Roger
Not to mention the 'No true Scotsman' logical construct which can be
mightily useful in geology.
Malcolm
On Fri27 Nov 09, at Fri27 Nov 09 -1:44 PM, Musson, Roger M W wrote:
> One could argue that adjectives play two roles in English. One is to
> distinguish nouns subject to the qualifying adjective from those not
> so qualified. Thus, "ultramafic basalts" are distinguished from
> other basalts that are not ultramafic. Under this interpretation, it
> would be absurd to write "igneous basalts", since there are no non-
> igneous basalts. However, it is quite common to find adjectives used
> merely as a way of expressing additional information about the noun.
> Thus, one could easily find someone writing "igneous basalts" to
> mean "basalts, which are igneous".
>
> Personally, I don't like it, and I prefer to strike out any
> adjectives that are not essential. Don't get me started on "organic
> vegetables".
>
> Roger Musson
>
>
>> -----Original Message-----
>> From: Tectonics & structural geology discussion list [mailto:GEO-
>> [log in to unmask]] On Behalf Of Eric Essene
>> Sent: 26 November 2009 18:51
>> To: [log in to unmask]
>> Subject: last comment
>>
>> Tim and all,
>> This is my last online response on this topic.
>> Maybe 'igneous intrusion' is used much more in the UK than here.
>> If the terms 'sedimentary intrusion' and 'metamorphic intrusion'
>> are
>> seldom used, why is the construct necessary? Next will we use
>> "sedimentary granite" or "sedimentary limestone"?
>> A problem can arise if we don't agree on the meaning of the
>> words.
>> Yes, indeed, I did not understand the meaning of this particular
>> notice that was just sent out by Rob and Zoe. Maybe some other
>> notice
>> was sent previously that was clearer.
>> cheers,
>> eric
>>
>>
>> On Nov 26, 2009, at 11:26 AM, Tim Needham wrote:
>>
>>> I'm not really sure why I'm replying to this but...
>>> Dare we consider that, unthinkably, Georef isn't quite up to speed
>>> on this?
>>> The 'keyword' approach is often frustrating and not very helpful. I
>>> suspect
>>> that most geoscientists worth their salt(!) know what an 'igneous
>>> intrusion'
>>> or 'clastic intrusion' is. The main benefit of this thread has been
>>> some of
>>> the highly informative references on clastic intrusions (thanks in
>>> particular to David Macdonald, Mads Huuse and Bob Holdsworth).
>>> Basically, we
>>> describe what we observe and go from there rather than try to
>>> pigeonhole
>>> into 'popular' terminology. Did anyone really misunderstand the
>> actual
>>> conference announcement?
>>> Cheers
>>>
>>> Tim
>>>
>>> -----Original Message-----
>>> From: Tectonics & structural geology discussion list
>>> [mailto:[log in to unmask]] On Behalf Of Eric Essene
>>> Sent: 26 November 2009 15:48
>>> To: [log in to unmask]
>>> Subject: Re: Anderson Stress Meeting: September 2010 reminder
>>>
>>> Carl,
>>> The term "sedimentary intrusion" has one citation in Georef.
>>> cheers,
>>> eric
>>>
>>> On Nov 26, 2009, at 6:24 AM, Carl Stevenson wrote:
>>>
>>>> Hi all,
>>>>
>>>> Sedimentary intrusions - does anyone know of any AMS (anisotropy of
>>>> magnetic susceptibility) work on these?
>>>>
>>>> Desperately resisting getting drawn in to a semantic debate, I
>>>> think
>>>> 'igneous intrusion' is fine. I guess it is as opposed to igneous
>>>> extrusion - lavas and ash etc. Sometimes in when subvolcanic roots
>>>> are exposed it is actually equivocal. There are instances when ash
>>>> can fall back into a vent.
>>>>
>>>> An example I am aware of is:
>>>> ALMOND, D. C. 1977. Sabaloka Igneous Complex, Sudan. Philosophical
>>>> Transactions of the Royal Society of London Series a - Mathematical
>>>> Physical and Engineering Sciences, 287, 595-633.
>>>>
>>>> Cheers
>>>> Carl
>>>>
>>>> -----Original Message-----
>>>> From: Tectonics & structural geology discussion list
>>> [mailto:[log in to unmask]
>>>> ] On Behalf Of Stu Clarke
>>>> Sent: 26 November 2009 10:23
>>>> To: [log in to unmask]
>>>> Subject: Re: Anderson Stress Meeting: September 2010 reminder
>>>>
>>>> Don't you hate it when someone gets that email in just before
>>>> you......
>>>>
>>>> I too have no particular stand on terminology, but I too was
>>>> surprised by
>>>> the stated scale of sedimentary intrusions. I have examined large
>>>> scale
>>>> sedimentary intrusions in deltaic settings and currently work with
>>>> colleagues using oil-industry datasets on the same thing. I don't
>>>> think
>>>> sedimentary intrusions have to be small scale......
>>>>
>>>> Stu
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: Tectonics & structural geology discussion list
>>>> [mailto:[log in to unmask]] On Behalf Of Macdonald,
>>>> Professor
>>>> David I. M.
>>>> Sent: 26 November 2009 10:11
>>>> To: [log in to unmask]
>>>> Subject: Re: Anderson Stress Meeting: September 2010 reminder
>>>>
>>>> Dear Eric
>>>> I have no particular stand on the terminology for igneous rocks,
>>>> but
>>>> you are
>>>> incorrect in your assertions on the scale of sedimentary
>>>> intrusions. Salt
>>>> is a sedimentary rock which can be injected through kilometers of
>>>> strata in
>>>> bodies hundreds of metres to kilometers across. Anyone who has
>>>> ever
>>>> worked
>>>> on deltas can point to mud diapirism on a similar scale. Even the
>>>> humble
>>>> sand injection feature is much larger than you make out; your
>>>> description
>>>> seems to be of sand filling pre-existing cracks, whereas most sand
>>>> injections are of a fluid slurry under pressure. These intrusions
>>>> can be
>>>> huge. In the Mesozoic forearc basin of the Antarctic Peninsula,
>>>> sandstone
>>>> dykes have been mapped with MINIMUM dimensions: 6 km long, cutting
>>>> 350 m of
>>>> strata, and 1 m wide. For more examples, see, among other papers:
>>>>
>>>> Hurst A. & Cartwright J. A. Eds. 2007. Sand Injectites:
>>>> Implications for
>>>> hydrocarbon exploration and production. Memoir 87 American
>>>> Association of
>>>> Petroleum Geologists
>>>>
>>>> Hurst A., Cartwright J. & Duranti D. 2003. Fluidization
>>>> structures in
>>>> produced by upward injection of sand through a sealing lithology.
>>>> In:
>>>> Subsurface sediment mobilization (eds. Van Rensbergen P.,Hillis
>>>> R.,Maltman
>>>> A. J. & Morley,C.K.), Geological Society Of London, London,
>>>> 123-127
>>>>
>>>> Jonk R., Hurst A., Duranti D., Mazzini A., Fallick A. E. & Parnell
>>>> J.
>>>> 2005.The origin and timing of sand injection, petroleum migration
>> and
>>>> diagenesis: the Tertiary petroleum system of the South Viking
>>>> Graben, North
>>>> Sea. AAPG Bulletin, 89, 329-357
>>>>
>>>> Hurst A. & Duranti D. 2004. Fluidisation and injection in the
>>>> deep-
>>>> water
>>>> sandstones of the Eocene Alba Formation (UK North Sea).
>>>> Sedimentology, 51,
>>>> 3, 503-529
>>>>
>>>> Hope this helps
>>>> David Macdonald
>>>>
>>>> -----Original Message-----
>>>> From: Tectonics & structural geology discussion list
>>>> [mailto:[log in to unmask]] On Behalf Of Eric Essene
>>>> Sent: 26 November 2009 07:39
>>>> To: [log in to unmask]
>>>> Subject: Re: Anderson Stress Meeting: September 2010 reminder
>>>>
>>>> Rob,
>>>> The term igneous intrusions is functionally a terrible term, a
>>>> distinction without a difference. More than 99.9% (or more?) of
>>>> the
>>>> time it means igneous rocks where the term is redundant. If one
>>>> talks
>>>> about sedimentary intrusions it is on a meter scale feature,
>> commonly
>>>> even less--I have seen some down to cm scale. When they formed and
>>>> well afterward they did not look like dikes, just fractures filled
>>>> with loose sediment. I discount the poor term "sandstone dikes" as
>>>> needing yet another confusing term.
>>>> On the other hand salt domes are metamorphic (recrystallized) but
>>>> not molten rock, well a little brine. They were not in the
>>>> sedimentary group during formation. Yes, we have diapirs of
>>>> metamorphic rock, although a lot of those gneiss domes probably
>>>> have a
>>>> little melt. I would agree about metamorphic diapirs but simply
>>>> would
>>>> not call them metamorphic intrusions to avoid confusion on a
>>>> transitional rock. Gneiss domes are a nice description for them.
>>>> It must be exceedingly rare for igneous petrologists/geochemists
>>>> to be presenting data on "sand dikes". Salt domes are much larger
>>>> but are as they form. Do you know of any igneous petrologist/
>>>> geochemist who would report on them in your symposium? So
>> "sandstone
>>>> dikes" are fractures filled with loose clastic material and water,
>>>> salt diapirs are all metamorphic and may have brine, gneiss domes
>> are
>>>> often partial melts then at least partly igneous, and the term
>>>> "igneous intrusion" is clearly redundant to the average passerby.
>> Is
>>>> this really a useful terminology?
>>>> cheers,
>>>> eric
>>>>
>>>> On Nov 26, 2009, at 12:17 AM, Butler, Robert wrote:
>>>>
>>>>> Eric
>>>>> Actually - there are lots of non-igenous intrusions in basins -
>>>>> sandstone dykes through 100s metres of strata. Not to mention mud
>>>>> diapirs, salt etc etc.... gas chimneys....
>>>>> go google!
>>>>> Cheers
>>>>> Rob
>>>>>
>>>>> ________________________________________
>>>>> From: Tectonics & structural geology discussion list
>>>> [[log in to unmask]
>>>>> ] On Behalf Of Eric Essene [[log in to unmask]]
>>>>> Sent: 26 November 2009 05:09
>>>>> To: [log in to unmask]
>>>>> Subject: Re: Anderson Stress Meeting: September 2010 reminder
>>>>>
>>>>> Rob, Zoe, and all,
>>>>> Igneous intrusions as opposed to all those sedimentary plutons?
>>>>> The phrase is nearly always meaningless and should not be used.
>>>>> Sounds like a great trip.
>>>>> cheers,
>>>>> eric
>>>>>
>>>>>
>>>>> On Nov 25, 2009, at 11:28 PM, Butler, Robert wrote:
>>>>>
>>>>>> Dear all
>>>>>> As we get our diaries together for 2010 we thought it timely to
>>>>>> remind you of the conference next year:
>>>>>>
>>>>>> Stress controls on faulting, fracturing and igneous intrusion in
>>>>>> the
>>>>>> Earth's crust
>>>>>>
>>>>>> A meeting to commemorate the work of Ernest Masson Anderson on
>>>>>> the
>>>>>> 50th anniversary of his death.
>>>>>>
>>>>>> 6-8 September 2010 at the University of Glasgow, UK
>>>>>>
>>>>>> Organisers: Zoe Shipton, Rick Sibson, Dave Healy, Rob Butler
>>>>>>
>>>>>> We will send out details of the meeting ("First Circular") in
>>>>>> January -
>>>>>> Abstract deadline will be end April with a preliminary programme
>>>>>> drawn up through May.
>>>>>> We are also planning a fieldtrip to the Hebrides and NW Scotland
>> to
>>>>>> examine a variety of faults and the Tertiary igneous complexes.
>>>>>> Again - further information will be included in the first
>> circular.
>>>>>>
>>>>>> Hope to see a bunch of you in Scotland next September!
>>>>>> Zoe, Rick, Dave and Rob.
>>>>>>
>>>>>>
>>>>>> The University of Aberdeen is a charity registered in Scotland,
>>>>>> No
>>>>>> SC013683..
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> The University of Aberdeen is a charity registered in Scotland, No
>>>>> SC013683..
>>>>>
>>>>>
>>>>
>>>>
>>>> The University of Aberdeen is a charity registered in Scotland, No
>>>> SC013683..
>>>>
>>>>
>>>
>>>
>
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