Every rock thatcrops out of the ground is a record of the past, and so, in one way or theother it te

Every rock thatcrops out of the ground is a record of the past, and so, in one way or theother it tells something about the environment in which it was formed. Forexample, the dark grey rock with fine and smooth texture you can see on thephoto, looks that way because it formed on deep water sea bottom, where wavesdid not disturb the sediment that make up this rock, nor coarser sandy materialwas brought into it. This was a clam environment which allowed the sea-bottom animalsto feed on the organic matter within the sediment (hence the dark colour) and is the reasonwhy there are so many fossils in it, which I showed in the ‘underwater lilies’post. So, it is all good,and all makes sense!But, then there arethose large pieces of light grey rock (not shown, but some bigger than sedancar) with rough texture and little holes. Like you can see, its pieces are largerthan anything else in a vicinity and are scattered all throughout the dark greyrock. This light grey rock does not belong to the sedimentary environment it isin, it got to where it is by other means than the sediment that surrounds it. Andso, the plot thickens… South coast NSW,Australia -- source link

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