TIGHAR

Amelia Earhart Search Forum => The Islands: Expeditions, Facts, Castaway, Finds and Environs => Topic started by: Ingo Prangenberg on May 25, 2012, 08:17:49 AM

Title: Difficulties regarding stratigraphic layers in coral rubble
Post by: Ingo Prangenberg on May 25, 2012, 08:17:49 AM
Due to the larger size and texture of the coral rubble (on land), can any dates be reliably taken from an objects position in the coral rubble strata?

Would one consider that the larger rubble may be subjected to a "churning effect" over time, allowing older objects to be placed above more recent items?

Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Ric Gillespie on May 25, 2012, 08:33:44 AM
Due to the larger size and texture of the coral rubble (on land), can any dates be reliably taken from an objects position in the coral rubble strata?

No, not reliably.

Would one consider that the larger rubble may be subjected to a "churning effect" over time, allowing older objects to be placed above more recent items?

There is churning due to vegetation growth but it's not predictable. 
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Tom Swearengen on May 25, 2012, 08:49:06 AM
Hi Ric! Looking forward to DC!
Tom
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Martin X. Moleski, SJ on May 25, 2012, 09:04:48 AM
Due to the larger size and texture of the coral rubble (on land), can any dates be reliably taken from an objects position in the coral rubble strata?

Here is a moderately comprehensive list of the articles on the archaeology of Nikumaroro (http://tighar.org/wiki/Archaeology_of_Nikumaroro).

I would say that the value of stratigraphy varies with the location and depth of the excavation.

The excavation of the putative "skull hole" (http://tighar.org/wiki/Niku_IIII_%282001%29) at the Seven Site revealed the depth of the original hole to be 80 cm. 

A putative grave site was also excavated (http://tighar.org/wiki/Niku_IIII_%282001%29#Results).  Layers apparently due to overwash were noted, but nothing else indicative of a burial was found.

Distinguishing between materials from 1890, 1929, 1937, 1939-1946, 1946-1963, and 1963 to the present by their position in the ground material at the Seven Site seems problematic.  In the 2010 expedition, the aim was to investigate the top 10 cm of the site (http://tighar.org/wiki/Niku_VI_%282010%29#Research_Design).
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Malcolm McKay on May 25, 2012, 06:59:13 PM
Due to the larger size and texture of the coral rubble (on land), can any dates be reliably taken from an objects position in the coral rubble strata?

Would one consider that the larger rubble may be subjected to a "churning effect" over time, allowing older objects to be placed above more recent items?

There would be very little chance of establishing relative dating sequences in any site composed of material like that. Complicating the problem is that the basic human occupation debris is all of a similar cultural type. Conventional relative dating might be possible in any pits that had been dug and then filled over time.
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Ingo Prangenberg on June 19, 2012, 10:09:16 AM
An interesting idea to keep in mind in regards to small material deposited in corral rubble is that small items would tend to travel deeper into underlying layers.

If one fills a plastic container with golf balls and small shards of glass, the glass pieces will disappear to the bottom of the container if shaken, churned or swirled (simulated storm action).

It's a bit like diving to the bottom of the pool of plastic balls at an amusement park in order to find the change that has fallen to the bottom.

Makes you wonder what can be found beneath 10 cm.  :o
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Martin X. Moleski, SJ on June 19, 2012, 10:49:29 AM
Makes you wonder what can be found beneath 10 cm.  :o

A Wildly Amateur Guess: not much.

The Seven Site is on and around a ridge.  It is not overwashed by storm surges.  I doubt that wind activity would move the coral rubble very much, especially where there is detritus from the trees covering it.

I suppose that if millions of bucks pour in to make more investigation of the Seven Site possible, someone might go deeper.  But the 10 cm mark set for Rolling Thunder pretty much exhausted the Niku VI team's time and energy.  A lot more could be done with a three-month expedition or the like, but that would take immensely more money--and put people's lives in greater danger--than the hit-and-run model used so far.  As long as a ship is standing offshore, help is right around the corner.  If the ship comes and goes, while a working party stays on the island, getting a response from 911 could take a week or more.  Niku is a long way from home.
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Andrew M McKenna on June 19, 2012, 12:12:14 PM
Ah, yes, the Brazil Nut effect, so to speak.

Yes, there is that possibility, but we've found that the metallic (and glass items) were basically all in the top 10 CM, verified by post collection metal detection sweeps, which would indicate that the more dense items do not migrate down in the pile of rubble / sediment.

As Marty points out, we have limited time and resources when we're there, so we've had to prioritize.

Andrew
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Gary LaPook on June 19, 2012, 03:45:52 PM
Ah, yes, the Brazil Nut effect, so to speak.

Yes, there is that possibility, but we've found that the metallic (and glass items) were basically all in the top 10 CM, verified by post collection metal detection sweeps, which would indicate that the more dense items do not migrate down in the pile of rubble / sediment.

As Marty points out, we have limited time and resources when we're there, so we've had to prioritize.

Andrew
A way to solve the "limited time" problem is to maroon someone on Gardner in July (with food, water, metal detector, a large solar still, a solar powered battery charger, an eight track tape player, one of those SPOT satellite communicators with the pre-programed message, "Have found the smoking gun, come pick me up now," a Wilson basketball and, maybe, a 406 mhz EPIRB) and pick him up next time.

gl
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Greg Daspit on June 19, 2012, 06:00:55 PM
Or use the island to test a NASA rover.
Maybe have a contest to see what University can build the best research rover for the island. Like the solar car contest MIT enters. Just drop them off and let researchers search year round from their air conditioned homes.
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Ric Gillespie on June 19, 2012, 06:10:07 PM
A way to solve the "limited time" problem is to maroon someone on Gardner in July (with food, water, metal detector, a large solar still, a solar powered battery charger, an eight track tape player, one of those SPOT satellite communicators with the pre-programed message, "Have found the smoking gun, come pick me up now," a Wilson basketball and, maybe, a 406 mhz EPIRB) and pick him up next time.

Offer accepted!  Thanks Gary.  Meet us on the dock in Hawaii.
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Ingo Prangenberg on June 19, 2012, 06:20:19 PM
Ah, yes, the Brazil Nut effect, so to speak.

Yes, there is that possibility, but we've found that the metallic (and glass items) were basically all in the top 10 CM, verified by post collection metal detection sweeps, which would indicate that the more dense items do not migrate down in the pile of rubble / sediment.

As Marty points out, we have limited time and resources when we're there, so we've had to prioritize.

Andrew
A way to solve the "limited time" problem is to maroon someone on Gardner in July (with food, water, metal detector, a large solar still, a solar powered battery charger, an eight track tape player, one of those SPOT satellite communicators with the pre-programed message, "Have found the smoking gun, come pick me up now," a Wilson basketball and, maybe, a 406 mhz EPIRB) and pick him up next time.

gl

And THAT is exactly why I like Gary! Would that be Bee Gees or Creedance Clearwater Revival on the 8-track?
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Gary LaPook on June 20, 2012, 12:50:49 AM


And THAT is exactly why I like Gary! Would that be Bee Gees or Creedance Clearwater Revival on the 8-track?
The Mamas and The Papas.

gl
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Martin X. Moleski, SJ on June 20, 2012, 08:30:03 AM
A way to solve the "limited time" problem is to maroon someone on Gardner in July (with food, water, metal detector, a large solar still, a solar powered battery charger, an eight track tape player, one of those SPOT satellite communicators with the pre-programed message, "Have found the smoking gun, come pick me up now," a Wilson basketball and, maybe, a 406 mhz EPIRB) and pick him up next time.

I nominate you for the job, Gary.   :D
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Monty Fowler on June 20, 2012, 10:18:21 AM
I'm sensing a pattern here ...

LTM, who would rather give money than dig in coral rubble,
Monty Fowler, TIGHAR No. 2189 CER
Title: Re: Difficulties regarding stratigraphic layers in coral rubble
Post by: Gary LaPook on June 20, 2012, 04:29:51 PM
Gary's a good, long-suffering fellow, but I wouldn't wish that on him...

Of course he probably would not be bored - I'd bet the nights on Niku are full of stars to be shot and re-shot!

LTM -
You can bet we will know the exact location of Gardner after I have taken a year's worth of celestial observations there.

gl