Growing the Geologic Column

It shows ways of contrasting intrusive with extrusive igneous rocks. The Cardenas Basalt looks essentially like the diagram. Edited by edge, : No reason given.

I don't know why HBD said such a thing. Buried geologic layers are made up of or include many of the same things we see on and near the surface today, such as lava basalt, volcanic ash, sand, silt, mud, clay, burrows, tracks, life (in the form of fossils), even things like entire oyster beds. To me the majority of geologic layers look like lithified ancestors of the layers forming today. You make it sound like an ancient Earth is just something geologists made up, instead of something that is supported by literally mountains of evidence. The side in this debate who is making things up left and right is you.--Percy

Oh come on!The way to tell the difference between a sill and a subaerial flow is by contact metamorphosis surfaces. In the problem presented, is there contact metamorphosis in the contact between the lava flow and the shale above it? NO. So the shale was not there when the lava extruded and it was NOT an intrusion into the shale layer.If you want to know if the Cardenas lava is intrusive or extrusive, look at the contact metamorphosis between it and the layer that overlies it.HBD

According to Old Earth assumptions, but they are just assumptions, something you take for granted, but if a worldwide Flood DID occur that would provide the very situation of changing sea levels where Walther's Law operates, but much faster. In the case of the Flood it took about five months for the level to rise to its fullest height and after it had stayed at its height for a month or two it took another five months to regress. Plenty of time to deposit all those sediments the forty days and nights of heavy rain had dumped into the rising water. Yes, that's the idea. And so much the more if the Pacific wandered up to meet the Atlantic in the Midwest.

You're right, but if you do a Google search for "intrusive basalt" (including the quotes) you'll get thousands of results. During the discussion while poking around on the web it seemed to me like there are many articles out there that aren't careful in their terminology and refer to sills and dikes as just "basalt" without the "intrusive" modifier.So I wonder if it might be better to not belabor the point about correct usage of the word "basalt" and instead just always be clear about whether we're talking about extrusive or intrusive, or about lava or magma, or about sills or lava layers.--Percy

I guess its just that to someone who doesn't study these things a lot, it can be hard to see the kind of processes that will someday, maybe, become rock. Its like looking at a still of a movie and trying to figure out the plot. I too see the same processes at work today that formed the features of the past. However, I can see how someone like Faith would see it as strangely different. It does take some research to understand it.HBD

I have yet to be shown that the supported assumption of an old earth is wrong. Perhaps you can do that? Well-supported assumptions. Not at all. I agree that some processes are rapid. Actually, the law would be in effect, but there would be vanishingly little time to produce a record. Not enough time to create the deposits that we find. Where did the sediments come from? How did dinosaur tracks form in the middle of the fludde? Where did evaporites come from?Why are these questions radioactive to YECs? Please show what rocks eroded to provide the sediments in 40 days. If, if, if...Please provide evidence of such a fludde.

It's hard sometime to wrap your mind around geological concepts. To me, a Mesozoic rock looks different from a Paleozoic rock, different from a Proterozoic rock. I can imagine someone trying to figure out how a modern stream channel gets incorporated into the geological record; keeping mind that all we really are familiar with is terrestrial processes. I think if you see a lot of rocks with similar depositional environments from various ages, it becomes easier.

You're probably right, but most stratigraphic sections I have found only identify them as "basalt" which Faith simply dismisses as intrusive. Just like I presented 4 sections with clear lava layers between sedimentary layers and what I get is "basalt IS usually intrusive into sedimentary rock,"Grrrr.HBD

I'm reading a fair amount of "Yes, but.." material from the evo side.Basalt, diabase (also called dolerite), and gabbro all have the same (general) chemical composition. I say "general", in that there is a considerable amount of variation.The difference is grain size, fine to coarse for the above. And yes, there are dikes and sills that are considered to be basalts (or basaltic).Shallow and/or small intrusives can be quite fine grained. On point about intrusives that didn't seem to be covered very well, is that they would tend to have chilled margins. In other words, the margins cooled faster and are finer grained, and the interiors cooled slower and are coarser grained. That they are sills or dikes automatically means "intrusive". Intrusive dike would be a redundancy.Gotta go.Moose

There are no assumptions. The amount of evidence for an ancient Earth is massive across many fields of science, not just geology. You're just tossing grenades into the discussion. Let's keep the focus on the topic. The tsunami wave that flowed over Japan did not leave behind anything resembling Walther's Law. That's because Walther's Law requires geologic time in order to operate. Waves have to pound shorelines day after day and year after year for eons while runoff from land feeds the process as a source of the sedimentary material laid down by Walther's Law. A flood, no matter how large, cannot leave behind this kind of sedimentary sequence nor even these kinds of sedimentary layers to any significant extent. If Edge was describing a situation where in just a few months the Atlantic Ocean transgressed all the way to the mid-west, then no, we wouldn't observe anything like the flood layers you keep describing, not even precursors.If Edge was instead describing a situation where in geologic time the Atlantic Ocean transgressed all the way to the mid-west, then yes, we would observe the beginnings of the types of layers normally seen in the geologic record.--Percy

I would say that the term 'basalt' generally refers to an extrusive igneous rock, unless qualified or otherwise determined by context.A coarse-grained basaltic (composition) rock would be called a gabbro, so many dikes are actually gabbro. These are almost certainly intrusive in character. I know of no extrusive gabbros, or granites.In a way it is unfortunate that geology is such an old science that there are many archaic terms, and casually used words, along with words derived from a variety of languages just to confuse things. However, it makes for a rich history and colorful language, just takes a long time to master it.ETA: I should add that 'basalt' definitely refers to a fine-grained rock. Being casually dismissed is a sure insult. Edited by edge, : No reason given.

Well, sure, but misuses like that are what you find on the Internet, and the Internet is where Faith finds most of the raw material from which she constructs her misimpressions. The first result of a Google search for "intrusive basalt" is a website with the phrase "intrusive basalt dike".But my main concern is when "basalt" is used without a modifier. We could insist that it always means extrusive, but we'd be fighting Faith forever on that definition because half the Internet uses it to also refer to sills, plugs and dikes.--Percy

I think this comes from trying to provide a textbook in piecemeal fashion. And most of the discrepancies are really not relevant to the actual discussion being driven by Faith's strange understanding of geological evidence.

Obviously. But it is far from unique on Earth. And yet you have claimed that all sedimentary layers were in place before these igneous layers formed.There's a lesson to be learned from that if one were interested in learning. Edited by Admin, : Fix typo.