How does a coin get there?

[king-ghidorah]

I understand how objects lost on the beach get immersed in the sand and get driven deeper in it but how is this process illustrated when on land?

I have been thinking about this for a while and then a non MD asked me and and he has a 42' yacht so he understands about stuff being lost and submerged on the sands but i couldn't really give him a detailed, good answer. I can understand if someone 40-50 years ago lost some change and then there was construction and then it gets covered over but in general what are the scenarios of coins getting buried 2,4,6,10 & 12" in the ground until Joe MD comes by and digs it up?

 

[Steve(OR)]

It's not too complicated - mainly two factors cause an object's burial:   

1. Gravity
2. Soil accumulation

Both of these work in opposite directions. Grass grows upwards; builds a thatch layer around root level; this thatch layer eventually degrades into soil, adding (upward) to the soil level. Gravity works downwards on the object at the same time, constantly pulling the object deeper into the ground. Of course, gravity doesn't change, but soil accumulation varies greatly (i.e. deeper in some areas; shallower in others; not always grass (weeds, leaves, etc.)).

SCM

 

[James N.D.]

Think of how many times lawns get mowed during a season King. If the clippings are not bagged then they slip under the grass blades and start to decompose, layer after layer. Also, any dirt or dust that blows around from gravel roads like alley's and dirt roads like in the country sides all play a role in Coins getting buried after periods of time. Rain also helps in these items sinking ever so slightly due to gravity over long periods of time also. This is my theory as to why Coins get buried and why some are so Deep. Other things like fill brought in to fill holes or just add dirt for better run off are also reasons for the Depths of Coins. Even when people are walking across grass when the ground has been wet, they walk over top of Coins...pushing them into the ground and starting them on their way to sinking in the dirt over the years. The ground could be turned over at one time also so what I'm trying to get at is that there is a lot of different ways Coins get to the Depths that they do. I hope this answers your question about how does a Coin get there King. It makes sense after all. Good Luck and HH to you.

 

[Chris(SoCenWI)]

Despite what some others have said it is not a matter of density and coins sinking to depth. We are not talking submarines. Fill a jar with soil, put a coin on top, cover the jar and let it sit for a century. Coin will still be on top of the soil. Do the same with another jar but leave it open and plant some grass seed. See what happens.

I've found a few coin purses over the years. If coins sunk according to density the leather would be on top of the soil and coins below. Just ain't so. The different materials all are at the same depth. Just look at some old side walks: The ground is often much higher than the sidewalk. The walks didn't sink, but the ground built up. Same process that creates black dirt; organic matter decomposes, forms new dirt. For the Midwest they estimate 4 to 6 inches a century, and most of the coins I find follow this rule of thumb.

That said there are many processes that speed up or slow down or completely disturb this process. Erosion, agriculture, construction/landscaping can either add or remove soil. On beaches with wave action sand and soil can be moved around considerably. Soil tends to build more slowly in forested areas, on hills, in shady areas around buildings. Often get a pile of Indian heads very shallow in these instances. Up north in Minnesota where we have a cabin coins are often very shallow. Didn't understand this until a friend told me they often added black dirt to try get a better lawn but the soil dissapeared. What is happening is that the underlying media is almost completely all sand, and any dirt not held by the sod's root structure will leach through the sand.

Chris

 

[lazyaussie]

this is a interesting post i agree with the mulch effect quite often i"ll dig 1940s-60s copper coins at 6-8 inch with grass blades attached to the under side of the coin so i think this is the ground level 60 years ago but i do disagree a little with Chris gravity dose affect a coin when the ground is wet & muddy it sinks down to a harder layer of dirt i"v detected areas with no vegetation & the coins were 2-3 inch deep on a denser layer of dirt.
just my two cents worth
lazyaussie

 

[king-ghidorah]

I like what I am seeing so far. I have learned a lot from this post already. Thanks for the input so far guys.

 

[jeff & Maria]

Research Specific Gravity and you will learn how it works in general, and thus how it will play into the depth factor. Natural ground build up is the biggest reason coins are deeper though.

 

[dewcon4414]

I agree with Jeff. Refer back to you high school science. Put sand, medium then large stones into a container... add any kind of movement and see what shifts to the top.

 

[ellis]

good reasoning in these posts and i enjoy all of it.another mystery to add to this subject is the fact that(my personal diggings) i have found wheaties at one to two incvhes deep,then one foot from there find a 1990 memorial at 4 to 5 inches..like i said --mystery--but very interesting.have fun with it and hh best hobby around!!!

 

[shadowman]

Don't forget the earth is a gaseous ball which means it is in a constant state of flux.
Also dust,freeze thaw cycle,traffic,trains and who knows what else.

 

[Steve(MS)]

Moles, humans working the soil, livestock, erosion or build up of soil, root systems of plants pushing the coin either up or down and ground freezing and thawing.

 

[Weasel_Loader]

WOW!!! Lot's of good talk here on this one. I posted a question like this when I first started detecting and still have not found a clear answer. Maybe because there is no clear answer since every area has a different reason for the depth of it's coins.

The ideal way to find out is a time lapse video/photo of a coin sinking over time. Don't think we'll ever see that though.

In my case in the areas I hunt (parks), I believe the answer is blowing dirt/dust, fertilizers, new seed laid out and of course the cutting of the grass will over time send the coins down deeper. I am surprised at the depth of some newer coins such as 1980s coins being at a depth of 4". That's pretty discouraging when your finding coins that new so deep!

I hope this thread keeps up and brings in more ideas of the sinking coins.

 

[king-ghidorah]

Weasel,
I know what you mean. In the parks I can hit clad at 4-5" and I if I see 7-8" 0-29 I start thinking maybe it's a silver or a SLQ and out pops a quarter dated 1997? On the other hand I have had stuff come out in the same general area at 4-5" and it was a 1925 wheatie.

Different area obviously have varying internal/external forces at work. What you see at a park or a playground might present itself differently way out in the woods.

Oh cool, I just seen you have some MD vids. I am going to watch a few over a coffee.