SSS 2008-09-24
时间：2018-12-24 作者：英语课 分类：Scientific American(九)月
This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.
There’s a Native American site in Ohio that appeared to be a fort. But recent discoveries by archaeologists at the University of Cincinnati show that’s not the case. Instead, it’s a two-thousand year old Shawnee water management system. It stretches out almost six kilometers. That’s much larger than what had been thought to comprise the so-called fort. It’s one of the largest such sites in the country.
What had been thought to be gates for military protection are actually a series of dams and irrigation canals. There are logs and clay bricks for damming; raceways for flowing water originate in far-off springs. The water was stored and channeled for irrigation. Drill cores show water sediments 1 and clay.
The site demonstrates a sophisticated knowledge of engineering—which archaeologists did not realize that Native American communities might have. The site also reveals an emphasis on public works, rather than on war. So this discovery might rewrite a bit of history. Another interesting note: Shawnee remains 2 from the time are typically of petite, graceful 3 men—and robust 4, muscular women. So it was probably the women who built the water system. Which means even more history to rewrite.
Thanks for the minute for Scientific American's 60-Second Science. I'm Cynthia Graber.
- When deposited, 70-80% of the volume of muddy sediments may be water. 泥质沉积物沉积后，体积的70-80％是水。
- Oligocene erosion had truncated the sediments draped over the dome. 覆盖于穹丘上的沉积岩为渐新世侵蚀所截削。
- He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
- The remains of the meal were fed to the dog.残羹剩饭喂狗了。