Sed

Question 1

Conglomerate

Answer 1

Chert clast, fine sand matrix, cement
Well rounded, high sphericity - rounded smooth clast indicate transported far, eroded.
Clastic
High energy env.
Braided river system, glacial melt

Question 2

Micrite

Answer 2

Fine lime mud formed through direct precipitation of calcium carbonate. Effervesces w HCl

Question 3

BIF

Answer 3

• Biochemical sedimentary rock
• formed due to deposition of siliceous or pelagic ooze in low energy settings
• deep marine setting
• red material : chert/jasper (h>6.5+ subconchoidal fracture)
• ## grey: haematite (streak, lustre, magnetic slightly)

Question 4

Coquina (shells shells shells)

Answer 4

• biogenic
• shallow marine env
• low degree of abrasion hence little reworking
  -calcite all round

Question 5

Quartz sandstone

Answer 5

Beige tan
- high sphericity well rounded medium grain
- high degree of reworking
- desert, low energy
- clear is quartz
- dull opaque is feldspar
- micaceous grains are shiny
- cement likely silica

Question 6

Silty claystone

Answer 6

Fine laminations of alternating fine silt, mud and silt, and fine sand materials. Clastic

-low to mod energy in cycles
-rive or shallow marine environment with seasonal pulses of sedimentary input
-clast is mica + calcite
- matrix is clay?