Solving problems with the stereonet 22 exercise 2a. In osxstereonet, there are also menus for saving lines or planes datasets as text file save dataset to txt, and for saving the stereonet image file save plot as pdf or save plot as eps. The longitudes are planes that intersect in a common line the ns line, and thus appear as great circles in the stereonet. We move the use of steroegraphic projection in structural geology by f. Wulff stereonet the wulff stereonet is perhaps the easier of the two projections to visualize, and so we will examine it first. Structural geology exercises with glaciotectonic examples part iii james s. The use of steroegraphic projection in structural geology.
The wulff net shown here is the stereographic projection of the grid of parallels and meridians of a hemisphere centred at a point on the equator such. Orient has constantly evolved, bringing new levels of accuracy and speed, with. It can read and write older stereonet text files but has a new binary format for its native file. Shift dragging the stereonet view and dropping it to the desktop produces a pdf of the stereonet. Imagine a sphere with lines of latitude and longitude marked on it. The stereonet used for the exercises is an equal area stereonet. Angelier or hoeppner plot, schmidt or wulff net, as well as upper or lower. Output in adobe portable document format pdf for individual files, and a single merged file. Stereographic projection the basics geological digressions. In the early 1990s, before adobe cofounder john warnock and an elite team codenamed camelot got to work on their new file format, things werent. The wulff net is arcs corresponding to planes which share a common axis in the x,y plane. You can also choose between equal area schmidt and equal angle wulff projections. Map projections a working manual stereographic projection on wikipedia. Each quadrangle on the stereonet is equal in size or area, whereas shape of quadrangles varies from almost square.
In geometry, a stereographic projection is a function that maps the points of a sphere onto a plane. Visible geology runs in the browser so there is no need to download anything, just click to add lines and double click to add planes. Imagine a plane cutting through the centre of a lower hemisphere figure 1a. It is an equal angle grid where meridians and parallels intersect at right angles. The figures throughout this manual are from the macintosh version of the program but windows and.
In order to make plotting of the stereographic projection easier, a device called a stereographic net or stereonet is used. Winwulff stereogram, stereographic projection, wulffnet. The projections of the latitudes, which are not planes but cones coaxial with the ns line, are usually referred to as small circles also their projections onto the stereonet. Stereographic projection simple english wikipedia, the. Structural geology laboratory manual third edition david t. Optionally, encapsulated post script eps is also available as output format, useful for publications. A stereonet is the plane of projection of the lower half of this sphere it is a lower hemisphere graph. The projection is defined on the entire sphere, except for one point, called the projection point intuitively, the stereographic projection is a way of picturing a sphere as a plane, with some inevitable compromises. Orientation from 0 to 360 dip from 0 to 90 wullf stereonet. A stereographic projection, or more simply a stereonet, is a powerful method for displaying and manipulating the 3dimensional geometry of lines and planes davis and reynolds 1996. Orient comes with numerous tutorials in the user manual to get you up to speed quickly. This special graph paper is called a stereonet or wulff net, after the russian mineralogist george yuri viktorovich wulff.
Phillips the use of steroegraphic projection in structural geology pdf, in that dispute you approaching on to the fair site. Lecture notes mineralogy stereographic projections. Stereonets can be exported in the following formats. Allison associate professor of geology department of geology and geography university of south alabama. The macintosh version is being made available here for those users who need binary file compatibility with the windows version. Stereonet plotting program for windows, macos x rose diagrams.
The description of the method of plotting faces on a wulff projection are found in all mineralogy textbooks such as manual of mineralogy klein and hurlbut, 1993. Equal area schmidt stereographic lowerhemisphere projection. The net that emerges from the particular projection described above is called the wulff net. Stereonet innstereo 0 documentation the documentation of. An online stereonet application that allows you to create and view all of your geologic stereonet information in 3d. Plotting techniques of plottingplotting a plane with attitude 120 30 p. Crystallography and mineralogy university of south. Visible geology is an interactive online educational tool for visualizing 3d geologic block models. Stereographic analysis application flexibility to the annotation creationediting component of the netprog application. Lecture notes mineralogy stereographic projections the stereographic projection is a device use by mineralogists and structural geologists to represent 3dimensional information in two dimensions.
Two types of stereonet wulff net equal angle used in mineralogy when angles are meant to be preserved. Stereonets, and faults probability graphs are exported in. Orient comes with numerous tutorials in the user manual to get you up to. Mineralogists use a wulff stereonet, which is constructed from a simple geometric recipe.
Stereonet 9 for macintosh uses the modern mac os x cocoa architecture. There are two types of stereonets available, equatorial and polar. Media in category stereographic projection the following 51 files are in this category, out of 51 total. Where the equator of the stereonet grid ew line would not be drawn in pdf and svg files. The intersection made by the line or plane with the spheres. The example data folder should also be copied for use in the tutorials. Or, open one of the sample files and replace that data with your own. Workbook 2 stereonets school of earth and environment. If the pole and the trace of a plane are represented on the same diagram, then we turn the wulff. The nagtdlese on the cutting edge project helps geoscience faculty stay uptodate with both geoscience research and teaching methods. Structural geology laboratory manual university of. Equalangle wulff b equalangle stereonets are used in crystallography because the plotted angular relationships are preserved, and can be measured directly from the stereonet plot.
Stereographic projection an overview sciencedirect topics. Both output options are possible in grayscale as well ideal for gray scale publications. Stereographic projection, with some lecturereading material on plotting small circles and doing stereonet rotations. To deinstall simply delete the orient application folder, and optionally the preference files. How the activity is situated in the course standalone exercise in a section where we study stereonet methods in analyzing borehole and core data. To do this, click on the stereonet in the shape list and then select from its inputs in the move to list. You can make further edits by clicking the edit button in the stereonet window. I would like you to plot the faces of three model crystals 4, 75, 167 on three separate stereonets wulff nets.
Spherical projections with osxstereonet sciencedirect. Small circles angles are slightly distorted and make the circles appear as ellipses. Software for stereographic projection there are several pieces of software that youd like to check out for that purposes. Grid using either equal area or equal angle without. Winwulff is a program for plotting stereographic projections of hkl and. They are also used as map projections, and for maps of the sky in astronomy or. Equalarea stereonet i schmidt stereonet the equalarea or schmidt stereonet is a different stereographic projection on which size is preserved, but angles and shape are distortedsee fig.
If you plot points on a wulff stereonet and include contours, you may note that the point densities and contours might not correspond. You can create your own topography and show the outcrop pattern of. The netlike grid is called a wulff net, or stereonet. Although the north n and south s poles are shown on the stereonet, these do not correspond to the north and south poles as defined in the projection above. The orientations of lines and planes can be plotted relative to the center of a sphere, called the projection sphere, as shown at the top of fig. As adobes senior vice president of cloud technology, bob wulff, describes it, pdf allows the user to view a file preciselydown to the pixel, essentially, of what the author had intended. The wulff net shown here is the stereographic projection of the grid of parallels and meridians of a hemisphere centred at a point on the equator such as the eastern or western hemisphere of a planet. Create a new datasheet and enterimport your strike and dip data into the datasheet. It is the successor to jwulff and the jwulff module in jcrystal. This is a printable 2 degree equal angle wulff stereonet in pdf format. In the samples folder, an example file \rockworks17 data\. Select a format and navigate to the folder where you wish to save the file. Borehole analysis using stereographic projection activities.
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