首页 > Term: era
era
The formal geochronologic unit next in order of magnitude below an eon, during which the rocks of the corresponding erathem were formed; e.g., the Paleozoic Era, the Mesozoic Era, and the Cenozoic Era. Each of these includes two or more periods, during each of which a system of rocks was formed. Long-recognized Precambrian Eras are the Archeozoic (older) and Proterozoic (younger).
- 词性: noun
- 行业/领域: 采矿
- 类别 一般矿业; Mineral mining
- Government Agency: USBM
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创建者
- ed.young
- 100% positive feedback
(Milwaukee, United States)