Critical thinking Essay Example | Topics and Well Written Essays - 250 words - 1

Critical thinking - Essay Example This is because, all the three planets originated from tiny grains of dust, forming rocky pebbles. The fact that they developed from similar particles may point to the similarity of their mineral components, though their climate and atmosphere significantly defers. While beach sand, diamond, gold nuggets, water, fishbone, and emerald are minerals, wood and vitamin pills are not a mineral. The former are minerals because they are naturally formed chemical substances that have assumed atomic features. Wood is not a chemical substance but a composition of hard tissues, while vitamin pills not naturally formed. The approximated age of the rocks found in Delaware is 1.2 billion years (Thompson, 2008). This information is obtained through radioactive dating of rocks, as done by the Delaware Geological Survey. Paleocene, approximated to be 65.5 to 56 million years ago, had a cooler and remarkably dry climate. It is during this period that the continents continued their movement to their present positions. There were warm seas that surrounded the world and the modern plant species emerged. Animals started growing bigger during this period and they started occupying diverse niches. Dinosaurs got extinct, and mammals, birds, and reptiles flourished, whi le grass started to grow. Examples of rocks found during this period are the Mesozoic sedimentary