• Places are incised by canali
○ Canali: width(3-10km)
○ Shorter channel: basaltic lava
○ BUT longer: enigmatic
§ Challenge: what fluid can flow?
□ Low-viscosity: hot or melting temperature
□ Basaltic & komatiitic lava
® Rapid cooling↓
◊ By formation of an Insulating cover
◊ By solid plates floating on
□ Other possibilities: liquid sulfur, C-rich lavas & water
® Liquid sulfur
◊ from oxidized atmospheric sulfur & silicate rocks
◊ But: evaporate too fast
® C-rich lava
◊ Low viscosities, erosive potentials & melting temperatures
◊ Could form in the shallow crust
已打卡 Canal——"long meandering channels"——made volcanic plains——most of them made by basaltic lavas
`shorter made by basaltic
`HOWEVER longer made by what?
`condition1: on the Venus)required\\a low-viscosity fluid\\not hot or had a melting temp close to Venus surface
`conclusion: not basaltic lavas or komatitc lavas
`condition2: another possible fluids)
liquid sulfur>>>>a plausible BUT low vapor pressure to evaporate too quick
☑️carbonate rich lavas>>> appropriately low viscosities\\erosive potentials\\suitable melting temperatures
even suitable water
`conclusion2:carbonate rich lavas are possible reason>>>plausible form in the shallow crust
54----讨论到底是什么造成了long channels
生词:ascribe归因
Most are ascribed to basaltic lavas // however, several place plains are incised by canali---引出讨论对象
Canali—long channels: 500-6800km; widths: 3-10 km and constant
==>shorter channels--->basaltic lava
==>longer Canali--->enigmatic神秘的
What sort of fluid could flow for this distance?
B: Canali required a low viscosity fluid either very hot or had a melting temperature close to surface.
可能的情况:
1.Lavas—rapid cooling rate---could be reduced by formation of a cover (as a roof) (but too wide) and by solid plates
2.Lava’s subsurface flows----can produce long channels, but not clear whether can produce the meanders
3.possibele other liquids (liquid sulfur---low vapor pressure---evaporate too rapidly; carbonate-rich lavas---low viscosities, erosive potential and melting temperature---could formed by burial of basalt rock; water) ---if at that time the surface is considerably cooler than at present