An X- ray fluorescence (XRF) spectrometer is an x ray instrument used for routine, relatively non-destructive chemical analysis of rocks, minerals, sediments and fluids. It works on wavelength-dispersive spectroscopic principles that are similar to an electron microprobe (EPMA). However, an XRF is used for bulk analysis of larger fractions of geological materials. The relative ease […]
X – Ray Fluorescence (XRF) Read More »
X- ray diffraction is a common technique that determine a sample’s composition or crystalline structure. For large crystals such it can be used to determine the structure of atoms within the sample. If crystal size is too small, it can determine composition, crystallinity, and phase purity. Bragg’s law reflection. The diffracted x-rays exhibit constructive interference
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Water requires a non gaseous surface to make a transition from a vapor to a liquid. Cloud Condensation Nuclei or CCN (also known as cloud seeds) are small particles about which cloud droplets coalesce. When no CCN is present, water vapor can be supercooled below 00C before droplets spontaneously form. In the above freezing temperatures
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This plot shows the average current velocities necessary for the erosion, transportation and deposition of the sediment particles of different sizes. The lower curve on the diagram, it shows that once eroded and moving a clay particle, but not a fine particles of sand can be transported by a week current. This is because the
HJULSTROM’S DIAGRAM Read More »
The slope of the sea floor greatly influences how quickly the sea floor affects the waves as the waves get closer to shore, and therefore how the waves break. A critical wave steepness occurs where the wavelength is 7 times the height of the wave and after that wave becomes unstable and breaks. There are
OCEAN WAVE BREAKERS Read More »
In adjusting to change in discharge and erodibility of it’s bed, a stream modifies it’s channel so that irregularities are minimized and the least energy is expended in the movement in of water and sediments along its course. Frequently this involves enlargement of the channel cross section by erosion or reductions of it’s dimensions through
CONCEPT OF GRADE AND GRADED STREAMS Read More »
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CHARACTERISTICS OF TILL DEPOSITS Read More »
The unstratified, unsorted debris dropped more or less randomly by the glaciers is called till. Tills can be of two types – It is laid down subglacially when debris is released directly from the sole of the ice. This involves pressure melting of basal so that debris in it is released and then lodges or
There are various forces that act upon the plates to make them move. Three possible mechanism of plate motion – Convectional Currents :- Slab Pull :- Slab pull is thought to operate at subduction zones where the subducting oceanic plate becomes colder and denser than the surrounding mantle (gabbro metamorphosed into eclogite) and pulls the
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Ichno-fossils are an expression of the alteration of the depositional fabric in sedimentary rocks by living organisms. Often these expressions are part of animal behavior or traces hence called “trace fossils”. Common structures are burrows, boring, trails and tracks. Trace fossils can be common in un-fossiliferous rocks, that can extend the geologists capability to interpret
