[1] During its exploration of the Columbia Hills, the Mars Exploration Rover ‘‘Spirit’’ encountered several similar samples that are distinctly different from Martian meteorites and known Gusev crater soils, rocks, and sediments. Occurring in a variety of contexts and locations, these ‘‘Independence class’’ samples are rough-textured, iron-poor (equivalent FeO 4 wt%), have high Al/Si ratios, an...

Haematite and haematite bearing rocks is a common raw material in Palaeolithic. Widespread in nature, it occurrs either in isolated oucrops or in privileged litostratigraphic formations (in Central Europe these are Lower Devonian, Lower Permian, Lower Triassic and Upper Triassic rocks). All must have provoked an interest of Palaeolithic people so we have searched for a fingerprint for all. So f...

Introduction: Orbiter and lander/rover studies of Mars' surface have identified and provided preliminary characterization of surficial materials including igne-ous and sedimentary rocks, possible volcaniclas-tic/pyroclastic rocks, and unconsolidated sediment. Some surfaces expose unaltered anhydrous silicates (militating against extensive interactions with water), but most results (including st...

High-resolution mapping by visible and near-infrared orbital spectrometers has revealed a diversity of hydrated mineral deposits on the surface of Mars. Quantitative analysis of mineral abundances within these deposits has the potential to distinguish depositional and diagenetic processes. Such analysis can also provide important constraints on the nature of putative global and local-scale mine...

Granite is a typical crystalline material, often used as a building material, but also a candidate host rock for the repository of high-level radioactive waste. The petrographic texture-including mineral constituents, grain shape, size, and distribution-controls the fracture initiation, propagation, and coalescence within granitic rocks. In this paper, experimental laboratory tests and numerica...

the study area is located in the northeast of iran. miankuhi formation is 500m thick and comprises homogeneous shales, brown granular sandstone and siltstone. in this study, 45 samples were taken from miankuhi shales and sandstones in order to determine their tectonic origin by using a polarizing microscope. samples were analysed by x-ray fluorescence (xrf) method to determine their chemical co...

Geochronology aims to establish the age of rocks, minerals, and geological events including fluid movement and mineralization, within a specific degree of uncertainty, using signatures inherent in the rocks themselves. Absolute dating is only accomplished through the use of naturally-occurring radioactive isotopes found within geological samples. The U–Th–Pb isotopic system is the benchmark for...

Gold production in New Zealand has been significant since the mid 1800s, totalling 900 t (29 Moz) to 2005. In addition, there is potential for a further 1230 t (39.5 Moz) of gold in known and undiscovered deposits. Most of the gold has originated from epithermal and mesothermal (orogenic) hydrothermal systems. Epithermal gold occurs in the Northland, Coromandel and Taupo volcanic zones in quart...