Authigenic silicates and Quaternary paleolimnology: Examples from Olduvai Gorge, Tanzania, and the Kenya Rift

The Third Fault, Olduvai Gorge, Tanzania, showing the stratigraphy of the Olduvai Basin.

 

The paleoclimatic framework of human evolution is central to the study of human origins. Several East African basins offer excellent examples of how authigenic silicates may be used in paleoenvironmental reconstructions, particularly when biotic indicators are absent or diagenetically modified.

In a Pleistocene section at Olduvai Gorge, Mg depletion in authigenic clays indicate freshening events occurring over a generally saline and alkaline environmental background. Five of the six events observed occurred at peak climatic precession, correlating with December insolation at 20°S. Peak amplitude of geochemical variation preceded the ca. 1.84 Ma eccentricity maximum by ~20 k.y., suggesting that eccentricity modulation was unexpectedly weak in this interval, or that other factors affected the water balance or geochemical record. 

Dan Deocampo, Georgia State University

Preliminary work has been carried out on deposits of the Lake Magadi, Koora Graben, and Baringo Basin cores obtained by the international Hominin Sites and Paleolakes Drilling Project. In these cores, authigenic clay minerals do not show much variation in chemistry, as these basins did not persist in the window of conditions of salinity and silica availability to promote authigenic clay precipitation. Instead, zeolites produced by alteration of volcaniclastic materials give insight into relative salinity conditions. In particular, different zeolites host different cations (i.e. Na, K, Ca) that provide clues as to cation ratios in the paleolake water. Major transitions of zeolite assemblages are observed in each basin, indicating salinity fluctuations. 

Authigenic silicates provide datasets that can add an important component to multi-proxy paleoenvironmental records from lake basins.

Dr. Deocampo is Professor and Chair of the Department of Geosciences at Georgia State University, in Atlanta.  He conducts geological research around the world, including in Europe, East Africa, and North America. He has published over 30 peer-reviewed scientific publications and has attracted funding support from the U.S. National Science Foundation, the U.S. Geological Survey, the Petroleum Research Fund, and the Departments of Transportation in both California and Georgia. He collaborates with environmental and public health scientists, anthropologists, biologists, chemists, geographers, and others to conduct research on both basic and applied research topics. Dr. Deocampo is an expert in the mineralogy and geochemistry of near surface environments, including soils, sediments, and aquatic systems, and is a Fellow of the Geological Society of America. 

Date: 30/06/2017, 10:00 h – 11:00 h

Location: Room 0.024, Biozentrum (Building 304), Zülpicher Str. 47b, Cologne


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40Ar/39Ar dating of Plio-Pleistocene Drill Cores from East Africa

East Africa provides the opportunity to acquire unique evidence toward understanding the influence of climate and environmental change on the evolution of the human lineage and technology during the Plio-Pleistocene. The Hominin Sites and Paleolakes Drilling Project (HSPDP) has extracted a total of 2 km of sediment drill core from the Rift Valley of East Africa, in paleolake basins adjacent to fossil hominin and archaeological sites of major significance. 40Ar/39Ar dating and chronology modeling of four of these sites will be discussed. Sites in the southern Kenya Rift will be compared to outcrop geology of the Olorgesailie area, which exhibits some of the earliest Middle Stone Age archaeology.

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Alan Deino, Berkeley Geochronology Center, California.

Alan Deino is a geochronologist at the Berkeley Geochronology Center, Berkeley, California. His career has been devoted to the application of the 40Ar/39Ar dating method to problems of volcanology, tectonics, climate change, faunal evolution, and hominin origins on several continents, but with recurring emphasis on East Africa.

 

 

 

Date: 14/06/2017, 16:00 h – 17:00 h

Location: Room 0.40, Biozentrum (Building 301), Zülpicher Str. 47a, Cologne
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Upper Quaternary soil development and paleo-environments on the Swiss Plateau: A progress report

heinz-veit-vortragThe existence of periglacial cover beds as forming an important part of soil parent material in Europe is widely accepted. The youngest of these cover beds, the “Upper Layer” (Hauptlage) is assumed to have developed during the Lateglacial. The formation of Luvisols (Parabraunerden) is assumed to have occurred afterwards, during the Holocene, under forest vegetation and stable surface conditions. Some authors describe initial soil formation during the lateglacial reforestation period (Bölling/Alleröd), but still interpreting the main part of Luvisol formation under forest during the Holocene. One consequence of this interpretation is the use of Bt-horizons as paleo-ecological and stratigraphic indicators of interglacials in Europe.

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On the Swiss Plateau, soils have mainly developed on glacial and glaciofluvial deposits of different ages, covered by periglacial cover beds. The known glacial chronology is an ideal prerequisite to study soil chronosequences on these Upper Quaternary deposits. We applied extensive OSL datings on the cover beds and the parent material of the soils. This allows a more detailed understanding of the timing of processes like decalcification and clay dislocation. The results question some of our basic understandings concerning the timing of soil formation and related paleo-geoecological conditions. These findings and preliminary conclusions from our ongoing research will be discussed in the talk. 

Prof. Dr. Heinz Veit, University of Berne

Prof. Dr. Heinz Veit, University of Berne

Heinz Veit holds the chair of Paleo-Geoecology at the Institute of Geography, University of Berne, since 1996. He did his studies, PhD and postdoc in geomorphology, soil science and geoecology at the universities of Frankfurt, Bayreuth and La Serena (Chile). His scientific interests are I) glacial history and chronology in high mountains (Andes, Bale Mountains, Alps), II) past and present periglacial dynamics and cover beds (Alps, Andes, Bale Mountains, Europe), III) tropical hillwash (Brazil, Kamerun, Nigeria), IV) geoarcheology (Bolivian Amazon, Bale Mountains) and V) soil genesis and paleosols (Europe, Kamerun, Nigeria, Chile, Argentina, Bolivia, Brazil).

Event Information:

Date, Time: 23/01/2017, 16:00 h – 17:00 h

Location: Room 0.024, Biozentrum (Building 304), Zülpicher Str. 47b, Cologne

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Socio-economic changes in flint production and consumption in the PPNB period of the Greater Petra Region, Southern Levant

purschwitz_blogThis presentation is the outcome of a Ph.D, which recently was completed at Freie Universität Berlin (Purschwitz 2016). This paper presents the results of the chipped lithic analysis from five Pre-Pottery Neolithic B (PPNB, ca. 8600-6900 BCE) sites (Ail 4, Ba’ja, Basta, Beidha and Shkârat Msaied) which all are situated at the Greater Petra Region. Major changes in the organization of flint production and blank consumption are in evidence with the emergence of the large mega-sites during the late PPNB (7500-6900 BCE). An increasing number of bidirectional blade consuming households are opposed to few producing workshops, which operate beyond their own demand and produce on a regional supply level. Households which have restricted access to the late PPNB bidirectional bade network respond with self-supply strategies by using alternative blade technologies. This phenomenon or “technological dualism” between inter-site production and household consumption rises with increasing specialization in crafts and comprises all levels of production from raw material procurement to exchange.

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Christoph Purschwitz, FU Berlin

Christoph Purschwitz, FU Berlin.

I argue that the emergence of the dualistic lithic economy (in the Greater Petra Region) is the result of changes in the network structure of the households. While MPPNB sites of the Greater Petra Region are small and only seasonal used, LPPNB mega-sites can be huge and permanently occupied by several hundreds to thousand inhabitants. According to general network theory the personal network (family, relatives, friends) of a MPPNB household is likely to be distributed over several more or less distant sites, while the personal network of a LPPNB household appears to be restricted to the mega-site itself. Additionally, it is likely that at mega-sites such as Basta or ‘Ain Ghazal an increasing number of inhabitant did not share the households personal networks and did not had social relations to each other. I expect that the lack of social control within the late PPNB mega-sites promoted profit-oriented thinking (negative reciprocity, surplus production) and constituted in increasing social inequality.

Literature:

Purschwitz, C. 2016. The Lithic Economy of Flint during the Early Neolithic of the Greater Petra Region. Geological Availability, Procurement, Production, and Modes of Distribution of Flint from the Early to Late PPNB-Period. Ph.D.-Thesis, Freie Universität Berlin (in German).

Event Information:

Date, Time: 12/12/2016, 16:00 h – 17:00 h

Location: Room 0.024, Biozentrum (Building 304), Zülpicher Str. 47b, Cologne

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From rock art to cultural heritage management: A brief history of Cologne’s archaeological engagement in Namibia

goodman_crc_lectureArchaeology in countries that were affected by deep and multiple colonialisms manifests itself in many distinct archaeologies. We are confronted by archaeologies that were entangled, such as amateur, professional, academic, cultural resource management and community/ public archaeology. Some archaeologies such as professional and academic were more prominent and that gave the impression that archaeological authority was only to be found in the results of such practices. The relevance of other archaeologies such as avocational and community archaeology remained overshadowed to an extent that they were dismissed as unscientific and therefore not archaeological practices. The emergence and development of archaeology in Namibia is closely connected to the University of Cologne’s Institute of Prehistoric Archaeology (Institut für Ur und Frühgeschichte) and the African Archaeology. It is rooted in rock art studies and was born out of avocational endeavours. Archaeology in Namibia became professionalised through legitimisation by academic institutions such as the Cologne Institut für Ur und Frühgeschichte. However, the process of legitimisation overlooked the challenges of converting the academic throughputs into material that local professional and administrative archaeologists can use for heritage management.

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Goodman Gwasira, University of Namibia.

This presentation examines the relevance of the Cologne rock art investigations in Namibia to heritage management and the nation building project. It interrogates the perception that Cologne practised “extractive archaeology” in Namibia, which led to a lack of institutionalisation of archaeology and capacitating of local institutions. The central argument of the presentation is that documentation of Namibian rock art by the University of Cologne represents an irreplaceable and invaluable throughput which needs to be adapted and converted for use in rock art heritage management. The Cologne rock art catalogues have the potential of leading to the development of new methods and theories of heritage conservation and preservation. The presentation draws from ongoing research on the history of Namibia’s archaeologies and from personal reflections.

Event Information:

Date, Time: 07/11/2016, 16:00 h – 17:00 h

Location: Room 0.024, Biozentrum (Building 304), Zülpicher Str. 47b, Cologne

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A 1.2 million year record of ecosystem evolution from Lake Malawi, Africa’s most biodiverse lake

Andy Cohen Lake

Long records of Quaternary ecological and climatic change are critical to understanding the range of potential responses of ecosystems to environmental forcing. In Africa, where complex and ancient tropical ecosystems are important parts of the landscape such records are still relatively rare. In this talk I will present an integrated lake and watershed paleoecological analysis from drill core records obtained by the Lake Malawi Drilling Project, documenting extraordinary fluctuations in climate, hydrology and ecosystem response for the southern tropics of Africa. High resolution lacustrine and terrestrial paleoecology and sedimentology data sets from these Early Pleistocene-Holocene drill cores provide the most complete record of this duration currently available from Africa.

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Time series analyses of these records demonstrate the important role that insolation, and especially ~400ka eccentricity modulated precessional cyles Malawi ecosystems. We observe shifts between more arid conditions (shallow alkaline and well mixed lake, with discontinuous desert vegetation) and more humid environments (deep, stratified, freshwater lake with dense forest). These broadly synchronous changes in lake paleoecology, lake sedimentology, and watershed vegetation demonstrate the major role of climate in regulating this system. Transitions between these lake/watershed state extremes is often very abrupt, suggesting that the combined lake/watershed repeatedly passed through hydroclimate thresholds, with important implications for the evolution of the lake’s endemic biodiversity and ecosystem. Lake Malawi also appears to have undergone a major state change after 800-700ka with an adjustement in base level of hundreds of meters that appears to reflect a change in outlet position driven by tectonics. All of these cyclic and non-cyclic changes provide an environmental template against which we can much better understand the adaptive radiation of cichlid fishes which has occurred in the lake, one of the most biodiverse lakes on earth.

 

Prof. Andrew Cohen (University of Arizona)

My research area is paleolimnology, the interpretation of lake history from sedimentary and paleontological records. Most of my work to date has involved studies of depositional environments, paleoecology, and climate history of the African Rift Lakes and the arid climate lakes of the western US. I use paleoecological and sedimentological records as primary tools in the interpretation of lake deposits, from both outcrops and sediment cores.

Event Information:

Date, Time:04/07/2016, 14:00 h – 15:00 h

Location: Room S12, Seminargebäude (Building 106), Universitätsstraße 37 , Cologne

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Water resources assessment in arid data-scarce regions – multidisciplinary research in Egypt

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Dr. Mohamed Youssif

Arid regions are highly vulnerable with respect to environmental and particularly hydrological changes. Data scarcity for most of these areas (such as Egypt and the most of Middle East) is a great challenge for hydrogeological investigation at practical scales. Moreover, climate change will exacerbate groundwater-related problems by reduction in recharge rates in some areas, increased reliance on groundwater resources due to decrease in the reliability of surface-water sources, saltwater intrusion due to sea-level rise, and deterioration of groundwater quality by increased flushing of urban and agricultural wastes.

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Tracing population movement across eastern Africa and Eurasia through lithic technology during the late Pleistocene (End of MIS 6 to MIS 4)

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MaeGoder

Dr. Mae Goder, Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Weizmann Institute of Science, Israel

Many archaeologists associate the appearance of Homo sapiens and modern behavior with the Middle Stone Age of Africa. Over the years numerous models have been developed to explain how and why modern humans left Africa and dispersed throughout the world. The majority of these models are based on skeletal and genetic data as well as climatic data, while paradoxically very few incorporate archaeological data.

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Long-term woodland dynamics in Central-Eastern Europe – coevolution of natural and anthropogenic forces

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petr kunes_neu

Dr. Petr Kuneš
Charles University, Prague

Forests have undergone gradual change since their formation after the end of the glacial. Until today, these forests have been influenced by humans for at least eight millennia being gradually transformed into today’s agriculture landscape. However, to the simple disappearance of woodland we have to account with various forest management regimes, which profoundly altered woodlands’ structure and species composition. Continue reading

Climate dynamics, biogeochemical cycles and ecosystem variability in the Eastern Mediterranean Sea

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Prof. Dr. Gerhard Schmiedl
University of Hamburg

The eastern Mediterranean Sea (EMS) responds sensitively to orbital and suborbital climate variability and related hydrological changes of the adjacent continents. Recurrent deposition of organic-rich sediment layers (sapropels) is caused by complex interactions between climatic and biogeochemical processes. Disentangling these influences is therefore important for Mediterranean palaeo-studies but also to understand climate links between the EMS and the African Monsoon system. Sapropels are diagnostic of anoxic deep-water phases, which have been attributed to deep-water stagnation, enhanced biological production, or both.

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