📌 Introduction
Welcome to Tung Ping Chau, the easternmost island of Hong Kong and a part of the Hong Kong UNESCO Global Geopark. Unlike most of Hong Kong, which is composed of volcanic granites and tuffs, Tung Ping Chau is famous for having the youngest rocks in the territory: sedimentary siltstones and mudstones formed about 55 million years ago (Early Tertiary period) in an ancient lake system.
One of the most famous landmarks on the island is Lung Lok Shui, which literally translates to "Dragon Entering the Water". It is a striking, long, triangular rock bed that runs from the hillside straight down into the sea, looking remarkably like the spiked spine of a mythical dragon.
📌簡介
歡迎來到香港最東端的島嶼——東平洲（香港聯合國教科文組織世界地質公園的一部分）。與香港大部分由火山花崗岩和凝灰岩構成的地質不同，東平洲以擁有香港最年輕的岩石而聞名：大約於5500萬年前（早第三紀）在古老湖泊中形成的沉積粉砂岩和泥岩。
島上最著名的地標之一是「龍落水」。這是一條引人注目的長條形、三角形岩層，從山坡一直延伸到海中，外形極像一條神話中的巨龍脊背潛入水中。
🧪 Geological Background
The unique appearance of Lung Lok Shui is a textbook example of differential weathering and erosion operating on sedimentary rock layers.
1. Sedimentary Layering & Composition
Tung Ping Chau's rocks are finely layered Ping Chau Formation sedimentary rocks. Over millions of years, different types of sediment settled in an ancient lake bed.
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The "Dragon Spine" (The Upper Bed): The layer that forms the spine of the dragon is a thick, light-colored bed of cherty siltstone / dolomitic siltstone. It is exceptionally hard, dense, and highly resistant to physical weathering.
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The Surrounding Layers (The Underbelly): The rock layers underneath and adjacent to the spine are made of softer, darker mudstones and siltstones which are rich in iron and other minerals.
2. Differential Erosion
As wind, rain, waves, and coastal tides battered the coastline over thousands of years, the softer mudstone layers underneath eroded away at a much faster rate. Because the upper cherty siltstone layer was so tough, it resisted the erosion, leaving it protruding sharply above the landscape as a long, continuous ridge.
🧪 地質背景
「龍落水」獨特的外觀是沉積岩層受到差異風化與侵蝕（Differential Weathering and Erosion）的教科書級範例。
1. 沉積地層與成分
東平洲的岩石屬於微細層理的「平洲組」沉積岩。數千萬年前，不同類型的沉積物在古老湖泊中沉澱。
2. 差異侵蝕
千百年來，隨著風、雨、海浪和潮汐不斷拍打海岸，下方較軟的泥岩層以更快的速度被侵蝕。由於上層的燧石質粉砂岩非常堅韌，它抵禦了侵蝕，最終凸顯出來，形成了一條長而連續、高聳於地面上的岩脊。
📋 Logging Tasks / Log 要求
To log this EarthCache, please visit the coordinates at Lung Lok Shui and answer the following questions. Do not post the answers in your log. You can log this cache without waiting for my confirmation, but you must send me the answers at the same time, by the system of Message Center of geocaching.com. If there is a problem with your answers I will notify you.
要log found這個 EarthCache，請前往龍落水坐標處並回答以下問題。請勿將答案發表在log中。透過 geocaching.com 的訊息中心系統將答案發送給我後，你可以直接log found此藏寶，無需等待我的確認。如果你的答案有任何問題，我會通知你。
1.Texture & Hardness (質感與硬度)：
Observe the 'Dragon Spine' and touch the light-colored "Dragon Spine" layer and then touch the darker, lower layers underneath it. Describe the difference in texture and grain size between the two layers. Which one feels more brittle or crumbly?
觸摸淺色的「龍脊」岩層，然後觸摸其下方顏色較深、位置較低的岩層。描述這兩層岩層在質感和顆粒大小上的差異。哪一層感覺更脆或更容易碎裂？
2.Measurement (現場測量)：
Look at the exposed section of the "Dragon Spine" near the edge closest to the sea. Estimate how thick (height/thickness of just the light-colored top block) this resistant layer is, and estimate how far (in meters) it extends across the shore into the water.
觀察靠近海邊邊緣顯露出來的「龍脊」截面。估計這層具抵抗力的堅硬岩層有多厚（僅計算淺色頂部岩塊的厚度/高度），並估計它橫跨海岸延伸入海的長度（以米為單位）。
3.Coloring (顏色與化學成分)：
Look closely at the lower rock layers underneath the dragon's spine. What distinct colors do you see there, and what geological process/mineral causes this coloration? (Hint: Think about what happens to metals when exposed to oxygen and water).
仔細觀察巨龍脊柱下方的較低岩層。你在那裡看到了什麼明顯的顏色？是什麼地質過程/礦物質導致了這種著色？（提示：想想金屬暴露在氧氣和水中時會發生什麼）。
4. Picture Time:
Take a photo of yourself with any place at Lung Lok Shui as the background, or another photo that can indicate your identity as a geocacher. This photo can be sent together with your answer or added to your log.
請以龍落水附近的任意地方為背景拍一張你自己或其他能表明你藏寶者身分的照片。這張照片可以與答案一起發送給我，也可以添加到你的log中。
⚠️ Safety First / 安全至上:
Tung Ping Chau is only accessible by ferry (usually on weekends). Please check the ferry schedules carefully. The coastal rocks can be very slippery, sharp, and dangerous during high tide or rough sea conditions. Do not attempt to walk on the rocks if waves are crashing over them. Leave no trace — do not damage, chip, or remove any rock samples from this protected Geopark!
東平洲只能渡輪前往（通常在週末）。請務必仔細檢查渡輪時間表。在海水高潮或風浪較大時，海岸岩石會非常濕滑、鋒利且危險。如果海浪拍打岩石，切勿強行在前。請保持環境清潔——切勿破壞、鑿取或帶走這個受保護地質公園內的任何岩石樣本！