Mod12

• Only a small percentage of ancient living remnants is preserved as fossils, and usually only those that have a solid and rigid skeleton were preserved.
• To be considered as an index fossil, a fossil must be rare.
• Preserved wastes products and worm burrows are examples of Trace fossils.
• Fossils are remnants, impressions or traces of plants and animals preserved in strata of the earth that give evidences of their presence in the geological past.
• The branch of the science that deals with the study of fossils is known as Paleontology.
• The process by which organic material becomes fossil and is turned into a stony substance is known as Petrification.
• The principle of superposition states that the oldest layer of rock is located at the bottom.
• The group does not include the Eras.
• When scientists use logic to determine the age of one fossil compared to another, it's called relative dating.
• Paleontologists believe the Earth is 4.6 billion years old.
• The principle used to determine whether one sedimentary rock is older than another is known as Law of Superposition.
• Geologic Time Scale is a record of the known history of rocks and fossils.
• The most recent era of time, the one that we are currently in, is the Cenozoic era.
• The Precambrian era covers almost 90% of the Earth’s history.
• The most important and the largest intervals of geological time are the Eras, which are many millions of years in duration.
• Index fossils are used to define and identify subdivisions of the geologic time scale.
• The history of the Earth can be understood through geologic time.
• The oldest sedimentary rock lies at the bottom and the youngest lies at the top.
• Index fossils are utilized in the formal architecture of geologic time for outlining the ages, epochs, periods, and eras of the geologic time scale.
• The Law of Superposition states that the oldest rock layer is located at the bottom.
• The oldest fossils in the fossil record date from 3.5 billion years ago, however it wasn't until around 600 million years ago that complex, multi-cellular life began was first preserved in the fossil record.
• Fossil preservation occurs when an organism is preserved to become a fossil.
• Strata refers to the layer in which fossils are found.
• Superpositions are layers that have hardened.
• Trace fossils are fossils that indicate the presence of an organism but do not include the organism itself.
• Under normal conditions, sedimentary rocks are laid down one over the other in ascending order; thus superpositions of rocks are maintained.
• The Phanerozoic eon has been divided into three eras – the Paleozoic (early life), Mesozoic (middle life) and Cainozoic (recent life).
• Coprolites are remnants of preserved plants and animals.
• The Geologic Time Scale is a table showing the sequence of geological periods with in the history of earth.
• Individual beds differ considerably from each other by their structure, texture, color etc.
• Index fossils are fossils used as guide fossils to mark the ages, epochs, periods, and eras of the geologic time scale.
• The largest intervals of geologic time are Eon which covers a period of several hundred million years.
• All the eras named in the table are divided into periods, which are generally named after the places in Europe where the rocks of that period were first studied.
• Some of the boundaries of those subdivisions are defined by mass extinction events, just like the Permian-Triassic extinction.
• Earth Science Quarter 2 - Module 13: Geologic History of the Earth is a module developed by the Department of Education - Division of Cagayan de Oro.
• Vital and important events in the development of the chronostratigraphic time scale were the realizations and assumptions by English engineer and geologist William Smith and Scottish geologist James Hutton.
• The first organism on Earth was probably bacteria.
• The Precambrian era covers almost 90% of the Earth’s history.
• The most important and largest intervals of geologic time are eras, which are many millions of years in duration.
• Various phenomena and events in widely separated parts of the planet are correlated using an internationally acceptable, standardized time scale.