Answer
the following questions:
Q 1: Write ( √ ) or ( × ) on the following
statements, and correct the "wrong" word(s):
(30 Marks)
1) Halite chevron is formed during shallow burial diagenesis
( )
2) Polymodal, non-planar dolomite consists of one size of euhedral
dolomite crystals ( )
3) Micrite envelope
means the filling of algal pores by micrite ( )
4) The increase in PCO2 in warm water favor carbonate
precipitation ( )
5) Grainstone contains mud and is matrix supported. ( )
6) Satin-spar gypsum veins are formed during uplift diagenetic
stage ( )
7) Meniscus calcite cement indicates phreatic diagenetic
environment ( )
8) Columnar stromatolites are formed in subtidal environment ( )
9) Ooids form in shallow, agitated water have concentric dolomite
structure ( )
10) Porphyroblastic gypsum crystals are formed in a sabkha setting ( )
Model Answer of Question No. 1:
1) Halite chevron is formed during shallow burial diagenesis
(primary) (× )
2) Polymodal, (Unimodal) non-planar (planar)
dolomite consists of one size of euhedral dolomite crystals (×
)
3) Micrite envelope means the filling of algal pores by micrite (√)
4) The increase (decrease) in PCO2 in warm water
favor carbonate precipitation (×)
5) Grainstone contains (lacks) mud and is matrix (grain)
supported. (×)
6) Satin spar gypsum veins are formed during uplift diagenetic
stage (√)
7) Meniscus Isopachus calcite cement indicates phreatic
diagenetic environment (×
)
8) Columnar stromatolites are formed in subtidal environment (√)
9) Ooids form in shallow, agitated water have concentric dolomite
(calcite) structure (×)
10) Porphyroblastic gypsum crystals are formed in a sabkha
setting (during uplift) (×)
Q
2: Complete the following statements: (15
Marks)
1)
……………………….. is composed of low-Mg
calcite that preserve the internal microstructure during diagenesis.
(Gastropodes, Corals, Cephalopodes)
2)
Planar stromatolites are formed in
…………………….….
(Protected tidal flats, subtidal
zone, supratidal zone)
3)
Enterolithic fold and chickenwire anhydrite textures are formed by the
coalescence of ………………………….
(nodules, rosettes, rafts)
4)
…………………….. are several carbonate
particles that are bound with organic matter.
(grapestones, intraclasts, peloids)
5)
Wackestone contains …………… lime
mud, and is mud Supported.
(< 90 %, > 90 %, 100 %)
Model Answer of Question No. 2:
1)
Corals are composed
of low-Mg calcite that preserve the internal microstructure during diagenesis.
2) Planar stromatolites are formed in Protected tidal flats
3)
Enterolithic fold and chickenwire anhydrite textures are formed by the
coalescence of nodules
4)
Grapestones are several
carbonate particles that are bound with organic matter.
5)
Wackestone contains < 90 % lime
mud, and is mud Supported.
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