South Fork and Heart Mountain Faults: Examples of Catastrophic, Gravity-Driven “Overthrusts,” Northwest Wyoming, USA

Overthrust faults have been a source of debate and discussion in creation literature for many years. Their interpretation demands a better explanation in a Flood context. Two fault systems are examined as analogies for an “overthrust” model. The South Fork Fault System (SFFS) and the Heart Mountain Fault System (HMFS) exhibit folding and faulting consistent with thin-skinned overthrust systems. Both systems moved catastrophically under the influence of gravity. The South Fork Fault system (SFFS, southwest of Cody, Wyoming, exhibits tear faults, tight folds, a triangle zone, and flat-ramp geometries along the leading edge of the system. Transport was southeast, down a gentle slope during early to middle Eocene time (Late Flood), approximately coeval with the Heart Mountain Fault system (HMFS). The SFFS detaches in lower Jurassic strata, rich in gypsum-anhydrite, overlain by about 1250 m of Jurassic through Tertiary sedimentary and volcanic rocks. Movement between 5 km and 10 km to the southeast spread the allochthonous mass over an area exceeding 1400 km2. A break-away fault and an area of tectonic denudation mark the upper northwest part of the system. The exposed denuded surface was buried by additional Eocene-age volcanic rocks soon after slip. Catastrophic rear-loading during emplacement of HMFS may have initiated subsequent movement on the SFFS, with dehydration processes trapping water in a near frictionless anhydrite-water slurry. Rapid development of near-surface folds, as observed in the toe of the SFFS, could only have developed while the sediments were still unlithified

Learning Ground Traversability from Simulations

Mobile ground robots operating on unstructured terrain must predict which areas of the environment they are able to pass in order to plan feasible paths. We address traversability estimation as a heightmap classification problem: we build a convolutional neural network that, given an image representing the heightmap of a terrain patch, predicts whether the robot will be able to traverse such patch from left to right. The classifier is trained for a specific robot model (wheeled, tracked, legged, snake-like) using simulation data on procedurally generated training terrains; the trained classifier can be applied to unseen large heightmaps to yield oriented traversability maps, and then plan traversable paths. We extensively evaluate the approach in simulation on six real-world elevation datasets, and run a real-robot validation in one indoor and one outdoor environment.Comment: Webpage: http://romarcg.xyz/traversability_estimation

Understanding crack versus cavitation in pressure-sensitive adhesives: the role of kinetics

We perform traction experiments on viscous liquids highly confined between parallel plates, a geometry known as the probe-tack test in the adhesion community. Direct observation during the experiment coupled to force measurement shows the existence of several mechanisms for releasing the stress. Bubble nucleation and instantaneous growth had been observed in a previous work. Upon increasing further the traction velocity or the viscosity, the bubble growth is progressively delayed. At high velocities, cracks at the interface between the plate and the liquid appear before the bubbles have grown to their full size. Bubbles and cracks are thus observed concomitantly. At even higher velocities, cracks develop fully so early that the bubbles are not even visible. We present a theoretical model that describes these regimes, using a Maxwell fluid as a model for the actual fluid, a highly viscous silicon oil. We present the resulting phase diagramme for the different force peak regimes. The predictions are compatible with the data. Our results show that in addition to cavitation, interfacial cracks are encountered in a probe-tack traction test with viscoelastic, \emph{liquid} materials and not solely with viscoelastic solids like adhesives.Comment: 44 page

When “conservation” leads to land degradation: lessons from Ban Lak Sip, Laos

Land degradation / Soil erosion / Farming systems / Environmental policy / Political ecology / Households / Population growth / Laos / Ban Lak Sip

Growth trends reveal the forest structure during Roman and Medieval times in Western Europe: a comparison between archaeological and actual oak ring series (Quercus robur and Quercus petraea)

At some point in time, man has influenced nearly all forests in Western Europe. Most of the original forest cover has been converted to arable land and pastures, or has been cut for the supply of firewood and construction timber. In order to secure a sustainable source of firewood, the structure of the remaining forests was often altered. Especially coppice of European oak became increasingly popular during the Roman era and the Middle Ages. Ring-width series of oak trees from Roman times and Medieval settlements were recorded. In order to extract more detailed information regarding past forest structure and management, those series were compared to growth patterns of contemporary oak. The modern oaks were selected on forests sites in Flanders (northern Belgium) with well-known structure and management. Some remarkable similarities in growth patterns were observed. These findings yield tentative assumptions regarding past forest structure and management.Les tendances de croissance révèlent la structure des forêts en Europe Occidentale aux époques Romaines et Médiévales : comparaison entre séries d'accroissements annuels archéologiques et contemporains (Quercus robur et Q. petraea). Au cours de l’histoire, l’homme a influencé quasiment toutes les forêts en Europe. De grandes surfaces boisées ont été transformées en champs et pâtis ou ont été abattues pour récolter du bois de chauffage et de construction. Pour s’assurer d’une source durable de bois de chauffage, la structure des forêts restantes a souvent été adaptée. Surtout les bois de taillis de chêne sont devenus très populaires pendant la période romaine et au Moyen Âge. Des séries dendrochronologiques de chênes provenant d’établissements romains et médiévaux ont été analysées. Pour obtenir plus d’informations précises concernant la structure et la gestion des forêts antérieures, les séries ont été comparées avec celles de chênes contemporains. Ces chênes modernes ont été sélectionnés dans des forêts, avec des structures bien connues, situées en Flandres (Belgique). Quelques similarités remarquables observées dans les modèles de croissance ont permis de formuler des hypothèses concernant la structure et l’aménagement des forêts antérieures

The Gender Gap in Start-up Funding: The Role of Investors\u27 Benevolent Sexism

Past research has consistently shown that female-led ventures tend to receive less funding than male-led ventures, but the reasons for this gap are unclear. Drawing on the ambivalent sexism theory, this study examines how investors’ benevolent sexism influences funding allocations to male- and female-led ventures. In particular, I propose that individuals who endorse benevolent sexism are less likely to perceive female-led ventures as viable because they may believe that entrepreneurship is too challenging for women due to their dual roles as home-makers and entrepreneurs. As a consequence, they may want to protect women from failure by giving women less funding as that would make their ventures smaller and easier to manage. I conducted an experimental vignette study where investors, i.e., business students with experience with early-stage venture context, rated their perceptions of the venture viability and made funding allocations for an early-stage venture. Contrary to expectations, benevolent sexism was not related to perceptions of venture viability or funding allocation for female-led ventures. However, investors’ benevolent sexism was positively associated with perceptions of venture viability for male-led ventures, which, in turn, was related to greater funding allocations. Although not entirely in line with my hypotheses, the results provided preliminary evidence for the role of benevolent sexism in underfunding of female-led ventures by giving men an advantage in venture evaluation and funding, while equally qualified women do not get the same advantages. Thus, benevolent sexism might be subtly and unnoticeably undermining success of female-led ventures