新奇事件簿 小行星岩层揭露恐龙灭绝细节（在线收听）

Scientists say they have unearthed details of how the dinosaurs were wiped out 65 million years ago. A team of geophysicists is analyzing rock formations in a crater under the seabed off Mexico. The rocks contain the remnants of the cataclysmic aftermath of a gigantic asteroid impacting with Earth. The scientists say the layers of rock they have extracted reveal a step-by-step account of the destruction that happened after the impact as rock and sediment settled on top of each other in revealing layers. Geophysicist Jay Melosh from Purdue University said: "It tells us what went on inside the crater on that day of doom that killed the dinosaurs. All of this mayhem is directly recorded in the core."

科学家们称他们发现了6500万年前恐龙灭绝的细节。一组地球物理学家正在分析墨西哥海底一个陨石坑的岩层。这些岩石中含有灾难性余波的残留物，这是一个巨大的小行星撞击地球后所产生的余波。科学家们表示他们所提取的岩石外层进一步揭示了撞击后的破坏过程，当时岩石和沉积物在裸露的岩石层上相互堆积。来自普渡大学的地球物理学家Jay Melosh说到：“它告诉了我们在恐龙灭绝的那一天陨石坑里发生了什么。这场混乱中的一切都直接记录在了核心内。”

Scientists say the asteroid was around three to four kilometers wide. It smashed into the ocean and created a hole 160kms wide and 20kms deep. This triggered a chain reaction of earthquakes, tsunami, icecap melting, landslides and fires that forever changed the geology and life forms on Earth, killing off the dinosaurs. The asteroid's impact hurled out rock and minerals and created a massive crater. Molten rock fell back into the crater, which was then filled with ocean water from tidal waves. This water was full of soil, vegetation, animal life and other debris, all of which settled in layers ready for scientists to analyze millions of years later. The scientists say this layer-forming process took just a few hours.

科学家们称这颗小行星约有3到4公里宽。它撞向海洋，造成一个宽160公里、深20公里的洞。这引发了地震、海啸、冰盖融化、山体滑坡以及火灾等连锁反应，对地球上的地质和生命形式造成永久改变，导致了恐龙灭绝。小行星的撞击抛出了岩石和矿物质并形成了一个巨大的陨石坑。熔岩落回火山口，火山口中满是来自潮汐波的海水。这些水中满是土壤、植被、动物生命和其他残骸，所有这些东西都一层层地沉淀下来，供科学家在数百万年后进行分析。科学家们称这一外层形成的过程仅需几小时。