Plot a line on a stereonet given its trend and plunge. Strike dip 030 30 057 33 043 33 078 40 092 53 100 59 107 70 011 32 335 43 325 55 315 63 311 73 2. Measure the plunge of the line of intersection and add an arrow pointing in the. Start at the top 0 degrees and count around the circle. Linear plunge and trend plunge is used to describe the tilt of lines, the word dip being reserved for planes. This part needs to be done with pencil and tracing paper, with a stereonet projection underneath. Trend orientation of horizontal component measured from north. Click the add button to add any structural data table in the project to the stereonet. You can also drag and drop structural data objects from the project tree into the stereonet. Plot data on stereonets polar graphs openground gint. Slickenlines on a fault plane represent the direction of some relative displacement between the two blocks separated by the fault.
The orientation is converted automatically to a line with a trend and plunge, but still remains veiwable as a rake. Data type code example description lines tp 277, 42 the trend value appears. A pcinteractive stereonet plotting program sciencedirect. Pay attention to minor fold asymmetries as you complete the map. Intersection of two planes in 3d, two planes will intersect in a line. The first element of intrend plunge is the trend azimuth measured clockwise from north, and the second is the plunge angle. The convention option does not affect the plotting of data, or the values in the grid in any way legend note that the legend for the pole plot and all stereonet plots in dips indicates the. Measure the plunge of the line of intersection and add an arrow pointing in the direction of plunge. A circular cone with its center at the center of a sphere cuts the sphere in a small circle. Aug 24, 2009 a polar stereonet is good for plotting large quantities of trend and plunge data directly, or reporting data like foliation planes and lineation in rock layers. These actions can remove the effects of dip and plunge. The trend and plunge is given as 89 the stereographic projection is a methodology used in structural geology and engineering to analyze orientation of lines eqhal planes with respect to each other. Structural geology laboratory university of south alabama. The intersection of the two planes represents the fold axis.
First plot your striketrend on the outer perimeter of the graph. We can define the cone in terms of the trend and plunge of its axis and the angular radius or apical halfangle of the cone. Now for some reason we want to find the intersection of the bedding and the fault, which is a linear feature, as plunge and bearing, and plot it. Stereonet 9 brings location and date tagging of individual measurements as well as a free form notes field. Plot all 50 measurements for site 3 on a schmidt stereonet. How to plot a line measured as trend and plunge on a stereonet, by hand. Reading measurements from a stereonet 27 practical exercises29.
The quantitative approach for kinematic analysis can be easily interpreted by professionals who are not familiar with the use of stereonets. The intersection of the great circles defines the fold axis. Plane dip and strike, lineation plunge and trend, structural. Measure trend and plunge of lines measure vertical angles measure bearings set local declination in determine the direction of strike and dip, there are four quadrants of a brunton compass. Your point should fall in the quadrant corresponding to the.
The trend and plunge of this line can be read directly off the stereonet. They are used for analysis of various field data such as bedding attitudes, planes, hinge lines and numerous other structures. How to use a stereonet to find the trend and plunge of a line plotted as a dot. Jul 25, 2017 how to plot a line measured as trend and plunge on a stereonet, by hand. Logical, if false, new plot will open in active window. We collected a bunch of planar data from the limbs of a fold. Rakes the stereonet program supports rakes through the input of a plane and an orientation rake in that plane. Trend orientation of horizontal component measured from north plunge inclination downward from horizontal planes strike and dip quadrant notation 360 notation pole line normal to plane measured down lower hemisphere dip vector direction of maximum dip or downward inclination in a plane. An inclined plane violet with a dip that matches the plunge of the line and that dips in the direcqon the line plunges visualizaon plong a line. The first element of intrendplunge is the trend azimuth measured clockwise from north, and the second is the plunge angle. Count in from the outside edge remember the centerline is 90.
Where that line passes through the stereonet project plane is where the line plots the dark green dot. Plot structural data on stereonets 60 minutes, at home a. B determine the trend and plunge of the intersection. Once a final screen plot is obtained, it may be printed on an associated graphics printer. How to plot the strike data to the rosette diagram aapg wiki. An online stereonet program that allows you to create and view all of your geologic stereonet information in 3d. The trend plunge convention is similar to the dip directiondip angle but it refers to linear data poles. In geology, geometrically, a conical fold is characterized by the trend and plunge of its axis and by the angle between the generatrix of the conical surface and the fold axis, also known as semiapical angle a2. The plunge is the angle made by the linear structure with the horizontal, in the vertical plane parallel to its trend. Prior to folding, the poles to a bedding plane plot as a single point or a concentration of points on a stereonet. Plot the planes collected from the fold and the corresponding poles.
To find the plunge rotate the intersection point to. Count off the trend around the circumference of the stereonet and mark it. It is the only geology compass app that can use augmented reality to record the strike and dip. Plot the line representing the strike of the axial surface n45w.
Extra columns allow you to record any additional qualitative or quantitative information, with convenient spreadsheet entry and unlimited file size. This function then plots the corresponding planecircle that has the lines point of entry as its pole. Rotate the completed stereonet back to its original position. How to plot a plane knowing its strike and dip on a stereonet. The number next to the arrowhead is the plunge amount. F specifying the orientation or attitude relative to the horizontal and vertical references will specify completely. The most common need is to plot the pitch or rake of a line within a plane. Stereonet mobile for ios free download and software. Make a solid geologic map from the given outcrop area, using extrapolative license. Jul 25, 2017 how to use a stereonet to find the trend and plunge of a line plotted as a dot. Rotate the overlay so the trend lies along one of the vertical great circles. To plot plunge or dip angles count inwards from along either the ns meridian or ew parallel.
It is a companion to my stereonet program for desktop computers. See plot options and data display options below for information on the different options available for stereonets. A plunge of 90 always plots at the center of the net. The great circle containing this line must also pass through with the second great circle pinned to north, read the dip of the axial surface.
Angles within planes are measured along the great circle of the plane. Introduction to stereonets 4 stereonet terminology 6 setting up a stereonet 7 1. The dip and dip direction provided is interpreted as the trend and plunge of a line into the stereonet. In either case, turn in your stereonet plot paper or pdf file. A negative plunge indicates a vector pointing into the upper hemisphere. Spherical projections with osxstereonet sciencedirect. Structural geology exercises with glaciotectonic examples part iii james s. The pole cursor position, the plane, the trend and plunge of the pole, and the strike and dip of the plane are shown as the mouse is dragged over the stereonet fig. Entries can be added to a planes dataset by clicking the stereonet dataadd data from plot menu. Mar 21, 2019 from north, read the fold axis trend and plunge.
Mathematica code for leastsquares cone fitting and equal. Plot the poles to bedding on the same stereonet in red. A plane can be represented with dip directiondip angle of the plane itself or the trend. Plot all bedding measurements as planes on a stereonet using a red pencil. Stereonet plots stereonet plots include pole, scatter, contour and planes plots. Trend and plunge of minoorldfs trend and plunge of linetiaons a. Latihan pengolahan data dan analisa training handout 3 rd international earth science olympiad. Plot the two ravenscrag fold limbs as planes on the stereonet. Each quadrangle on the stereonet is equal in size or area, whereas shape of quadrangles varies from almost square. Mixed orientation formats can be included within a single dips file. Plot a small circle cone whose axis trends 290 degrees, plunges 50 degrees, and has an angular radius of 25 degrees. 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. Plot the axial plane of folded bedding on the stereonet in green.
Stereonet mobile is designed to help you collect, visualize, and analyze geological orientation data. Count in along the great circle and plot the point at the appropriate plunge. Stereographic projection poles to planes geological. Is the till fabric at site 3 parallel, transverse, or mixed in style. Stereonets make it easy to calculate apparent dips.
Then locate your dipplunge along the eastwest line of the graph. In all plots, the stereonet view direction is given as trend t and plunge p in a, or latlong in b. Create any type of planar geologic fault, as well as faultbendfolds and blindthrust faults. Slope stability earthquake analysis problem set out 120, due 129.
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. Stereonets and rose diagrams in python geology and python. Procedure for plotting the stereographic projection of a. Remember the simplest interpretation is usually the right one. Part 1 plotting and manipulating elements on a stereonet. These are 2 degree increments from 0 to 90 to 0, going both ways. Save your data file periodically as you add more values. The green represents the planes orientation when north is rotated back to its standard topofthestereonet position. The plunge fully expresses the threedimensional orientation of a line and has two parts. Contents scoo o t n nvironent 4 introduction to stereonets a stereonet is a lower hemisphere graph on to which a variety of geological data can be plotted. This module is based on the assumption that the stereonet has a unit radius i.
Rotate the tracing paper until the intersection of the two planes lies on the eastwest diameter of the stereonet. Fault data include both the fault plane and slicken line orientations, the latter including the. The actual plot in the stereonet will be a maximum circle for a plane and a point for a line figure2 strikes and trends should be given as azimuth i. Stereonet practice problems do them first, then check solution on p.
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