LATEST PLEISTOCENE IN NORTHEASTERN IBERIA: OXYGEN ISOTOPE ANALYSIS AND PALAEOENVIRONMENT INFERENCES FROM RODENT ASSEMBLAGES OF ARBREDA CAVE (SERINYÀ, GIRONA)

Get Complete Project Material File(s) Now! »

Classification of levels

The 37 studied levels have been grouped, in accordance with their chronology, in three time intervals:
– Early Late Pleistocene (ELP). This includes all archaeological levels from ca. 128 to 40 ka BP, generally related to the Middle Palaeolithic and consequently to Homo neanderthalensis activity. Since in the northeast of Iberia there are only a few Middle Palaeolithic sites with chronologies older than 60 ka BP, the greater part of the assemblages belong to MIS 3 (ca. 60-30 ka BP). Thirteen levels of five different fossil sites are included: Levels III and II from Teixoneres cave (López-García et al., 2012b); Levels O, N and E from Abric Romaní (Fernández-García, 2014; López-García, 2011); Levels I, V and III from Cova del Gegant (López-García et al., 2012c); Levels C8, C7, C6 and C4 from Xaragalls Cave (López-García et al., 2012a) and Level I from Arbreda cave (Alcalde, 1986; López-García, 2011). This group represents a total of 946 individuals.
– Latest Late Pleistocene (LLP). This comprises all archaeological levels from ca. 40 to 11.7 ka BP, commonly related to the Upper Palaeolithic and the presence of Anatomically Modern Humans. This time interval is equivalent to end of MIS 3 and the complete MIS 2 (ca. 30-14 ka BP). Twelve levels from four different fossil sites are included: Levels I, H, G, F, E, D, C, B and A from Arbreda cave (Alcalde, 1986; López-García, 2011); the assemblage from Galls Carboners cave (López García et al., 2014b); Levels 3 and 2 from Toll cave (Fernández-García & López-García, 2013) and Level CE15 from Cova Colomera (López-García et al., 2010). This group represents a total of 1455 individuals.
– Holocene (HOL). Groups all archaeological sites recent than 11.7 ka BP, including Epipalaeolithic, Neolithic, Chalcolithic and Bronze Age sites. All these levels belong to MIS 1. Twelve levels from four different fossil sites are included: Level CE13-14, CE12, EE1 and A. sup. from Cova Colomera (López-García et al., 2010); the assemblage from Cingle Vermell (Alcalde, 1986); Level 6, 5, 4 and 3 from Cova del Frare (Alcalde, 1986) and Level III, II and I from Cova 120 (Alcalde, 1986). This group represents a total of 666 individuals.

Multivariable Statistical methodology

To provide a better understanding of such a large corpus of data, multivariate statistical methods have been applied, allowing us to reduce the number of variables involved in order to facilitate our ecological interpretations. Methods of multivariate analysis without previous assumptions of dependence and independence have been selected, with the aim of defining coherent patterns in space and time (Shennan, 1997). The original data correspond to absolute frequency variables, so the most recommended multivariate statistics proxy is correspondence analysis (López-Roldan & Lozares-Colina, 2000). However, this method has been shown to have limitations for the studied data, such as its low representativeness and the low explanatory capacity of its results. Consequently, other methods have been applied. On the one hand, a principal component analysis (PCA) has been applied. This analysis has been performed after the transformation of the data from absolute frequency variables to ratio variables, replacing the original values by percentages. This data for which the sum over the variables is 100% is equivalent to compositional data (Baxter, 2003). The PCA makes it possible to analyse the sample in standardized form and yields advantages in interpretation by placing the different variables on a coordinate axis, distinguishing different components (the resulting variables) that indicate the weight of each original variable in the graphical representation obtained (Jolliffe, 2002). The covariance matrix has been used, because it proves to be the most appropriate to increase the total variance obtained in the first, second and third components (Shennan, 1997; López-Roldan & Lozares-Colina, 2000).

Early Late Pleistocene environment (128-40 ka BP)

During MIS 4, solar insolation was minimal, initiating a global cold period. Long-term pollen records obtained from French lacustrine deposits, such as La Grande Pile and the Velay Maars (Guiot et al., 1992), indicate the predominance of boreal forests during MIS 4, declining at the end of MIS 4 with the expansion of steppe–tundra vegetation (Fletcher et al., 2010; Sánchez-Goñi et al., 2008). According to pollen analysis, MIS 3 is characterized in southern Europe by a dynamic that alternates between phases of forest development and the expansion of semi-arid areas in accordance with the warming and cooling, respectively, of the sea-surface temperatures (Fletcher et al., 2010; Harrison & Sánchez-Goñi, 2010). However, various proxies, including pollen and small mammals, have shown that this alternation of dryness and wetness and the consequent reduction-extension of forest are not straightforward.
There are many Middle Palaeolithic sites located in the northeast of Iberia during MIS 3. Some of them present interesting climatic reconstructions based on small mammals, such as Level II from Teixoneres cave (60-30 ka BP), Level IV from Cova del Gegant (60 ±3.8 ka BP), Level O from Abric Romaní (54.24 ±0.42 ka BP), Level C8 from Xaragalls cave (> 43.5 ka BP), Level I from Arbreda cave (40 – 32 ka BP) and Galls Carboners (31.38 – 31.17 ka BP) (Fernández-García, 2014; López-García, 2011; López-García et al., 2012a; 2012b; 2012c; 2014b). As has previously been reported by López-García et al. (2014c), small-mammal proxies show lower mean annual temperatures and higher precipitation levels throughout this period in this region (Fernández-García, 2014). Coexistence is also observed between temperate and cold rodent species, which underwent changes in proportion depending on the stadial-interstadial fluctuations. Moreover, Mediterranean species (M. (T.) duodecimcostatus or I. cabrerae) are always present in the assemblages. However, the predominance of typical woodland species (A. sylvaticus and E. quercinus) in MIS 3 assemblages becomes a defining characteristic of the environment conditions, independent of whether it was a stadial or interstadial phase. These two latter trends are probably related with the clustering of the ELP sites with HOL assemblages in the statistical proxy in this paper.

READ  Distributed adaptive MAC protocol for WSN-based wildlife protection

Latest Late Pleistocene (40 – 14.7 ka BP)

The LLP is basically represented by the end of MIS 3, the complete MIS 2 and the beginning of MIS 1 (ca. 14.7 ka BP) (Lisiecki & Raymo, 2005). These stages are highlighted in all geological sources as the most intense glacial phases, characterized by rapid and major climatic changes (Vermeersch, 2005), and ranging chronologically from ca. 27 to 11.7 ka BP. MIS 2 contains two Heinrich Events (H2 and H1), dated respectively to ca. 24 ka BP (H2) and to 16 ka BP (Oldest Dryas or H1), and also the Last Glacial Maximum (LGM) (ca. 22-19 ka BP), the moment of maximum cold in the Northern Hemisphere which represents the time of maximum extension of ice sheets at the polar caps (Fletcher & Sánchez-Goñi, 2008). This singularity of the LLP (Upper Palaeolithic) can be observed beyond the changes in the fauna composition and is clear in our statistical proxy, associated with an important increase in the species related with mid-European requirements and open environments (M. arvalis, M. agrestis and C. nivalis) and a lower representation of woodland species (A. sylvaticus).
According to the available data, the rodent species present in the northeastern Iberian Peninsula during the LLP were predominantly mid-European taxa with an ecological preference for cold environmental conditions (M. arvalis and M. agrestis), humid meadows (M. agrestis and M. (T.) gerbei) and, to a lesser extent, open forests (A. sylvaticus and E. quercinus) (Alcalde, 1986; López-García, 2011). Assemblages with such characteristics have been described in Levels C4-C1 of Cova dels Xaragalls (48.2-13.7 ka BP) (López-García et al., 2012a), Level III of Balma de la Griera (21.2 ka BP) (Nadal, 2000) and the oldest levels of Arbreda cave (39.9-17.3 ka BP) (Alcalde, 1986; López-García, 2011). LLP levels from Arbreda cave (39.9-17.32 ka BP) present a clear predominance of rodent species associated with open humid conditions (M. arvalis, M. agrestis and M. (T.) duodecimcostatus), whereas species associated with forest conditions are present in much lower proportions (A. sylvaticus, G. glis and E. quercinus). The association is also characterized by a strong representation of mid-European species (M. arvalis and M. agrestis), meaning cold conditions and open landscapes (Alcalde & Brunet-Lecomte, 1985; Alcalde, 1986). This great relative abundance of M. arvalis and M. agrestis is a common trend in other sites in Iberia (López-García, 2011). Additionally, it has been detected in some southern French sequences, accompanied by a high presence of Microtus gregalis, as at Tailles-des-Coteaux (Jeannet, 2011; Royer at al., 2014), and is also common in the LLP sites of the Italian Peninsula, such as Grotta della Serratura, Cava Filo, Grotta de la Ferrovia, Grotta Paglicci, Riparo Tagliente and Grotta del Romito (Bertolini et al., 1996; Berto, 2013; López-García et al., 2014a).

Table of contents :

THESIS STRUCTURE
CHAPTER 1. INTRODUCTION, FRAMEWORK AND OBJECTIVES
1. SMALL MAMMALS AS ENVIRONMENTAL PROXIES
2. THE ORIGIN OF SMALL MAMMALS AND THEIR PRESERVATION IN FOSSIL DEPOSITS
3. BASIC PRINCIPLES OF OXYGEN ISOTOPE COMPOSITION STUDIES ON SMALL MAMMALS
4. THE LATE PLEISTOCENE CLIMATE AND NEANDERTHAL SETTLEMENTS
5. PROBLEMATIC SYNTHESIS
6. OBJECTIVES
CHAPTER 2. MATERIAL AND METHODS SYNTHESIS
1. MAIN DISCIPLINES USED TO A MULTIDISCIPLINARY APPROACH
2. MATERIAL AND SAMPLES
3. RECOVERY OF SMALL-MAMMAL REMAINS
4. ANALYTICAL TECHNIQUES AND IDENTIFICATION
5. QUANTIFICATION OF REMAINS
6. SAMPLING CRITERIA FOR OXYGEN ISOTOPE ANALYSES
7. WET CHEMISTRY PROTOCOL AND MASS SPECTROMETER
8. TAPHONOMIC ANALYSIS
9. PALAEOECOLOGICAL METHODS
10. PALAEOTEMPERATURES RECONSTRUCTION
11. PRESENT-DAY DATA SOURCES
12. STATISTICS CALCULATIONS
CHAPTER 3. PALAEOECOLOGICAL IMPLICATIONS OF RODENTS AS PROXIES FOR THE LATE PLEISTOCENE – HOLOCENE ENVIRONMENTAL AND CLIMATIC CHANGES IN NORTHEASTERN IBERIA
1. INTRODUCTION
2. MATERIALS AND METHODS
3. RESULTS
4. DISCUSSION
5. CONCLUSIONS
CHAPTER 4. PALEOENVIRONMENTAL CONTEXT OF NEANDERTHAL OCCUPATIONS IN NORTHEASTERN IBERIA: THE SMALL-MAMMAL ASSEMBLAGE FROM ABRIC ROMANÍ (CAPELLADES, BARCELONA, SPAIN) . 
1. INTRODUCTION
2. SITE DESCRIPTION
3 MATERIALS AND METHODS
4. RESULTS AND DISCUSSION
5. CONCLUSIONS
CHAPTER 5. UNRAVELLING THE OXYGEN ISOTOPE SIGNAL (Δ18O) FROM RODENT TEETH IN NORTHEASTERN IBERIA, AND THE IMPLICATIONS FOR PAST CLIMATE RECONSTRUCTIONS
1. INTRODUCTION
2. COVA DELS XARAGALLS (TARRAGONA, SPAIN)
3. MATERIAL AND METHODS
4. RESULTS AND DISCUSSION
5. CONCLUSIONS
CHAPTER 6. COMBINED PALAEOECOLOGICAL METHODS USING SMALL-MAMMAL ASSEMBLAGES TO DECIPHER ENVIRONMENTAL CONTEXT OF A LONG-TERM NEANDERTHAL SETTLEMENT IN NORTHEASTERN IBERIA
1. INTRODUCTION
2. THE ABRIC ROMANÍ SEQUENCE
3. MATERIAL AND METHODS
4. RESULTS AND DISCUSSION
5. CONCLUSIONS
CHAPTER 7. PALAEOECOLOGICAL RECONSTRUCTION OF TEIXONERES SITE (MOIÀ, BARCELONA) BASED ON SMALL MAMMALS: ORIGIN OF THE ASSEMBLAGE AND PALAEOCLIMATIC INFERENCES
1. INTRODUCTION
2. TEIXONERES CAVE
3. REMARKS ON MATERIALS AND METHODS
4. RESULTS AND DISCUSSION
5. CONCLUSIONS
CHAPTER 8. LATEST PLEISTOCENE IN NORTHEASTERN IBERIA: OXYGEN ISOTOPE ANALYSIS AND PALAEOENVIRONMENT INFERENCES FROM RODENT ASSEMBLAGES OF ARBREDA CAVE (SERINYÀ, GIRONA)
1. INTRODUCTION
2. ARBREDA CAVE
3. SYNTHESIS OF METHODS
4. RESULTS AND DISCUSSION
5. CONCLUSIONS
CHAPTER 9. GENERAL DISCUSSION
1. OXYGEN ISOTOPE MEANING, PREDATOR-PREY INTERACTIONS, AND SEASONALITY
2. METHODS FOR PALAEOTEMPERATURE AND PALAEOPRECIPITATION RECONSTRUCTIONS FROM RODENT ASSEMBLAGES
3. PALAEOENVIRONMENT OF LATE PLEISTOCENE AND MIS3 IN NORTHEASTERN IBERIA
4. SINGULARITY OF IBERIA AND ITS IMPORTANCE IN PREHISTORY
5. NEANDERTHAL SUBSISTENCE IN NORTHEASTERN IBERIA
CHAPTER 10. CONCLUDING REMARKS AND FUTURE PERSPECTIVES
1. CONCLUSIONS
2. FUTURE PERSPECTIVES
GENERAL REFERENCES
LIST OF FIGURES
LIST OF TABLES
APPENDIX 1. TAXONOMICAL IDENTIFICATION
APPENDIX 2. SUPPLEMENTARY MATERIAL
APPENDIX 3. MANUSCRIPTS

GET THE COMPLETE PROJECT

Related Posts