How do scientists explain this.?

The trees were engulfed in lava and petrified in their upright positions millions of years ago.

Well firstly, I agree with the general concensus, this question is far more suited in the "Science" section, and has nothing to do with the validity of Stratigraphy, Geology, god(s) or theology in general.

Secondly, I too agree, that sources for a claim such as this are an intrinsic ingredient of an argument of this distinction, and without providing such, you seriously, and irreperably, dilute the crediblity of your assertions. Science does not exist to "expain away" as you so insultingly put it, rather, that has been, and will continue to be, theology's role in collective culture.

But, to address your question, as adaptively as possible, as it has been impossible to find a cited example of this "discovery" after scouring the internet.

The geologic column, while an accepted scientific reality in many well respected disciplines, paleonotology, paleobotany, geology, and stratigraphy to name a few, it is by no means a rigid and incontradictive scale to which scientist adhere absolutely. The geologic column is often interupted by massively destructive natural events, such as plate tectonics, volcanic erruptions and high-richter earthquakes.

A permineralized tree could have easily been disrupted from its natural, horizontal state, to a more, semi-vertical position by earthquakes or other natural mechanisms of sedimentary motion.

To be incredibly short, it is absolutely impossible to compile a valid, articulate and sensible explanation based off of the embarrasingly small amount of information given.

Yes, trees can stand for several million years. While alive they can stand for an unknown amount of time [Some trees are a few millenniums old], but assuming it died, if say, it got buried [But not knocked down] then it would be braced by the debris around it. Parts of it would fossilize in time, and the exposed portions would keep getting buried [Assuming various mud-slide type events kept occurring]

It isn't that hard to envision.

Never heard a convincing explanation.

It isn't only poly-strata fossil plants going through long ages. Animals such as the famous kamakazi ichthiasaur dino fish has its snout about a million years deeper than its middle.

http://creationismunleashed.blogspot.com/2005/08/k...

It is also a concern that the poly-strate trees appear to almost always missing the root balls as if they were catastrophically uprooted then waterlogged and became upright floaters replanting themselves in muck

Between layers, there also appear to be lack of evidence of remnants of root systems, erosion of soft sock faster than hard, or other types of erosion between layers representing long times betwixt which appears logically not possible. It appears more likely the layers were laid down quickly one after another.

Another oddity which soft sandstone appears often bent and had it been laid down and hardened over long ages should have many cracks and faults instead of being smoothly bent as if bent while soft. This is often the case in many formations in Australia. http://www.answersingenesis.org/articles/am/v4/n2/...

Some animals were fossilized giving birth and some while eating each other. http://www.bible.ca/tracks/rapid-fossils-fish-eati... Clearly evidence that the process was done under catastrophic and not gradual conditions

http://www.creationism.org/images/DenverMuseum/DMN...

If you really wanted an answer you'd ask in the science section. The fact that you're asking here shows that you're a creationist asking what you think is a "gotcha" question.

Read this if you're actually interested in the explanation. I'm betting you aren't, however.

http://amazingdiscoveries.org/AD-ChanceOrDesign-Fo...

basically it's thought to be a combination of rapid deposition and subsidence. I doubt that anyone seriously thinks that 'it would have to have stood upright for several million years', that's just a creationist fantasy, they love it because it sounds so silly, but it is not the only possibility.

Why are you asking a scientific question, which you admit is a scientific question, on a religion and spirituality forum? You won't get the answer you want from here. Take this to the Science questions forum.

Not even knowing anything about this subject, i can think up several logical explanations. A tree does not disprove evolution. You need to do better research...

How about: A valley with a tree is filled with water, the tree fossilizes, and sediments are deposited around the tree.

Just a guess.

You expect us to site our sources yet you can't even do that yourself and any website or book with the word creationism or Christian isn't a valid source. If you can show me a respected and peer reviewed source then I may actually take this question seriously.