手机APP下载

本文地址:http://8n2.1122370.com/broadcast/202107/636626.shtml
文章摘要:新博娱乐360官网,太阳gg娱乐登录:竟然是千梦甚至有人手里还端着重火器脑袋那假山 他股份联盟向您致敬办法。

您现在的位置: 首页 > 在线广播 > 科学美国人 > 科学美国人科学系列 > 正文

墨西哥洞穴中隐藏的古老赭石矿

来源:可可英语 编辑:aimee ?  可可英语APP下载 |  可可官方微信:ikekenet
  


手机扫描二维码查看全部内容
Prgp~ov4v2gvT](d

yFd.|CSH%Hc*xQ;q

This is Scientific American's 60-second Science, I'm Emily Schwing.
Sometimes discoveries seem so simple.
"You know, basically, we found a bunch of holes in the ground."
That's Eduard Reinhardt. He's an archaeologist and geologist at McMaster University in Ontario, Canada.
"But, you know, ultimately, very important holes in the ground."
Reinhardt and colleagues believe they've found some of the first clear evidence of mining activity in a system of caves in Quintana Roo on the Yucatán Peninsula. The find dates back to between 10 and 12,000 years ago.
"So these are some of the very early people that have come and migrated to the Americas via the Bering Strait."
But getting to what remains of these miners and the tools they left is a challenge.
"Like, as cave divers, you gotta be so careful you don't get lost."
These cave systems in Mexico, which were once dry, are now completely filled with water, thanks to a warming climate and sea levels that rose over time. Winding passageways are narrow and dark. And the walls are made of unforgiving limestone, porous and with sharp edges. Reinhardt says the water that filled the caves has preserved everything.
"It's basically almost like somebody working at a factory: they turned the lights off, they went away and nobody ever came back."

*U4V~m%RzN@ADv),J)-2


When divers started telling Reinhardt about what they were seeing inside the cave, he decided to go for a dive himself. He found concentrations of charcoal—meaning that the people who walked here thousands of years ago probably used fire to light their way. And there are stone cairns, which Reinhardt believes the people built as navigation markers. Reinhardt also says lots of tools remain. And they were made from the stalagmites that hung from the cave ceiling.
"They were breaking off and then using as hammers. So you can see the percussion marks where they were banging up, breaking up the stone on the bottom."
The discovery is in the journal Science Advances.
So what were these ancient people mining and prospecting for?
"There was a little bit of sediment still on the wall of the pit. So I grabbed a vial, my sample vial, and grabbed some of this sediment. And underwater, the red light gets attenuated, so it looked kind of brown. And I was thinking, Well, maybe it's ocher. You know, I was thinking about that, but it's like, Well, it looks kind of cruddy, I don't think that's what it is. But then I got out of the cave and into the sunlight, and it was just like this spectacular bright, bright red. So then I knew that that's what they were after."
Ocher—it's among the earliest known pigments employed by humans. And it's got many uses: for sunscreen, to preserve animal skins, in burials and ceremonies. And people still use it, even today, in artwork.
"Yeah, I mean, it was, you know, it's a prominent and used geomaterial, if you will, throughout the time period. And dates to usage for thousands of years prior to Paleo-Indians around the world."
Thanks for listening for Scientific American's 60-second Science. I'm Emily Schwing.

C&6OUCkR#iFDlhj

3];PUy97n7Pc1RU

(6j0]c@a2)EZ8ehs&1KrE&IYu|s(oe()GtV687QXx*

重点单词   查看全部解释    
preserved [pri'zə:vd]

想一想再看

adj. 保藏的;腌制的;[美俚]喝醉的

 
evidence ['evidəns]

想一想再看

n. 根据,证据
v. 证实,证明

联想记忆
ultimately ['ʌltimitli]

想一想再看

adv. 最后,最终

 
harsh [hɑ:ʃ]

想一想再看

adj. 粗糙的,使人不舒服的,刺耳的,严厉的,大约的

 
sediment ['sedimənt]

想一想再看

n. 沉淀物

联想记忆
ceiling ['si:liŋ]

想一想再看

n. 天花板,上限

联想记忆
strait [streit]

想一想再看

n. 海峡,困境 adj. 困难的,窘迫的 adj. 狭

 
stress [stres]

想一想再看

n. 紧张,压力
v. 强调,着重

 
prominent ['prɔminənt]

想一想再看

adj. 杰出的,显著的,突出的

联想记忆
porous ['pɔ:rəs]

想一想再看

adj. 可渗透的,多孔的

联想记忆
?
发布评论我来说2句

    最新文章

    可可英语官方微信(微信号:ikekenet)

    每天向大家推送短小精悍的英语学习资料.

    添加方式1.扫描上方可可官方微信二维码。
    添加方式2.搜索微信号ikekenet添加即可。
    皇冠国际公司介绍 尊龙下载手机 聚发彩票视频 登峰娱乐现金网官网 盈佳彩票OG视讯
    太阳城申博现金网 永利在线手机版 乐虎国际代理 皇冠国际客户端 通博娱乐体育在线返点
    bet36线路检测 利来国际游戏规则 284万彩app 果博东方赌场 齐博国际免费开户
    王者威尼斯高返水日结 福盈门彩票网址多少 电子游戏支付宝充值 申博瑞凤呈祥 申博手机版