The great Seas and Rivers of the Supercontinents.

[Mike Smith Cosmos]

Mike, .....

 

 

My interest is the basins which fill in with eroded sediments, and how these turn into kilometers-deep rock formations. I'm thinking they are not deep when formed; but that the basin sinks as more sediments are deposited, while always staying roughly level with the (perhaps flooded) surface. ...thus over time, pushing down into the continent and perhaps deforming the lighter continental crust downward into (or more "firmly" onto) the mantle. Ice, built up to several kilometers in height over certain parts on a continent, might also have similar effects.

To a large degree (afaik) those "basin" deposits/sediments were the first soils. That is probably too over-generalized, but until life (plant life) came up onto the continents roughly 500 Mya, soils wouldn't exist except as sandy or silty sediments; but with no clay or organic matter to bind the grit together.....

 

 

.......except for the insects, which were already here on the land, .......But what I found interesting was that they said the land, at that time, was a barren rocky landscape covered in black algae!

 

......

Black algae! Well that won't translate well into your paintings, but as a highlight or offset it could be worked in, I'll bet. But I think the (slick/shiny?) black algae is interesting for several reasons. It would be the first large source of organic matter to help bind the sediments into soils, as well as being a food source for insects perhaps, and also a source of acids to help dissolve nutrients .........

 

 

But don't think the "barren rocky landscape" was completely devoid of plant life, even before the animals (frogs) came up onto land. Rockworts and various primitive plants took over whatever areas they could exploit, I'm sure; and then the ferns came along (once enough soil had built up, I suppose) to reach up above the surface more than just a few inches. But I don't know the timing of those different (evolutionary) plant successions, in relation to when the amphibians came to dominate.

The evolution of lignin (wood) is a very interesting story too, but that is a hundred million years or so later.

 

 

All this about the change from grit to soil , that you speak about and specialise in, is a very interesting subject in its own right . Yet tied closely into plants and small life.

 

I think I need to do a perspective or painting at a different scale factor to capture this aspect ... Sort of liverwort down to grit ...

 

before

 

after

 

Mike

Edited July 3, 2014 by Mike Smith Cosmos

[Mike Smith Cosmos]

New views on the inland warm seas, in basins of a supercontinent .

. The dim Sun , U[lifted mountain ranges, Glaciers, Black Algae, Slime, frogs , salamander, liverwort, and grasses

 

Including illustrative peat brought to me from Sneem, County Kerry, Southern Ireland , cut by Mike Murphy , this peat probably from the last ice age as opposed to peat from 350,000,000 years of the supercontinent period

Mike

Edited July 7, 2014 by Mike Smith Cosmos

[Mike Smith Cosmos]

Here is a bit of research ref great rivers of the super continents .:-

Courtesy of :- Richard D. Little Professor of Geology, Greenfield Community College, Greenfield, MA

CONNECTICUT VALLEY

PANGEA - THE SUPERCONTINENT
While the bedrock basement of the Connecticut Valley is the Paleozoic metamorphic and igneous rocks described above, below,something very different is about to begin. The supercontinent of Pangea starts to split. Stretching stresses break the preexisting rocks creating faults that are much different from those due to compressional stresses of Paleozoic orogeny. These faults are "rifts" -- great "pull-aparts" that create prominent valleys (rift valleys or grabens) such as seen today in Death Valley and its relatives out West, as well as the famous east African valleys where our ancestors lived and evolved.

The present-day Atlantic Ocean begins to form as water spills into the largest of these cracks, and the Connecticut Valley develops along one of the adjacent rifts known as the Eastern Border Fault. It defines the eastern edge of the Connecticut Valley and is over 100 miles long, from Keene, NH to New Haven, CT and beyond.

Rivers washed great amounts of sediment into this valley. Great alluvial fans formed against the Eastern Border Fault margin as rivers deposited thick piles of gravel adjacent to the mountain front. Farther into the valley sand and mud were left. Many times lakes formed in the valley flats with sandy shorelines and muddy bottoms.

The Connecticut Valley has as much as 30,000 feet of sediment preserved, but in the Franklin and Hampshire County area of the valley, the thickness is about 6,000 feet. But think of that -- over a mile of river and lake deposits, layer by layer, representing 10's of millions of years of history.

)

JURASSIC ANIMALS AND PLANTS (HYPOTHETICAL SCENE FROM THE CONNECTICUT RIVER VALLEY

Background information from same article :-
GENERAL SETTING

Greenfield, bounded on the east by New England's largest river, the Connecticut, and on the west by the highlands of the Berkshire Hills, is one of the best places in the world to study geology. All three rock types (igneous, sedimentary, and metamorphic) are easily visible on our landscape and sand, gravel, and clay deposits from the last ice age are also abundant. Topographically, Greenfield's main residential and business area is about 250' above sea level, on the flat lake bottom plain of Lake Hitchcock, a glacial lake that drained about 14,000 years ago. To the west early Paleozoic Era schist rocks of the Berkshire Hills reach elevations of 1100', while several miles away at the east end of town a prominent, scenic ridge, site of Poets Seat Tower, rises 250' abruptly above the flat valley lowlands. It's composed of early Jurassic age lava, 194 million years old, that was tilted by faulting as the great supercontinent of Pangea broke up. The more gentle eastern side of the lava ridge slopes to the shoreline of the Connecticut River which has a scenic 40' waterfall (Turners Falls) just before entering Greenfield, and flows along a valley with abundant outcrops of red sandstone sedimentary layers, which, sometimes, display dinosaur footprints!.
PALEOZOIC ERA EVENTS

Things were quite different in early Paleozoic times. About 600 million years ago this region was south of the equator and under the sea at the tropical edge of North America, located in the old Atlantic (known as Iapetus Ocean, named for the father of Atlas). Over several hundred million years the processes of plate tectonics propelled several landmasses to collide with this edge of North America, making mountains with each impact. The first of these orogenies (mountain-building episodes) was the Taconic. It has been recently proposed that an impact with western South America (which was part of the great southern continent called Gondwana) pushed up these mountains 430 million years ago because similar rocks and fossils are found there. As with all mountains, erosion lowered them over 10's of millions of years, and eventually the warm, tropical seas covered the region once again.
An even bigger collision came next. About 400 million years ago the northwest Africa side of Gondwana hit North America creating the Acadian Orogeny which built the northern Appalachian Mountains. Greenfield and surroundings were now part of a major mountain range as high as the Himalayas. The effect of all this stress on the rock was to change these tropical marine sedimentary layers into metamorphic rocks: banded gneisses, shiny schists, and slates. Commonly parts or all of these layers melted and the magma cooled slowly into the igneous rock, granite.
As the Paleozoic Era ended, erosion had worn down these lofty peaks, but the ocean never again came to Western Massachusetts. We were in the middle of the great supercontinent known as Pangea.
MESOZOIC ERA

 

The above text :-

Courtesy of :- Richard D. Little Professor of Geology, Greenfield Community College, Greenfield, MA

 

Mike

Edited July 14, 2014 by Mike Smith Cosmos

[Mike Smith Cosmos]

.

Images of the .CONNECTICUT VALLEY ( There must be 1000.s of meters of silt below this river from Super continent times ?)

 

http://www.google.co.uk/imgres?imgurl=http%3A%2F%2Fab.mec.edu%2Fdepartments%2Ftechinteg%2Fresources%2Fstudents%2Fnewlife%2Fimages%2Fctriver2.jpg&imgrefurl=http%3A%2F%2Fab.mec.edu%2Fdepartments%2Ftechinteg%2Fresources%2Fstudents%2Fnewlife%2Fconnrivervalley.htm&h=321&w=490&tbnid=BQdsXDvREVhC0M%3A&zoom=1&docid=MMMK8hKK2CLxmM&ei=6I3DU5-yO8HA7AbT34DYBA&tbm=isch&ved=0CCEQMygAMAA&iact=rc&uact=3&dur=1228&page=1&start=0&ndsp=14

 

 

INLAND SEAS and Large Rivers

 

If this is typical, it would seem that the rivers of the super continents were set at the collisions of other sections of the super continents colliding with each other ( Guandana etc). Oroginy , by way of mountain range uplift and splitting of super continents (Pangaea) causing rifts, allowed absolutely colossal inflows of water, complete with massive inflow of silt, pebbles rocks and general sludge. ( eg Connecticut ) also the African Rift valley, with lakes( Lake Tanganyika & Lake Victoria etc ) and presumably the Nile and the Congo River?

 

 

 

 

Surely this can be construed as an inland Sea in a Continent , then as part of a super continent , when Africa collided with Eurasia and Americas ?

 

Mike

Edited July 14, 2014 by Mike Smith Cosmos

[Mike Smith Cosmos]

I have found out an Orogeny occurred when Eurasia was touched by the Americas causing mountains to uplift from Germany through Northern France , in and above the granite Torres on Dartmoor , past up through Ireland .

 

These were called I believe THE HERSINIAN VARISCA . and from these mountains a massive river flowed across dessert sands past Dawlish , depositing pebbles in the pebble beds of Budliegh Salterton .

 

The massive river flowed north across England I believe as deposits are found , with finer and finer grades as one goes north .

 

Finally to flow out into a warm shallow sea off the north east coast of England /Scotland ( as it is now ) , some people think the river may have started where now the Rhine is in Germany .

 

Having discussed this with a professional yet retired geologist , this appears to be the gist of one of the major rivers caused by the Orogeny and coming past us ( in the past ) near us in S.w. England . (Triassic ) times.

 

 

 

Essay. This may fit in with your reference to the basalt outflow causing the Fingles pavement of hexagonal shapes .

 

See the sketch I made , while conversing with the geologist , while at Beer Cliffs . Note. The small map of England on the right hand side and how the mountain Orogeny goes up past Ireland and Scotland . ( very quick sketch , while walking on slippery ,flint pebbles . Pencil slipped a bit . )

 

Mike

Edited July 18, 2014 by Mike Smith Cosmos

[Ophiolite]

Essay. This may fit in with your reference to the basalt outflow causing the Fingles pavement of hexagonal shapes .

Fingle's cave in Scotland, the Giant's Causeway in Ireland, the Cuillins and Red Hills in Skye, Rhum, Ardnamurchan, etc are all part of the Tertiary vulcanicity that was rampant as the Atlantic opened up. Long after the Hercynian orogeny build the Variscide moutain chain. (Note some of those spellings, please.)

 

The granite tors of Dartmoor are Carboniferous in age and thus predate the Triassic. I think we have previously covered the fact that the basic and ultrabasic rocks forming The Lizard, at the end of your peninsula, are oceanic crust and upper mantle obducted onto the continental mass, during the Devonian. I mention this again only because these rocks are called, collectively, ophiolites.

[Mike Smith Cosmos]

Fingle's cave in Scotland, the Giant's Causeway in Ireland, the Cuillins and Red Hills in Skye, Rhum, Ardnamurchan, etc are all part of the Tertiary vulcanicity that was rampant as the Atlantic opened up. Long after the Hercynian orogeny build the Variscide moutain chain. (Note some of those spellings, please.)

 

The granite tors of Dartmoor are Carboniferous in age and thus predate the Triassic. I think we have previously covered the fact that the basic and ultrabasic rocks forming The Lizard, at the end of your peninsula, are oceanic crust and upper mantle obducted onto the continental mass, during the Devonian. I mention this again only because these rocks are called, collectively, ophiolites.

Yes, well I am trying to get my head round , how the different time periods make a different contribution to the rock strata , pebble or particle content , that one may have in ones hand.

 

Eg it might have been part of the ophiolite pushed up on top of Dartmoor granite, later eroded off to become part of the sediment , appearing at Beer greensand . Or a pebble carried by the River discussed to relocate at Budleigh Salterton . ( to be seen now, today )

 

 

Essay

 

I have visited both the caldera at Tenerife and Tiede as well as the fresh eruption on La Palma (1974) .

 

 

 

Mike

Edited July 18, 2014 by Mike Smith Cosmos

[moth]

Hi Mike, I've been hoping to find more time to submit a detailed post, but my dis-organized approach to schedule has left me with too many loose ends needing attention.
You may find the geology of New Zealand worth a look.

It is formed of material eroded from the shore of a super-continent, and it's location on a plate boundary give it an interesting array of geologic features like fast growing mountain range ,volcanoes and alluvial plains.

Absolutely BEAUTIFUL country too.

[studiot]

Mike,

This is a good site to plot changes of ancient boundaries etc.

 

You can check on each of the major geological ages.

 

http://www.scotese.com/earth.htm

[Mike Smith Cosmos]

Hi Mike, I've been hoping to find more time to submit a detailed post, but my dis-organized approach to schedule has left me with too many loose ends needing attention.

You may find the geology of New Zealand worth a look.

It is formed of material eroded from the shore of a super-continent, and it's location on a plate boundary give it an interesting array of geologic features like fast growing mountain range ,volcanoes and alluvial plains.

Absolutely BEAUTIFUL country too.

 

Great I shall have to look all that up. Thanks

 

mike

Mike,

This is a good site to plot changes of ancient boundaries etc.

 

You can check on each of the major geological ages.

 

http://www.scotese.com/earth.htm

I have just tried out your link Eric and I can see the warm inland sea I spoke about illustrated In or during The Triassic version of the history , on the link .

 

Great , very useful , I am going to have a good time with that.

 

 

Mike

Edited July 18, 2014 by Mike Smith Cosmos

[Mike Smith Cosmos]

What a look inside one of these vast rivers might have looked like during the late dinosaur era .

Courtesy of the national geographic magazine

 

Mike

 

Link

http://www.bbc.co.uk/news/science-environment-29143096

Edited September 20, 2014 by Mike Smith Cosmos

[MigL]

Vert interested in the ancient geology, Mike.

 

But what I really want to know about are your paintings

It looks like watercolor ( or acrylic ) on the screen.

Is this a hobby, do you do it professionally, does it help clear your mind ?

 

I used to do watercolor ( my favourite medium ) myself until I ran out of time and gave it up.

I've been meaning to get back into it, but its like working out, I always say to myself "I'll re-start tomorrow".

Edited September 21, 2014 by MigL

[Mike Smith Cosmos]

Vert interested in the ancient geology, Mike.

 

But what I really want to know about are your paintings

It looks like watercolor ( or acrylic ) on the screen.

Is this a hobby, do you do it professionally, does it help clear your mind ?

 

I used to do watercolor ( my favourite medium ) myself until I ran out of time and gave it up.

I've been meaning to get back into it, but its like working out, I always say to myself "I'll re-start tomorrow".

See ' Personal Messenger ' and 'Art in Science' under Other Sciences

 

Mike

[Mike Smith Cosmos]

See ' Personal Messenger ' and 'Art in Science' under Other Sciences

 

Mike

Very interested in the ancient geology, Mike.

 

----------------------------------------------

Hi copy of message sent to your personal message area ( not sure you have received it )

I paint mainly in Acrylic .

 

I have developed this mainly in my retirement. Although I sketched in pencil up through my life ,

 

My development of painting in Acrylic , was my retirement project , along with doing personal research in Science . Hence my contributions on the science forum.

 

My profession through my working life has been in the Electronic industry as an Electrical/Electronic Engineer.

 

Would love to compare notes ,about Art . and Art in Science .

 

(should be clear to discuss about now )

 

 

Ps yes , it does clear my mind . In fact I find it very therapeutic . You go into some form of 'time warp ' while in the painting experience

 

Edited by Mike Smith Cosmos, 2 October 2014 - 09:28 AM.

Edited October 26, 2014 by Mike Smith Cosmos

[Mike Smith Cosmos]

Just attended the Exeter branch of the U3A , Geology meeting March 2015.

 

Discussions of the movement of the massive plates Sub ducting among the Tongan chain., in the Pacific Ocean , With the associated volcanoes , forming islands as we speak.

 

We discussed the general geological history of the Earth. We have a member who is a retired Lecturer for the Open University Geology Department. I commented, and asked again with marvel about a summer geology field trip with him to the pebble beds of South Devon / Dorset

 

Wow!

 

The pebbles on the shore at Budleigh Salterton ( SouthDevon , England ), are from the bottom of the great river come sea passage , running across what is now Germany , Northern France , diagonally across the English Channel , the east side of England out into , what is now the North Sea.

 

These pebbles are just there 20 miles down the road , from the bed of that ancient river channel .

 

THE HERCYIAN VARISCA from the Hercynian orogeny ( spelling courtesy of Ophiolite ) , the upwelling of continental crust . And presumably some ocean crust or ophiolite.

 

From the ancient super continent of Pangea, as it broke up ! 200,million years ago !

I find it mind blowing ! Totally mind blowing !

 

Wow !

 

Bingo , I have found the bed of one of the great water courses/( river) of an ancient supercontinent . As water flowed presumably in/ of the Tethys Sea , and the newly formed Atlantic Ocean . I have walked on the exposed bed of that water course, I have touched and peered at the pebbles from the bed of that ancient river , when it's location was at where North Africa is today ! wow !

 

 

 

Mike

Edited January 22, 2015 by Mike Smith Cosmos

[Mike Smith Cosmos]

Right this moment 3;16 pm mon , 30th march 2015 ,, and ... I recon I am sitting on the bed of a 100, to 250 million old river bed : one of the rivers of the old supercontinents, as was before Pangea split , then the river torrent swept down out of now Germany, France and across to Now Lympstone then this started to become part of the English Channel .

 

.

 

Mike

Edited March 30, 2015 by Mike Smith Cosmos

[Mike Smith Cosmos]

...AGE OF A CHUNK OF CLIFF ..

 

It's always difficult to imagine when one stands against a cliff of the same deposition , say sandstone or chalk cliffs , what time period did it take to deposit such a cliff.

 

I have asked various geologists, but I usually get a ' it depends ' type answer , which is never very satisfying . There are usually comments like " well most of it has been worn away! " Or there could have been a flash flood !

 

However ,I am getting near to a rough guide of .... 50 to 100 million years per cliff . .....

 

Meaning that a cliff that is 50 meters high is likely to have taken 50- 100 million years to lay down . Sort of one geological period ( say the ..Cretaceous . .( white cliffs ) .

So when you look at the cliff close up , say the cliff is 50 meters high . Then the whole cliff might have taken 50 million years to deposit the particles, sand ,shells or whatever. So

 

One meter will represent 1,000,000 ( one million years ) .that 1 meter thick chunk in front of your eyes took 1 million years to deposit .

 

Is that right ?

 

Bempton cliffs . Yorkshire . U.k.

 

Mike

 

50,million years from top of cliff to bottom .

Edited April 3, 2015 by Mike Smith Cosmos

[Acme]

...AGE OF A CHUNK OF CLIFF ..

 

However ,I am getting near to a rough guide of .... 50 to 100 million years per cliff . .....

 

Meaning that a cliff that is 50 meters high is likely to have taken 50- 100 million years to lay down . Sort of one geological period ( say the ..Cretaceous . .( white cliffs ) .

So when you look at the cliff close up , say the cliff is 50 meters high . Then the whole cliff might have taken 50 million years to deposit the particles, sand ,shells or whatever. So

 

One meter will represent 1,000,000 ( one million years ) .that 1 meter thick chunk in front of your eyes took 1 million years to deposit .

 

Is that right ?

 

Mike

No, it's not [necessarily] right. As your geologist friends told you, it all depends on which chunk you are in front of. The cliff is not like a clock, it's like a time card. For the time card the clock is always ticking, but you are not always working. For the cliff, the clock is also always ticking, but layers are not always being deposited (or weathered).

.

Next time you're at the cliff, get your nose right up to it and take notice of the different thickness of the layers.

.

I'll be back in a few minutes with a different type of cliff example from my area.

OK. So this cliff was once the bottom of a glacial lake. I and my compadres measured the exposed part @ ~30 ft. Such deposits are called varves

 

Unlike your chalk cliff, in a varve each layer is 1 year, where a layer has a thick part and a thin part. During summer when the lake is thawed, dust blows onto the water and sinks and this forms the thick part. In Winter the lake is frozen and the finer organic material sinks & forms the thin part of a layer. Rinse & repeat.

 

While this is very like a clock -and used to that end by geologists- one cannot simply measure the cliff and a section of layering and deduce the overall age, because the layers are not all the same thickness. Here's a nose close look at a 15 year section that I collected.

 

Another interesting thing that shows up in these deposits is embedded stones called erratics. They get there when a stone in Winter falls onto the frozen lake top and slides out, and when the thaw comes drops to the bottom like...well, like a stone in a lake. Here are a couple such erratics.

 

Dating the age of either your cliff or mine requires lab work that looks at the particulars of layers, whether that is embedded plant or animal remains or radiometric dating. Once a single layer in my cliff is dated one can just count layers from that measured to get dates, whereas with your chalk deposits each layer would have to be individually dated. In either case one cannot simply look at the whole and extrapolate its age from its height/thickness.

 

We can of course deduce that the lowest layers in both deposits are the oldest and the upper layers the youngest and this deduction is the basis of geology's law of superposition.

 

PS Here's the exact coordinates for my varve in the Gifford Pinchot National Forest; you can enter them in Gaggle Earth and go have a look. >>

45º56'41" N

122º16'28" W

elev. 838ft.

Edited April 4, 2015 by Acme

[pavelcherepan]

One meter will represent 1,000,000 ( one million years ) .that 1 meter thick chunk in front of your eyes took 1 million years to deposit .

 

Is that right ?

 

 

You can find geological assessment of the area in the link starting from page 4. I'll quote a part of it:

 

 

The Chalk Group comprises carbonate-rich sediments, which

were deposited in a shelf sea that covered much of north-west

Europe for some 40 million years in the later part of the

Cretaceous period.

 

So here you have it. Cliffs are some 100m high and sedimentation took some 40 million years, so on the very rough and average you get about 400k years per meter of sediment. But then again, that is assuming the constant rate of sedimentation which is most likely not true.

[Mike Smith Cosmos]

You can find http://nora.nerc.ac.uk/3700/1/RR06004.pdf"]

 

So here you have it. Cliffs are some 100m high and sedimentation took some 40 million years, so on the very rough and average you get about 400k years per meter of sediment. But then again, that is assuming the constant rate of sedimentation which is most likely not true.

Good! So I was not a mile apart my 1 million years a meter , your 1/2 million miles a meter . You notice I am rounding up numbers , ( the only way I will ever remember them ) . So if I think in terms of looking at a meter of cliff , it could be ( allowing for all the uncertainties mentioned above , and I am still getting my head around what ACME is saying with his post above ) .

 

A million years a meter . ( but more likely half of that , 1/2 million a meter )

.

That then brings me to something I noticed the other day, and with ACME's picture.

 

The inset stones? In the layers!

 

If a meter is half a million years (500,000 years ) , then 10 cm is going is going to be (50,000 years ) , then 1 cm is going to be ( 5000 years ) , which is like human civilisation ( Egyptians to today ) .

 

So if I see an inbuilt stone in the layers , say a small 1 cm stone , it must have been sitting there for the same length of time ( a human civilisation length time 5000 years ) . And if it is a 10 cm stone , that's quite big , it must have been sitting there , layer by layer for 50,000 years . That seems incredible ?

 

I need to go back and examine ACME,s year by year lake and the stones on the ice .

 

Mike

Edited April 22, 2015 by Mike Smith Cosmos

[pavelcherepan]

The lake sediments that ACME has shown in his picture have a different sedimentation history, regime and rate compared to chalk cliffs. You can't use 500ky number for layers on his picture.

 

Also ACME explained how it was sedimented with yearly layers.

Edited April 22, 2015 by pavelcherepan

[Mike Smith Cosmos]

The lake sediments that ACME has shown in his picture have a different sedimentation history, regime and rate compared to chalk cliffs. You can't use 500ky number for layers on his picture.

Also ACME explained how it was sedimented with yearly layers.

Yes , I thought it was radically different, more like tree rings , working on an annual basis .

Thanks ! It is very interesting all the same what ACME is explaining .

 

Going back to the 'normal ' sedimentary rock , if anything is normal . How does it work? That a 1 cm stone is found buried 'alive' in such a ' civilisation life span of time ' deposit . Did it take a whole ' civilisation life time span' to cover over a 1 cm stone ? It does not seem to make sense?

 

Or have I got something fundamentally wrong? Quite probable ! If so what is it I am getting wrong?

I need to fix this , as I am supposed to be giving a presentation to the local Geology Group of the U3A later this year . I have three months to get it right!

 

For instance, do stones always come down in flash floods in an afternoon , then the other sediment blown in by wind , over 100's or 1000's of years ?

 

Mike

Edited April 22, 2015 by Mike Smith Cosmos

[Acme]

Good! So I was not a mile apart my 1 million years a meter , your 1/2 million miles a meter . You notice I am rounding up numbers , ( the only way I will ever remember them ) . So if I think in terms of looking at a meter of cliff , it could be ( allowing for all the uncertainties mentioned above , and I am still getting my head around what ACME is saying with his post above ) .

 

A million years a meter . ( but more likely half of that , 1/2 million a meter )

You cannot make any valid assumptions about the age of a section simply because you know the age of the whole. This applies both to the absolute age of a section, i.e when it formed, as well as how long it took to form.

 

...

If a meter is half a million years (500,000 years ) , then 10 cm is going is going to be (50,000 years ) , then 1 cm is going to be ( 5000 years ) , ...

No. It may be true, but it is not necessarily true. You can't logically make such assumptions. You have to measure and date every particular section.

 

Yes , I thought it was radically different, more like tree rings , working on an annual basis .

Thanks ! It is very interesting all the same what ACME is explaining .

 

Going back to the 'normal ' sedimentary rock , if anything is normal . How does it work? That a 1 cm stone is found buried 'alive' in such a ' civilisation life span of time ' deposit . Did it take a whole ' civilisation life time span' to cover over a 1 cm stone ? It does not seem to make sense?

 

Or have I got something fundamentally wrong? Quite probable ! If so what is it I am getting wrong?

I need to fix this , as I am supposed to be giving a presentation to the local Geology Group of the U3A later this year . I have three months to get it right!

 

For instance, do stones always come down in flash floods in an afternoon , then the other sediment blown in by wind , over 100's or 1000's of years ?

 

Mike

Yes you have something fundamentally wrong. What's wrong is assuming a steady rate of deposition and that there was no intermediate erosion. Edited April 22, 2015 by Acme

[Mike Smith Cosmos]

You cannot make any valid assumptions about the age of a section simply because you know the age of the whole. This applies both to the absolute age of a section, i.e when it formed, as well as how long it took to form. No. It may be true, but it is not necessarily true. You can't logically make such assumptions. You have to measure and date every particular section. Yes you have something fundamentally wrong. What's wrong is assuming a steady rate of deposition and that there was no intermediate erosion.

O.k. Thanks ACME.

It really is back to the drawing board .

 

Are there tables that show the rate of deposition of sediment and thicknesses , for each of the geological periods?

The Cambrian, the Ordovician, the Silurian, the Devonian, the Carboniferous , the Permian, the Triassic , the Jurasic, the Cretaceous , the quartinary , the tersary ? ( hope I have not missed any period or miss spelled?

 

Mike

[Acme]

O.k. Thanks ACME.

It really is back to the drawing board .

 

Are there tables that show the rate of deposition of sediment and thicknesses , for each of the geological periods?

The Cambrian, the Ordovician, the Silurian, the Devonian, the Carboniferous , the Permian, the Triassic , the Jurasic, the Cretaceous , the quartinary , the tersary ? ( hope I have not missed any period or miss spelled?

 

Mike

You can't generalize deposition rate by period any more than by height of a cliff or thickness of a cored deposit, so no there are no tables. For any particular deposit you need to refer to a detailed geological study. Depending on the location and type of sediment, many things can influence the rate of deposition; weather, climate, volcanic eruptions, flooding, or water acidity to name just a few.

 

I haven't looked for a geologic study of your cliffs and the aquifer study cited by pavelcherepan does not look at any specifics of the layers as to age, makeup, thickness or other specifics.