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After precambrian time what are the two basic divisions of the geologic time scale?
The two basic divisions following the Precambrian on the geologic time scale are the Paleozoic Era and the Mesozoic Era. These eras are further divided into periods, such as the Cambrian, Devonian, and Permian in the Paleozoic Era, and the Triassic, Jurassic, and Cretaceous in the Mesozoic Era.
What two gases probably dominated Precambrian Earths atmosphere?
The two gases that probably dominated Earth's atmosphere during the Precambrian era were carbon dioxide (CO2) and nitrogen (N2). These gases were likely present in much higher concentrations than oxygen.
How many periods are in each era?
there are different periods in each era. In the Cenozoic era, there are 2 periods, Quaternary and Tertiary. Mesozoic era has 3 periods, Cretaceous, Jurassic, and Triassic. Paleozoic has 7 periods, Permian, Carboniferous, Devonian, Silurian, Ordovician, and Cambrian. Precambrian is just the present, no time periods in it.
What are the two basic units of the geologic time scale?
EonEraPeriodEpoch! :)
What are two characteristics of precambrian rocks?
Precambrian rocks are typically highly metamorphosed, meaning they have undergone intense heat and pressure. They also often exhibit a lack of fossils due to the limited life forms present during that time.
The two eras of the Precambrian period are?
Archeozoic and ProterozoicThe two periods of the Cenozoic Era are the Tertiary and the Quatemary.
After precambrian time what are the two basic divisions of the geologic time scale?
The two basic divisions following the Precambrian on the geologic time scale are the Paleozoic Era and the Mesozoic Era. These eras are further divided into periods, such as the Cambrian, Devonian, and Permian in the Paleozoic Era, and the Triassic, Jurassic, and Cretaceous in the Mesozoic Era.
How long did the PreCambrian era last?
The Precambrian Era. The name means: "before the Cambrian period." This old, but still common term was originally used to refer to the whole period of earth's history before the formation of the oldest rocks with recognizable fossils in them. In the last few decades, however, geologists have found that there are some hard-to-discern fossils in some Precambrian rocks, so this period is now also known as the Cryptozoic or "obscure life" Eon (from the words "crypt" = "hidden," and "zoon" = "life"). The Precambrian covers almost 90% of the entire history of the Earth. It has been divided into three eras: the Hadean, the Archean and the Proterozoic. Source: Unknown The Precambrian Era comprises all of geologic time prior to 600 million years ago. The Precambrian was originally defined as the era that predated the emergence of life in the Cambrian Period. It is now known, however, that life on Earth began by the early Archean and that fossilized organisms became more and more abundant throughout Precambrian time. The two major subdivisions of the last part of the Precambrian are the Archean (oldest) and the Proterozoic. Rocks younger than 600 Ma are considered part of the Phanerozoic.
What two gases probably dominated Precambrian Earths atmosphere?
The two gases that probably dominated Earth's atmosphere during the Precambrian era were carbon dioxide (CO2) and nitrogen (N2). These gases were likely present in much higher concentrations than oxygen.
Name two subdivisions of the dorsal cavity in humans?
The two subdivisions of the Dorsal Cavity are the Cranial Cavity and the Vertebral Cavity.
What are the subdivisions of Psilotum?
Psilotum is divided into two main subdivisions: Psilotum and Tmesipteris. These subdivisions are based on differences in sporangial structure and plant morphology.
Was the mesozoic era during the precambrien era?
No. The Precambrian Era extended from 4.5 billion years ago to 542 million years ago. The Mesozoic Era lasted from 251 million years ago to 65 million years ago. The Paleozoic Era came in between the two.
What are the two subdivisions of this group?
yea
What is the name given to the early continents?
When the continents were one big land mass it was called Pangaea, the great land mass of Pangaea split in two creating, Laurasia and Gondwanaland.
What is spinal vertebrae called?
Spinal vertebra are called just that. There are subdivisions: cervical (neck), thoracic (chest), and lumbar (lower back). There are two sets that have fused in the adult: the sacrum and the coccyx (tail bones).
Autonomic and somatic refer to the two main subdivisions of what?
peripheral nervous system
What were James Monroe's two terms as president were called the?
The Era of Good Feelings
