Hannibal's trek across the alps: Geomorphological Analysis of sites of geoarchaeological interest

International audienceA ~2200 year-old question related to Hannibal's invasion route across the Alps into Italia, has been argued by classicists without recovery of material evidence. A comparison of topographical descriptions in the ancient literature with environmental parameters in the Alps, attempted here for the first time, provides a database against which various pathways can be assessed. Identification of sites using geological, geomorphological, astronomical, chemical and petrological methods leads to the exclusion of certain transit points and targeting of others where geoarchaeological excavation might yield important evidence related to the military culture of ancient Carthage

Bridging between litterbags and whole-ecosystem experiments: a new approach for studying lake sediments

Nearshore sediments have a major influence over the functioning of aquatic ecosystems, but predicting their response to future environmental change has proven difficult. Previous manipulative experiments have faced challenges controlling environmental conditions, replicating sediment mixing dynamics, and extrapolating across spatial scales. Here we describe a new approach to manipulate lake sediments that overcomes previous concerns about reproducibility and environment controls, whilst also bridging the gap between smaller microcosm or litterbag experiments and whole-ecosystem manipulations. Our approach involves submerging moderate-sized (~15 L) artificial substrates that have been standardised to mimic natural sediments within the littoral zones of lakes. We show that this approach can accurately mirror the absolute dissolved organic carbon concentrations and pH of pore water, and to a lesser degree inorganic carbon concentrations, from natural lake sediments with similar organic matter profiles. On a relative basis, all measured variables had similar temporal dynamics between artificial and adjacent natural sediments. Late-summer zooplankton biomass also did not differ between natural and artificial sediments. By offering a more realistic way to manipulate freshwater sediments than previously possible, our approach can improve predictions of lake ecosystems in a changing world

Biostratigraphic Evidence Relating to the Age-Old Question of Hannibal's Invasion of Italy, II: Chemical Biomarkers and Microbial Signatures

Open access article. Creative Commons Attribution 4.0 International License (CC BY 4.0) appliesAs discussed in Part I, a large accumulation of mammalian faeces at the mire site in the upper Guil Valley near Mt. Viso, dated to 2168 cal 14C yr., provides the first evidence of the passage of substantial but indeterminate numbers of mammals within the time frame of the Punic invasion of Italia. Specialized organic biomarkers bound up in a highly convoluted and bioturbated bed constitute an unusual anomaly in a histosol comprised of fibric and hemist horizons that are usually expected to display horizontal bedding. The presence of deoxycholic acid and ethylcoprostanol derived from faecal matter, coupled with high relative numbers of Clostridia 16S rRNA genes, suggests a substantial accumulation of mammalian faeces at the site over 2000 years ago. The results reported here constitute the first chemical and biological evidence of the passage of large numbers of mammals, possibly indicating the route of the Hannibalic army at this time. Combined with the geological analysis reported in Part I, these data provide a background supporting the need for further historical archaeological exploration in this area.Ye

Biostratigraphic Evidence Relating to the Age-Old Question of Hannibal's Invasion of Italy, I: History and Geological Reconstruction

Controversy over the alpine route that Hannibal of Carthage followed from the Rhône Basin into Italia has raged amongst classicists and ancient historians for over two millennia. The motivation for identifying the route taken by the Punic Army through the Alps lies in its potential for identifying sites of historical archaeological significance and for the resolution of one of history's most enduring quandaries. Here, we present stratigraphic, geochemical and microbiological evidence recovered from an alluvial floodplain mire located below the Col de la Traversette (~3000 m asl—above sea level) on the French/Italian border that potentially identifies the invasion route as the one originally proposed by Sir Gavin de Beer (de Beer 1974). The dated layer is termed the MAD bed (mass animal deposition) based on disrupted bedding, greatly increased organic carbon and key/specialized biological components/compounds, the latter reported in Part II of this paper. We propose that the highly abnormal churned up (bioturbated) bed was contaminated by the passage of Hannibal's animals, possibly thousands, feeding and watering at the site, during the early stage of Hannibal's invasion of Italia (218 bc)

Sediment routing applied to paleoenvironmental reconstruction in the upper Fraser River watershed, British Columbia

grantor: University of TorontoClosely related floodplain and delta sites near Moose Lake, British Columbia (Canadian Rocky Mountains) are examined for evidence of environmental change and to assess the effects of upstream storage and reworking of sediment on downstream sedimentary records. The simultaneous development of composition-based provenance techniques facilitates the interpretation of downstream sediments in terms of source area, sediment production processes and hydroclimatic forcing. Initially, Fraser River bed material is used to characterize upstream source areas and to estimate mixing of source materials downstream. Although sedimentary rocks provide minimal contrast in terms of geochemical trace elements, it is possible to distinguish sediments from two main watershed source areas based on major elements associated with carbonate and aluminosilicate bedrock lithologies. Complications arise due to the effects of particle size, hydrodynamic sorting, and transport-related and post-depositional alteration. Currently the Moose River sub-basin contributes a greater proportion of the total and fine-grained sediment load delivered to Moose Lake than expected based on catchment area. The imbalance is related to greater elevations, runoff, and glacier cover in the sub-basin. A substantial area of the Moose Lake-Fraser River delta-top floodplain derives from the early half of the Holocene, and is characterized by fragmentary, low-discharge paleochannels containing bed materials characteristic of the uppermost Fraser River. Most floodplain development since ca. 4 ka BP records persistently higher sediment loads, aggradation and larger, more active channels. Detailed variations in the composition of laterally and vertically accreted floodplain sediments and of channel morphology reflect regionally documented glacier advance and retreat stages. Except for possible till deposits in the northwest, most valley-fill below Moose Lake and the delta is glaciolacustrine in origin, deposited rapidly as ice retreated up-valley at the end of the Wisconsinan. A large proportion of the delta was apparently constructed prior to ca. 10 ka BP and is either paraglacial or deglacial in origin. It is estimated that progradation and channel shifting on the delta surface could account for a gradual increase of up to 21% in distal lacustrine accumulation rates over Neoglacial time. More episodic variations likely occurred due to channel splitting and meander cutoff on the floodplain.Ph.D

Glaciolacustrine sediments and Neoglacial history of the Chephren Lake basin, Banff National Park, Alberta

Modern and historical sedimentation in Chephren Lake are examined in order to assess the relations between glacier activity, sediment production, and the lacustrine depositional record. Bottom sediment data and lake morphology indicate that sediments in the distal part of the lake primarily settled from suspension and that glaciers are the most important source. A 4.3 m core obtained from the distal sediments reveals that accumulation of fine, glacially-derived material has increased since at least 2 420 BP. Simple geochemical indicators reflect this and support regional evidence for progressive (though punctuated) climate deterioration through the Neoglacial period. Distinct rhythmite sequences (especially beginning ca. 3 460, 2 330, 1 470 and 530 BP) are thought to represent minor glacier retreats which help define separate phases of Neoglacial advance identified by previous workers. In contrast, increasing slope stability indicated by a reduction in graded sand and clast facies may be specific to slopes overlooking the coring site.La sédimentation moderne et passée est étudiée ici dans le but d'établir les relations entre l'activité du glacier, la production de sédiments et la mise en place de dépôts lacustres. Les données sur les sédiments de fond et la morphologie lacustre montrent que les sédiments en suspension de la partie distale du lac ont été les premiers à se déposer et que les glaciers en sont la princiaple source. Une carotte de 4,3 m recueillie dans les sédiments distaux révèle que l'accumulation du matériel fin d'origine glaciaire a augmenté depuis au moins 2 420 BP. Les indicateurs géochimiques traduisent cette situation et reflètent, comme le font les indices régionaux, une détérioration climatique progressive (plus ou moins accentuée) au cours du Néoglaciaire. Des séquences de rythmites distinctes (surtout à partir de 3 460, 2 330, 1 470 et 530 BP) semblent traduire des retraits glaciaires mineurs ; elles contribuent à mieux définir des phases distinctes de récurrence néoglaciaire dèjà identifiées par d'autres chercheurs. Par contre, la statibilité accrue des versants reflétée par la réduction des faciès composés de sables grano-classés et de gros fragments pourrait être caractéristique des versants dominant le site de carottage.Die moderne und vergan- gene Sedimentierung im Chephren Lake wird untersucht, um die Beziehungen zwis- chen Gletscheraktivität, Sedimentproduktion und der Ablagerung von Seesedimenten festzustellen. Die Angaben zu den Ablagerungen auf dem Grund und die Morphologie des Sees zeigen, daß Suspensions-Sedimente im distalen Teil des Sees sich zuerst abgelagert haben und daß Gletscher deren wichtigste Quelle sind. Ein Bohrkern von 4,3 m von den distalen Sedimenten läßt erkennen, daß die Akkumulation von feinem Material glazialen Ursprungs seit mindestens 2420 v.u.Z. zugenommen hat. Einfache geochemische Indikatoren spiegeln dies und stützen den regionalen Beleg für eine progressive (wenn auch nicht kontinuierliche) Klima-Verschlechterung in der neoglazialen Periode. Deutlich unterschiedene Sequenzen von Rhythmiten (vor allem ab ca. 3 460, 2 330, 1 470 und 530 v.u.Z.) bezeugen wohl unbedeutendere Gletscherrückzüge; sie helfen dabei, getrennte Phasen neoglazialer Vorstöße zu definieren, die frühere Forscher indentifiziert hatten. Dagegen könnte die wachsende Stabilität der Hänge, welche an einer Abnahme an sortiertem Sand und an groben Fragmenten erkennbar ist, für die Hänge über dem Bohrgelände charakteristisch sein