A revised lithostratigraphy and glacial history of north Hertfordshire and south Bedfordshire is based upon detailed textural data in the clay to fine gravel fraction, carbonate content, small clast lithological data and macrofabrics, derived from laboratory and field analyses of tills from 30 sites. These include four deep boreholes sunk within the Hitchin Gap. A range of statistical procedures was used, including multivariate analysis of the petrographic properties, enabling the identification of tills from two separate incursions into the Gap. A further till-type was identified in south Bedfordshire indicating an ice advance from the northwest/NNW extending at least as far east as Milton Bryan. Statistical comparison with tills in the neighbouring Vale of St. Albans suggested the presence of the Ware Member till within the Gap. Two hypotheses are suggested to explain variations in lithological content of tills north of the Chalk scarp. The first envisages ice entering the study area along the different trajectories suggested by Fish and Whiteman (2001). During the early part of the glaciation, ice reaching the west of the study area would approach from the north, crossing a shorter distance over Chalk bedrock and collecting less chalk and flint than ice moving into the eastern part of the study area. The second hypothesis invokes an incursion of ice from a northwest - NNW direction into the west of the study area, depositing a chalk-free till. This is subsequently assimilated by ice from the northeast, resulting in the final deposition of a homogeneous mixture of debris from the two advances, with a lower chalk content than tills found to the east. The outcome of either of these scenarios is a till with a low acid-soluble content and low flint/quartz ratio in the west of the study area, as found during this work. Within the Hitchin Gap, a lobe of ice, probably an early part of the northeasterly advance, deposited a lower till. This is considered to be earlier than the Ware Member till and has more variable lithological characteristics and a finer matrix that the higher tills. The latter are mainly melt-out, flow or slumped tills with occasional instances of lodgement and deformation. They represent in situ wasting of dead ice within the Gap. Surface tills in the Gap form a continuum with tills to the north and comprise mainly deformation tills, deposited by the final northeasterly re-advance of ice responsible for widespread coverage of the region, with the exception of the Chiltern Hills southwest of Hitchin. No evidence is found of more than one lithostratigraphic unit of till outside the Hitchin Gap.

This thesis presents the results of geoarchaeological investigations conducted at two new test pits, M11 and M12, at the paleoanthropological site of Dmanisi during the 2012 field season. This research is important for understanding the site formation processes occurring along the north-south axis of the Dmanisi site and how that affects the chronostratigraphic sequence and interpretation of archaeological materials here. With these excavations we can build a stronger interpretation for how broader areas of this site formed and changed both geologically and archaeologically. The geologic results of this study indicate that changes in sediment deposition and development episodes can affect interpretations of how long these sediments accumulated, how likely bones are to preserve, as well as how secondary gravel deposition can influence several archaeological interpretations. The archaeological results suggest that there could have been changes in occupation intensity between the stratum A and B phases although different rates of sediment deposition and surface stability could affect such artifact accumulations. In addition, during the stratum B phase there appears to be little change in artifact procurement behaviors and reduction characteristics by these hominins. The overall results of this research indicate that geologic factors should be addressed and cautions should be taken prior to making interpretations about archaeological assemblages.

The submitted diploma thesis deals with relative dating of the youngest glacigenic sediments (moraines) in the upper parts of some selected valleys in the High Tatra Mountains. These moraines were stabilized after the last cold events of the last glaciation cycle. The Schmidt hammer (SH) test was used for the assessment of their relative age. This method is based on the assumption that there is a mutual relation between the degree of weathering of a tested surface and the duration of its exposure. Information about the degree of weathering is expressed by the Rebound (R) value. The measurements were taken on fifteen moraines in four valleys in the High Tatra Mountains (Mengusovská, Velká Studená, Malá Studená and Litvorova valley). A large statistical population of measurements obtained from moraine surfaces were used to analyse the variability of R values means in the same lithology. The moraines were divided on the base of SH measurements into two groups of different age. R value means and standard deviation for these groups (SK_1: R=53,5±1,2 a SK_2: R=58,6±1,5) are significantly statistically different. The results of the weathering indexes were used for the reconstruction of the pattern of deglaciation in selected upper parts of valleys (cirques). Key words: relative dating, the Schmidt Hammer,...

The mechanism of Holocene barrier formation aids in determining island geomorphologic responses to modifying climatic processes of the surrounding environment. The geometry and composition of local antecedent topography plays a role in barrier formation by providing an elevated base, nucleus for sedimentation and local sediment supply. Investigation of barriers' subsurface geology provides insight into island formation and evolution. High-resolution shallow seismic data acquired in the island's nearshore zone and interior canals, correlated with existing drillcore data, reveal that Cat Island, MS is situated over an Oxygen Isotope Stage 3 Phase 3 paleochannel located between two topographic high-grounds of the Pleistocene surface. Beach ridge strandplain sets on Cat Island provide additional evidence supporting the island's formation over a relict depocenter. A new, 4-stage model for Cat Island development and evolution incorporating the influence of pre-existing topographic high-grounds and abundant local sediment supply provided by a backfilling fluvial channel is presented here.

Student Number : 9903519M - MSc research report - School of Geography, Archaeology and Environmental Studies - Faculty of Science / Goldsmith’s is a newly discovered fossil and archaeological site 4km south-west of the famous Sterkfontein Cave Site, in the buffer zone of the Cradle of Humankind World Heritage Site. It preserves one of the rare occurrences in South African fossil cave sites of stone artefacts with associated fossil fauna. Thirteen artefacts from two Stone Age cultures are represented within the site: namely the Earlier Stone Age and the Middle Stone Age. Eleven stone artefacts represent the Earlier Stone Age, dated to ca, 2-1 million years within the Sterkfontein Valley sites, while two artefacts represent the MSA. The stone tools from both cultures are not embedded in breccia and may have originated from decalcified breccias, or alternatively from slope wash. Various faunal taxa were recovered including bovids, primates, carnivores and others. Carnivores are the most highly represented, followed by bovids. Analysis of bone surface modifications indicate that the majority of the bones are slightly weathered, and some bone specimens are also abraded, suggesting that they may have accumulated through slope wash. The high frequencies of carnivore remains, including Dinofelis and a representation of most carnivore body parts, support a possible death trap scenario. The fauna suggests a palaeoenvironment with open woodland or savannah within the vicinity of a closed environment.

In order to better understand the interactions between climate change, landscape erosion and sedimentation, a detailed study was conducted on Plio-Pleistocene non-marine deposits of the Palm Spring Group in the Fish Creek-Vallecito basin, California, USA. Three inter-related studies focused on (1) local response to global climate change in late Pliocene-early Pleistocene time, (2) large-scale evolution of lithofacies architecture, and (3) climate modulation of late Pliocene sediment flux on Milankovitch time scales. Stable isotopes and paleosol classification reveal that between ~4.0 and 0.75 Ma, aridity increased in the study area concurrent with a shift towards a less intense and more winter-dominated precipitation regime. These changes are interpreted to reflect the long-term waning of summer monsoon precipitation in southern California. A dramatic and enigmatic reorganization of basin strata occurred at 2.9 Ma. Detailed basin analysis shows that locally-derived sediment was supplied by the predecessors of two modern drainages, Vallecito and Carrizo creeks. Initial progradation of alluvial deposits from these two sources across the Colorado River delta plain began between 4.0-3.4 Ma. At 2.9 Ma, rapid progradation of these two deposystems was coeval with emplacement of a megabreccia and transgression of Borrego Lake. My data indicate that tectonic realignments at both local and regional scales drove this reorganization. Time series analysis of rock magnetic data from a densely-sampled stratigraphic section of the lacustrine Tapiado Formation reveals that between 2.9 and ~2.75 Ma landscape denudation in the Carrizo Creek catchment was partly modulated by orbital obliquity. Peaks in landscape denudation implied by my data correspond to obliquity highs. More frequent high intensity precipitation events (i.e. monsoons and tropical storms) probably drove increased erosion during these time periods relative to obliquity lows. The breakdown of this relationship at around 2.75 Ma corresponds to a dramatic increase in northern hemisphere glaciation and may reveal a reduction in monsoonal influence in southern California. A geologic map of the Fish Creek-Vallecito basin is included as a supplemental file to this dissertation. This dissertation contains previously published and unpublished coauthored material.

O gênero Tapirus (Perissodactyla, Tapiridae) é de origem holártica e entre o Mioceno e Plioceno final é amplamente distribuído na América do Norte, Europa e Ásia. Os tapires aparecem na América do Sul após a formação do Istmo de Panamá, durante o Grande Intercâmbio Biótico Americano, Pleistoceno inicial - médio. Neste trabalho, é revisado o material tipo das espécies atribuídas ao gênero na América do Sul; descrito material inédito proveniente da Venezuela e Brasil; realizado estudo comparativo morfológico e morfométrico; e proposto hipóteses quanto à origem e filogenia dos tapires na América do Sul. A partir da revisão das espécies de Tapirus do Quaternário da América do Sul, foi possível considerar válidas as espécies: T. greslebini, T. rioplatensis, e T. mesopotamicus (todas para a Argentina); T. oliverasi (Uruguai); T. tarijensis (Bolívia); T. cristatellus e T. rondoniensis (Brasil). A análise morfométrica permitiu estabelecer dois morfótipos para as espécies fósseis sulamericanas com base no tamanho do dentário. Um morfótipo que está dentro da variação de tamanho de T. terrestris, constituído pelas espécies T. rondoniensis e T. mesopotamicus, e outro, um morfótipo maior, com tamanho superior ao máximo de variação encontrado em T. terrestris, como T.tarijensis, T. rioplatensis, T. greslebini, e alguns espécimes de T. cristatellus. O gênero Tapirus apresentou-se como um clado monofilético, sendo Nexuotapirus marslandensis seu táxon-irmão. Os tapires sulamericanos não formam um clado monofilético, sendo T. pinchaque o grupo-irmão dos demais tapires sul-americanos atuais e fósseis, bem como das formas derivadas norte-americanas; e T. cristatellus seria o táxon irmão do clado T. indicus + T. bairdii +T. polkensis + T. lundeliusi + T. haysii + T. veroensis. O resultado da análise filogenética sugere uma relação próxima entre os tapires sul-americanos e T. webbi, o que corrobora a hipótese de um evento de dispersão da América do Norte para a América do Sul durante o Mioceno. Por outro lado, nossos dados indicam um segundo evento de dispersão da América do Sul para a América do Norte, possivelmente a partir de uma forma proximamente relacionada a T. cristatellus, que teria dado origem às formas derivadas do sudoeste da América do Norte. / The genus Tapirus (Perissodactyla, Tapiridae) is of Holarctic origin and between the Miocene and late Pliocene is widely distributed in North America, Europe and Asia. Tapirs appeared in South America after the formation of the Isthmus of Panama, during the Great American Biotic Interchange, early – middle Pleistocene. In this work is reviewed the type specimen of the species assigned to the genus in South America; described new material from Venezuela and Brazil; conducted comparative morphological and morphometric study; and proposed hypotheses regarding the origin and phylogeny of South American tapirs. Based on the review of the species of Tapirus of Quaternary from South America, could be considered as valid species: T. greslebini, T. rioplatensis, and T. mesopotamicus (all from Argentina); T. oliverasi (Uruguay); T. tarijensis (Bolivia); T. cristatellus and T. rondoniensis (Brazil). Morphometric analysis allowed us to establish two morphotypes for the South American fossil species based on the size of the teeth. A morphotype which is within the size variation of T. terrestris, comprising the species T. rondoniensis and T. mesopotamicus, and another, larger one morphotype, much larger than the maximum of variation found in T. terrestris, as T. tarijensis, T. rioplatensis, T. greslebini, and some specimens of T. cristatellus. The genus Tapirus appeared as a monophyletic clade and Nexuotapirus marslandensis as its sister taxon. The South American tapirs do not constitute a monophyletic clade, since T. pinchaque is the sister group of other extant and fossil South American tapirs, and of the forms derived from North American; and T. cristatellus would be the sister taxon of the clade T. indicus + T. bairdii +T. polkensis + T. lundeliusi + T. haysii + T. veroensis. The result from phylogenetic analysis suggests a close relationship between the South American tapirs and T. webbi, which supports the hypothesis of a dispersal event from North America to South America during the Miocene. Moreover, our data indicate a second dispersal event from South America to North America, possibly from a form closely related to T. cristatellus, which would have resulted to the derived forms of southeast North America.

Saltville, Virginia (Smyth County and Washington County) has been known for its late Pleistocene megafauna since the 1700s. Based on reviews of past excavations and material in collections, the most prominent fossils found at Saltville are proboscideans. Teeth of Mammuthus (mammoth) and Mammut (mastodon) from East Tennessee State University Museum of Natural History, Virginia Museum of Natural History, and Smithsonian were the focus of this research. Evidence of sedimentary abrasion and degree of concretion development was used to address the taphonomic history of the assemblage. Evidence of root resorption, tooth expectoration, and eruption and wear of proboscidean molars was used to understand age-related patterns in the proboscidean assemblage. The Saltville proboscidean assemblage contains a disproportionate amount of juvenile mammoth and mastodon teeth, some of which were lost in life. This assemblage has also been modified extensively by sedimentary abrasion.

Since the earliest explorations of the Colorado Plateau, geologists have suspected that cliffs are retreating back laterally. Clarence Dutton envisioned “the beds thus dissolving edge wise until after the lapse of millions of centuries their terminal cliffs stand a hundred miles or more back from their original position” when he wrote about the landscape in 1882. While many geologic studies have determined how fast rivers cut down through the Plateau, only a few studies have calculated how quickly cliffs retreat laterally, and geologists have been arguing since the 1940’s what exactly drives cliffs to retreat in the first place. We study the Book Cliffs in central Utah, and in particular remnant landforms and deposits related to a 120,000-year history of erosion and deposition, which we date by optically stimulated luminescence methods. Our dataset shows that deposits along the Book Cliffs are preserved especially during times of climate instability, which suggests that escarpment retreat locally is driven by climatic disturbances. This disproves older hypotheses suggesting escarpments retreat in response to local factors regardless of shifts in climate, and it is consistent with the few other well-studied escarpment records globally. We also constrain the rates of cliff retreat via a new measurement approach and luminescence age control, showing that the Book Cliffs have retreated at 1-3 meters per thousand years while local toeslope drainages have incised at about 0.5 meters per thousand years, which confirms that cliffs of shallow-dipping, layered rock retreat laterally faster than streams lower the landscape vertically.

During the last two decades, a broad spectrum of short- and long-term studies on different taxonomic groups has enriched our understanding about how dynamics of taxonomic and ecological diversification have changed through geologic time. There are two major issues that have impacted these studies: the quality and quantity of data used are often insufficient in various ways and the methods used may produce results that are more equivocal than supposed. To investigate these issues more fully, this dissertation focuses on studies on two major aspects: 1) short-term studies examining the nature of successful and unsuccessful predatory attacks on Plio-Pleistocene bivalves; and 2) a Phanerozoic-scale project examining trends in bivalve richness and ecological differentiation. The short-term studies, focusing on shell-breaking predation on bivalves, have shown that the existing methodologies which only study either successful or unsuccessful component of predation in isolation are fraught with potential issues in developing effective interpretations. When these two components (i.e., successful and unsuccessful) are studied in tandem as was done here, however, traces of predation can be used to better constrain potential paleoecological interpretations related to predation intensity, predator's attack strategies, and predator-prey dynamics. The long-term project includes two Phanerozoic studies on bivalves' taxonomic and ecological richness. The taxonomic study has shown how the elements included in various datasets used can affect the Phanerozoic richness trajectory of bivalves. The revised and newly compiled dataset developed here reveals that bivalves showed three major episodes of diversification - a Ordovician radiation of orders and families, a Mesozoic diversification of families, and a dramatic Cenozoic rise in the total number of genera - all of which were synchronous with ecological diversification in terms of appearances of new life forms capable of colonizing new ecospace (i.e., cubes). However, these synchronous changes in taxonomic-ecologic richness were influenced by many biotic (e.g., predation, competition, and adaptive innovations) and abiotic (e.g., nutrient availability, sea level, and temperature) components, for which I propose a multilevel mixed model such that all these components can be studied in tandem.