the time of the physical formation and development of the earth (especially prior to human history)

hence it is considered that a galactic year can be based on to institute an ideal geologic time scale in which a galactic year is an era.

银河年是建立理想地质年代表的基础，每一个银河年就是一个代。

although rare on human timescales, over geologic time earthquakes are frequent in the area.

影响地质时期的大地震虽然在人类的历史中非常罕见，但该地区地震活动自古以来就非常频繁。

over geologic time the central volcano becomes extinct, followed by erosion and subsidence beneath the sea surface, leaving the coral reefs as a ring around (or cap on) the submerged island remnant.

由于侵蚀和海底的下沉，经过地质时代的变迁，中心的火山已经不见蹤影，而只留下珊瑚礁环绕或覆盖在沉入海底的火山岛上。

as he explains, the geologic time scale is largely based on the stratigraphic record.

他解释说，地质时间尺度很大程度上基于对地层的记录。

for the response of the ice sheets to a still warmer world, older periods in geologic time offer parallels.

对于冰川对变暖世界的回应，以前的地质时期也出现过相似的状况。

geologic time unit, rock stratigraphic units and time stratigraphic unit.

地质年代单位、巖石地层单位、年代地层单位。

the vastness of geologic time and the slowness of geological processes are difficult to capture in a simple chart.

地质时代的浩瀚和地质作用的缓慢是难以在一幅简单的表格中表达的。

igneous rock reservoirs are characterized by their extensive distribution, long geologic time and no exclusiveness of rock types.

火成巖油气储层具有分布范围广、地质时代长、不具巖石类型的专属性。

a key aspect of plate tectonic theory is that on geologic time scales ocean basins are transient features, opening and closing as plates shift.

板块运动理论的一个关键点就是在地质历史的尺度内，海洋盆地的开合是因为板块转换，具有转换特征。

「it must have happened in a matter of weeks, 」 says elrick. 「what we see here is the death of a peat swamp, a moment in geologic time frozen by an accident of nature.」

elrick说：「当时的那场变故一定是在几周内发生的，我们现在所看到的这片泥炭沼泽遗迹，在地质学时间上只是大自然一次瞬间意外的快照。」

using the codes (1 to 6) representing the different time periods in the evolutionary time scale shown in figure 1), indicate the geologic time period that best corresponds to each description.

用地质年代表（表1）中的不同年代的编号1-6，来代表每个描述所出现的地质年代。

though they seem to creep along at impossibly slow speeds, in geologic time glaciers are relatively fast, powerful landscape artists that can carve out valleys and fjords in just a few thousand years.

尽管它们的变化速度似乎缓慢的不可思议，但相对于地质时期来说，冰川是个快速、强大的雕刻艺术家，仅在数千年时间内就雕刻出了大量的山谷和峡湾。