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The Permian rocks lie just below the next geological period, the Triassic.
二疊紀(jì)巖層的上方自然是下一個地質(zhì)年代，三疊紀(jì)。
This is the Permian/Triassic boundary, the boundary between the Permian rocks below us and the Triassic rocks above us,
這就是二疊系-三疊系界線層，這個界線層是在我下方的二疊紀(jì)巖層和我上方的三疊紀(jì)巖層之間，
and this is the boundary where the mass extinction takes place.
這個界線層就是生物大滅絕發(fā)生的時期。
What we're trying to do here is to determine
我們在此的工作就是測定
how long it took for the sediments at the boundary in which the mass extinction took place to be deposited.
在這個發(fā)生大滅絕的地層中的沉淀物的堆積經(jīng)過了多長時間。
Rampino's system relied on the observation that the earth's orbit round the sun alters minutely every 23,000 years.
Rampino的系統(tǒng)依賴一個現(xiàn)象，即地球圍繞太陽運(yùn)行的軌道每隔23000年就會發(fā)生微小的改變。
This produces small changes in the climate.
這也導(dǎo)致氣候發(fā)生些許變化。
This, in turn, produces distinctive bands in the rock one every 23,000 years.
繼而造成每隔2.3萬年形成一個獨立的巖層。
Rampino took photos of the rock bands and fed them into a laptop.
Rampino拍下了巖層的照片，并把它們輸入手提電腦。
When I digitally enhance the photographs, I can manipulate the data to bring out the 23,000 year cycle,
我增強(qiáng)照片的分辨率，通過分析數(shù)據(jù)我就能找出2.3萬年的周期，
and that gives me a time-frame in which to put the mass extinction.
由此我也能找出大滅絕發(fā)生的時段。
