While gigantic vertebrae and other bones have been turning up for thousands of years to become woven into the legends of Native Americans and other cultures, the first scientifically recorded finds of what became known at first as “ceteosaurs”—and then sauropods—began in the 1830s. Like the evolution of the animals themselves, our human understanding of these dinosaurs took time to grow, often taking diversions until new finds and changes in scientific thinking happened to raise the curtain, each time a little bit more. <...>

A velocity model can have enduring and growing interpretive value, beyond its initial creation as a means to optimize the seismic image. The 3D velocity model is often built carefully with a combination of geophysical and geological input, because of the accuracy demands placed on it by the requirements of depth imaging. As such, this model becomes an increasingly effective interpretive tool.
This course addresses the ways in which the interpreter should participate in the development of the velocity model, and underscores its interpretive value with numerous case study examples. <...>

The Selwyn Line is the name adopted for an open arcuate zone of iron-copper-gold mineralisation, located ~150 km southeast of Mount Isa, in the Mount Isa Proterozoic inlier, northwest Queensland, Australia. Since the discovery of gold mineralisation in the Selwyn Hills in the 1970's, 5 small mines have been operated. These exploited high grade ironstone hosted gold-copper mineralisation, located within a zone of poly-aged shearing and complex alteration. The mines are located within the Starra Shear which has a history of ductile-brittle, brittle-ductile and brittle deformation. The structure is altered over widths of between 100 m and 500 m, and for over 10 km along strike. The alteration involved early albite +quartz +calcite +scapolite +actinolite replacement of the host sheared meta-sediments of the Staveley Formation. This was followed by a magnetite/hematite+biotite+quartz(+pyrite) overprint, and finally post tectonic oxidation of the magnetite, and chlorite-calcite alteration with associated chalcopyrite and gold mineralisation, and limited pyrite fonnation (Rotherham 1997). The high grade zones exhibit indications of strong structural controls. They typically plunge steeply to the north along magnetite bearing extensional duplex structures and shear planes which include portions of the hanging wall bounding shears and link structures to the footwall bounding shears. The dimensions of the mined and mineable resource (<8 mt) have always been regarded as small for typical Fe-Cu-Au systems. However resource work done on lower cut-off grades indicates that the system is more typical of the large systems of this sort found elsewhere in the district, with a pre-mining global resource of at least 29 mt at 2.5g/t Au and 1.4% Cu (at a 1.5% Cu Equivalent cutoff using a factor of- 0.8 depending on where the ore is from), 49 mt at 1.76 g/t Au and 1.05% Cu using a 1.0% cut off, or 95mt at 1. lg/t Au and 0.74%Cu at a 0.5% cutoff. These are embraced within a larger mineralised system with a global resource of 253 mt @ 0.48g/t Au and 0.34% Cu at measured, indicated and inferred categories, to a depth of ~300m below surface (using a 0.2% Cu Equivalent cut off).

Geophysics is a diverse science. At its best it has the rigour of physics and the vigour of geology. Its subject is the Earth. How does the Earth work? What is its composition? How has it changed? Thirty years ago many of the answers to these questions were uncertain. We knew the gross structure of our planet and that earthquakes occurred, volcanoes erupted and high mountains existed, but we did not understand why. Today we have a general knowledge of the workings of the planet, although there is still much to be discovered. <...>