Fossil Preservation
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When one considers the many ways by which organisms are completely destroyed after death, it is remarkable that fossils are as common as they are. Attacked by scavengers and bacteria, chemical decay, and destruction by erosion and other geologic agencies make the odds against preservation very high. However, the chances of escaping complete destruction are vastly improved if the organism happens to have a mineralized skeleton and dies in a place where it can be quickly buried by sediment. Both of these conditions are often found on the ocean floors, where shelled invertebrates (organisms without spines) flourish and are covered by the continuous rain of sedimentary particles. Although most fossils are found in marine sedimentary rocks, they also are found in terrestrial deposits left by streams and lakes. On occasion, animals and plants have been preserved after becoming immersed in tar or quicksand, trapped in ice or lava flows, or engulfed by rapid falls of volcanic ash.
當我們考慮到生物體在死後被完全摧毀的許多方式時，值得注意的是，化石和它們一樣普遍。受到清道夫和細菌的攻擊，化學腐蝕，侵蝕和其他地質作用的破壞，使得保存的機率非常高。然而，如果有機體碰巧有一個礦化的骨架，並且死在一個可以很快被沉澱物掩埋的地方，那麼逃過完全破壞的機會就會大大提高。這兩種情況都經常出現在海底，那裡有殼無脊椎動物（沒有刺的生物體）繁茂，並被連續不斷的沉積顆粒雨所覆蓋。雖然大多數化石是在海相沉積巖中發現的，但它們也存在於河流和湖泊留下的陸相沉積物中。有時，動物和植物會被浸在焦油或流沙中，困在冰或熔巖流中，或被火山灰的快速下落吞沒，從而得以保存下來。
organism: 有機體 a living thing, especially one that is extremely small
remarkable: 引人注目的 unusual or surprising in a way that causes people to take notice
scavenger: 清道夫 an animal, a bird or a person that searches through waste for things that can be used or eaten
decay: 腐蝕 the process or result of being destroyed by natural causes or by not being cared for
erosion: 侵蝕 the process by which the surface of something is gradually destroyed through the action of wind, rain, etc.
geologic: 地質的 connected with the scientific study of the earth, including the origin and history of the rocks and soil of which the earth is made
agency: 作用 a thing or person that acts to produce a particular result
odds: 可能性 the degree to which something is likely to happen
preservation: 保存 the act of keeping something in its original state or in good condition
mineralize: 使礦物化 convert (organic matter) wholly or partly into a mineral or inorganic material or structure
skeleton: 骨架 the structure of bones that supports the body of a person or an animal; a model of this structure
bury: 埋葬 to place a dead body in a grave
sediment: 沉積 sand, stones, mud, etc. carried by water or wind and left, for example, on the bottom of a lake, river, etc.
shelled: 帶殼的 having a protective outer case or covering
invertebrate: 無脊椎的 (of an animal) without a backbone
spine: 脊柱 the row of small bones that are connected together down the middle of the back
flourish: 繁茂 to develop quickly and be successful or common
sedimentary: 沉積形成的 connected with or formed from the sand, stones, mud, etc. that settle at the bottom of lakes, etc.
particle: 顆粒 a very small piece of something
marine: 海洋的 connected with the sea and the creatures and plants that live there
terrestrial: 陸地的 (of animals and plants) living on the land or on the ground, rather than in water, in trees or in the air
deposit: 沉積物 a layer of a substance that has been left somewhere, especially by a river, flood, etc., or is found at the bottom of a liquid
stream: 溪流 a small narrow river
on occasion: 有時 sometimes but not often
preserve: 保存 to keep something in its original state in good condition
immerse: 浸在 to put somebody/ something into a liquid so that they or it are completely covered
tar: 焦油瀝青 a thick black sticky liquid that becomes hard when cold. Tar is obtained from coal and is used especially in making roads.
quicksand: 流沙 deep wet sand that you sink into if you walk on it
trap: 困住 to catch or keep something in a place and prevent it from escaping, especially so that you can use it
lava: 巖漿 hot liquid rock that comes out of a volcano
engulf: 吞沒 to surround or to cover somebody/ something completely
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The term "fossil" often implies petrifaction, literally a transformation into stone. After the death of an organism, the soft tissue is ordinarily consumed by scavengers and bacteria. The empty shell of a snail or clam may be left behind, and if it is sufficiently durable and resistant to dissolution, it may remain basically unchanged for a long period of time. Indeed, unaltered shells of marine invertebrates are known from deposits over 100 million years old. In many marine creatures, however, the skeleton is composed of a mineral variety of calcium carbonate called aragonite. Although aragonite has the same composition as the more familiar mineral known as calcite, it has a different crystal form, is relatively unstable, and in time changes to the more stable calcite.
「化石」一詞通常意味著石化，字面意思是變成石頭。生物體死亡後，軟組織通常被清道夫和細菌消耗。蝸牛或蛤蜊的空殼可能會被留下，如果它足夠耐用和抗溶解，它可能會在很長一段時間內保持基本不變。事實上，海洋無脊椎動物的未經改變的殼是從超過1億年前的沉積物中發現的。然而，在許多海洋生物中，骨骼是由一種叫做文石的碳酸鈣礦物組成的。雖然文石的成分與更常見的礦物方解石相同，但它的晶體形態不同，相對不穩定，並在時間上轉變為更穩定的方解石。
imply: 意味著 to suggest that something is true or that you feel or think something, without saying so directly
petrifaction: 石化 the process of decaying, especially that of a dead body
literally: 字面上 in a literal way
transformation: 變化 a complete change in somebody/ something
tissue: 組織 a collection of cells that form the different parts of humans, animals and plants
ordinarily: 通常情況下 in a normal way
snail: 蝸牛 a small soft creature with a hard round shell on its back, that moves very slowly and often eats garden plants. Some types of snail can be eaten
clam: 蛤蜊 a shellfish that can be eaten. It has a shell in two parts that can open and close
sufficiently: 足夠 enough for a particular purpose; as much as you need
durable: 耐用的 likely to last for a long time without breaking or getting weaker
dissolution: 溶解 the action or process of dissolving or being dissolved
basically: 基本的 in the most important ways, without considering things that are less important
unaltered: 未改變的 that has not changed or been changed
creature: 生物 a living thing, real or imaginary, that can move around, such as an animal
compose: 組成 to combine together to form a whole
mineral: 礦物質 a substance that is naturally present in the earth and is not formed from animal or vegetable matter, for example gold and salt. Some minerals are also present in food and drink and in the human body and are essential for good health
calcium carbonate: 碳酸鈣 a white solid substance that exists naturally as chalk, limestone and marble
composition: 組成部分 the different parts which something is made of; the way in which the different parts are organized
calcite: 方解石 a white or clear mineral consisting of calcium carbonate. It forms a major part of rocks such as limestone, marble and chalk.
crystal: 晶體 a small piece of a substance with many even sides, that is formed naturally when the substance becomes solid
unstable: 不穩定的 likely to change suddenly
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Many other processes may alter the shell of a clam or snail and enhance its chances for preservation. Water containing dissolved silica, calcium carbonate, or iron may circulate through the enclosing sediment and be deposited in cavities such as marrow cavities and canals in bone once occupied by blood vessels and nerves. In such cases, the original composition of the bone or shell remains, but the fossil is made harder and more durable. This addition of a chemically precipitated substance into pore spaces is termed 「permineralization."
許多其他的過程可能會改變蛤蜊或蝸牛的殼，增加其保存的機會。含溶解二氧化矽、碳酸鈣或鐵的水可在周圍沉積物中循環，一旦被血管和神經所佔據，便會沉積在骨髓腔和骨小管等腔內。在這種情況下，骨頭或貝殼的原始成分仍然存在，但化石變得更加堅硬和耐用。在孔隙中加入化學沉澱物質稱為「完全礦化」
alter: 改變 to become different; to make somebody/something different
enhance: 增加 to increase or further improve the good quality, value or status of somebody or something
dissolve: 溶解 (of a solid) to mix with a liquid and become part of it
silica: 矽 a chemical containing silicon found in sand and in rocks such as quartz, used in making glass and cement
circulate: 循環 when a liquid, gas or air circulates or is circulated, it moves continuously around a place or system
enclose: 包圍 (especially of a wall, fence, etc.) to surround something
cavity: 洞 a hole or empty space inside something solid
marrow: 骨髓 a soft fatty substance in the cavities of bones, in which blood cells are produced (often taken as typifying strength and vitality).
canal: 腔 a tube inside the body through which liquid, food or air can pass
occupy: 佔據 to fill or use a space, an area or an amount of time
vessel: 血管 a tube that carries blood through the body of a person or an animal, or liquid through the parts of a plant
nerve: 神經 any of the long threads that carry messages between the brain and parts of the body, enabling you to move, feel pain, etc.
original: 最初的 existing at the beginning of a particular period, process or activity
precipitate: 沉澱 cause (a substance) to be deposited in solid form from a solution
substance: 物質 a type of solid, liquid or gas that has particular qualities
pore: 孔隙 one of the very small holes in your skin that sweat can pass through; one of the similar small holes in the surface of a plant or a rock
permineralization: 完全礦化
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Petrifaction may also involve a simultaneous exchange of the original substance of a dead plant or animal with mineral matter of a different composition. This process is termed " replacement" because solutions have dissolved the original material and replaced it with an equal volume of the new substance.
石化還可能涉及將死去的植物或動物的原始物質與不同成分的礦物質同時交換。這個過程被稱為「替換」，因為溶液溶解了原材料，並用等量的新物質替換了原材料。
petrifaction: 石化 the process of decaying, especially that of a dead body
simultaneous: 同時 happening or done at the same time as something else
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Another type of fossilization, known as carbonization, occurs when soft tissues are preserved as thin films of carbon. Leaves and tissue of soft-bodied organisms such as jellyfish or worms may accumulate, become buried and compressed, and lose their volatile constituents. The carbon often remains behind as a blackened silhouette.
另一種類型的石化，稱為碳化，發生在軟組織作為碳薄膜保存時。軟體生物的葉子和組織，如水母或蠕蟲，可能會積累、埋藏和壓縮，並失去其揮發性成分。碳元素經常以黑色輪廓留在身後。
carbonization: 碳化 the process of becoming or being made into carbon
film: 薄膜 a thin layer of something, usually on the surface of something else
carbon: 碳 a chemical element. Carbon is found in all living things.
jellyfish: 水母 a sea creature with a body like jelly and long thin parts called tentacles that can give a sharp sting
worm: 蠕蟲 a long thin creature with no bones or legs, that lives in soil
accumulate: 積累 to gradually get more and more of something over a period of time
compress: 壓縮 to press or squeeze something together or into a smaller space; to be pressed or squeezed in this way
volatile: 揮發的 (of a substance) that changes easily into a gas
constituent: 成分 one of the parts of something that combine to form the whole
blacken: 變黑 to make something black; to become black
silhouette: 輪廓 the dark outline or shape of a person or an object that you see against a light background
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Although it is certainly true that the possession of hard parts enhances the prospect of preservation, organisms having soft tissues and organs are also occasionally preserved. Insects and even small invertebrates have been found preserved in the hardened resins of conifers and certain other trees. X-ray examination of thin slabs of rock sometimes reveals the ghostly outlines of tentacles, digestive tracts, and visual organs of a variety of marine creatures. Soft parts, including skin, hair, and viscera of ice age mammoths, have been preserved in frozen soil or in the oozing tar of oil seeps.
雖然擁有堅硬的部分確實有助於提高保存的機率，但擁有軟組織和器官的有機體也偶爾被保存下來。昆蟲甚至小型無脊椎動物被發現保存在針葉樹和某些其他樹木的硬化樹脂中。對巖石薄片的X光檢查有時會顯示出各種海洋生物的觸鬚、消化道和視覺器官的幽靈般輪廓。冰河時期猛獁象的皮膚、毛髮和內臟等柔軟部分，都保存在凍土或滲油的焦油中。
possession: 擁有 the state of having or owning something
prospect: 成功機會 the possibility that something will happen
organ: 器官 a part of the body that has a particular purpose, such as the heart or the brain
occasionally: 偶爾 sometimes but not often
hardened: 變硬的 having become or been made hard or harder
resin: 樹脂 a sticky substance that is produced by some trees and is used in making varnish, medicine, etc.
conifer: 針葉樹 any tree that produces hard dry fruit called cones.
slab: 石板 a thick flat piece of stone, wood or other hard material
reveal: 揭示 to show something that previously could not be seen
ghostly: 幽靈般的 looking or sounding like a ghost
outline: 輪廓 the line that goes around the edge of something, showing its main shape but not the details
tentacle: 觸鬚 a long thin part of the body of some creatures, such as squid, used for feeling or holding things, for moving or for getting food
digestive: 消化的 connected with the digestion of food
tract: 道 a system of organs and tubes in an animal's or person's body that has a particular function, especially the function of processing a substance in the body.
visual: 視覺的 of or connected with seeing or sight
viscera: 內臟 the large organs inside the body, such as the heart, lungs and stomach
mammoth: 猛獁象 an animal like a large elephant covered with hair, that lived thousands of years ago and is now extinct
ooze: 滲出 if a thick liquid oozes from a place, or if something oozes a thick liquid, the liquid flows from the place slowly
seep: 滲出 (especially of liquids) to flow slowly and in small quantities through something or into something
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The probability that actual remains of soft tissue will be preserved is improved if the organism dies in an environment of rapid deposition and oxygen deprivation. Under such conditions, the destructive effects of bacteria are diminished. The Middle Eocene Messel Shale (from about 48 million years ago) of Germany accumulated in such an environment. The shale was deposited in an oxygen-deficient lake where lethal gases sometimes bubbled up and killed animals. Their remains accumulated on the floor of the lake and were then covered by clay and silt. Among the superbly preserved Messel fossils are insects with iridescent exoskeletons (hard outer coverings), frogs with skin and blood vessels intact, and even entire small mammals with preserved fur and soft tissue.
如果生物體在快速沉積和缺氧的環境中死亡，那麼實際的軟組織殘餘將被保存的可能性就會提高。在這種情況下，細菌的破壞性作用減弱了。德國始新世中期的梅塞爾頁巖（距今約4800萬年）就是在這樣的環境中堆積起來的。頁巖沉積在缺氧的湖中，湖中有時會冒出致命的氣體，殺死動物。它們的殘骸堆積在湖底，然後被粘土和淤泥覆蓋。在保存完好的梅塞爾化石中，有外骨骼（堅硬的外殼）呈彩虹色的昆蟲、皮膚和血管完好無損的青蛙，甚至還有整個皮毛和軟組織保存完好的小型哺乳動物。
deprivation: 缺乏 the lack or denial of something considered to be a necessity
diminish: 減弱 to become or to make something become smaller, weaker, etc.
shale: 頁巖 a type of soft stone that splits easily into thin flat layers
deficient: 缺乏 not having enough of something, especially something that is essential
lethal: 致命的 causing or able to cause death
bubble: 冒泡 to form bubbles
clay: 黏土 a type of heavy, sticky earth that becomes hard when it is baked and is used to make things such as pots and bricks
silt: 淤泥 sand, mud, etc. that is carried by flowing water and is left at the mouth of a river or in a harbour
superbly: 出色的 extremely well; to a very high standard
insect: 昆蟲 any small creature with six legs and a body divided into three parts. Insects usually also have wings.
iridescent: 色彩斑斕的 showing many bright colours that seem to change in different lights
exoskeleton: 外骨骼 a hard outer covering that protects the bodies of certain animals, such as insects
covering: 覆蓋 a layer of something that covers something else
intact: 未受損害的 complete and not damaged
mammal: 哺乳動物 any animal that gives birth to live babies, not eggs, and feeds its young on milk. Cows, humans and whales are all mammals
3. The word "terrestrial" in the passage is closest in meaning to
○land
○protected
○alternative
○similar
alternative: 選擇 a thing that you can choose to do or have out of two or more possibilities
5. Why does the author mention "aragonite" in the passage?
○To emphasize that some fossils remain unaltered for millions of years
○To contrast fossil formation in organisms with soft tissue and in organisms with hard shells
○To explain that some marine organisms must undergo chemical changes in order to fossilize
解釋一些海洋生物必須經歷化學變化才能石化
○To explain why fossil shells are more likely to survive than are fossil skeletons
undergo: 經受 to experience something, especially a change or something unpleasant
12. According to the passage, all of the following assist in fossil preservation EXCEPT
○the presence of calcite in an organism's skeleton
○the presence of large open areas along an ocean floor
○the deposition of a fossil in sticky substances such as sap or tar
化石在樹液或焦油等粘性物質中的沉積
○the rapid burial of an organism under layers of silt 在淤泥層下快速掩埋有機體
sticky: 粘的 made of or covered in a substance that sticks to things that touch it
sap: 樹液 the liquid in a plant or tree that carries food to all its parts
burial: 埋葬 the act or ceremony of burying a dead body
14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
The remains of ancient life are amazingly well preserved in the form of fossils.
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Answer Choice:
○Environmental characteristics like those present on ocean floors increase the likelihood that plant and animal fossils will occur.
像那些存在於海底的環境特徵增加了動植物化石出現的可能性。
○Fossils are more likely to be preserved in shale deposits than in deposits of clay and silt.
○The shells of organisms can be preserved by processes of chemical precipitation or mineral exchange.
生物的外殼可以通過化學沉澱或礦物交換過程來保存。
○Freezing enables the soft parts of organisms to survive longer than the hard parts.
○Comparatively few fossils are found in the terrestrial deposits of streams and lakes.
在河流和湖泊的陸地沉積物中發現的化石相對較少。
○Thin films of carbon may remain as an indication of soft tissue or actual tissue may be preserved if exposure to bacteria is limited.
碳薄膜可能仍然是軟組織的標誌，或者如果接觸細菌有限，實際組織可能會被保存。
characteristic: 特點 very typical of something or of somebodyʼs character
likelihood: 可能性 the chance of something happening; how likely something is to happen
precipitation: 沉澱 a chemical process in which solid material is separated from a liquid
comparatively: 相對的 as compared to something/ somebody else
indication: 標誌 a remark or sign that shows that something is happening or what somebody is thinking or feeling