stratigraphy and geological time

Question 1

stratigraphy

Answer 1

• study of rock layers and layering, linking layers with time periods
• primarily for sedimentary and volcanic rocks
• the spatial and temporal distribution and formation of all the rocks

Question 2

Lithologic stratigraphy

Answer 2

deals with:

• physical lithologic (rock type)
• change both vertically in layering
• changing environments of deposition (facies change)

Question 3

Law of Superposition of Strata

Answer 3

the oldest strata occur at the base of a sequence.

Question 4

principle of original horizontality and lateral continuity

Answer 4

correlates strata at adjacent sites for stratigraphy

Question 5

Conformity of strata

Answer 5

• upper and lower strata are continuous
• lithology (rocks)/fossils are same in upper/lower
• no erosion surface between upper/lower

Question 6

Unconformity of Strata
Type A (parallel)

Answer 6

• upper and lower strata are about parallel
• between them, discontinuous/eroded strata
• lithology/fossils of top and bottom are different
• basically missing a stratum

Question 7

Unconformity of Strata
Type B (Angular)

Answer 7

• upper and lower strata are not parallel

- shows evidence of sub-aerial/submarine erosion/non-deposition, and hiatus (discontinuous)

Question 8

Biologic Stratigraphy

Answer 8

-strata containing similar fossils from different areas can be correlated in time

Question 9

principle of fossil succession for correlating rocks

Answer 9

• a rock age is determined by the fossils they contain

- there is an index of fossils to define time periods

Question 10

Geological Time Scale

Answer 10

relative and absolute when in regards to carbon dating vs fossils in sedimentary rocks

Question 11

5 level system in Geo Time Scale

Answer 11

Eon>Era>Period>Epoch>Age

Question 12

Eon and 6 eras

Answer 12

Phanerozoic     Cenozoic
                      Mesozoic
                       Palaeozoic
Pre-cambrian   Proterozoic
                      Archean
Azoic              Azoic

Question 13

One of the biggest eras (P)

Answer 13

Palaeozoic
Periods:
-permian
-carboniferous
-devonian
-silurian
-ordovician
-Cambrian

Question 14

One of the biggest eras (M)

Answer 14

Mesozoic
Periods:
-Cretaceous
-Jurassic
-Trassic

Question 15

One of the Biggest eras (C)

Answer 15

Cenozoic
periods:
-Quaternary
-tertiary

Question 16

Geological map

Answer 16

• map that shows geological features

- shows strata layers, sometimes shows underlying deposits

Question 17

Geological Cross-Section

Answer 17

• interpretation of a vertical slice of earth

- very important for geo engineers

Question 18

Geo History in HK

Answer 18

Quaternary, palaeogene, cretaceous, upper jurassic, lower jurassic, permian, carboniferous, devonian, look at Q06-10-10