拱门国家公园的北窗框景中的炮塔拱门, 犹他州, 美国 Turret Arch framed by North Window in Arches National Park, Utah, USA (© Jim Patterson/TANDEM Stills + Motion)

拱门国家公园的北窗框景中的炮塔拱门, 犹他州, 美国 Turret Arch framed by North Window in Arches National Park, Utah, USA (© Jim Patterson/TANDEM Stills + Motion)

古老岩石的传奇 OldRockArch

古岩石日

今天，让我们重新审视时间的尺度。古岩石日，揭开地球深藏的秘密：亿万年的风沙、海洋与火焰，塑造了我们脚下的世界。在犹他州拱门国家公园，透过北窗眺望炮塔拱门，仿佛凝视一段漫长的史诗。如今的拱门由恩特拉达砂岩构成，而那些砂岩曾是流动的沙丘和浅海，经过漫长侵蚀才雕刻出如今的拱形。可即便如此，这些地质构造仍算年轻。地壳在板块、侵蚀与火山的轮回中不断重生，唯有古老的大陆地盾守护着真正的远古。加拿大的阿卡斯塔片麻岩，约有40亿年历史，是目前已知最古老、仍扎根原处的岩石。

古岩石日不仅讲述岩石的故事，也铭记地质学先驱。泰奥弗拉斯托斯与老普林尼记录了早期矿物研究；1603年，阿尔德罗万迪让“地质学”成为一个学科的名字；150年后，威廉·史密斯绘出了首张地质地图；1785年，詹姆斯·赫顿掀开地球年龄的面纱，让我们第一次意识到脚下世界的浩瀚时光。

Old Rock Day

Today is a day that puts time into perspective. Old Rock Day highlights the vast geological processes that have shaped our world since its earliest eras. In Arches National Park, Utah, Turret Arch—seen through North Window—offers a striking reminder: landscapes can take hundreds of millions of years to assemble. The Entrada Sandstone that forms these arches began as shifting dunes and shallow seas long before erosion carved today's shapes. Even so, these formations are relatively young. Most rocks on Earth disappear over time because plate tectonics, erosion, and volcanism continually recycle the crust. Only the planet's ancient continental shields preserve truly old material. Canada's Acasta Gneiss, about 4 billion years old, is the oldest known rock still rooted where it formed.

Old Rock Day also remembers the pioneers of geology. Theophrastus and Pliny the Elder recorded early mineral studies, while Ulisse Aldrovandi helped establish the term 'geology' in 1603. One hundred fifty years later, William Smith drew the first geological map. And in 1785, James Hutton revealed the Earth's immense age, providing insights that continue to shape our understanding of the ground beneath our feet.