2 1. Research aims 3 2. Introduction 3 3. Materials and methods 5 3.1. Origin of samples 5 3.2. Methods 5 4. Experimental results 7 4.1. Petrographic description 7 4.2. Main petrophysical properties 7 4.3. Overall mineralogy 8 4.4. Clay minerals quantification 9 4.5. Hydromechanical behavior 10 5. Discussion 11 5.1. Identification and origin of the swelling layers 11 5.2. Influence of swelling ...

The temporal evolution of past martian surface temperatures is poorly known. We used thermochronology and published noble gas and petrographic data to constrain the temperature histories of the nakhlites and martian meteorite ALH84001. We found that the nakhlites have not been heated to more than 350 degrees C since they formed. Our calculations also suggest that for most of the past 4 billion ...

Fieldand petrographic studies of the Paleozoic metamorphic rocks of New York City suggest a new interpretation of the stratigraphy and structure of the region and has delineated a number of ductileand brittle faults. The belt of rocks originally lumped together as the Manhattan Schist is now interpreted to consist of three mappable units structurally imbricated by two major ductile faults, the ...

Petrographic thin sections of pottery from five Formative Mexican archaeological sites show that exchanges of vessels between highland and lowland chiefly centers were reciprocal, or two-way. These analyses contradict recent claims that the Gulf Coast was the sole source of pottery carved with iconographic motifs. Those claims were based on neutron activation, which, by relying on chemical elem...

We study certain function algebras and their operator algebra completions on r-discrete abelian groupoids, the corresponding conditional expectations, maximal abelian subalgebras (masa) and eigen-functionals. We give a semidirect product decomposition for an abelian groupoid. This is done through a matched pair and leads to a C*-diagonal (for a special case). We use this decomposition to study ...

The development of tough high-peformance composites often employs a variety of analytical methods that correlate morphological, yield and fracture characteristics to the corresponding properties of a composite. Most of these techniques can be severely limited due to the high concentration of fibres used in high performance composites (nominally 60 wt %). Several light microscopy techniques can ...

Introduction: Individual grains and small lithic clasts in thin-sectioned suevitic breccia samples from the International Continental Scientific Drilling Program (ICDP) Bosumtwi impact crater drillcore LB07A were examined petrographically to evaluate the occurrence , abundance, and characteristics of unshocked and shock-metamorphosed quartz. The analyzed samples were taken across a ~42-m-long (...

Residual elastic strain in naturally deformed, quartz-containing rocks can be measured quantitatively in a petrographic thin section with high spatial resolution using Laue microdiffraction with white synchrotron X-rays. The measurements with a resolution of 1 μm allow the quantitative determination of the deviatoric strain tensor as a function of position within the crystal investigated. The o...

The Paleoproterozoic Changzhougou Formation (Changcheng Group) of North China contains compression-like structures, illimeters to centimeters in diameter and about a millimeter thick that are circular, elliptical, elongate, and irregular in shape. hese structures were interpreted to be carbonaceous compressions of megascopic eukaryotes by Zhu et al. (2000). Some of the ompression-like structure...