https://padlet.com/303947/y8tvdwmb0ff9 Made with charm en-us 2018-01-30 18:26:42 UTC 2018-01-30 19:00:42 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Terminator.png 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226252600 Uniformitarianism is defined in the authoritative Glossary of Geology as "the fundamental principle or doctrine that geologic processes and natural laws now operating to modify the Earth's crust have acted in the same regular manner and with essentially the same intensity throughout geologic time.

]]> 2018-01-30 18:28:12 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226252600 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226255373 In physics and systems theory, the superposition principle, also known as superposition property, states that, for all linear systems, the net response caused by two or more stimuli is the sum of the responses that would have been caused by each stimulus individually.

]]> 2018-01-30 18:32:45 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226255373 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226256404 Organisms buried in sediment may decay or dissolve away leaving a cavity or mold. If the space is subsequently filled with sediment, an external cast can be made. Molds and casts are three dimensional and preserve the surface contours of the organism.

]]> 2018-01-30 18:34:26 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226256404 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226257303 In geology, petrifaction or petrification is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals.

]]> 2018-01-30 18:36:01 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226257303 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226259037 When dinosaurs walked through the mud they left footprints, just like you do on a muddy trail. Over time these footprints were filled with sand or small pebbles and eventually hardened into rock. The footprints were preserved for millions of years until erosion brought them to the surface where people can see them.

]]> 2018-01-30 18:38:57 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226259037 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226260023 A mold is the impression and void (space, hole) that an organism or organism's body or body part leaves in the sediment. ... A cast is made of different material than a mold. Both casts and molds are types of fossils. Sometimes the mold and cast are found together, although molds are more than casts.

]]> 2018-01-30 18:40:35 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226260023 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226261464 These rock layers formed from sediments deposited in a lake. ... In the same way, geologists figure out the relative ages of fossils and sedimentary rock layers; rock layers, and the fossils they contain, toward the bottom of a stack of sediments are older than those found higher in the stack. Radiometric Dating.

]]> 2018-01-30 18:42:59 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226261464 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226261774 Scientists who study fossils are called paleontologists. ...Rocks formed during the Phanerozoic Eon may have fossilsof complex animals and plants such as dinosaurs, mammals, and trees. We study Earth's history by studying the record of past events that is preserved in the rocks.

]]> 2018-01-30 18:43:33 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226261774 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226263065 By dating the rocks in the ever-changing crust, as well as neighbors such as the moon and visiting meteorites, scientists have calculated that Earth is 4.54 billion years old, with an error range of 50 million years.Feb 27, 2014

]]> 2018-01-30 18:45:42 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226263065 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226263529 It's a bug trapped in amber from the dinosaur age.]]> 2018-01-30 18:46:28 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226263529 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226265673 With the passage of time and the accumulation of more particles, and often with chemical changes, the sediments at the bottom of the pile become rock.Gravel becomes a rock called conglomerate, sand becomes sandstone, mud becomes mudstone or shale, and the animal skeletons and plant pieces can become fossils.Aug 14, 1997]]> 2018-01-30 18:49:56 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226265673 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226266057 law of superposition. noun. Geology. a basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.

]]> 2018-01-30 18:50:35 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226266057 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226266796 The Eras are the next largest interval units into which the Geologic Time is divided and represented on the chart. Eras encompass major intervals of Time and are defined based on the fossil life-forms found in the rock layers, and the Law of Superposition.]]> 2018-01-30 18:51:41 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226266796 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226267394 The Cenozoic Era is the most recent of the three major subdivisions of animal history. The other two are the Mesozoic and Paleozoic Eras. The Cenozoic spans only about 65 million years, from the end of the Cretaceous Period and the extinction of non-avian dinosaurs to the present. The Cenozoic is sometimes called the Age of Mammals, because the largest land animals have been mammals during that time. This is a misnomer for several reasons. First, the history of mammals began long before the Cenozoic began. Second, the diversity of life during the Cenozoic is far wider than mammals. The Cenozoic could have been called the "Age of Flowering Plants" or the "Age of Insects" or the "Age of Teleost Fish" or the "Age of Birds" just as accurately.]]> 2018-01-30 18:52:39 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226267394 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226267933 Petrified fossils form when minerals replace all or part of an organism. Water is full of dissolved minerals. It seeps through the layers of sediment to reach the dead organism. When the water evaporates, only the hardened minerals are left behind.]]> 2018-01-30 18:53:32 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226267933 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226268521 A fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.]]> 2018-01-30 18:54:27 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226268521 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226269138 A metamorphic rock is a result of a transformation of a pre-existing rock. The original rock is subjected to very high heat and pressure, which cause obvious physical and/or chemical changes. Examples of these rock types include marble, slate, gneiss, schist.]]> 2018-01-30 18:55:23 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226269138 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226269559 Rock that has formed through the deposition and solidification of sediment, especially sediment transported by water (rivers, lakes, and oceans), ice ( glaciers ), and wind. Sedimentary rocks are often deposited in layers, and frequently contain fossils. Note :Limestone and shale are common sedimentary rocks.]]> 2018-01-30 18:56:06 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226269559 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226269856 Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks. They are formed by the cooling of molten magma on the earth's surface. The magma, which is brought to the surface through fissures or volcanic eruptions, solidifies at a faster rate.]]> 2018-01-30 18:56:33 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226269856 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226270294 Replica casts are created by molding and then casting an original fossil so all of the detail is preserved, but the original is safely stored in a museum or other responsible collection. ... Sometimes replicas are made by reconstructing partial casts or by paleo-artists who sculpt fossils based on scientific references.

]]> 2018-01-30 18:57:19 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226270294 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226270677 In physics and systems theory, the superposition principle, also known as superposition property, states that, for all linear systems, the net response caused by two or more stimuli is the sum of the responses that would have been caused by each stimulus individually.]]> 2018-01-30 18:57:53 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226270677 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226271075 From largest to smallest, this hierarchy includes eons, eras, periods, epochs, and ages. ... The time before the Phanerozoic is usually referred to as the Precambrian and is usually divided into the three eons shown. The Phanerozoic is subdivided into three major divisions: the Cenozoic, Mesozoic, and Paleozoic Eras.]]> 2018-01-30 18:58:33 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226271075 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226271492 relating to or denoting the present epoch, which is the second epoch in the Quaternary period and followed the Pleistocene.]]> 2018-01-30 18:59:12 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226271492 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226271769 Paleontology is the study of the history of life on Earth as based on fossils. Fossils are the remains of plants, animals, fungi, bacteria, and single-celled living things that have been replaced by rock material or impressions of organisms preserved in rock. ... Amber, for instance, is hardened, fossilized tree resin.Apr 29, 2011]]> 2018-01-30 18:59:37 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226271769 303947 https://padlet.com/303947/y8tvdwmb0ff9/wish/226272326 These rock layers formed from sediments deposited in a lake. ... In the same way, geologists figure out the relative ages of fossils and sedimentary rock layers;rock layers, and the fossils they contain, toward the bottom of a stack of sediments are older than those found higher in the stack. Radiometric Dating.]]> 2018-01-30 19:00:30 UTC https://padlet.com/303947/y8tvdwmb0ff9/wish/226272326