Eons represent the greatest expanses of time.
Which of the following represents the longest expanse of geologic time?
In formal usage, eons are the longest portions of geologic time (eras are the second-longest). Three eons are recognized: the Phanerozoic Eon (dating from the present back to the beginning of the Cambrian Period), the Proterozoic Eon, and the Archean Eon. Less formally, eon often refers to a span of one billion years.
Which one of the following represents the greatest expanse of geological time?
| Question Answer | Which one of the following represents the greatest expanse of geological time? Precambrian | During the early Paleozoic era, South America, Africa, Australia, Antarctica, India, and perhaps China comprised the vast southern continent of ________ Gondwanaland |
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What subdivision of the geologic time scale represents the largest expanse of time?
An eon , the largest division of the geologic time scale, spans hundreds to thousands of millions of years. Geologists generally agree that there are two major eons: the Precambrian eon and the Phanerozoic eon.
Which era of geologic time spans about 88 of Earth’s history?
Precambrian. The Precambrian is the name given to the span of time prior to the Cambrian. The Precambrian period accounts for 88 per cent of geological time.
Which era do we live in?
Officially, we live in the Meghalayan age (which began 4,200 years ago) of the Holocene epoch . The Holocene falls in the Quaternary period (2.6m years ago) of the Cenozoic era (66m) in the Phanerozoic eon (541m).
What are the 4 eras in order?
The four main ERAS are, from oldest to youngest: PreCambrian, Palaeozoic, Mesozoic and Cenozoic .
Which is the shortest Eon?
Quaternary Period
The Quaternary spans from 2.58 million years ago to present day, and is the shortest geological period in the Phanerozoic Eon. It features modern animals, and dramatic changes in the climate. It is divided into two epochs: the Pleistocene and the Holocene.
What is the longest era?
The longest timeframe officially designated as an era is the Paleoproterozoic , which lasted 900 million years from 2,500-1,600 mya.
What is the current era is called?
Our current era is the Cenozoic , which is itself broken down into three periods. We live in the most recent period, the Quaternary, which is then broken down into two epochs: the current Holocene, and the previous Pleistocene, which ended 11,700 years ago.
What are the 4 major divisions of geologic time?
The geologic time scale is divided into eons, eras, periods, epochs and ages with eons being the longest time divisions and ages the shortest.
What are the 3 epochs?
These Epochs are the Paleocene, Eocene, Oligocene, Miocene, and Pliocene .
What is the order of geologic time scale?
The geologic time scale is the “calendar” for events in Earth history. It subdivides all time into named units of abstract time called—in descending order of duration— eons, eras, periods, epochs, and ages .
How long was the Paleozoic era?
Paleozoic ( 541-252 million years ago ) means ‘ancient life. ‘ The oldest animals on Earth appeared just before the start of this era in the Ediacaran Period, but scientists had not yet discovered them when the geologic timescale was made.
How are geologic periods named?
In the early 1800’s a system for naming geologic time periods was devised using four periods of geologic time. They were named using Latin root words, Primary, Secondary, Tertiary and Quaternary . ... Each period name is a link to a web page with details about the geology, climate, plants and animals of that time.
How long is the Precambrian era?
Precambrian, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago .
