12

I don't think there is a really conclusive absolute test one can carry out without further preparations. In the case of a permineralised fossil, this would probably require thin sectioning and close examination to see if any cellular structure diagnostic of wood remains. Overall I'd think though that if it looks like wood and has been replaced by minerals, ...


6

I'm not sure why you are including shale in your question, unless you are referring to carbonaceous shale, which in not coal, but shale with carbon throughout the matrix of the shale. Shale is an argillaceous rock, and argillaceous rocks are "detrital sedimentary rocks" [1]. They are composed of clays and the bedding plane within the shales is "due to the ...


5

I'm not going to give an extensive account on "mass extinction" epistomology here but I think the first thing one has to consider is the difficulty of studying numerically paleobiodiversity (mostly because of a gappy fossil record but also an historically unbalanced sampling effort and the rock availability for some of the time periods); although, along the ...


3

Depends upon the species. If the pollen spores are large enough, and of wide spatial distribution, and easily recognizable, and preserves well in sediments, and of distinctive age range (geologically), then it could be used. There have been mistakes in the past where modern pollen collected in microscopic pores in older rock, giving the illusion of rock ...


2

Prior to the carboniferous period, and until the human industrial era, the majority of carbon dioxide in the atmosphere was due to volcanoes. For billions of years, geological processes like volcanic eruptions controlled the carbon concentration in the atmosphere, as volcanism is the major way that carbon rises from the mantle into the atmosphere. Most ...


2

In addition to what @GordonStanger said, there are a few other points to consider. Pollens and spores are made out of sporopollenin which preserves way better than what one would expect. Although there isn't probably a perfect 1-to-1 correspondance between pollen morphospecies and the plant species that produced them, there is still a wide variety of pollen ...


2

Rocks are not necessarily made out of minerals. Yes, most of them are but it's not a requirement. Also, not every collection of minerals is a rock. For instance, sand is not a rock. This is not limited to rocks of biogenic origin. Take for example obsidian, or volcanic glass. In some cases there is not a single mineral in the rock, yet it is a rock. My own ...


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