Ok, i have to ask this cos its bugging me and i don't know the answer and being a Marine Engineer i'll never work it out for myself...
Where does all the earth come from that covers the archaeology, i cannot believe (though i am happy to be proved wrong) that all the plant litter and animal / human waste would accumulate that quickly!!!
I know this is prob basic stuff to you guys but it bugs me now knowing...
The stone flagged path at the bottom of my garden is now covered by over 30cm of leaf and tree litter - and it was clear only a couple of weeks ago.
Nearby, there was a path clearly visible ten years ago. It is now covered by a natural extension of the lawn because I didn't bother to keep it clear of the encroaching soil and grass. It shows up as a "crop mark" in dry weather. (I prefer it this way.)
Welcome to the maddest show on earth Fancy, you a Marine Engineer an' all (just like my late Dad) and don't know about accretion? What dy'e think the 'orrible black stuff is that collects inside the cylinders and the exhaust manifold of yer engine? It's the wee mannie inside continually breaking wind Same with archaeology. It's the Great Archaeologist in the Sky continually farting A bit like the Big Bosun Washing Down when she is shipping them green!
Darwin, who had quite an enquiring mind, spent time at Stonehenge studying the rate at which earthworms caused fallen sarsens to "sink" into the ground!
Bruce - Darwin measuring sinking sarsens - you said "Out of interest - if what you say is true - how exactly did he measure that?"
Hmmm, yes, see where you're going with that. Bit hard to measure on a day trip to Stonehenge!
I believe though he studied the subject for forty years (said he was prouder of his book on the subject than the Origin of the Species!). So I guess he had time to measure the process elsewhere. Maybe he just wanted to use his knowledge to calculate how long the sarsens had been lying there, I don't know.
There's not much he didn't look into. He's my all time hero, and should have won Greatest Britons hands down.
bad news, the depth contribution due to metortite is minute. Quick & nasty calculation: radius of the earth 6350km. surface area (4PI(r)sq) is approx 5 x 10E8 km2. (5x10E14m2)
Volume of material, average 57,000 tonnes. If the density is the same as the earth, call it 5.7, then volume of meteorites is 10,000m3 (0.01km3)
thickness is 0.01/5E8, = 2E-11km,= 2E-8m =20nanometres, Per year. For 1000 years 0.02mm(have I got that right? its tiny?)
Mass of the earth is estimated at 6,586,842,500,000,000,000,000 tons so the addition of an average 57,500 tons per year is indeed so trivial as to be almost meaningless.
Sunlight, yes, but through the agency of plants first and soil organisms second. And the greatest of these is worms (obsessed? moi?)
One inch of soil can take a century to form, but if you add worms they can do it in five years. They bring back everything that's been leeched out of the reach of plants.
Yes, but that comes from cow food, which is plants.
ditto human skin, which came from human food, which was either plants or cows. (There's good eating on them animals!) (veggies better igonore that last bit! )
Can anyone give me a reference for Darwin's book on the earthworms at Stonehenge? Preferably the full title, date, publisher and place of publication, but just the title would be a help. I want to quote it in an essay!
I think the book you are looking for is the snappily titled: The Formation of Vegetable Mould Through the Action of Worms with Observations of Their Habits
The details are: publisher: John Murray date: 1881 or 1883 place of publication: London this obviously predates ISBN numbers.
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Lovely long title too - all adds to the word count without being accused of waffling (which I am, really! 3500 words on archaeological theory is very hard going!)
Don't know if this is relevant or not but to give you some idea of the Earth's size I recently heard this fact.
It takes 30 seconds to fall from the edge of space to the surface of the Earth but it would take 34 HOURS if it was possible were to continue falling to the centre of the Earth!
What dy'e think the 'orrible black stuff is that collects inside the cylinders and the exhaust manifold of yer engine? It's the wee mannie inside continually breaking wind 
Same with archaeology. It's the Great Archaeologist in the Sky continually farting 
