The time units used by scientists to divide Earth's history are part of the
What are your choices?
A. geologic time scale.
B. 24-hour model.
C. 180° longitude.
D. 360° latitude.
and i think the answer is A
yea i was right hopefully this help someone
The time units used by scientists to divide Earth's history are part of the Geologic Time Scale (GTS). The GTS is a system that organizes the history of our planet into different time intervals based on significant geological events and changes.
To determine the time units in the Geologic Time Scale, scientists rely on a combination of methods. These methods include:
1. Absolute Dating: Scientists use various techniques, such as radiometric dating, to determine the actual ages of rocks and fossils. This provides essential data for establishing the time boundaries between different units in the Geologic Time Scale.
2. Fossil Record: Fossils offer important evidence of past life forms and contribute to the development of the GTS. By studying the distribution and characteristics of fossils in different rock layers, scientists can correlate them across different regions and establish relative time relationships.
3. Stratigraphy: Stratigraphy involves the study of rock layers (strata) and their arrangement. The relative positions of different rock layers can indicate the sequence of events and provide additional information for constructing the Geologic Time Scale.
Based on these methods, the Geologic Time Scale is divided into several hierarchical units. The largest units are called Eons, which represent the longest periods of time. The current eon is the Phanerozoic, which began around 541 million years ago.
Eons are further subdivided into Eras, which are characterized by major geological and biological changes. The Phanerozoic Eon is divided into three Eras: the Paleozoic (541-252 million years ago), the Mesozoic (252-66 million years ago), and the Cenozoic (66 million years ago to the present).
Each Era is composed of Periods, which represent shorter intervals of time. For example, the Cenozoic Era includes the Paleogene, Neogene, and Quaternary Periods.
Lastly, Periods are subdivided into smaller units called Epochs, marking even shorter intervals within the geological timescale.
Overall, the time units used by scientists to divide Earth's history are part of the Geologic Time Scale, and their determination relies on a combination of absolute dating, fossil record analysis, and stratigraphy.