Creationist explain the Miocene please

[juvenissun]

Late Carboniferous tectonic subsidence in South Wales: Implications for Variscan basin evolution and tectonic history in SW Britain​

Abstract: Detailed stratigraphic data have been used to backstrip seven sections from the Carboniferous South Wales coal basin. Resulting tectonic subsidence curves for the interval 319-305 Ma (NamurianWestphalian D) are convex-up, indicating increasing subsidence rate with time, with rates between 130 and 250 m Ma-1, suggesting aforeland basin setting. Forward modelling of subsidence due to flexural loading in front of a propagating orogenic wedge shows that an orogenic load migrating in a north-northeasterly direction across SW England between 319 and 305 Ma could have generated the backstripped subsidence patterns. Sensitivity tests show that while many of the forward model parameters are poorly constrained, and the model results non-unique, backstripped subsidence patterns allow reasonable constraint on the different model cases, so that model predictions can be treated as one possibility in a limited range. The predicted load evolution is consistent with current knowledge of tectonic and stratigraphic features of SW England. These results suggest that subsidence in other Late Carboniferous UK basins may also have been influenced by flexure due to a propagating orogenic load.

LINK

Map showing area affected by Variscan orogeny: The South Wales Coal field is located below the R in FORELAND as in BASIN.

Am i educating you yet Juv'y

Two points:

1) A tectonic subsidence of 0.2 mm/yr is NOT fast. Magnitude of sea level fluctuation should be much faster than that to make cyclothem. Crust with such a rate of movement is properly called stable during the cyclic deposition.

2) The orogeny took place AFTER the cyclothem was made. This is part of the meaning in the word "backstrip". The same situation also happened at the same time in North America (The Allegheny). It made the "frontal" part of the cyclothem deeply buried in the foreland basin during the orogeny.

 

[pgp_protector]

A foreland basin does not mean it has to be active. The Atlantic Coast of North America is currently a foreland basin.

My patience to you is getting thin. If you insult me ONE more time, I will not talk to you any more.

[edit] naa too easy.

 

[ChordatesLegacy]

Two points:

1) A tectonic subsidence of 0.2 mm/yr is NOT fast. Magnitude of sea level fluctuation should be much faster than that to make cyclothem. Crust with such a rate of movement is properly called stable during the cyclic deposition.

When talking about sea level rise or fall it is relative rise or fall. If sea levels are falling at let’s say 2 mm a year and a land mass is subsiding by 3 mm a year, what we would observe is a relative sea level rise of 1 mm a year, even though both land and sea levels are dropping.


Using your 0.2 mm as a first order sea level rise (this is quite small)

First order sea level change (tectonic) in the context of the South Wales coal field, the Variscan oroneny.

As far as your 0.2 mm a year; in a million years that is 200 m, assuming that rate of relative sea level rise and the carboniferous is 40 million years in duration, which would make a total relative sea level rise of 8000 m.

On top of this you would have 2nd order sea level fluctuations, as seen when ice caps advance and retreat and yes there were climate fluctuations during the Carboniferous.

Thus what you see in the South Wales coal field is a combination of 1st and 2nd order sea level change.

South wales coal field

The Variscan front laying across the south edge of the South Wales coal field. First order sea level change.

Second order sea level change.

During the Upper Carboniferous Period (a.k.a. Pennsylvanian Period: 286 - 320 mya) nearly all the continents were joined as one giant landmass called Pangea (meaning "all lands"). While massive glaciers existed at the south pole, tropical swampland forests along the equator produced vast peat beds which after deep burial and subsequent heat and pressure were transformed into the Great Bituminous Coalfields of the eastern U.S and western Europe.​

This image courtesy of Christopher R. Scotese Paleomap Project


See Juv'y you do not need massive changes in sea level, just large time frames and we have plenty of time.

P.S. Do you now know what passive margins and foreland basins are?

 

[ChordatesLegacy]

We are digressing off the Miocene somewhat, so I want to move back to Miocene brown coals.

Creationists suggest that Miocene brown coals are magical mystical biblical flood deposits, total ignorance I know, so creationists need to explain the following.


LINK

In a deep, open mine in northeastern Hungary, archaeologists have uncovered an 8 million-year-old forest of preserved cypress trees – and what makes them remarkable is that they’re not fossilized! These trees weren’t petrified nor turned into coal although they had been buried under sand for eight million years – which happened as a result of a sudden sandstorm that covered the forest floor up to about six meters high.

Quite clearly these are in-situ and are NOT magical mystical biblical flood deposits. So the Miocene coals formed as science suggests and that is over 10s of thousands of years.

 

[juvenissun]

When talking about sea level rise or fall it is relative rise or fall. If sea levels are falling at let’s say 2 mm a year and a land mass is subsiding by 3 mm a year, what we would observe is a relative sea level rise of 1 mm a year, even though both land and sea levels are dropping.


Using your 0.2 mm as a first order sea level rise (this is quite small)

First order sea level change (tectonic) in the context of the South Wales coal field, the Variscan oroneny.

As far as your 0.2 mm a year; in a million years that is 200 m, assuming that rate of relative sea level rise and the carboniferous is 40 million years in duration, which would make a total relative sea level rise of 8000 m.

On top of this you would have 2nd order sea level fluctuations, as seen when ice caps advance and retreat and yes there were climate fluctuations during the Carboniferous.

You don't get it (or pretended so). Geology does not work this way. You start to talk geology like creationist does.

 

[ChordatesLegacy]

You don't get it (or pretended so). Geology does not work this way. You start to talk geology like creationist does.

Yes it does work this way.

When you talk about sea level changes in a geological context it's relative sea level changes.


NAME: Relative sea level


BRIEF DESCRIPTION: The position and height of sea relative to the land (relative sea level - RSL) determines the location of the shoreline [see shoreline position]. Though global fluctuations in sea level may result from the growth and melting of continental glaciers, and large-scale changes in the configuration of continental margins and ocean floors, there are many regional processes that result in rise or fall of RSL that affect one coastline and not another. These include: thermal expansion of ocean waters, changes in meltwater load, crustal rebound from glaciation, uplift or subsidence in coastal areas related to various tectonic processes (e.g. seismic disturbance and volcanic action), fluid withdrawal, and sediment deposition and compaction. RSL variations may also result from geodetic changes such as fluctuations in the angular velocity of the Earth or polar drift. Tide-gauge records suggest an average global sea-level rise over the past century of 0 to 3 mm per year, though there is no firm evidence of acceleration in these rates. Indeed, a recent study by the US Environmental Protection Agency predicts that global sea level is likely to rise 15 cm by 2050 (about 3 mm/year) as a result of human-induced climate warming.

SIGNIFICANCE: Changes in RSL may alter the position and morphology of coastlines, causing coastal flooding, waterlogging of soils and a loss or gain of land. They may also create or destroy coastal wetlands and salt marshes, inundate coastal settlements, and induce salt- water intrusion into aquifers, leading to salinization of groundwater. Coastal ecosystems are bound to be affected, for example, by increased salt stress on plants. A changing RSL may also have profound effects on coastal structures and communities. Low-lying coastal and island states are particularly susceptible to sea-level rise. It is estimated that 70% of the world's sandy beaches are affected by coastal erosion induced by RSL rise.

 

[ChordatesLegacy]

Relative sea levels have gone down in parts of Scotland and North West Britain, due to isostatic rebound, which is manifested in raised beaches.

Remember Juv’y this is at the same time sea levels have been rising; last 10000 years.

Caves, formed by the action of the sea, now exist above sea level on a raised beach, North England


Raised Beaches - Arran Scotland

Raised beach North Wales


So Juv'y this is relative sea level fall, becuase the land has raisen faster than sea levels.

 

[juvenissun]

So Juv'y this is relative sea level fall, becuase the land has raisen faster than sea levels.

In the past 10,000 years? You got be kidding, creationist.
Why is the Severn Estuary so wide?

 

[RobertByers]

Tas Walker is full of creationist bull excrement and what does that say about persons who soak up this crap.

If you want to defend him, explain why the brown coals are interleafed with subaerial basaltic flows.

I bet you cannot do it without invoking miracles.

As you said Tas Walker is bullseye about much. 9You did say that right?)
I'm not defending this is a flood event. I would have to study it with proper info. Are you saying these coals have basaltic layers within the coal mass? Fine. The basalt came later.
By the way you keep bringing up about this sand covered forest. Fine. its a post flood event to this creationist and it not being so severly changed by its covering shows a reduced power behind its sudden covering. As this creationist would expect.
You will make points against creationists who insist all these things are from the flood. yet creationism can and I think will become more liberal about allowing post flood events.

 

[ChordatesLegacy]

As you said Tas Walker is bullseye about much. 9You did say that right?)
I'm not defending this is a flood event. I would have to study it with proper info. Are you saying these coals have basaltic layers within the coal mass? Fine. The basalt came later.
By the way you keep bringing up about this sand covered forest. Fine. its a post flood event to this creationist and it not being so severly changed by its covering shows a reduced power behind its sudden covering. As this creationist would expect.
You will make points against creationists who insist all these things are from the flood. yet creationism can and I think will become more liberal about allowing post flood events.

OK you are not defending Tas Walker, that makes sense because his paper on the brown coals is un-defendable.

The basalts and coals are interleafed, i.e. coal-basalt-coal-basalt etc. The basalts are subaerial thus the sequence is subaerial; the basalts did NOT come later.

OK Rob, if the Miocene sand covered coals are a post flood event then the Australian Miocene brown coals are a post flood event, proving Tes Walker wrong.

All you have to do now is explain how the geological record of northern Germany can include all the evidence for a prolonged Ice Age (~2,000,000 years) as well as having the largest in-situ brown coal deposits in the world (~5,000,000 years) and not to mention all the other geological processes during this time.

We also know this area has not changes geologically speaking since Roman written history. So I reckon you have about 1000-2000 years to play with to explain the Tertiary of northern Europe.

Good luck with that.

 

[paug]

Oh my, the creationists are really getting served on the geology front. Thanks CL

I love how, in response to long, structured posts by CL, they muster a one- or two-rowed answer, which attempts to refute something. This refutation is then nulled in the next post.

 

[ChordatesLegacy]

Why is the Severn Estuary so wide?

In what respect; relative to the Atlantic it is not that wide, and of course it narrows to the east, so i am not entirely sure what the question is asking?

 

[ChordatesLegacy]

In the past 10,000 years? You got be kidding, creationist.

Isostatic rebound is the response of the earths crust to the removal of thick ice sheets that covered Northern Europe and Northern North America. In particular the Areas of Eastern Canada and Western Europe, particularly Scandinavia.

Isostatic Rebound in Scandinavia

Isostatic Rebound in Canada


It's probably no accident that two of the largest epicontinental seas (seas extending deep into the continent) on Earth are Hudson Bay and the Baltic, both dead center in areas of active isostatic uplift. In all likelihood, the crust in these regions is still depressed and has not finished rising, and when uplift is complete both seas will mostly or entirely disappear. Gravity measurements suggest that the crust in the Hudson Bay region has another 100 meters still to rise.

So you see Juv'y, all other things being equal, the Baltic Sea and Hudson Bay are both undergoing relative sea level falls.

Rates of Isostatic Rebound
in Great Britain (in mm/yr)

The first change is the result of a very long-term process that operates over geological timescales. During the last Ice Age, northern and central parts of the land mass of Great Britain were covered with glacial ice. As this ice melted, so the loading on the land mass altered. The result of this is the gradual and long-term re-adjustment of the land mass, with the north of Great Britain uplifting and the south sinking as a consequence.

The scientific literature suggests that the fulcrum of this re-adjustment is (very approximately) along an imaginary line drawn from just north of Tees Bay in the east to the Dee Estuary in the west (pictured, left).
The mechanisms involved in this isostatic re-adjustment, as this process is called, involve a considerable time-lag between the melting of the glaciers and completion of the land mass movements.

The existing literature suggests that the rate of uplifting of northern England is beginning to demonstrably slow. This means that the eustatic components of global sea level rise will start to become more pronounced in the region.

So in the North of Britain the maximum present day isostatic uplift is in the order of 2 mm per year, which has slowed considerable over time, however it still gives an uplift of 20 m at this present but slowed rate, which is more than enough to explain the raised beaches of Northern Britain.

Lichen covered beach boulders in an area of Sweden called Höga Kusten (High Coast). This former beach is now several hundred metres above sea level due to isostatic rebound since the retreat of ice from the High Coast 9 600 years ago. The uplift so far is approximately 285 m, which is the highest known rebound. The land is still rising at about 1 cm/year. Höga Kusten was designated a world heritage site on January 27, 2005.

Beach ridges on coast of Novaya Zemlya, arctic Russia. Such ridges are formed by pushing of sea ice; older ridges have been uplifted inland (to left) as a result of Holocene glacio-isostatic rebound. Photo © by J.J. Zeeberg; used here by permission.



If you want more evidence there is mountains of it out there.

So do you now understand Juv’y that when speaking of sea level fluctuations, it is relative.

 

[juvenissun]

So you see Juv'y, all other things being equal, the Baltic Sea and Hudson Bay are both undergoing relative sea level falls.

Here is your problem. On two competing processes, you only recognized the slower one.

To a lay person like Paug, the above line is too simple to explain thing. But I thought to a Master in geology, it should not.

But, I guess it still is. So, here is one more line of explanation: the isostatic rising of ice-covered land is too slow in comparison to the sea level rise by the fast melting ice. The land may be rising in the past few thousand years, but it is a slow rising AFTER a big submerge. Do you see that even the land is continue to rise today, the sea level is rising faster (again)?

I don't believe I need to explicitly spell this out. CL, you are no longer a geologist as you think you were. If you treat me respectfully, I won't mind to help you to review some of the stuff you knew before. After all, in this forum, you are the one closer to be called a geologist.

 

[ChordatesLegacy]

Here is your problem. On two competing processes, you only recognized the slower one.

To a lay person like Paug, the above line is too simple to explain thing. But I thought to a Master in geology, it should not.

But, I guess it still is. So, here is one more line of explanation: the isostatic rising of ice-covered land is too slow in comparison to the sea level rise by the fast melting ice. The land may be rising in the past few thousand years, but it is a slow rising AFTER a big submerge. Do you see that even the land is continue to rise today, the sea level is rising faster (again)?

I don't believe I need to explicitly spell this out. CL, you are no longer a geologist as you think you were. If you treat me respectfully, I won't mind to help you to review some of the stuff you knew before. After all, in this forum, you are the one closer to be called a geologist.

Europe 15,000 years ago

Isostatic Uplift

Present day isostatic uplift

Now Juv’y do you understand relative sea level rise and of course isostatic uplift.

If you have a creationist explanation for raised beaches, feel free to share it with us.

 

[juvenissun]

Now Juv’y do you understand relative sea level rise and of course isostatic uplift.

Judged by your response, I really don't think you are interested in honest discussion. And certainly you are not trying to learn.

Well, that is fine with me.

 

[Tomk80]

Judged by your response, I really don't think you are interested in honest discussion. And certainly you are not trying to learn.

Well, that is fine with me.

And you are? Really, all you have offered so far is one-liners. That does not indicate either an interest in honest discussion or a willingness to learn.

Remove the beam in your own eyes first, juvenissun.

 

[juvenissun]

And you are? Really, all you have offered so far is one-liners. That does not indicate either an interest in honest discussion or a willingness to learn.

Remove the beam in your own eyes first, juvenissun.

One line is all it takes for a reply to lower level gibberish. Sometimes, it only takes one word. Sometimes, it only takes one look at the face.

That is the art of teaching.

 

[Nathan Poe]

One line is all it takes for a reply to lower level gibberish. Sometimes, it only takes one word. Sometimes, it only takes one look at the face.

That is the art of teaching.

It's also the art of blather.

 

[paug]

One line is all it takes for a reply to lower level gibberish. Sometimes, it only takes one word. Sometimes, it only takes one look at the face.

That is the art of teaching.

Creationist hot air - gotta love it.


Juvenissun, if you're so "in-touch" with the art of teaching, why not share some of it? Provide us with some sound claims backed with reasonable evidence and I assure you, your reputation will get much much better. No point in whining that "Boohoo, atheists are unwilling to learn, I tried my best", when it's quite clear that you haven't. Or can't - because your curriculum can't bear its own weight.