Soil production and the soil geomorphology legacy of Grove Karl Gilbert

© 2019 The Authors. Soil Science Society of America published by Wiley Periodicals, Inc. on behalf of Soil Science Society of America Geomorphologists are quantifying the rates of an important component of bedrock's weathering in research that needs wide discussion among soil scientists. By using cosmogenic nuclides, geomorphologists estimate landscapes’ physical lowering, which, in a steady landscape, equates to upward transfers of weathered rock into slowly moving hillslope-soil creep. Since the 1990s, these processes have been called “soil production” or “mobile regolith production”. In this paper, we assert the importance of a fully integrated pedological and geomorphological approach not only to soil creep but to soil, regolith, and landscape evolution; we clarify terms to facilitate soil geomorphology collaboration; and we seek a greater understanding of our sciences’ history. We show how the legacy of Grove Karl Gilbert extend across soil geomorphology. We interpret three contrasting soils and regoliths in the USA's Southern Piedmont in the context of a Gilbert-inspired model of weathering and transport, a model of regolith evolution and of nonsteady systems that liberate particles and solutes from bedrock and transport them across the landscape. This exercise leads us to conclude that the Southern Piedmont is a region with soils and regoliths derived directly from weathering bedrock below (a regional paradigm for more than a century) but that the Piedmont also has significant areas in which regoliths are at least partly formed from paleo-colluvia that may be massive in volume and overlie organic-enriched layers, peat, and paleo-saprolite. An explicitly integrated study of soil geomorphology can accelerate our understanding of soil, regoliths, and landscape evolution in all physiographic regions

Multimethodological study of non-linear strain effects induced by thermal stresses on jointed rock masses

A multimethodological method based on environmental, stress–strain, microseismic, and ambient seismic noise monitoring is here presented, with a view to identifying non-linearity of thermally-induced deformation of jointed rock masses at different dimensional scales. Rock masses experience non-negligible deformation cycles due to the continuous fluctuations of their surficial temperatures. However, the interpretation of such strain effects, in terms of the ratio between elastic and inelastic percentages, is still debated. In particular, the relation between microseismic emissions, considered as primary indicators of crack-growth related energy release, and resonant frequencies fluctuations of rock structures, witnesses of the thermally-induced effect at the macro- or structure-scale, have not been yet studied within a coupled framework. The combination of different approaches able to investigate the behavior of rock masses from micro- to macro-scale, then from fracture-scale to joint-isolated rock blocks up to rock structures, could provide new insights and perspectives on the effects related to shallow thermal stresses fluctuations. This paper presents the preliminary outcomes from two case studies, the Acuto experimental test-site (Italy) and the Wied Il-Mielaħ sea arch (Malta), where multiparametric monitoring surveys were conducted and are still ongoing, aiming at the assessment of the cause-to-effect relation between near-surface thermal stresses and induced strains. Data analysis was carried out following different approaches, with a particular emphasis on the Acuto test-site dataset recorded so far, allowing to establish a well-constrained correlation among temperature fluctuations and rock mass deformation both at the daily and seasonal scale

San Bernardino Cave (Italy) and the appearance of Levallois technology in Europe: results of a radiometric and technological reassessment.

The introduction of Levallois technology in Europe marked the transition from the Lower to the early Middle Paleolithic. This new method of flake production was accompanied by significant behavioral changes in hominin populations. The emergence of this technological advance is considered homogeneous in the European archaeological record at the Marine isotopic stage (MIS) 9/MIS 8 boundary. In this paper we report a series of combined electron spin resonance/U-series dates on mammal bones and teeth recovered from the lower units of San Bernardino Cave, Italy, and the technological analyses of the lithic assemblages. San Bernardino Cave has yielded the earliest evidence of Levallois production on the Italian Peninsula recovered to date. In addition to our results and the review of the archaeological record, we describe the chronological and geographical differences between European territories and diversities in terms of technological developments. The belated emergence of Levallois technology in Italy compared to western Europe corresponds to the late Italian Neanderthal speciation event. The new radiometric dates and the technological analyses of San Bernardino Cave raise the issue of the different roles of glacial refugia in the peopling and the spread of innovative flaking strategies in Europe during the late Middle Pleistocene