polarity chron中文什么意思

极性时

• polarity:    n. 1.【物理学】(分)极性，磁性 ...
• chron:    时间; 用于元音之前表示
• chron-:    comb. f. 表示“时间”： c ...

百科释义

A Polarity Chron, or chron, is a term used in stratigraphy (a branch of geology) to name the time interval represented by a magnetostratigraphic polarity unit. It represents a certain time period in geologic history where the Earth's magnetic field was in a "normal" and "reversed" position.