★★★

TPO48聽力lecture2 ?Origin Of Volcanos 姊妹篇

筆記草稿：

para 1: 地球整體板塊結(jié)構(gòu)大致介紹，主要是在板塊交界的地方是火山和地震多發(fā)區(qū)域；

段中說到的三種板塊交界情況的大致展示：

volcanism??/'vɑlk?n?zm/

para 2: 那板塊內(nèi)部一般都很太平，可是太平洋板塊上有很多火山島，說明板塊內(nèi)部也不太平；

uneventful

para 3:?夏威夷島解釋了這種板塊內(nèi)部也會(huì)有火山活動(dòng)的情況，就是一塊大陸在一個(gè)固定的地底火山源上漂過，從而在地表形成一條火山山脈，而且JD和TW的研究也驗(yàn)證了這一點(diǎn)；

para 4: 所以這些火山就是在這些“地幔涌流”（mantle plume）產(chǎn)生的“熱點(diǎn)”（hot spot）上形成的；

para 5:?

①The oceanic volcanic islands and their hot-spot trails are thus especially useful for geologists because they record the past locations of the plate over a fixed source. ②They?therefore?permit the reconstruction of the process of seafloor spreading, and consequently of the geography of continents and of ocean basins in the past. ③For example, given the current position of the Pacific Plate, Hawaii is above the Pacific Ocean hot spot. ④So?the position of the Pacific Plate 50 million years ago can be determined by moving it such that a 50-million-year-old volcano in the hot-spot trail sits at the location of Hawaii today. ⑤However, because the ocean basins really are short-lived features on geologic time scales, reconstructing the world’s geography by backtracking along the hot-spot trail works only for the last 5 percent or so of geologic time.

這些火山的運(yùn)行軌跡就很好的記錄了板塊在固定火山源上的運(yùn)行軌跡。

常錯(cuò)題

6 修辭目的題。James Daly and Tuzo Wilson 定位很好定，Daly是個(gè)發(fā)現(xiàn)，Wilson 是個(gè)觀點(diǎn)，這都是GRE的事實(shí)、觀點(diǎn)的考點(diǎn)了，并且又是順承關(guān)系，所以選A，觀點(diǎn)理論解釋事實(shí)現(xiàn)象。

7 修辭目的題。依然是關(guān)注信息之間的關(guān)系而非信息本身。其實(shí)題干信息就是為當(dāng)句中的 ...,?just as Daly had suggested. 服務(wù)的。?

10?What can be inferred about the Pacific Plate from paragraph 5?

? ? ? ? ? ? ?

定位到原文②③④句：可以利用板塊移動(dòng)過程，來了解過去的地質(zhì)情況。比如現(xiàn)在夏威夷就在一個(gè)“熱點(diǎn)”上，所以太平洋板塊的位置就可以通過把夏威夷山脈上一個(gè)五千萬年前火山的位置還原而得知。從而得到C

• A.?????The hot spots on the Pacific Plate are much older than the ones located on the other tectonic plates.

• B.?????Most of the volcanic sources beneath the Pacific Plate have become extinct.
  

• C.?????The Pacific Plate has moved a distance equal to the length of the Hawaiian Island chain in the past 50 million years.
  

• D.?????The Pacific Plate is located above fewer mantle plumes than other plates are.
  

13?

This pattern remained unexplained for a long time.

句前是個(gè)不明原因的pattern，句后找到解釋。

下面藍(lán)色字體對(duì)應(yīng)句中pattern

In the 1840s American geologist James Daly observed that the different Hawaiian Islands seem to share a similar geologic evolution but are?progressively?more eroded, and therefore probably?older, toward the northwest.?Then in 1963, in the early days of the development of the theory of plate tectonics, Canadian geophysicist Tuzo Wilson realized that?this age progression?could result if the islands were formed on a surface plate moving over a fixed volcanic source in the interior.?