[Auscope-geosciml] Event type vocabulary? what is it

Laxton, John L jll at bgs.ac.uk
Thu Mar 18 12:42:55 EDT 2010


Steve,

At present data providers generally give a GeologicUnit an age and I would be wary about moving from this to telling users 'these are the ages of all the things that have happened to the rock, pick which age you want'. The latter approach implies that all users wanting the age of a rock will be aware of what the most significant event in the geologicHistory is which I doubt is always the case. We have to assume that our data is not just going to be accessed through clients under our control and with queries created by us.

Maybe asking how old a rock is isn't as simple a question as it sounds, but it is one we have traditionally answered and I think we need to continue to do so.

John

From: Stephen M Richard [mailto:steve.richard at azgs.az.gov]
Sent: 18 March 2010 16:16
To: Laxton, John L
Cc: auscope-geosciml at lists.arcs.org.au
Subject: Re: [Auscope-geosciml] Event type vocabulary? what is it

John--I think the logic is that one would have to pose the 'how old is the rock' question by specifying the process of interest that defines what 'how old' means. For sedimentary and igneous rocks, the answer is generally simple-- deposition, intrusion, or eruption, for altered or metamorphic rocks (composite genesis), the answer could be cooling, peak metamorphism, or protolith deposition, intrusion, or eruption.

This issues is a good example of use of the interchange format for information encoding vs. a geologist-friendly query language. Same issue that was the basis for the recent geologic unit morphology discussion. I think the stored query approach with a 'common queryable' element (like CSW common queryables) for 'preferred age' is a better solution to the problem, because preferred age depends on the user in some cases (design decision is are there enough of these cases to allow flexibility?).

steve

On 3/18/2010 8:56 AM, Laxton, John L wrote:
Steve,

I think we have got confused somewhere here!

The v2 preferredAge was there to answer the question 'How old is the rock?'. After deprecating preferredAge in order to answer the same question there needs to be a way of flagging one of the events in the geologicHistory as being the one that is deemed to represent the age of the rock. I don't see how this can be achieved with a query on eventProcess and numericAgeDate so I don't see how Action 15 from Quebec follows from the decision to deprecate preferredAge. That said I don't see how a query on eventType would either. I think eventType may have been introduced simply to follow the typing pattern used elsewhere (eg faultType), but faultType was introduced because of the complexity of querying for commonly used concepts such as 'reverse fault' without such a property. I'm not sure there is a similar use case for eventType, and as you say there is a danger of confusion with eventProcess and eventEnvironment. I think the requirement I identified for the ability to relate local events to larger scale events such as orogenies is best met through the use of  a classifier.

So:

1. I'm unclear of the requirement for eventType and unless there is a clear use case for it it might be best dropped

2. I'm unclear how we can replicate the preferredAge concept with geologicHistory

John

From: auscope-geosciml-bounces at lists.arcs.org.au<mailto:auscope-geosciml-bounces at lists.arcs.org.au> [mailto:auscope-geosciml-bounces at lists.arcs.org.au] On Behalf Of Stephen M Richard
Sent: 17 March 2010 17:46
To: auscope-geosciml at lists.arcs.org.au<mailto:auscope-geosciml at lists.arcs.org.au>
Subject: Re: [Auscope-geosciml] Event type vocabulary? what is it

Yikes-- We added Classifier on event as well. That would be the logical place to have association of an event with a specific geologic event that might be reused (like Hercynian Orogeny, K-T boundary impact) and have its own GeologicEvent prototype description.
So what use does that leave for EventType. The only one I can see that doesn't create confusion with eventProcess -  eventEnvironment is to use it in the sense of GeologicUnitType as a category that specifies variations in the content model/intention of the actual GeologicEvent element ('type' in the sense of data type). Examples --extended event (orogeny), instantaneous event (bolide impact, volcanic eruption). Maybe some coherent abstraction of the eventProcess vocabulary could be made to categorize events that have different kinds of prototype descriptions, but the danger is that if the eventTypes are just the broader categories from the eventProcess vocabulary, then its unclear which property to filter for those categories -- eventProcess or eventType.

steve

On 3/17/2010 9:58 AM, Stephen M Richard wrote:

EventType property on GeologicEvent feature scope notes currently read: term 'to broadly categorise the type of event (e.g. depositional, tectonic, biological, metallogenic)'. Figuring out what should be in the EventType vocabulary opens a host of questions -- how to categorize events?, what are the use cases?. Kinds of event would be defined by process and environment by my reckoning, so it would appear that EventType would act as a short cut for some combination of eventEnvironment and eventProcess.


....snip...



Does eventType implements this classifier concept?  That seems like a potentially useful interpretation. In that case, something like the OneGeologyEurope OrogenicEvent vocabulary is a gsml:EventType vocabulary, and we get into the 'ontologic level' discussion about names, classifiers, types etc. (see the Dec Twiki summary to review that...). These categories are specific geologic events - they involve geologic process, geologic environment, geologic age, and geographic location.  This looks like a slippery slope. Does one look for the depositional age by specifying the eventProcess or eventType?. Does one look for structures related to the Laramide orogeny by specifying the GeologicEvent/gml.name, or specifying the EventType...

steve



snip...




--

Stephen M. Richard

Section Chief, Geoinformatics

Arizona Geological Survey

416 W. Congress St., #100

Tucson, Arizona, 85701 USA



Phone:

Office: (520) 209-4127

Reception: (520) 770-3500

FAX: (520) 770-3505



email: steve.richard at azgs.az.gov<mailto:steve.richard at azgs.az.gov>

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--

Stephen M. Richard

Section Chief, Geoinformatics

Arizona Geological Survey

416 W. Congress St., #100

Tucson, Arizona, 85701 USA



Phone:

Office: (520) 209-4127

Reception: (520) 770-3500

FAX: (520) 770-3505



email: steve.richard at azgs.az.gov<mailto:steve.richard at azgs.az.gov>

-- 
This message (and any attachments) is for the recipient only. NERC
is subject to the Freedom of Information Act 2000 and the contents
of this email and any reply you make may be disclosed by NERC unless
it is exempt from release under the Act. Any material supplied to
NERC may be stored in an electronic records management system.

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