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Normal faults are generated throughout the crater from the impact force. Fault blocks form along the crater walls, breaking off and sliding back into the crater following impact. Rocks around the crater rim fill in much of the crater as it collapses. Furthermore, resurge waves deposit large amounts of rock fragments in and around the crater. It is common for the crater to almost completely refill and subsequently be buried[.]

A well-preserved crab-like fossil that was found by scientists from Curtin University, Australia, has provided evidence of a toxic ocean environment in the Devonian Period, potentially responsible for the mass extinction 380 million years ago. A study, published in the journal Geology, shows that hydrogen sulphide dependant organisms -- known as Chlorobi -- and sulphate-reducing bacteria had preserved the shell and the muscles of the crab-like creature. "The research presents organic geochemistry as a new tool for paleontologists, enabling them to identify invertebrate fossils and reconstruct their environments from a molecular point of view," explained lead author Ines Melendez, a...

In a quest that has taken him from Oklahoma to Morocco and Poland, Brett has analyzed multiple examples of mass trilobite burial. A smothering death by tons of hurricane-generated storm sediment was so rapid that the trilobites are preserved in life position. These geologic "snapshots" record behavior in much the way that ancient Roman life was recorded at Pompeii by volcanic ash. Burial was rapid, Brett said, but also somewhat delicate. Trilobites, like other arthropods, shed their hard exoskeletons from time to time. "We find molted pieces lying immediately adjacent to each other," he said. "This is proof that the...