Bonnefille Raymonde

Bonnefille Raymonde
Aix-Marseille Université | AMU · Centre de recherche Geosciences de l'Environnement

PH'D DOCTOR OF SCIENCES

About

150
Publications
32,754
Reads
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8,019
Citations
Additional affiliations
January 1999 - present
Aix-Marseille Université
Position
  • CNRS Directrice de recherche honoraire
Description
  • Variations climatiques en Afrique tropicale Histoire forestière et climatique au Burundi, Biome 6000. Inde

Publications

Publications (150)
Article
Full-text available
The paper provides new data on the age and formation processes of Garba I (Melka Kunture, Upper Awash, Ethiopia). The site, one of the largest handaxe accumulations of the African Acheulean, was extensively excavated in the 1960s of the last century by J. Chavaillon but left largely unpublished. The chronology was also poorly constricted. Quartz gr...
Conference Paper
Full-text available
Simbiro III, comprising the Monumental Section (MS) and the gully, is part of the Melka Kunture cluster of prehistoric sites, located in the Ethiopian highland at ~2000 m a.s.l. The MS, discovered in the Sixties and then not extensively investigated, looks like a ~5 meters high cliff and includes the impressive remnant of deposited multiple layers...
Article
Abstract Melka Kunture is a cluster of Pleistocene sites, extending over ⁓100km2 between 2000 and 2200m asl, in the upper Awash Valley of Ethiopia. Starting around 2 million-years ago, the archaeological sequence includes sites with lithic productions of the Oldowan, early Acheulean, middle Acheulean, final Acheulean, Early Middle Stone Age, Middle...
Conference Paper
Full-text available
Stable isotopes and phytoliths analysis have been widely used in archaeological research, providing key information in the study of paleoclimate and paleoecology, and allowing to test hypotheses on adaptation and habitat changes in Africa during human evolution. Here, we report on both stable isotopes (13C, 18O) (14 fossil teeth samples) and phytol...
Poster
Full-text available
Stable isotopes and phytoliths analysis have been widely used in archaeological research, providing key information in the study of paleoclimate and paleoecology, and allowing to test hypotheses on adaptation and habitat changes in Africa during human evolution. Here, we report on both stable isotopes (13C, 18O) (14 fossil teeth samples) and phytol...
Article
While the emergence of the Acheulean is well documented in East Africa at ~1.7 Ma, subsequent developments are less well understood and to some extent controversial. Here, we provide robust evidence regarding the time period between 1.6 Ma and 1.2 Ma, based on an interdisciplinary approach to the stratigraphic sequences exposed in the Gombore gully...
Book
Full-text available
Chapter
In this paper, we present and discuss pollen data from the Early Pleistocene (1.8 to 1.6 Ma) – we use the revised timescale approved by IUGS, in which the base of the Pleistocene is defined by the GSSP of the Gelasian Stage at 2.588 (2.6) Ma (Gibbard et al. 2010) – and from the Mid-Pleistocene Transition (0.9 to 0.6 Ma) at Melka Kunture (Upper Awas...
Article
Full-text available
Quaternary records provide an opportunity to examine the nature of the vegetation and fire responses to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. The best documented examples of rapid climate change in the past are the warming events associated with the Dansgaard–Oeschger (D–O) cycles dur...
Article
Full-text available
Quaternary records provide an opportunity to examine the nature of the vegetation and fire responses to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st century. The best documented examples of rapid climate change in the past are the warming events associated with the Dansgaard-Oeschger (D-O) cycles dur...
Poster
Full-text available
A brief presentation of the cluster of Early and Middle Pleistocene sites discovered at Melka Kunture, Upper Awash, Ethiopia
Article
Environment, climatic change and human evolution have been debated over the last 50 years giving special attention to the Plio-Pleistocene sites of the Rift Valley. In this paper we discuss the environment and the limits of hominin adaptability based on evidence from Melka Kunture, at 2000 m asl on the Ethiopian highlands, and specifically on the ~...
Article
Full-text available
The Middle Awash palaeontological study area in Ethiopia is widely known for the recovery of abundant faunal remains including the recently discovered hominid Ardipithecus ramidus. In this paper, we describe eleven new fossil wood specimens from three distinct units of the Pliocene Sagantole Formation. The anatomical (xylotomical) characters of the...
Chapter
In Africa the lowland rainforest occurs under significantly drier conditions than in other continents, within an average precipitation of 1,600 to 2,000mmyr_1, although higher rainfall is observed around the Atlantic coast of Cameroon, Gabon, and in the Central Zaire Basin. Seasonal distribution of precipitation is far from being uniform (White, 19...
Article
Full-text available
This paper presents a description of fossil wood materials from the late Miocene Adu-Asa Formation of the Middle Awash, located in the Afar Rift of Ethiopia. The three fossilized wood fragments were collected on the surface of outcrops of the upper Adu Dora Member, at Adu Dora north. The Adu Dora Member is dominated by lacustrine and diatomite stra...
Article
To reconstruct the response of vegetation to abrupt climate changes during the last glacial we have compiled pollen records from the circum-Atlantic tropics between 23°N and 23°S from both marine and terrestrial sediment cores. Pollen data were grouped into mega-biomes to facilitate the comparison between the different records. Most tropical Africa...
Article
Full-text available
In this article we describe the microscopic structures of a silicified piece of wood collected in the Middle Awash Valley (Ethiopia). The fossil wood was extracted from sediment precisely dated 4.4 Ma. Its attribution to the Ficoxylon species is based upon detailed comparison with published data and with comparisons of some modern species of the ge...
Article
Full-text available
Pollen data collected in Africa at high (Kuruyange, valley swamp, Burundi) and low altitude (Victoria, lake, Uganda; Ngamakala, pond, Congo) showed that after 6 ky before present (BP), pollen of deciduous trees increase their relative percentage, suggesting thus the reduction of the annual amount of precipitation and/or an increase of in the length...
Article
Full-text available
Sediments containing Ardipithecus ramidus were deposited 4.4 million years ago on an alluvial floodplain in Ethiopia's western Afar rift. The Lower Aramis Member hominid-bearing unit, now exposed across a >9-kilometer structural arc, is sandwiched between two volcanic tuffs that have nearly identical (40)Ar/(39)Ar ages. Geological data presented he...
Article
Full-text available
A nearshore core (LT03-05) from the north basin of Lake Tanganyika provides diatom, pollen, and sedimentary time series covering the last ca. 3800 yr at 15–36 yr resolution. A chronology supported by 21 AMS dates on terrestrial and lacustrine materials allows us to account for ancient carbon effects on 14C ages and to propose refinements of the reg...
Article
Full-text available
Pollen data collected in Africa at high (Kuruyange, valley swamp, Burundi) and low altitude (Lake Victoria; Ngamakala, pond, Congo) showed that after 6 ky Before Present (BP), pollen of deciduous trees increase their relative percentage, thus suggesting the beginning of a drier climate and/or an increase of the dry season length. Until now, pollen-...
Article
Sedimentological and geochemical studies conducted on a 15.82-m long core collected from Lake Garba Guracha (Ethiopia) associated with a precise AMS-14C time-scale document a unique record of the sedimentary processes linked to the progressive retreat of a high-altitude glacier in the Bale Mountains since 17,000 yr cal BP. Lake sedimentation is int...
Article
This chapter considers three aspects of the evolution of the Serengeti–Mara ecosystem, focusing on the possible origins of a broadscale migratory system. Firstly, it examines the geoecology of the system, including the evolution of the eastern plain, the wet-season pasture of the wildebeest and zebra today, and the Mara River and Lake Victoria as p...
Conference Paper
Full-text available
At decennial resolution, sedimentary or biochemical records (e.g., tree rings, stromato-lites) enable to reconstruct the local environment variability far beyond the instrumental record. However, unravelling the local processes and their geodynamic, climatic
Chapter
The Horn of Africa extends from the Sahara desert eastwards to the Red Sea, the Gulf of Aden and the Indian Ocean. Due to its complex volcano-tectonic evolution over the past 15 million years (Mohr 1971), the region is characterised by considerable changes in elevation within short distances. The Ethiopian highlands, which rise to altitudes exceedi...
Article
Full-text available
A sediment core recovered from Garba Guracha, a glacial lake at 3950 m altitude in the Bale Mountains of Ethiopia, at the boundary of the Ericaceous and Afroalpine vegetation belts, provides a 16,700-year pollen record of vegetation response to climatic change. The earliest vegetation recorded was sparse and composed mainly of grasses, Amaranthacea...
Article
Full-text available
African pollen data have been used in many empirical or quantitative palaeoenvironmental reconstructions. However, the pollen types used in these studies were not controlled and standardised, preventing the precise understanding of pollen–plant and pollen–climate relation that is necessary for the accurate quantification of continental scale climat...
Article
We present a synthesis of modern phytolith studies from Africa, to infer the potential and limitations of phytolith assemblages to reconstruct vegetation and tree cover density. The modern dataset includes 149 phytolith assemblages of surface soil samples from 10 phytogeographical zones and sub-zones from East and West Africa, as well as 500 m-reso...
Article
Full-text available
This paper provides the first set of quantitative reconstructions of annual precipitation for mid-Holocene Africa, based on pollen data. The estimates of precipitation are based on 85 pollen sites 14C dated at 6000 ± 500 years B.P and distributed over the whole of Africa. To improve the reliability of the pollen-based climate reconstruction, two me...
Article
Vegetation changes are documented from a well-dated pollen record from Lake Emakat, Empakaai Crater, northern Tanzania. This pollen record includes the time interval covering the Pleistocene/Holocene transition, analysed at a resolution interval averaging 200 yr. Around the crater lake, an Hagenia-forest development starting at 14,500 cal yr BP las...
Article
We present here a pollen record from the northern Indian Ocean that goes back to 200 ka, the boundary between marine isotopic stages (MIS) 7 and 6. Pollen, oxygen-isotopic composition and organic carbon have been examined for two sediment cores from the eastern Arabian Sea (15°02′N and 71°41′E, 13°16′N and 71°00′E), to reconstruct the long-term pal...
Article
Full-text available
Plio-Pleistocene global climate change is believed to have had an important influence on local habitats and early human evolution in Africa. Responses of hominin lineages to climate change have been difficult to test, however, because this procedure requires well documented evidence for connections between global climate and hominin environment. Th...
Article
This study analyses the pollen signature of tropical lowland forests (< 1000 m a.s.l.) in the Asian monsoon climate. Its aim is to investigate how well the pollen data can reproduce the vegetation patterns in tropical India, and how the variations in the pollen composition are related to the gradient of decreasing plant moisture availability (measu...
Article
Full-text available
Lake Abiyata is a small, closed, saline–alkaline lake located in the central part of the Ethiopian Rift Valley, East Africa. A multi-proxy study of a sediment core, 116 cm long and with undisturbed mud–water interface, was performed to test the sensitivity of the lake system and of different proxies to the changes in climate and human activities th...
Chapter
The pollen record presented here gives a high resolution proxy data for recent climate changes in Ethiopia. This study emphasizes fluctuations of strong amplitude that affected the vegetation of the highland countries far above the tree line on the mountains during the last three thousand years that include the historical period. Because these vege...
Article
Pigment analysis (Chlorophyll Derivatives — CD, and Total Carotenoids — TC) from surface and core sediments of three lakes: Langano, Abijata and Shalla in the Central Ethiopian Rift Valley are presented. The results show that pigment concentration is very low in modern sediments with CD generally higher than TC. This is in accordance with the prese...
Article
The Holocene hydrological changes of a tropical swamp is reconstructed using a high resolution pollen record (ca 50 yrs) from the Kuruyange valley (Burundi, Africa, 3°35'S, 29°41'E), at 2000 m elevation. The sequence was dated by 10 radiocarbon dates, allowing reconstruction between ca 12 500 and 1000 cal yr B.P. In the Kuruyange swamp, peat accumu...
Article
Full-text available
BIOME 6000 is an international project to map vegetation globally at mid-Holocene (6000 14C yr bp) and last glacial maximum (LGM, 18,000 14C yr bp), with a view to evaluating coupled climate-biosphere model results. Primary palaeoecological data are assigned to biomes using an explicit algorithm based on plant functional types. This paper introduce...
Article
We have analyzed the pollen content of 51 surface soil samples collected in tropical evergreen and deciduous forests from the Western Ghats of South India sampled along a west to east gradient of decreasing rainfall (between 11°30-13°20′N and 75°30-76°30′E). Values of mean annual precipitation (Pann, mm/yr) have been calculated at each of the 51 sa...
Article
Full-text available
Palaeoclimatic estimates of mean annual rainfall in the equatorial highlands of Central East Africa have been established for the last 40 kyr. The values are inferred from nine fossil pollen sequences, collected from six peat bogs located between 2° and 4°S latitude, in the forest belt, from 1800 to 2240 m a.s.l. The transformation of pollen data i...
Article
This paper presents a spatial reconstruction of climate in East Africa at 6000 14C yr B.P. Two different approaches using pollen data have been used, the standard "best modern analogues" method and the new "plant functional type" method, based on groups of pollen taxa. Both methods have been applied to 32 fossil pollen spectra dated at 6000 14C yr...
Article
Full-text available
Pollen data from 18,000 14C yr bp were compiled in order to reconstruct biome distributions at the last glacial maximum in southern Europe and Africa. Biome reconstructions were made using the objective biomization method applied to pollen counts using a complete list of dryland taxa wherever possible. Consistent and major differences from present-...
Article
Full-text available
A total of 39 soil surface samples collected between 11 degrees 30'N 76 degrees 45'E and 12 degrees 45'N 78 degrees 15'E from the mainly deciduous forests in the Biligirirangan-Melagiri hills of the southern Eastern Ghats were analysed for their pollen content. The samples are distributed among four different deciduous and evergreen vegetation type...
Article
Full-text available
 Palaeodata in synthesis form are needed as benchmarks for the Palaeoclimate Modelling Intercomparison Project (PMIP). Advances since the last synthesis of terrestrial palaeodata from the last glacial maximum (LGM) call for a new evaluation, especially of data from the tropics. Here pollen, plant-macrofossil, lake-level, noble gas (from groundwater...
Article
Summary We analysed the pollen content of 106 surface soil samples from evergreen and deciduous tropical forests distributed between 6° and 13° of latitude north in South India and Sri Lanka. The samples were collected along altitudinal gradients, ranging from 50 to 2420 m, in five regions that experience different rainfall regimes. Original pollen...
Article
Phytolith assemblage analysis offers the potential to refine our knowledge of paleoecosystems where grasses and sedges predominate. In this work, Holocene and Pleistocene sediments from an arid tropical region in Ethiopia have been analyzed for their phytolith content, presented as detailed counts and diagrams according to the Twiss classification....
Article
Full-text available
In the central sector of the Main Ethiopian Rift, the Ziway–Shala lake basin system includes four present-day residual lakes, from north to south, lakes Ziway, Langano, Abijata, and Shala. This region of East Africa is under the influence of the Intertropical Convergence Zone seasonal migration. Thus it has been designated as a potential core site...
Article
The relationship between organic carbon accumulation rates and 13C/12C ratios of total organic carbon (TOC) was investigated in an highland peat bog core (Ru-3) from Equatorial Africa. This core yielded a sequence spanning the last 14 kyr and was analysed with a 100–300 yr resolution for TOC-δ13C values. The Holocene section shows contrasted TOC ac...
Article
Variations in pollen assemblages and in physical and chemical composition of a dated sediment record from the small Lake Haubi in north central Tanzania, reveal lake level fluctuations since the late 19th century. Lake Haubi changed from a seasonally inundated swamp to a lake in the beginning of the 20th century. With the exception of 1942-44, when...
Article
Full-text available
Biome reconstruction from pollen and plant macrofossil data provides an objective method to reconstruct past vegetation. Biomes for Africa and the Arabian peninsula have been mapped for 6000 years bp and provide a new standard for the evaluation of simulated palaeovegetation distributions. A test using modern pollen data shows the robustness of the...
Article
Full-text available
Pollen analysis of a 1 m 80 core, taken from Tamsaa swamp at 3000 m on the northern side of the Bale Mountains, southern Ethiopia, shows, from ca. 13,000–10,000 year BP, Apiaceae-dominated pioneer treeless vegetation on the deglaciated landscape. A rise in Chenopodiaceae/Amaranthaceae around 10,000 year BP may indicate a change to a drier climate....
Article
Full-text available
New compilations of African pollen and lake data are compared with climate (CCM1, NCAR, Boulder) and vegetation (BIOME 1.2, GSG, Lund) simulations for the last glacial maximum (LGM) and early to mid-Holocene (EMH). The simulated LGM climate was ca 4°C colder and drier than present, with maximum reduction in precipitation in semi-arid regions. Biome...
Article
New compilations of African pollen and lake data are compared with climate (CCM1, NCAR, Boulder) and vegetation (BIOME 1.2, GSG, Lund) simulations for the last glacial maximum (LGM) and early to mid-Holocene (EMH). The simulated LGM climate was ca 4°C colder and drier than present, with maximum reduction in precipitation in semi-arid regions. Biome...