Matt et al.,
I think a term much like that, if not the same, has also been used for dating petroglyphs in the SW and elsewhere. But I agree with Matt that this term is a solution in desperate search of a problem. John Rodgers had a wonderful tongue-in-cheek list of "Rodgers' Rules of Bad Writing" that he gave to all his Yale students and young colleagues (like me) - one of them effectively was "Never use a simple word when a mysterious and more complicated word would do." (An analogous one was "Never use a few words when a lot more words will suffice.")
I suspect some knickers really do need twisting here. Good on ya, Matt!
Bob
Dr. Robert Tracy
Professor of Geosciences
Associate Department Head
Director, Museum of Geosciences
Virginia Tech
Blacksburg VA 24061-0420
540-231-5980
540-231-3386 (F)
On Jun 19, 2013, at 1:10 PM, Matthew Kohn <[log in to unmask]> wrote:
> Hey, not to twist anyone's undergarments in a bunch, but what's with this term "Petrochronology"?
>
> The earliest reference I can find to it is from 1969 in anthropology, in regards to a Yoruba (Nigeria) river god cult as a way of dating duration and intensity of devotion. Basically the number of rocks in a pot indicates how long (and devoted) you've been.
>
> In geology die Fraser et al. (1997) first propose it? Martin Engi certainly popularized it in a 2009 abstract.
>
> What I don't get is that "Petrochronology" literally means dating of stones. How is that substantively different from "Geochronology," which means the dating of Earth (materials)?
>
> I think John's session description below and Martin's 2009 abstract ultimately propose that petrochronology is different from geochronology by virtue of petrologic and geochemical context - textures, trace element chemistry, etc. But who would _ever_ employ, say, metamorphic geochronology _without_ that context? That is, metamorphic (and igneous) geochronology IS (or should be) petrochronology anyway.
>
> I know the term is catching on, but it really does seem redundant to me.
>
> Matt
>
>
> On Jun 19, 2013, at 8:10 AM, John Cottle wrote:
>
>> We invite contributions to session T157 and participation in our short-course at the upcoming 125th Anniversary GSA Annual meeting, which takes place in Denver, October 27-30, 2013
>>
>> Session T157: Frontiers in Petrochronology
>>
>> Conveners: John Cottle, Andrew Kylander-Clark
>>
>> Petrochronology is the interpretation of isotopic dates in the light of complementary geochemical/textural information gleaned from the same mineral(s). Continued advancements in geochronologic measurement techniques have increased the precision and accuracy with which individual dates can be measured. Geologic "events," once considered as having occurred at a single point in time, are now commonly recognized as a series of processes that occurred over a period of time, whether it be a few kyr or several Myr. Thus, as geochronologic precision and accuracy increase, so must the accompanying textural and chemical information that allows one to match a measured date to a specific geologic process, whether it be melt crystallization, or responses to changes in pressure, temperature, and/or fluid/melt infiltration, with or without accompanying deformation. This session aims to both highlight the array of emerging analytical techniques, as well as the application of these methods to provide insight into a range of tectonic and geochemical processes.
>>
>> Invited Speakers:
>>
>> - Julia Baldwin (University of Montana)
>> - Nigel Kelly (Colorado School of Mines)
>> - Mark Schmitz (Boise State)
>>
>> Abstract deadline is 6th August 2013 at 23:59 (Pacific Time)
>>
>> We look forward to seeing you in Denver!
>>
>> John and Andrew
>>
>> --
>>
>>
>> *************************************
>> John Cottle
>> Associate Professor
>> Department of Earth Science
>> & Earth Research Institute
>> University of California, Santa Barbara CA 93106-9630
>> Tel: +1 805-893-7315
>> Email: [log in to unmask]
>> Web: http://www.geol.ucsb.edu/faculty/cottle
>
> ****************************************************
> Dr. Matthew J. Kohn, Professor
> Department of Geosciences
> Boise State University
> 1910 University Dr.; MS1535
> Boise, ID 83725-1535
> [log in to unmask]
> http://earth.boisestate.edu/mattkohn/
> phone: (208)-426-2757 fax: (208)-426-4061
> ****************************************************
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