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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 DUNGĐịnh nghĩa?

Phân loại?

Ví dụ?

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Định nghĩa?Unconformity is the contact between sedimentary rocksthat are significantly different in age, or betweensedimentary rocks and older, eroded igneous ormetamorphic rocks.

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D (Youngest)CBA (Oldest)

Unconformity

How Unconformities Form?Unconformities happen for two reasons: sediment

deposition stopped for a considerable time and/orexisting rocks were eroded prior to being covered byyounger 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; andwhether older sedimentary rock layers were tilted prior tobeing eroded.

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Phân loại?

An angular unconformity is the result of erosion oftilted layers of sedimentary rock. The erosion surface isburied under younger, horizontal layers of sedimentaryrock

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A disconformity also involves erosion of sedimentaryrocks. But here, the older rock layers were not tiltedbefore they were eroded. In the least obvious case, thedisconformity (the erosion surface) is parallel to thelayering of both rock layers. Those can be difficult toidentify, and usually require dating of the rocks

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Disconformity ?Angular conformity ?

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?Youngest

Oldest

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THANK YOU !

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CHUẨN BỊ:• CHƯƠNG 5: DẠNG NẰM CỦA ĐÁ