Extracting geochemical (I-data) per stratigraphy layer

[Vincent Verswijvel]

Hi all

 

I am looking for a way to extract geochemical data from a specific layer. For example, I have put all the arsenic levels into the I-data tab of Rockworks (17) and I have a stratigraphy model.

Is it possible to know all the statistics (mean, st.d., etc.) of arsenic in a layer of my choosing? I have not modelled the geochemical data, is this necessary? 

 

Kind regards

 

Vincent Verswijvel

[Mitch]

If you model the arsenic you'll have several choices for extracting the level data.

First you can create an I-Data Plan map for the elevation of your choice which creates a grid of the values. You can the use the Grid Statistics program on the grid.

Secondly you can use your stratigraphic layers to filter the arsenic model and then run Solid Statistics on the filtered model.

 

Mitch

[Vincent Verswijvel]

Hi Mitch 

 

Thank you for your response. I will definitely look at this. 

However, it may seem a little weird, but it is not preferable to model the arsenic for my project. 

Do you think it's possible to get the statistics from the raw input, so without modelling the arsenic? 

 

Kind regards

Vincent

[Mitch]

Somebody else may suggest a way to do this without modeling but if you use the Closest Point method with a small distance cutoff there will be no manipulation of the values. Just the original values and nulls.

[Vincent Verswijvel]

Now that I think of it, this sounds very obvious. Thank you very much, this is very helpfull.

[Molly]

Hi Vincent,

 

You can get a statistics report for the raw data using the I-Data | Statistics program. On the right side of the window, turn on "Spatial (XYZ) Filtering", specifically an Upper Surface and Lower Surface. Click the Adjust Filtering Options button to browse for those surfaces.

 

Molly Mayfield

RockWare Inc.

[Vincent Verswijvel]

Hi Molly

 

Thank you so much. This is exactly what I was looking for. I have, however, 1 question. Filtering my boreholes on arsenic, I get 40 non-zero values across 11 different boreholes. 

When I create the statistics report, the population (Non-null) is equal to 80. This is the exact double. Is this as intended? 

I calculated the mean myself and this corresponds to the mean in the statistics report.

 

Kind regards

Vincent

[Mitch]

I'd look at your cutoff distance, half the cell size should work but if the cell size varies in the x, y  and z spacing then it will be more hit or miss.

 

Mitch