Eruptions

Eruptions Word of the Day: Peperite

Posted by Erik Klemetti on August 2, 2010
(68)
More »

Continuing my series where I try to define words of volcanic interest, the new Eruptions Word of the Day is a favorite of mine, mostly because my undergraduate thesis on Vinalhaven Island in Maine ended up dealing with a lot of these types of deposits … so, without further ado, the word is peperite!

Now, what exactly is a “peperite”?

Well, a picture is worth 1,000 words, right (so that will save me some time):

i-3c662c403c572586398089d692f808d8-Peperite-thumb-400x267-53930.jpg
Peperite in the Vinalhaven Diabase, Vinalhaven Island, Maine. Image by Erik Klemetti. Click on the image to see a larger version.

Let’s make some observations:

  1. The rock is full of red-to-black clasts of various sizes and shapes.
  2. The clasts are almost all basaltic andesite in composition.
  3. Some of the clasts look like they have a “chilled” margin, where hot molten material came into contact with colder material.
  4. Some of the clasts look like you could piece them back together – as if they were shattered.
  5. The material between them (the matrix) is mostly light grey/tan, looks to be fine grained.
  6. On closer inspection, the matrix looks like mud or sand.
  7. In some spots, the matrix looks “baked”, like it was exposed to high temperatures.
  8. In other spots, the matrix looks like it was squeezed into cracks and open spaces in the basaltic andesite clasts.

So, what does this suggest?
First off, it looks like sediment (the muddy matrix) is mixed with magma (basaltic andesite clasts). The chilled margins on the clasts and the baked areas of the sediment suggest that the magma was still hot and the sediment was cool (relatively speaking). This is supported by shattered clasts of basaltic andesite in the deposit (thermal shock). The sediment looks to have squeezed its way into spaces between clasts, so the sediment was likely not solid – unconsolidated sediment – and like wet, as mud should be. First order conclusion: It appears that hot basaltic andesite magma interacted with wet, unconsolidated muddy sediment.

And there you have it: peperite – magma interacting, sometimes explosively, with wet, unconsolidated sediment, producing a mixed rock with magmatic clasts and a sediment matrix.

The image above is from Vinalhaven Island in Maine, where the Siluro-DevonianVinalhaven Diabase, a thick basaltic andesite sill intruded the Seal Cove Formation (a sedimentary unit). Along the contact in places you find these peperites where the sill intruded into this wet sediment. This likely means that the sill was being intruded fairly shallowly in the crust as sediment begins to compact and loose pore water quickly as it is buried. Peperites have been recognized in locales all over the world and has been interpreted as one of the steps towards explosive hydrovolcanism – and experiments have been tried to recreate a peperite in the lab. There is some evidence that even lava flows on the surface can form peperite deposits as well. However, the thing to remember is that when you find peperites in the rock record, what you are seeing is evidence of shallow emplacement of magma in the crust where it can interact with wet, soft sediment – a current analog might be if magma intruded underneath Mono Lake in California or in the shallow seas along an oceanic arc like the Marianas or Tonga (think about the Hunga Tonga-Hunga Ha`apai eruption).


Another example of a peperite, courtesy of Highly Allochthonous.

And from where is the name “peperite” derived? It comes from the type locality of peperites, Peper Limagne d’Au- vergne region of central France, where the rocks reminded George Scropes in 1827 of ground pepper.

Keywords: , , , , , ,
(68)
More »

Comments

  1. #1 Greg
    August 2, 2010

    http://www.aip.de/thinkshop/posterpaper/mukherjee1.pdf

    http://www.mdpi.com/1424-8220/8/12/7736/pdf

    Interesting articles on the Sun/earthquake interface…

  2. #2 Jack
    August 2, 2010

    Looks nice. I’d like to have one in my aquarium.

  3. #3 birdeyeUSA
    August 2, 2010

    Ah, one of the ‘good rocks’ of Home! : )

  4. #4 Lurking
    August 2, 2010

    I’ve heard mention of the Sun-EQuake connection before, but it was only from the … “excitable” community.

    This should make for a good read later. Thanks.

    Ref the word of the day, this one caught my attention. It’s always a good thing when you learn something new and unique.

    Is there a relationship between clast size and violence of the interaction?

  5. #5 Diane N CA
    August 2, 2010

    @Paaerby from last thread: thanks for the references. I will have to get to them eventually. As for the wobble issue, I am not sure I was referring to it having anything to do with quakes or eruptions. I think it is an interesting feature that happens, but I don’t know of any relationship to quakes or eruptions. It may or may not and I don’t think we even have an idea what the wobble (or wobbles)do to the magnetic field or the earth itself. I can see why there would be some angst about it if it stopped. That is probably just because we don’t have a full understandin of it. I would suppose it has done that before when no one was able to notice.

    I find this stuff interesting rather than scary or having some kind of import about what is going to happen.

  6. #6 Diane N CA
    August 2, 2010

    OOPS! That is supposed to be “Passerby” above! I think my computer is playing games with me. :-}

  7. #7 mike don
    August 2, 2010

    Seems like peperites (fairly mafic magma intruding wet sediments at shallow depth) ought to have some connection to maar formation (often fairly mafic magma interacting with wet sediments at shallow depth) Are there cases where the presence of peperites could be used to infer the likely former presence of a maar at the surface, a volcanic landform which can sometimes be rapidly destroyed by other geological processes?

  8. #8 Birger Johansson
    August 2, 2010

    (OT) Regarding mixing of magma… “Eruptive characteristics of Oregon’s Mount Hood analyzed” http://www.physorg.com/news199976527.html

  9. #9 Erik Klemetti
    August 2, 2010

    @8 – I’ll have more to say about Hood in the nearish future (especially considering I helped collect some of the samples used in that study!)

  10. #10 VMJC
    August 2, 2010

    Where is Peper in France?

    Google maps seems to have never heard of it! If anyone can help out here I would appreciate it.

  11. #11 Erik Klemetti
    August 2, 2010

    VMJC – Thanks for catching that mistake, I misinterpreted the origin. It is now fixed!

  12. #12 Kultsi, Askola, FI
    August 2, 2010

    Wikipedia explains the name to be because of the look of the stone (black pepper) and the original region to be Limagne region of France.

  13. #13 Passerby
    August 2, 2010

    Lacustrine means ‘lake environment’. In this case, it refers to limestones that formed in

    Perpite originates from the Gergovie Volcanic Complex.
    The Gergovie plateau is a plateau of the Massif Central Auvergne.

    A quickie look at Wikipedia for peperite affords a reference to the LeMagne Trench.

    Further lookup on Wiki gives us the LiMagne Plain in the Massif Central (Central France).

    en.wikipedia.org/wiki/File:MC_Limagnes.jpg

    Volcanism accompanied the rifting and continued into the Pleistocene. The sediments deposited in the basin are affected by numerous intrusions. The area was the first where peperites were described, from a basaltic intrusion into lacustrine limestone.

    The reference can be read through Google Books.

    The LiMagne Plain lies in the département of Puy de Dôme (region).

    gitelink.com/auvergne/departments.htm

    ‘The “Puy de Dome” in the middle – largely mountainous, but with a large fertile agricultural plain, the Limagne, in the middle, to the east of Clermont Ferrand. ‘

    http://en.wikipedia.org/wiki/Gergovie_plateau

    Type locality would be the plain or town of Gergovie, located in the commune (county) of La_Roche-Blanche
    en.wikipedia.org/wiki/La_Roche-Blanche_%28Puy-de-D%C3%B4me%29.

  14. #14 Passerby
    August 2, 2010

    Sedimentation episodes that formed the limestones mentioned above, but truncated to point to general locale first.

    Clarification of the LiMagne Plain and Gergovie volcanic complex:

    Morphostructural evolution of the Gergovie Lower Miocene volcano-sedimentary system : geodynamical implications on the late-tectonic Limagne rift (Massif central, France).
    Canadian J. Earth Sci. (2008). 45(6):641-650.

    Abstract: The Gergovie plateau is a Lower Miocene topographically inverted volcano-sedimentary system located in the monogenetic volcanic field of the Limagne rift Tertiary basin. It is composed of three east-west aligned maars partly covered by a basaltic lava flow. The eruption of the central maar (maar 1) occurred at the Oligocene-Miocene transition, during the first volcanic phase.

    This phreatomagmatic structure was almost totally cut through by the opening of a second maar (maar 2) during the next eruptive phase. The basaltic lava flow at the summit and the eastern maar (maar 3) were placed during a third and last eruptive phase during the Middle or Upper Burdigalian (similar to 19-16 Ma).

    Between these periods of volcanism, three fluvial to fluviolacustrine sedimentation episodes, separated by two erosive stages, followed one another. A bedrock thickness of 100-300 m was eroded from maar 2 during the upper Aquitanian and (or) the lower Burdigalian (similar to 22-19 Ma). This erosion is partly due to a volcano-tectonic uplift in the southern Limagne.

    The complex morphostructural evolution of the Gergovie plateau demonstrates the north-south geodynamic differentiation of the Limagne rift during the Lower Miocene, since the northern part of the basin corresponded to a relatively calm lacustrine sedimentation area. More generally, the Miocene volcanic field in the South of the Limagne gives an opportunity to study interactions between volcanism, tectonics, and erosion during the late passive rifting activity phase.

  15. #15 Passerby
    August 2, 2010

    Above post also made to answer Mike Don’s question.

  16. #16 Henrik, Swe
    August 3, 2010

    Is “Peperite” an internationally recognised term? The International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks* refers to “Peperite” as a “local term” but does not give the locality, nor a recognised scientific name other than “a tuff or breccia” (formed by the intrusion of magma into wet sediments). Obviously, there is a need for a specific name for this type of rock as “Vinalhaven Island peperite” is far more succinct than “the tuff (or breccia) formed by the intrusion of magma into wet sediments found at Vinalhaven Island, Maine”. However, the name is not officially recognised by the International Union of Geological Sciences?

    * Le Maître, R. W. et al. (Eds.). Igneous Rocks: A Classification and Glossary of Terms: Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks p.126, Cambridge University Press, Cambridge 2002

  17. #17 leon
    August 3, 2010

    space.com northern lights show sun waking up http://www.space.com/scienceastronamy/sun-eruption-aurora-activity-100802.html
    and found this also shift an pole reversal http://survive2012.com/index.php/geryl-pole-shift.html

  18. #18 Lurking
    August 3, 2010

    @leon [16]

    Dunno how wakey wakey the sun is…

    http://i37.tinypic.com/f5gqu.png

    A CME does not make a highly active sun. They happen all the time. We just happen to have been in the bore sight of this one.

    And now that some sources are starting to use the Solar Dynamics Observatory with it’s much greater resolving power, you have to wonder just how skewed the reported and official sunspot numbers are going to be. This was not available for most of the observations (1749 to 2010.) How do reconcile the Sunspot Number with new equipment with old data? In fact, there are some people who take exception to some of the “sun specks” that have been reported as full on “spots.”

    http://www.landscheidt.info

    Either way, the plot that I made uses the SIDC count, which is accepted as the internationally recognized “official” count. And with that, you can see that cycle 24 is a bit behind the power curve.

    BTW, the first of 2 CME’s hit at 1730 UT today. Iceland’s earthquake count responded with indifference. So far, it looks like that idea presented in the paper http://www.mdpi.com/1424-8220/8/12/7736/pdf is worth a good airplane or two.

    (The author didn’t really present anything to support his argument other than cherry picking a quake here or there… and you know how plentiful they are)

  19. #19 leon
    August 4, 2010

    @17 lurking, thanks for that yeah looking at one of your links above i came across ‘A massive winter heading for the Northern hemisphere?/planetary theory moves’ which is linked to solar activity being low and your graphs shows this, so does the PDO. were we going in to a La’nina and a continued one, according to this site-Joe Bastardi from accuweather.com is an avid follower of this site is also predicting the same cooling trend.he also adds the possible cooling effects that could result from impending volcanic eruptions,and to expect conditions similar to the little ice age[1250-1850] http://www.landscheidt.info/?q=node/189 and looking at my weather world temp map [weatheronline he right you clearly see the drop happening except the Atlantic which will do in the near month or so when the hurricanes carry all that heat and spread that all out.so much media on global warming when in fact we just coming or have already come out of a strong El nino moving to La nina phrase. ‘global warming v global cooling’ we have to see who right

  20. #20 Lurking
    August 4, 2010

    Not really a strong El Nino either. The press tends to like to toss “strong” “above normal” “greater than expected” and other such modifiers to various things.

    Recently, a phenomena known as El Niño “Modoki” or Central-Pacific El Niño has been discovered. And, as regular as clockwork “the new El Niño leads to more hurricanes more frequently making landfall in the Atlantic.” And yet 2010 is another year with a very late “first named storm.” On average, from 1995 to 2008, the First Named Storm occurred by 16 Jun. In 2009, it formed 11 August. In 2010, 25 June saw the formation of Alex which immediately headed for the speed bump known as the Yucatan. The season so far seems a bit anemic to me. It doesn’t mean that it wont become worse later in the year, but the predictions of a highly active season seem to be as wrong as it is every year.

    So, when you see a headline like

    “El Nino Modoki a Climatic Hybrid for 2009-2010
    Winter Weather Forecast Predicts Hurricanes, Rain, and Flooding    ”

    You have to sit back and think to yourself “Okay…”

  21. #21 leon
    August 4, 2010

    but 1998 was record El Nino and 2007 2nd strongest El Nino i need more time on this i get to this later very complex stuff

  22. #22 Lurking
    August 4, 2010

    Tough things about records. They only apply for the period that the data was being collected.

    That’s right back to that tree in the forest thing.

    With ENSO (also referred to as the El Nino / El Nina thing or any variety of Multidecadal Oscillations), some weather guessers/analysts/prognosticators have noted what appears to be a step pattern to the heat flow as it progresses further and further north.

    I dug around trying to find the link, but was unsuccessful. I ran across it while reading some of Bob Tisdale and Anthony Watts’ post at Watts Up with That.

    bobtisdale.blogspot.com/2009/04/misunderstandings-about-pdo-revised.html

    wattsupwiththat.com/2009/04/28/misunderstandings-about-the-pacific-decadal-oscillation/

    Alternatively, Passerby posted a fascinating link that references El Nino/El Nina as it relates to Earth’s rotational momentum:

    http://www.examiner.com/x-17371-Raleigh-Climate-Examiner~y2009m8d30-Atmospheric-Angular-Momentum-AAM-oversimplified

  23. #23 mike don
    August 5, 2010

    Passerby: Thanks for that info. Only just got back to checking this topic, hence delay in reply, sorry.

  24. #24 motel townsville
    October 19, 2010

    Impossibly kindly and want upon the significance of brio

  25. #25 Tanya Loiko
    November 1, 2010

    There is an exception to every rule

  26. #26 Caprice Flegal
    December 17, 2010

    I went to the physician and he mentioned that he doesn’t do that kind of factor. I’m just a little over 200 pounds it wasn’t like i was asking for bypass surgery but i he couldn’t do something for me. So which type of physician do you imply, i just have to have somewhat guidance/help and i was turned away, so i’m so confused now.

  27. #27 tube8
    January 24, 2011

    This is tough. I’m not saying you are responsible, I think it is everyone else out there that isn’t taking notice.

  28. #28 male masturbator
    March 4, 2011

    I read blogs every day, for all sorts of reasons, but I turn to blogs especially when I want to hear alternative viewpoints.

  29. #29 Harman Kardon
    April 10, 2011

    howdy fellow web master! I really like your website! I liked the make of your sidebar.

  30. #30 no faxing loans
    May 3, 2011

    Hey! Are you going to be submitting a follow up? My room mate and I really enjoyed the read. We had been both surprised how well you covered the topic. Way to go!

  31. #31 love sms
    May 4, 2011

    I am very motivated with your blog looks, after taking a look of your site i think i am a small newbie cos my sms blog actually looks very ugly.i hope my sms blog will look great good soon.

  32. #32 Mathew Hollars
    May 5, 2011

    Are you making this up as you go along?

  33. #33 Taylor
    May 17, 2011

    This was novel. I wish I could read every post, but i have to go back to work now… But I’ll return.

  34. #34 diettablets
    May 20, 2011

    It’s exhausting to find educated individuals on this subject, however you sound like you realize what you’re talking about! Thanks

  35. #35 Claudio Chrismon
    May 28, 2011

    This is some good stuff. It took me a while to come across this blog but it was worth the time. I noticed this page was buried in google and not the number one spot. This web publication has a lot of enjoyable stuff and it does not deserve to be burried in the search engines like that. By the way Im going to save this site to my list of favorites.

  36. #36 Felton Ebey
    June 29, 2011

    Who’s Mark Rafcliffe anyway…..I meant Radcliffe! Although I think ‘Raf’ is much more appropriate.

  37. #37 Gout Home Remedies
    June 29, 2011

    It’s interesting,But if we properly read then we can get something really informative from the above details, but i admire your hard work

  38. #38 Gout Home Remedies
    June 29, 2011

    It’s interesting,But if we properly read then we can get something really informative from the above details, but i admire your hard work

  39. #39 rente
    July 17, 2011

    Ich war heraus zu suchen dieser internet-site.I gesucht auf diese glorreiche Sprachreisen! I definitiv genießen jede etwas und ich Sie ein Lesezeichen heraus zu überprüfen neue Slideshows Sie weblog schreiben.

  40. #40 千术
    July 18, 2011

    This nice idea that all of the sudden develop into a new healthy involving tears is definitely yerning for ones sweeter attention. Many cultures on the planet nod to the present habit all children are generally familiar with.

  41. #41 Jeane Degonia
    July 19, 2011

    pritulak adenoid refrain strazimir mulloy pendant kampa venohr pravdy

  42. #42 Limas Sweed Jersey
    July 24, 2011

    I am least established they at one’s desire deliver assign to a reams of new trash here than anybody else!

  43. #43 ysl replica shoes
    July 29, 2011

    Very well said, your blog says it all about that particular topic.’,~-~

  44. #44 Möbelpacker
    July 29, 2011

    Great post over again. Thank you;)

  45. #45 Life Insurance Quote
    August 1, 2011

    Get Life Insurance quote, auto insurance quote

  46. #46 invitation code
    August 3, 2011

    What i find tough is to discover a blog that may capture me for a minute but your weblog is different. Bravo

  47. #47 pregnancy miracle
    August 4, 2011

    [...]we came across a cool site that you might enjoy. Take a look if you want[...]…

  48. #48 Lisa
    August 10, 2011

    I sort of found this blog by mistake, but it caught my attention and I thought that I would post to let you know that I really like it. I enjoyed this post and will be telling my friends about this site.

  49. #49 Alisa Conde
    August 11, 2011

    Toller Beitrag. Ich freue mich auf mehr Artikel zu dem Thema.

  50. #50 John Medical Malpractice Lawyer
    August 13, 2011

    Not sure why this is not posting??

    Peperite:

    # The rock is full of red-to-black clasts of various sizes and shapes.

    # The clasts are almost all basaltic andesite in composition.

    … lol just about fell asleep thought I was in school. Would much rather look at eruption pics 8) OK, back to my medical malpractice lawsuit preparation.

  51. #51 Tifany Theil
    August 20, 2011

    I’m curious how creative writing instructors at colleges and universities handle students who write about really disturbing things and who seem potentially dangerous to themselves and others? Are instructors privy to students’ mental health records? Do they let such students get away with violent or disturbing writing in an effort NOT to stir too much trouble? Do you become proactive in trying to help these students? Do you undergo training to deal with problem students? As a creative writing student at a university, I often see disturbing stuff brought into workshops. I’m wondering what the profs think of all this. Thanks to any answers!.

  52. #52 Leroy Gazaway
    August 24, 2011

    Eurozone leaders upon Thurs . consented to any sweeping deal which will allow A holiday in greece a massive new bailout — but probably help it become the 1st euro region to fall behind * as well as significantly reshape your foreign currency union’s relief pay for, letting it work pre-emptively when downturn build up.

  53. #53 nike mercurial superfly
    September 5, 2011

    You will notice NONE of the governing documents (The Constitution and Bill of Rights)thereafter written have us answerable to any power other than right and reason.

  54. #54 Chicas Sexy
    September 7, 2011

    OMG!!!! ur baby is sooo freaken cute jamie.. we have a 1 year old boy so i know how u feel take good care of her she will grow up fast then what u can only imagin

  55. #55 jordans for sale
    September 8, 2011

    Such a heroic post. Thank you very much for supplying this information..

  56. #56 seo marketing
    September 14, 2011

    Hallo, sehr interessanter Beitrag. Ich liebe dieses Themengebiet und warte auf weitere Artikel zu dem Thema.

  57. #57 Antonette Cheevers
    September 20, 2011

    Al, LTC, watched the Kings destroy the Preds last nightTerry Murray has been really ripping into his team for lazy play, and they have responded.

  58. #58 nail polish, nail pictures, nail health, nail treatment, nail acrylic, nail diseases
    September 25, 2011

    It sounds like you are creating troubles by yourself by attempting to clear up this problem as an alternative of looking at why their can be a problem to begin with

  59. #59 tnx invite
    October 17, 2011

    I have found your website on Google and the information written on your post is interesting. I enjoy reading this one, looking forward to reading more of your posts!!

  60. #60 wholesale beads
    October 25, 2011

    Die Seite konnte etwas besser zu Navigieren sein, aber der gesamt Eindruck ist schon Ok, wollte ich mal so als Info hier lassen.

  61. #61 torrance dental
    October 29, 2011

    This is probably is one of the great website I’ve seen in a while :D !

  62. #62 tory burch selma riding boot almond
    November 9, 2011

    There are certainly many details prefer that to take into consideration. That is a great point to bring up. I offer the thoughts above as general inspiration but clearly there are questions like the one you bring up where the most important thing will be working in honest good faith. I don?t know if best practices have emerged around things like that, but I am sure that your job is clearly acknowledged as a fair game.

  63. #63 Chicken Mushrooms Recipe
    November 15, 2011

    Howdy I stumbled upon this great internet site while searching for assorted techniques and losing weight, I have to show you your website is very worthwhile and i also enjoy this topic. My partner and i won’t have a very considerable amount of your energy so that you can understand your complete blogposts nevertheless We’ve publication proclaimed it as well when opted in for ones Feed rss feeds. I will be back in a short time. many thanks to get a great webpage.

  64. #64 CAIRNS TOURS
    November 15, 2011

    I found your blog web site on google and examine a few of your early posts. Proceed to keep up the superb operate. I just further up your RSS feed to my MSN News Reader. In search of ahead to reading more from you later on!…

  65. #65 moncler online shop
    November 17, 2011

    This is getting a bit more subjective, but I much prefer the Zune Marketplace. The interface is colorful, has more flair, and some cool features like ‘Mixview’ that let you quickly see related albums, songs, or other users related to what you’re listening to. Clicking on one of those will center on that item, and another set of “neighbors” will come into view, allowing you to navigate around exploring by similar artists, songs, or users. Speaking of users, the Zune “Social” is also great fun, letting you find others with shared tastes and becoming friends with them. You then can listen to a playlist created based on an amalgamation of what all your friends are listening to, which is also enjoyable. Those concerned with privacy will be relieved to know you can prevent the public from seeing your personal listening habits if you so choose.

  66. #66 Nike Air Max 90s
    November 17, 2011

    You wrote very interesting post i love your blog it contains very informative article i will share it with my friends.

  67. #67 rugs
    November 17, 2011

    I like your way of blogging. I bookmarked it to my bookmark website list and will be checking back soon.

  68. #68 Dan Cairns
    November 30, 2011

    The Great Barrier Reef is situated approximately 22 miles off Cairns. Most people visit the Great Barrier Reef, Daintree Rainforest and Kuranda skyrail while on holiday in Cairns