Page 43 - 雕鐫海之角
P. 43

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
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