that DNA in lakes does not seem to reflect pollen when there is no vegetative biomass in the catchment, that forb taxa were a surprisingly large component of glacial-age vegetation across unglaciated Eurasia, and that the Holocene DNA record from Svalbard shows rapid early colonization and resilience of the flora in the face of climatic deterioration. New and stricter protocols for sequencing and bioinformatics filtering are improving the ability to determine false positives in the data, which were likely a problem in the first, pioneering studies.

# Thursday 29th January 2015, 5.30pm - Dr. Heather Ford (Lamont Doherty Earth Observatory, Columbia University)
El Niño and El Padre: a deep equatorial Pacific thermocline during the Pliocene warm period
Venue: Cripps Meeting Room 4, Cripps Court Building, Chesterton Road, Magdalene College

Abstract not available

# Thursday 15th January 2015, 5.30pm - Prof Eric J. Steig, Department of Earth and Space Sciences, University of Washington (US)
The role of the ocean and the atmosphere in the expression of D-O and AIM events in Antarctica: new evidence from the WAIS Divide Ice Core
Venue: Cripps Meeting Room 4, Cripps Court Building, Chesterton Road, Magdalene College

Abstract not available

# Thursday 4th December 2014, 5.30pm - Dr Peter Abbott (University of Swansea)
Cryptotephrochronology in the North Atlantic Region: Linking North Atlantic Marine Sediments to the Greenland ice-cores
Venue: Thirkill Room, Clare College

Tephrochronology is a powerful technique that can be utilised for the correlation and synchronisation of disparate palaeoclimatic records from different depositional
environments. Thus, this technique has considerable potential for addressing key questions relating to rapid climatic events that characterised the last glacial period. In particular, our search for microscopic tephra layers or cryptotephras within the Greenland ice-cores and marine cores from the North Atlantic Ocean has the potential to test the phase relationships between the atmospheric and oceanic responses to these high-magnitude and abrupt climatic events.
Tephrochronological investigations are currently being undertaken on a network of marine cores from a range of locations and depositional settings within the North Atlantic as part of the ERC-funded project Tephra constraints on Rapid Climate Events (TRACE). Tephra horizons have been identified in the marine records through the successful use of cryptotephra extraction techniques more commonly applied to the study of terrestrial sequences. The two main challenges associated with cryptotephra work in the glacial North Atlantic are i) determining the dominant transportation processes and ii) assessing the influence of secondary reworking processes and the integrity of the isochrons. The potential influence of these processes is investigated by assessing shard size, geochemical (major and trace element) heterogeneity and co-variance of IRD input for some cores. We are also applying the innovative techniques of micromorphology and X-ray tomography to the study of these processes.
Early comparison of the tephrochronological record of cores within the network highlight a number of potential marine to ice linkages and the potential for these to allow an assessment of the relative timing of climatic changes between the ocean and atmosphere will be discussed.

# Friday 14th November 2014, 5.30pm - Dr Lauren Gregoire (School of Earth and Environment, University of Leeds)
The North American deglaciation: linking rapid climate change, ice sheet retreat and sea level rises
Venue: Latimer Room, Clare College

The last deglaciation (approx. 21-7ka) was punctuated by several abrupt climatic and sea level changes in which ice sheets are thought to have played an important role.
This talk describes the role of the N. American ice sheet in two of the most important event of rapid sea level change:
(i) the MWP-1a, a ~ 14-18 m global sea level rise in less than 350 years which coincided with the rapid N. Hemisphere Bolling warming;
(ii) the ‘8.2 kyr event’, a century long cooling event attributed to the sudden release of N. American glacial lakes.
By combining, climate, ice sheet and sea level modelling with a variety of palaeo-environment data I evaluate (i) the mechanisms that lead to accelerated ice melt and (ii) the impacts of these on the climate. I will present recent efforts to constrain the contribution of the N. American ice sheet to MWP1a from the Bolling warming and a mass balance mechanism named the saddle collapse. Finally, I will introduce the recent plans of the Palaeo Model Intercomparison Project for simulating the climate of the last deglaciation.

# Thursday 6th November 2014, 5.30pm - Prof Dr Hubertus Fischer (Oeschger Centre for Climate Change Research, University of Bern)
Changes in the Global Carbon Cycle over the last 800,000 years - an ice core perspective
Venue: Thirkill Room, Clare College

Abstract not available

# Wednesday 22nd October 2014, 4.00pm - Prof Bill Ruddiman (Department of Environmental Sciences, University of Virginia, US)
Top-down and bottom-up evidence for the early anthropogenic hypothesis
Venue: Tilley Lecture Theatre, Department of Earth Sciences, Downing Street

Abstract not available

# Monday 7th July 2014, 5.00pm - Professor Richard Alley, Evan Pugh Professor of Geoscience, Penn State University, USA
People should be aware that 7th July is Tour de France day, but we hope things will have become accessible by 5.00 pm.
Fracking the fjords: Earthquakes and glacial erosion, with some additional thoughts about stability of the West Antarctic Ice Sheet
Venue: Tilley Lecture Theatre, Department of Earth Sciences

Abstract not available

# Wednesday 27th November 2013, 5.00pm - Dr. Patrick Grunert (U. of Graz, Austria)
CHANGE OF DATE: now on Wednesday Nov. 27th
Benthic foraminiferal assemblages as proxies of paleoceanographic changes across Pleistocene glacial terminations in the NE Atlantic
Venue: Thirkill Room, Clare College

The study of fossil foraminifera goes back to the early 19th century, making them one of the best studied microfossil groups. More recently, our increasing understanding of their distribution and ecological requirements in the present-day oceans has made the quantitative evaluation of foraminiferal assemblages a powerful means of actualistic paleoenvironmental reconstruction.
In this paper I present examples for the application of benthic foraminiferal assemblages from IODP Site U1385 (“Shackleton Site”) as proxies of paleoceanographic Change in the Pleistocene NE Atlantic. A brief introduction to the present-day distribution of benthic foraminifera in the area and the relation to the oceanographic setting is followed by an evaluation of differences between the present-day situation and major glacial/interglacial transitions. The presentation is wrapped up by a discussion of the implications of observed turnovers in the benthic foraminiferal fauna for changes of sea-water properties at the water/sediment interface during these rapid climatic transitions.

# Thursday 7th November 2013, 5.00pm - Prof. Eric Wolff (Dept. of Earth Sciences, Cambridge)
Interglacials of the last 800,000 years
Venue: Thirkill Room, Clare College

Abstract not available

# Thursday 24th October 2013, 4.00pm - Prof. Howard J. Spero (University of California)
Note unusual time
The paleoceanography frontier: proxies, new technologies and novel questions
Venue: Latimer Room, Clare College

Please note different time and venue: Latimer Room, 4pm

In recent years, new geochemical proxies and emerging technologies have been combined to explore novel paleoclimatic questions that were only dreamed about a decade ago. In this presentation I will discuss how the application of new technologies such as laser ablation ICP-MS (e.g. Mg/Ca, Ba/Ca), SIMS (e.g. d18O, d13C) and nanoSIMS can be used to address old and new paleoceanographic problems. I will present data from laboratory experiments with living planktonic foraminifera that have allowed us to calibrate these proxies and reduce the spatial resolution of geochemical analyses to the micron and sub-micron level. These data confirm many of the fundamental geochemical relationships used by researchers to reconstruct ocean temperatures and water geochemistry from the fossil record. When individual foraminifera from a fossil assemblage are analyzed using LA-ICP-MS (Mg/Ca, Ba/Ca) and coupled to d18O measurements from standard isotope ratios mass spectrometry (IRMS), we may be able to extract novel information from the fossil record that was not previously possible. I will present data collected at the interface of these two geochemical technologies that has allowed us to calculate the oxygen isotopic composition of Laurentide Ice Sheet meltwater during the last deglaciation.

# Thursday 17th October 2013, 5.00pm - Dr. Maryline Vautravers (Cambridge)
Canceled
Taking a closer look at the last glacial sediments
Venue: Thirkill Room, Clare College

Abstract not available

# Thursday 14th March 2013, 5.15pm - Dr. Katy Pol (British Antarctic Survey)
Evidence for enhanced Antarctic climate variability during the last interglacial period
Venue: Thirkill Room, Clare College

Abstract not available

# Thursday 21st February 2013, 5.00pm - Prof. James Rose (Dept. of Geography, Royal Holloway U. of London)
The Bytham river story - key evidence for understanding pre-glacial environmental change and early human occupance in Britain
Venue: Thirkill Room, Clare College

A special double session on the Bytham river!

# Thursday 21st February 2013, 5.00pm - Prof. Philip Gibbard (Dept. of Geography, U. of Cambridge)
Testing the Bytham river hypothesis
Venue: Thirkill Room, Clare College

A special double session on the Bytham river!

# Thursday 7th February 2013, 5.00pm - Prof. Liping Zhou (Peking University, China)
Late Quaternary loess records from northern China and central Asia: implications for variations in monsoon and westerly circulation
Venue: Thirkill Room, Clare College

Abstract not available

# Thursday 24th January 2013, 5.00pm - Prof. Graeme Barker (McDonald Institute of Archaeological Research, U. of Cambridge)
Modern human adaptations to Pleistocene rainforest: the archaeology of the Niah Caves, Sarawak, Borneo
Venue: Thirkill Room, Clare College

Abstract not available

# Thursday 10th January 2013, 5.00pm - Dr. David Thornalley (Woods Hole Oceanographic Institution, USA)
The release of d14 C and d18 O-depleted water from the Arctic Ocean upon glacial termination
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 30th November 2012, 5.00pm - Dr Anna-Lena Grauel (Dept. of Earth Sciences, Cambridge)
New estimates of tropical ice age temperature
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 23rd November 2012, 5.00pm - Dr Emilie Capron (BAS)
Please note change of speaker
Using nitrogen isotopes to constrain the age of the air extracted from antarctic ice cores
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 9th November 2012, 5.00pm - Dr Aline Govin (MARUM, Bremen)
Precipitation changes in the Amazon Basin during the last 240 ka
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 26th October 2012, 5.00pm - Dr David Wilson (Dept. of Earth Sciences, Cambridge)
Decoupled ocean circulation and carbon cycling during glaciations: Implications for the dynamics of glacial cycles
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 18th May 2012, 5.00pm - Dr Natalia Vazquez-Riveiros (Earth Sciences, University of Cambridge)
Carbon isotopes and glacial-interglacial CO2: the curious case of Marine Isotope Stage 12
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 11th May 2012, 5.00pm - Prof. Martin Jones (Archaeology, University of Cambridge)
The Moravian Gate project: new insights into the human food quest in Stage 3 Central Europe
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 4th May 2012, 5.00pm - Dr Luke Skinner (Earth Sciences, University of Cambridge
A bipolar seesaw in Atlantic deep-water ventilation: Wally was right
Venue: Thirkill Room, Clare College

Due to the absence of key individuals this week, there has been a change to the topic of the seminar scheduled.

# Friday 27th April 2012, 5.00pm - Prof. Hema Achyuthan (Anna University, Chennai)
Quaternary palaeoclimate changes from the margins of the Indian Thar Desert
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 24th February 2012, 5.00pm - Prof. Veli-Pekka Salonen (Dept. of Geosciences and Geography, University of Helsinki, and Visiting fellow at Clare Hall)
Lessons from the High Arctic: new results from late Quaternary studies in Nordaustlandet, Svalbard
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 20th January 2012, 5.00pm - Kate Darling (University of Edinburgh)
Genetic diversity, global phylogeography and seasonality of the planktonic foraminifera G. bulloides: implication for palaeoproxies
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 2nd December 2011, 5.00pm - Dr Aleksey Sadekov (Department of Earth Sciences, Cambridge)
Role of the Tropical Pacific in Millennial-Scale Climate Events
Venue: Seminar Room 3, Cripps Court, Magdalene College

IMPORTANT: In order to avoid conflict with the new CCfCS seminar series held on on Thursdays, we have had to reschedule these QDGs to Fridays and host them in MAGDALENE COLLEGE. The seminars will take place in CRIPPS COURT in Meeting Room 3. Cripps Court is opposite Magdalene College on Chesterton Road (http://conference.magd.cam.ac.uk/find-us). The room will be signposted to help you find us.

As usual, wine and discussion will follow the seminars.

# Friday 18th November 2011, 5.00pm - Outi Hyttinen (Department of Geosciences and Geography, University of Helsinki, FInland)
Traces of the Baltic Ice Lake drainage in the northern Baltic Sea and southern Finland
Venue: Seminar Room 3, Cripps Court, Magdalene College

IMPORTANT: In order to avoid conflict with the new CCfCS seminar series held on on Thursdays, we have had to reschedule these QDGs to Fridays and host them in MAGDALENE COLLEGE. The seminars will take place in CRIPPS COURT in Meeting Room 3. Cripps Court is opposite Magdalene College on Chesterton Road (http://conference.magd.cam.ac.uk/find-us). The room will be signposted to help you find us.

As usual, wine and discussion will follow the seminars.

# Friday 4th November 2011, 5.00pm - Professor Harry Elderfield (Department of Earth Sciences, Cambridge)
Evolution of ocean temperature and ice volume from the Mid Pleistocene Climate Transition
Venue: Thirkill Room, Clare College

Abstract not available

# Wednesday 26th October 2011, 5.00pm - Dr Ian Bailey (School of Ocean & Earth Science, National Oceanography Centre Southampton)
New insights on old questions concerning Quaternary northern hemisphere glaciation
Venue: Thirkill Room, Clare College

Abstract not available

# Tuesday 31st May 2011, 5.00pm - Dr Axel TImmermann (SOEST, University of Hawai'i, USA); Dr Jess Adkins (CALTECH, USA)
A special set of QDG talks
Venue: Latimer Room, Clare College

5:00 pm – Dr Axel TImmermann (SOEST, University of Hawai’i, USA): ‘Understanding orbitally-driven climate change in the Southern Hemisphere’

5:45 pm – Discussion, wine and finger food

6:00 – Dr Jess Adkins (CALTECH, USA):
‘The deep ocean’s role in glacial-interglacial cycles’.

6:45 – Discussion, and more wine!

All are welcome; you may not get another chance to hear how the Southern Hemisphere and the deep ocean both control global glacial-interglacial climate change, in one sitting!

# Thursday 19th May 2011, 5.00pm - Martin Ziegler, Cardiff University
Orbital forcing of Late Pleistocene climate variability - From the global monsoon to glacial terminations
Venue: Thirkill Room, Clare College

Abstract not available

# Thursday 28th April 2011, 5.00pm - Dr Samuel Toucanne (IFREMER, France)
Pleistocene Fleuve Manche palaeoriver discharges : Response to glacial oscillations and climate changes
Venue: Latimer Room, Clare College

Abstract not available

# Friday 18th February 2011, 5.00pm - Dr Phillip Hughes, The University of Manchester
Quaternary glaciation in the Mediterranean mountains: new results from North Africa and the Balkans
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 11th June 2010, 5.00pm - Richard West (Professor emeritus, Cambridge University, Clare College)
The History of Quaternary Research at Cambridge University
Venue: Thirkill Room, Clare College

Abstract not available

# Friday 13th February 2009, 5.15pm - Steven Pawley (Royal Holloway, University of London)
Canceled
Glacial Chronologies Spanning the Past 450 ka Around the Margins of the Southern North Sea and implications for the age of the Strait of Dover
Venue: Lloyd Room, Christ's College

Abstract not available

# Friday 30th January 2009, 5.15pm - Peter Koehler (Alfred Wegener Institute, Germany)
The carbon cycle during the Pleistocene
Venue: Lloyd Room, Christ's College

Abstract not available

# Friday 23rd January 2009, 5.15pm - Anne Osborne (Bristol University)
A humid corridor across the Sahara for the migration "Out of Africa" of early modern humans 120,000 years ago.
Venue: Lloyd Room, Christ's College

Abstract not available