>From: Joel Z. Bandstra [mailto:firstname.lastname@example.org]
>Sent: Sunday, February 10, 2002 5:09 PM
>To: 'Glenn Morton'; email@example.com
>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
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.
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>From: firstname.lastname@example.org [mailto:email@example.com] On
>Behalf Of Glenn Morton
>Sent: Sunday, February 10, 2002 6:22 PM
>To: Allen Roy; firstname.lastname@example.org
>Subject: RE: New Guinea tsunami information.
>>From: email@example.com [mailto:firstname.lastname@example.org]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
>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
>>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
>>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
>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
>>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.
>>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
>>who said that tsunami and turbidite depositions were nearly
>Unamed sources, like with newspapers, are untrustworthy. Sources please.
>>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.
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