A fossil needs four things at once: rapid burial, low oxygen, hard parts or mineral replacement, and long-term stability. Most living things get none of them. Here is how the rare cases happen.
A teaspoon of healthy soil contains more microorganisms than there are people on Earth. That is the first clue that soil is not simply dirt. What is soil, properly defined, is a porous mixture of mineral particles, organic matter, water, air, and living organisms, structured into layers and capable of supporting plant roots. Soil Is … Read more
A glacier looks like a static thing. It is not. Ice a few hundred meters thick behaves like an extremely viscous fluid, creeping downhill at a pace you cannot see and cannot ignore over a few thousand years. What is a glacier, in the strict sense, is a body of ice on land, formed from … Read more
Disclosure: Some links on ScienceBases are affiliate links, which means we may earn a commission if you buy through them. That never changes what we recommend or how we score it — see “How we assessed this” below for the method behind every rating. Read the small print on a fossil kit before buying it. … Read more
What is a volcano? Structurally it is just an opening in a planet’s crust where molten rock, gas, and ash reach the surface. But the interesting question is why rock melts down there in the first place — because under most conditions, the mantle is solid. Why Rock Melts Underground There are three ways to … Read more
What causes earthquakes? The short version: rock on either side of a fault wants to move, friction holds it in place, stress builds for decades or centuries, and then friction loses. The rock snaps to a new position in seconds and the stored elastic energy radiates outward as seismic waves. That is the shaking. The … Read more