Page 42 - 雕鐫海之角

交錯層理
風化紋

Weathering rings

Weathering rings form as a result of differential 自然界中的水和空氣，常常會沿著岩石的裂
erosion between the softer original rock and the harder
縫(節理)進行風化作用，若水中或岩石內含有鐵
iron oxide that is periodically redeposited on the rocks.
質，長期作用的結果，鐵質會氧化生成氧化鐵，
A weathering ring is caused by the redeposition of
iron oxide (Fe 2 O 3 ) on the rock. 顏色也轉為褐色或咖啡色。氧化作用越完全，顏
Some of the Fe 2 O 3 is harder than the original rock 色也越深，形成風化紋。風化紋又稱鏽染紋，有
蜂窩岩 and this has caused differential erosion resulting in 時風化後的氧化鐵會和旁邊岩石內的小沙粒，或
numerous weathering patterns on the surface of the
其他物質再結合、膠結，使得岩石硬度變得比周
Honeycomb rock rocks. 圍的大。

蜂窩岩因岩石表層 Honeycomb rock is

呈現蜂窩狀、窗櫺狀的外 a unique landscape to
the area. It is the result
形而得名。其表面凹凸不
of differential erosion
平的原因，為生物在岩石
o n s a n d s t o n e . T h e
上挖掘出小凹穴，加上海 arrangement and abundance
水積蓄在這些凹穴中，沿 of depressions in the
rock surface resembles a
著凹穴的四周產生風化侵
honeycomb.
蝕；或是鹽結晶的生長
與海水重複乾濕作用所產生之化學、物理風化所

致。其中，鼻頭角亦有來自砂岩中的泥糰被侵蝕
所形成之蜂窩岩。

▲ 江惠美 攝
Photography by Jiang Huei-Mei

地質圖書 Geopark at Northeast and Yilan Coast National Scenic Area