"We are likely to be disconcerted....by hiatuses of thought"
-Edmund Wilson
Hiatus-a break, a gap, an interruption, Pause or the unrepresented time. Geologically speaking, hiatus indicates a break or gap in the geologic record, a period of erosion or non deposition. When such hiatus is evident in stratigraphic sections, geologists call it an unconformity. The Earth's crust is changing continuously with upliftment, subsidence and erosional activities. The data preserved in the rocks or as rocks is not complete and continuous. It is much like a book, layer by layer represented by pages. However some pages are torn or missing! These are unconformities. No, they aren't insignificant. They provide you with enough details you need to unravel. They mark the junction where different rocks, formed at different geologic times, by varied forces exist and sometimes they are separated by millions (even billion) of years. We realize that human life span is not even a moment compared to the geologic time!
Here, Precambrian schists which have been tried and tested by heat, pressure over time, folded and faulted may be overlain by smooth and calm horizontal beds of Cambrian (Nonconformities separate igneous/metamorphics from overlying sedimentary strata). Here, the inclined beds may be overlain by horizontal beds (angular unconformity). Some times, both the sedimentary deposits may be horizontal and separated by an erosional surface (disconformity).
James Hutton, often called as 'Father of Modern Geology' (a Scottish farmer and naturalist) and a revolutionary observer of geological sections, made an important observation at the Siccar Point, Scotland in 1788. The juxtaposition of almost vertical layers of gray shale and overlying horizontal layers of red sandstone is seen here. Hutton put forth that the gray shale were deposited, uplifted, tilted, eroded and subsequently covered by ocean, when again the red sandstone was deposited. The boundary between the two rock types at Siccar Point is now called the Hutton's Unconformity, a geological landmark.
(Animations for unconformity formations
Moving away from the geology, we do need to take a break and slow down some times. Essentially, to channelise the thoughts, to erode away the negativities and let new opportunities deposit! A newer self! So, taking a hiatus, doesn't mean calling it a day! :) It means hitting back with a zeal! Happy Hiatus.
