[Auscope-geosciml] Composition Category [SEC=UNCLASSIFIED]

Laxton, John L jll at bgs.ac.uk
Wed Aug 19 10:24:52 EDT 2009


Folks,

The scope notes for compositionCategory refer to it as  a 'Term to specify the gross chemical character of geologic unit' - so it has perhaps got a misleading name. My understanding was that this was for very broad-brush categorisations of Geologic Units to enable simple retrievals, so we should be careful about shovelling too much petrological information into it. Also are these really properties of the Geologic Unit as opposed to the lithology (earth material) of the unit? They might be best added as one or more Description packages in EarthMaterial.

John

From: auscope-geosciml-bounces at lists.arcs.org.au [mailto:auscope-geosciml-bounces at lists.arcs.org.au] On Behalf Of Oliver.Raymond at ga.gov.au
Sent: 19 August 2009 07:28
To: auscope-geosciml at lists.arcs.org.au
Cc: Linda.Bibby at dpi.vic.gov.au
Subject: Re: [Auscope-geosciml] Composition Category [SEC=UNCLASSIFIED]

That's OK with me too


-----Original Message-----
From: auscope-geosciml-bounces at lists.arcs.org.au [mailto:auscope-geosciml-bounces at lists.arcs.org.au] On Behalf Of Simon Cox
Sent: Wednesday, 19 August 2009 4:20 PM
To: auscope-geosciml at lists.arcs.org.au
Cc: Linda.Bibby at dpi.vic.gov.au
Subject: Re: [Auscope-geosciml] Composition Category [SEC=UNCLASSIFIED]

Ollie suggested:
> 2.  The vocabulary be restructured into several separate vocabularies so that the classification system (ie: chemical, mineralogical, sedimentary etc) can be adequately reflected in the codespace.

This is not such a good idea. If you want to add some additional semantics, then either the 'compositionCategory' element should be split into different kinds of composition category, or an additional paramter must be added. Its not good to overload the codeSpace string, which also requires micro-parsing.


--------------------------------------------------------
Simon Cox

European Commission, Joint Research Centre,
Institute for Environment and Sustainability,
Spatial Data Infrastructures Unit, TP 262
Via E. Fermi, 2749, I-21027 Ispra (VA), Italy
Tel: +39 0332 78 3652
Fax: +39 0332 78 6325
mailto:simon.cox at jrc.ec.europa.eu
http://ies.jrc.ec.europa.eu/simon-cox

SDI Unit: http://sdi.jrc.ec.europa.eu/
IES Institute: http://ies.jrc.ec.europa.eu/
JRC: http://www.jrc.ec.europa.eu/

--------------------------------------------------------


________________________________
From: auscope-geosciml-bounces at lists.arcs.org.au [mailto:auscope-geosciml-bounces at lists.arcs.org.au] On Behalf Of Oliver.Raymond at ga.gov.au
Sent: Wednesday, 19 August 2009 05:48
To: auscope-geosciml at lists.arcs.org.au
Cc: Linda.Bibby at dpi.vic.gov.au
Subject: [Auscope-geosciml] Composition Category [SEC=UNCLASSIFIED]
Hi all,

Food for thought before Quebec, about the structure of the CompositionCategory attribute and the associated vocabulary...

1.  The cardinality of composition category is 0..1 on geologic units and 0..* on earth materials.  Why?  This is inconsistent, and limiting for geologic units.

                                i.            Example using the CGI vocabulary: How can I convey that a granite unit is both "Peralkaline" and "High silica chemistry", or a sedimentary unit is "Polymictic" and "Carbonate-bearing"?

                               ii.            Example using other vocabularies: How can I convey that a granite unit is "calc-alkaline", "strongly fractionated", "high K2O", and "high silica"?

Currently to do this, I have to encode an earth material associated with a unit, but that begs the question.... if I have to encode an earth material to do this, why have CompositionCategory on GeologicUnit at all?

2.  The vocabulary contains several non-exclusive composition category concepts - chemical (including specific igneous classifiers and more generic classifiers), mineralogical, and sedimentary petrological.  In a WFS, a user could not tell which of these classification systems is being used because several different classification systems are included within this one "codespace".  This also potentially leads to mixed type compositional data being delivered in a WFS within a single GeoSciML element.

I propose that:

1.  The cardinality of CompositionCategory be changed to 0..* on GeologicUnits

2.  The vocabulary be restructured into several separate vocabularies so that the classification system (ie: chemical, mineralogical, sedimentary etc) can be adequately reflected in the codespace.

          eg: something like

<gsml:compositionCategory>
    <gsml:CGI_TermValue>
        <gsml:value codeSpace="urn:cgi:classifierScheme:CGI:CompositionCategory_chemical:200811 ">carbonate chemistry</gsml:value>
    </gsml:CGI_TermValue>
</gsml:compositionCategory>

or

<gsml:compositionCategory>
    <gsml:CGI_TermValue>
        <gsml:value codeSpace="urn:cgi:classifierScheme:CGI:CompositionCategory_mineralogical:200811 ">mafic</gsml:value>
    </gsml:CGI_TermValue>
</gsml:compositionCategory>

or

<gsml:compositionCategory>
    <gsml:CGI_TermValue>
        <gsml:value codeSpace="urn:cgi:classifierScheme:GA:CompositionCategory_fractionation:2009 ">strongly fractionated</gsml:value>
    </gsml:CGI_TermValue>
</gsml:compositionCategory>

or

<gsml:compositionCategory>
    <gsml:CGI_TermValue>
        <gsml:value codeSpace="urn:cgi:classifierScheme:GA:CompositionCategory_graniteType:2009 ">A-type</gsml:value>
    </gsml:CGI_TermValue>
</gsml:compositionCategory>

Cheers,
Ollie

------------------------------------------------------------------------------------------------
Ollie Raymond
National Advice,  Maps and Standards Project
Geoscience Australia

Address: GPO Box 378, Canberra, ACT, 2601, Australia | ABN: 80 091 799 039
Ph: (02) 62499575 | Fax: (02) 62499992 | Email: Oliver.Raymond at ga.gov.au
Web:  http://www.ga.gov.au/minerals/research/national/nat_maps/nat_geol_maps.jsp

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