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GEOPET
BÀI GIẢNG CHỈ DÀNH CHO SINH VIÊN THEO HỌC LỚP
ĐỊA CHẤT KIẾN TRÚC & ĐO VẼ BẢN ĐỒ ĐỊA CHẤT
TS. Nguyễn Huỳnh Thông
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NỘI DUNG
Định nghĩa?
Phân loại?
Ví dụ?
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Định nghĩa?
Unconformity is the contact between sedimentary rocks
that are significantly different in age, or between
sedimentary rocks and older, eroded igneous or
metamorphic rocks.
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D (Youngest)
C
B
A (Oldest)
Unconformity
How Unconformities Form?
Unconformities happen for two reasons: sediment
deposition stopped for a considerable time and/or
existing rocks were eroded prior to being covered by
younger sediment.
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Types of Unconformities ?
The type of unconformity (in other words, what we
call it) is based upon what rock types are involved;
whether it is the result of erosion or no deposition; and
whether older sedimentary rock layers were tilted prior to
being eroded.
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Phân loại?
An angular unconformity is the result of erosion of
tilted layers of sedimentary rock. The erosion surface is
buried under younger, horizontal layers of sedimentary
rock
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Adisconformity also involves erosion of sedimentary
rocks. But here, the older rock layers were not tilted
before they were eroded. In the least obvious case, the
disconformity (the erosion surface) is parallel to the
layering of both rock layers. Those can be difficult to
identify, and usually require dating of the rocks
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