Stereonet software 9

hi

Manual approach: 1. plot all poles of fold limbs. 2. Construct great circle which fit all the pole distributions (for examample: antiform will 'locate' all poles close to the centre of the stereonet, synform tend to be away from the centre of the stereonet). The 'imagery' great circle will pass through 'somewhere' the middle of each groups of limb's poles concentrations. 3. The centre of the 'phi' great circle with respect to the centre point of each pole's group and the intersection of the limb planes (intersection means the best fit centre of the intersection) shall be in the same 'new great circle' 4. This new great circle is the axial plane of the fold. Using stereonet software: 1. Plot all planes and their poles. 2. Having ploted the poles, calculate the 'cylindrical best fit' solution to obtain 'phi' great circle. 3. You can operate the interlimb angle calculation if you wish from each pole concentrations (but i suggest to use conical best fit for each seperate pole groups (each limbs)). 4. The axial plane, since it's calculated by computation approach might slightly differ to manual approach but not really sugnificant in terms of the quantitative discrepancy. Use calculation menu to ovtain axial plan finder by determining each pole group center line (you can use conical or coulntouring best fit) but to be precise do not to far (shall be) along the phi line.

Which factor is which? contouring? There is terzaghi correction and grid size of contouring correspon to the data size. in faultkin (another stereographic approach to solve fault and paleostress data (also made by professor Rick Allmendinger) we can adjust the 'stress' magnitude factor to acomplish better eigen value and eigen vectors thelat are useful for solving the kinematic axis.

Angular comformity can be obtained through field data measurement or geological reconstruction. If you want stereonet to resolve the issue it merely requires our geological interpretaion prior to deploy stereographic reconstructions. 1. Case 1: you measure the bedding attitude of beds above and below the uncomformity.. therefore by these kind of data we can presume (as consideration) the bed above uncomformity had undergone tilting that correspond to the comformity plane attitude. We can use stereonet, hence to restore the 'rotation' prior to uncomfomity tilting. It is required rotational axis with respect to uncomformity beds (beds above umcormity) then apply similar procedure to rotate the beds abelow uncomformity to accomplished removing tilting effect prior to tectonic tilting of underlying beds before uncomformity. 2. Case 2. The line structures that need restoration. Poles and strike can be usefult to be rotational axis deoends on the problems. Usually for folded strata we need to figure out the attitude of certain linear structure on another limb which the linear structure is known from the opposite limb.

looks like stereonet 9

its free. google stereonet 9

thomas fegan plz provide the downloading link..

www.petromehras.com/petroleum-software-directory/geology-software/stereonet-9