oasis montaj complete workflow tutorial

8/17/2019 Oasis Montaj Complete Workflow Tutorial

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CURTIN EXPLORATION GEOPHYSICS

GEOPHYSICS 3000

WORKSHOP 1 – 3 March 2016

OBECTI!E

This workshop is an introduction to the software package Geosoft Oasis Montaj which

we will be using extensively in Geophysics 3000 and in other units of the Geophysics

undergraduate course. n this workshop we will be using aero!agnetic data fro! the"avensthorpe area of #$. This is an interesting and varied dataset fro! an area with

known !ineral deposits and potential to find !ore.

The dataset is contained within three files % rav3.xy&' rav(.xy&' rav).xy&. These files are

in the *lackboard folder workshop + , 3 !arch -0+ /ach of these files containseastings' northings and aero!agnetic values in that order.

eep good detailed notes 1 2O" 4$* *OO – ha"#$r%&&'" a"# '('c&r)"%c

*'r+%)"+ 5 on what you do to help you in the learning process and for assess!ent during

this course.

STEPS

+. 6opy files rav3.xy&' rav(.xy&' rav).xy&' and !ag!ap.con to a working directory

within your geophysics co!puting account.

-. 4og in to Oasis Montaj

7tart 8 $ll 9rogra!s 8geosoft 8 oasis !ontaj 8 oasis !ontaj

3. 6reate new project. se file 8 project 8 new

/nter project na!e

(. 6reate new database , allow for up to )00 flight lines. ey in )00 in place of

default value of -00. :atabase 8 1ew :atabase

/nter new database na!e

). !port rav3.xy& to the new database using :atabase8 i!port8geosoft xy&

This file is in geosoft xy& for!at

. !port rav(.xy& into the database using a,,'"# option

;. !port rav).xy& into the database using a,,'"# option.


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6oordinates?.7elect current x'y'& coordinates and select x'y and & channel na!es' followed by

O

7elect coordinate syste! and go to 6oordinate syste! at botto! of this window7elect 9rojected @x'yA. 7elect projection !ethod as $ustralian !ap grid &one )+.

7elect datu! $G:


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To restrict the profiles to just the selected subset area , go to viewCgroup !anager

@ left hand icon on third row down of the iconsA' highlight profiles in data area andselect >Masked to Eiew region?

+). Open database and create profiles of individual lines using split screen , data intop panel' profile in lower panel.

+. Grid filtering using M$GM$9 to create derivative in F directionsing input of !agnetic grid created in step ++ of these notes.

This derivative is often called the first vertical gradient of the !agnetic field and

shows how the !agnetic field varies with height above the ground. t is very

useful in interpretation.

M$GM$9 is where !ost freDuency do!ain gird filtering is done.

7teps% Gx 8 load !enu8 !ag!ap.o!n

This brings up M$GM$9 in top row of options7elect M$GM$9 +57tep5filtering'

n 7et6onile select :erivative in F direction' order +.

n 7etTrend select first order and edge points.n 7et/xpand select +0 H expansion and rectangular

n 7etill select !axi!u! entropy option

To run select O at botto! left of !ag!ap processing window

:isplay this new grid using sun illu!ination. Iow does this grid co!pare with

previous !agnetic grid B #hat is average value of the vertical gradient B

+;. 7ave all !ap changes' database changes' save project and exit fro! Oasis Montaj

to end session.

TO BE CONTINUE- IN WORKSHOP 2

9G#

-( ebruary -0+

oasis montaj complete workflow tutorial

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