Sedimentary dykes (fractures filled
with Cambrian sandstone) occur in the Precambrian basement of southeastern
Sweden. Have a look in the following report and references therein:
Röshoff, K. and Cosgrove, J., 2002:
Sedimentary dykes in the Oskarshamn-Västervik area. A study of the mechanism
of formation. SKB R-02-37, Swedish Nuclear Fuel and Waste Management Co.
You can download the report from the
following website: http://www.skb.se or http://www.skb.se/Templates/Standard____17139.aspx
Good luck!
Carl-Henric Wahlgren
Carl-Henric Wahlgren
Sveriges geologiska undersökning
Box 670
SE-751 28 Uppsala
Sweden
Tel. +46 (18) 17 91 99
Fax. +46 (18) 17 92 10
Mob. +46 (70) 222 88 50
E-mail: [log in to unmask]
Re: Anderson Stress Meeting: September
2010 reminder
Greetings, Carl and others,
AMS on sandstone intrusions: Mike Petronis and I have an investigation
underway of sandstone dikes within crystalline rock in the Front Range
of
Colorado. Our recent abstract with initial results is at:
http://aapg09.mapyourshow.com/2_1/sessions/session.cfm?ScheduledSessionID=15
32. The scale of the intrusions, incidentally, is 5 cm to >7 meters,
with
many exceeding 2 m in width.
I'd like to now ask, can any list members tell me of other examples of
clastic dikes within a crystalline host? My web searches yield little!
> 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.
