OG12-20 即 OG11-19 (地理题材)文章结构分析 - 矿物形成新理论
初读一遍, 一头雾水, 不知道具体在讲什么, 主要是好多术语我都不认得, 对于文章内容的理解存在很大困难,
但是对文章结构算是大致有个把握, 全文共分四段:
第一段: 提出最近一个关于某种系统形成机制的新理论, 并指出它与另一个被广泛认可的理论的差异;
第二段: 说明这个该理论在黄金等矿物探测方面的实践重要性;
第三段&第四段: 探讨该理论能够使一些矿物探测的高科技手段可行;
虽然花了不少时间阅读原文和做题, 所幸7道题才错了1题~错的1题也不难, 错在自己没看清楚题干!
备注: 黄色高亮是主题句定位, 灰色高亮是细节题定位, 蓝色高亮是推断题定位,蓝色字体是逻辑题定位
先将原文帖一个~
According to a recent theory, Archean-age
gold-quartz vein systems were formed more than
two billion years ago from magmatic fluids that
originated from molten granite-like bodies deep
(5)beneath the surface of the Earth. This theory is
contrary to the widely held view that the systems
were deposited from metamorphic fluids, that is,
from fluids that formed during the dehydration of
wet sedimentary rocks.
(10)The recently developed theory has considerable
practical importance. Most of the gold deposits
discovered during the original gold rushes were
exposed at the Earth's surface and were found
because they had shed trails of alluvial gold
(15)that were easily traced by simple prospecting
methods. Although these same methods still lead
to an occasional discovery, most deposits not yet
discovered have gone undetected because they are
buried and have no surface expression.
(20)The challenge in exploration is therefore to
unravel the subsurface geology of an area and
pinpoint the position of buried minerals. Methods
widely used today include analysis of aerial images
that yield a broad geological overview; geophysical
(25) techniques that provide data on the magnetic,
electrical, and mineralogical properties of the
rocks being investigated; and sensitive chemical
tests that are able to detect the subtle chemical
halos that often envelop mineralization. However,
(30) none of these high-technology methods are of any
value if the sites to which they are applied have
never mineralized, and to maximize the chances of
discovery the explorer must therefore pay particular
attention to selecting the ground formations most
(35) likely to be mineralized. Such ground selection relies
to varying degrees on conceptual models, which
take into account theoretical studies of relevant
factors.
These models are constructed primarily from
(40) empirical observations of known mineral deposits
and from theories of ore-forming processes.
The explorer uses the models to identify those
geological features that are critical to the formation
of the mineralization being modeled, and then tries
(45) to select areas for exploration that exhibit as many
of the critical features as possible. |
