RE: New Guinea tsunami information.

From: Glenn Morton (
Date: Mon Feb 11 2002 - 09:41:55 EST

  • Next message: Moorad Alexanian: "Re: Glenn makes front page of AiG today"

    >-----Original Message-----
    >From: Joel Z. Bandstra []
    >Sent: Sunday, February 10, 2002 5:09 PM
    >To: 'Glenn Morton';
    >Subject: RE: New Guinea tsunami information.
    >In the post below, Glen wrote: "An onshore landslide simply mixes things
    >up with little sorting."
    >I don't think this is correct. See R.M. Iverson, The physics of debris
    >flows, Rev. Geophys. v35 pp245-296 August 1997. This is not my field so
    >I'm sure there is a better reference but this one should suffice.
    >The observation, as I understand it, is that coarser grained material
    >sorts to the edges of both landside and debris flow runouts. I guess it
    >probably works just like the big nuts in the mixed nuts can floating to
    >the top.

    You are correct there is the nuts in the can phenomenon in a landslide on
    earth. But this isn't quite the same type of fining that I am speaking of.


    for lots of creation/evolution information
    personal stories of struggle
    >-----Original Message-----
    >From: [] On
    >Behalf Of Glenn Morton
    >Sent: Sunday, February 10, 2002 6:22 PM
    >To: Allen Roy;
    >Subject: RE: New Guinea tsunami information.
    >Hi Allen,
    >>-----Original Message-----
    >>From: []On
    >>Behalf Of Allen Roy
    >>Sent: Sunday, February 10, 2002 8:47 AM
    >>There is a simularity with the Haymond deposits in that the tsunami
    >>deposited consisted of two layers: the bottom one of sand, the top one
    >>clay/silt. To be sure the quantites of each are certainly different
    >>the Haymond deposits.
    >Yes, there are several differences. As you note, the quantities of sand
    >shale are different in the tsunami deposit. There is the lack of marine
    >burrows in the tsunami deposit which exist in the Haymond. And most
    >importantly, the Haymond consistes of 15,000 layers, the tsunami
    >consists of
    >one pair with very, very little shale. NOw, if the tsunami had deposited
    >15,000 layers of sand and shale then you might have a case. As it is,
    >will have to wait several hundred years for the next tsunami at that
    >The tsunami simply is not analogical to the Haymond.
    >>The article also makes the following points:
    >>1. "The recently deposited tsunami sand is believed to have come from
    >>offshore of the beach as numerous sand dollars were found near the
    >>of the deposit."
    >But no burrows.
    >>2. "Another common characteristic of recently deposited tsunami sand
    >>normal grading (a decrease in the size of the sand grains from the
    >>bottom to
    >>the top in the deposit)"
    >typical hydrodynamic sorting according to Stoke's Law. This is nothing
    >>3. "The deposit fined landward (near the shore the sand particles were
    >>larger than the sand farther inland)."
    >Once again, this is what Stokes law would predict.
    >>Lets start with point 1.
    >>In this case, as the tsunami swept ashore it picked up beach sand
    >>and nearly
    >>simultaneously deposited it as it swept inland. What if, instead
    >>of a sandy
    >>beach, the wave had swept across a muddy delta? What would be the
    >>load carried by the wave? What would be the major deposition?
    >True, but most of it would have remained suspended in the draining
    >waters as
    >Stoke's law would not let it settle as rapidly as you require for a
    >>The point being that tsunami deposition reflects the compsition of
    >>the soils
    >>across which the tsunami came as it swept ashore. So it could consist
    >>lots of sand/little clay, or some sand/some clay, or little sand/lots
    >There are several tsunami's per year. Find one with little sand and lots
    >clay. I don't think you can.
    >>Point 2.
    >>One of the major means of identifying turbidite deposition is the fact
    >>it has normal grading (although reverse grading is sometime noted),
    >>sand through silt to clay. At the New Guinea tsunami depsition site
    >>deposit displays "normal grading" (including clay/silt on top). This
    >>confirms an off hand statement from a non-creationary geologist I
    >>heard once
    >>who said that tsunami and turbidite depositions were nearly
    >Unamed sources, like with newspapers, are untrustworthy. Sources please.
    >>Point 3.
    >>The tsunami deposition also display landward fining. It is curios to
    >>that ALL Grand Canyon formations display horizontal fining in one
    >>or another. I wonder if anyone has checked to see if the Haymond
    >>layers graded horzontally. I would not be the least bit surpried to
    >>that they do grade horizontally.
    >Of course they grade. Almost all clastic beds do. That doesn't mean that
    >Haymond was a tsunami deposit. Your tsunami deposit has little shale and
    >>> Thirdly, this is a tsunami deposit which is above sea level which
    >>> shale-containing water to flow down through the porous sand as noted
    >>> Below sea level, this won't happen. The water will not flow through
    >>> like it does on land.
    >>This is a good point. I like it! It makes deposition of clay/silt
    >>faster than I had thought. It is still note worthy that the clay/silt
    >>there because the tsunami picked it up and carried it into place.
    >Don't jump on it for a marine deposit, which is what the Haymond is.
    >Landslides on land don't sort th way that turbidites do. In the water,
    >turbulence separates the shale from the sand with the sand flowing close
    >the water bottom and the shale going into suspension and depositing over
    >vastly larger area. Only over a long time can shale be deposited on top
    >the sand in a marine environment. An onshore landslide simply mixes
    >up with little sorting.
    >>> So, this has nothing to do with a turbidite.
    >>If it is true that turbidite and tsunami deposits are nearly
    >>indistinguishable, then whos to say that the Haymond deposits are not
    >>tsunami rather than turbidite deposits?
    >Tsunami's and turbidites are distinguishable. You are depending upon
    >some unnamed, unreferenced, unknown and possibly non-existent person is
    >supposed or claimed to have said, in order to support your argument.
    >Geologists can tell the difference between marine and land deposits and
    >between tsunamis and turbidites.
    >This is from R. Peters et al, ITS 2001 proceedings "An Overview of
    >Deposits along the Cascadia Margin," p. 479
    >"Tsunami deposits may be distinguished from river deposits by disntinct
    >biological markers, spatial distribution, sediment characteristics, and
    >geochemistry. Tsunami deposits contain marine or brackish water
    >microfossils while fossils in river deposits, if present, would be fresh
    >water varieties. Tsunami deposits fine landward, while river deposits
    >generally fine seaward. The composition texture of the sand grains can
    >used to determine a coastal or upriver source. Geochemical indicators,
    >as bromine enrichment, may indicate a marine source."
    >Turbites and tsunami's fine in opposite directions. Turbidites fine
    >the sea, tsunamis fine toward the land. Turbidites show burrows and
    >ichnotraces in the shale above the sand which is thick and tsunami's
    >as the shale is too thin.
    >for lots of creation/evolution information
    >personal stories of struggle

    This archive was generated by hypermail 2b29 : Mon Feb 11 2002 - 01:44:02 EST