Black Mackarble #rocktype #blackmarble
Dr. Mackay Statue Introduction
The posted coordinates lead you to the Dr. Mackay Statue, sculpted from black marble. This earthcache will lead to you to observe black marble and compare it to the rocks used in the pedestal.
This statue is located near Tamsui Old Street, commemorating the contributions of Dr. George Leslie Mackay, a Canadian missionary, to Taiwan. The statue was created by sculptor Chang Zi-Long and represents Dr. Mackay’s dedication to education, medical care, and cultural exchange.
Black Marble Introduction
Black marble is a type of metamorphic rock formed from limestone under high temperature and pressure. Compared to the more common white marble, black marble appears dark due to the presence of organic materials or graphite. It has a dense texture, can be polished to a glossy surface, and may display subtle veins or speckles.
Rock Type Introduction
Rocks in nature are generally classified into three types:
Metamorphic Rocks: Formed when existing rocks undergo metamorphism under high temperature and pressure. Their structure is usually compact. Some, like marble, have indistinct foliation, while others, like schist and gneiss, show distinct foliation.
Igneous Rocks: Formed by the cooling and solidification of magma. The size of mineral grains depends on the cooling speed, such as granite or basalt.
Sedimentary Rocks: Formed by the lithification of sediments, often displaying layered structures or bedding, such as sandstone or shale.
The size of mineral grains is closely related to the rock type:
Metamorphic rocks usually have fine-grained textures with tightly packed minerals.
Igneous rocks: Plutonic rocks (e.g., granite) cool slowly, forming large crystals, while volcanic rocks (e.g., basalt) cool quickly, resulting in smaller crystals or even glass-like textures.
Sedimentary rocks have grain sizes that depend on the origin and environment of the sediments.
This statue is not only a historical symbol but also a testament to nature’s craftsmanship in shaping rocks.
Logging Tasks
1. Walk to the back side of the statue and carefully observe the stone materials of both the statue and the pedestal. Describe the differences in color, texture, or grain size between them.
2. Determine whether the statue and the pedestal belong to the same type of rock. Explain your answer and, if possible, provide geological evidence.
3. Take a photo of the black marble with you, your identifying item, or your GPS device.
Log this EarthCache as “Found it” and send me your suggested answers via message. Please do not post your answers, except for tasks 3, in your log. I hope you enjoy this EarthCache. Favorite Points Appreciated.
馬偕雕像介紹
公布點為由黑色大理岩雕塑而成的馬偕醫師像，這個地質寶會帶您觀察黑色大理岩，並和底座的岩石做比較。
淡水馬偕雕像位於淡水老街附近，紀念加拿大傳教士馬偕醫師對台灣的貢獻。雕像由雕塑家張子隆創作，展現馬偕醫師推廣教育、醫療與文化的精神。
黑色大理岩介紹
黑色大理岩是變質岩的一種，由石灰岩經過高溫與高壓的變質作用形成。與常見的白色大理岩相比，黑色大理岩因含有有機質或石墨而呈現深色。它質地緻密，表面經打磨後會呈現光滑的亮面，有時可見細微的紋理或斑點。
岩石類型介紹
大自然中的岩石可分為三大類：
變質岩：由其他岩石經過高溫、高壓環境下的變質形成，結構通常緊密，有些變質岩葉理不明顯，像大理岩，有些變質岩會有葉理，像片麻岩與片岩。
火成岩：由岩漿冷卻凝固而成，結晶顆粒大小取決於冷卻速度，像花崗岩或玄武岩。
沉積岩：由沉積物膠結化而成，常見顆粒層理或交錯層，像砂岩或頁岩。
岩石的結晶顆粒大小與其類型密切相關：
變質岩通常質地細緻，礦物顆粒排列緊密。
火成岩中的深成岩（如花崗岩）冷卻較慢、顆粒較大，岩石中礦物可以慢慢結晶；噴出岩（如玄武岩）冷卻較快，顆粒較細，甚至形成像是玻璃一樣的岩石。
沉積岩的顆粒大小則取決於沉積物的來源與沉積環境。
這座雕像不僅是歷史的象徵，也是大自然在岩石上的巧手雕琢。
登錄任務
1. 請走到雕像背面，仔細觀察雕像與底座的岩石材質，描述兩者在顏色、紋理或顆粒上的差異。
2. 請判斷兩者是否屬於同一類型的岩石？解釋您的答案，可能的話請提出地質證據。
3. 請與黑色大理岩拍照，照片包含黑色大理岩與你、你的代表物、或你的GPS裝置。
登錄此地質寶為「found it」並透過 geocaching.com 訊息發送給我您建議的答案。除了任務3，請不要在log中公布你的答案。希望你喜歡這個地質寶，歡迎給予FP.
參考書目
台灣地區戶外藝術彙編(北部)，1998