The end-Permian mass extinction was followed by the formation of an enigmatic rock layer with a distinctive macroscopic spotted or dendroid fabric. This deposit has been interpreted as microbial reef rock, digitate dendrolite, digital thrombolite, dendritic thrombolite, or bacterial deposits. Agreement has been reached in considering them as microbialites, but not in their formation. This study...

The total organic carbon content (TOC) is a crucial indicator for the evaluation of shale gas reservoirs, traditionally estimated by measuring cores, cuttings or sidewall cores in laboratory with source rock evaluation instruments. Limited by the number of rock samples, the experimental results are not continuous and it is impossible to show the whole face of a source rock bed. Continuous high ...

In this paper we present a new digital ultrasonic instrument for nondestructive inspection of rock bolts using guided waves. The Rock Bolt Tester (RBT) instrument applies long-range ultrasound to investigate bolt’s status, especially its grouting condition. RBT features an application tailored ultrasound probe that transmits high-energy, low frequency (below 100kHz) guided waves and is capable ...

Field, laboratory, and modeling studies of fractured rock have generated great interest from both fundamental and applied perspectives. Many practical applications of these studies are crucial for the exploitation of petroleum and geothermal reservoirs, the safe environmental management of groundwater, the isolation of radioactive waste in under­ ground repositories, cleanup technologies for ot...

This paper describes the application of a new methodology to estimate permeability of clastic rock formations based on the numerical simulation of the physics of mudfiltrate invasion. The methodology assumes a key well with a complete suite of well logs and rock-core laboratory measurements of porosity, permeability, capillary pressure, and relative permeability. For additional wells in the sam...

A casting technique has betn developed for ding translucent replicas of the void space of natural rock measurui by means of light attenuation. Digital h g e analysis yields a virtuatly pointwise definition of fracture am. The casting technique for muring fratfractures. Amnuation of light &n& through the cast combin& with digital image analysis a pointtWe Wid space geometry has evaluated by comp...

Recording of archaeological sites has long been studied by many scientific organizations. However, the analyses and evolution of human beings through rock art is one of the most challenging tasks in prehistoric archaeology, not only because of the unpredicted contribution to the understanding of the past but also because of the difficulties for appropriate recording. Tracing, rubbing and photog...