Lithological characteristics, mineral composition, physical properties of water and physical and mechanical properties, weathering zone distribution and other factors of bedrock weathering zone in coal-seam roof determine the strength of its watertight performance, while its performance has a direct impact on impermeable overlying loose surface water aquifers as well as the possible collapse in...

Spacecraft exploring Mars such as the Mars Exploration Rovers Spirit and Opportunity, as well as the Mars Science Laboratory or Curiosity rover, have accumulated evidence for wet and habitable conditions on early Mars more than 3 billion years ago. Current conditions, by contrast, are cold, extremely arid and seemingly inhospitable. To evaluate exactly how dry today's environment is, it is impo...

The end of the Palaeozoic is marked by two mass-extinction events during the Middle Permian (Capitanian) and the Late Permian (Changhsingian). Given similarities between the two events in geochemical signatures, such as large magnitude negative dC anomalies, sedimentological signatures such as claystone breccias, and the approximate contemporaneous emplacement of large igneous provinces, many a...

The formation and stabilization of soil aggregates play a key role in soil functions. To date, few studies have been performed on the variation of soil aggregation with increasing soil weathering degree. Here, soil aggregation and its influencing factors along the weathering gradient were investigated. Six typical zonal soils (derived from similar parent materials) were sampled from temperate t...

The appearance manifold [WTL∗06] is an efficient approach for modeling and editing time-variant appearance of materials from the BRDF data captured at single time instance. However, this method is difficult to apply in images in which weathering and shading variations are combined. In this paper, we present a technique for modeling and editing the weathering effects of an object in a single ima...

The Earth has an average surface temperature of about 15°C, which is, in terms of planetary conditions suitable for life, the equivalent of winning the cosmic lottery. Yet, without an atmosphere filled with biological waste gases capable of retaining heat (O2, N2O, CH4, CO2), the average temperature of the planet would be about −18°C (Smil 2002), making the present diversity and abundance of li...

Heavy rare earth elements (HREE) are dominantly mined from the weathering crusts of granites in South China. Although weathering processes occur globally, no economic HREE resources of this type have yet been found outside China. Here, we report the occurrence of unidentified REE minerals in the granites from South Chinese deposits. They contain high levels of both HREE and light REE, but are s...

It is unclear why atmospheric oxygen remained trapped at low levels for more than 1.5 billion years following the Paleoproterozoic Great Oxidation Event. Here, we use models for erosion, weathering and biogeochemical cycling to show that this can be explained by the tectonic recycling of previously accumulated sedimentary organic carbon, combined with the oxygen sensitivity of oxidative weather...

The behaviour of 25 major and trace elements, together with mineral changes, has been examined in a deep weathering profile on the Cammenellis granite, Cornwall. The bulk chemical and mineralogical composition of the regolith shows only minor changes from the parent rock indicating a low degree of chemical weathering. However, within the regolith marked differences occur between the fine fracti...

Mineralogy, microbial ecology, and mineral weathering in the subsurface are an intimately linked biogeochemical system. Although bacteria have been implicated indirectly in the accelerated weathering of minerals, it is not clear if this interaction is simply the coincidental result of microbial metabolism, or if it represents a speciŽ c strategy offering the colonizing bacteria a competitive ec...