Chapter 10 Lakes Flashcards
T or F, A true lake is defined as a body of water that has no open exchange with the ocean
True
What are the characteristics that define a hydrologically open lake vs a hydrologically closed lake?
Open: The lake is at the spill point and has a balance of water supply in and out of the basin
Closed: The lake has no outflow and relies entirely on evaporation for output
What sized sediment can be moved around by wind-driven currents in a freshwater lake?
Fine Sediments like silt and fine sand
How is the epilimnion different from the
hypolimnion?
Epilimnion: Warmer top water
Hypolimnion: Colder deep water
They are seperated by the thermocline
What are the major facies that form in a clastic lake. What processes are responsible for the facies
distribution found in both marginal and deep parts of a lake?
Deep
Marginal
???
Where do the carbonate deposits in a freshwater lake come from?
Biological activity/algal and microbial sources
What are the major cations and anions found in saline lakes?
Cations: sodium, calcium, magnesium
Anions: carbonate, chloride, sulphate
What are the
dominant ions found in saline lakes (soda)? What are the dominant minerals that precipitate in each type?
bicarbonate ions
sodium carbonate minerals
What are the
dominant ions found in saline lakes (Sulphate)? What are the dominant minerals that precipitate in each type?
Magnesium and calcium ions
sulphate minerals
What are the
dominant ions found in saline lakes (salt)? What are the dominant minerals that precipitate in each type?
Chloride ions
evaporite materials
What type of depositional features would indicate the presence of an ephemeral lake?
Depositional couplets (mud layer over evaporites). Found in arid environments
How are lacustrine deposits similar to that of low-energy marine environments? What unique
characteristics of a lacustrine deposit can be used to distinguish it from a marine deposit?
Similar: Wave ripples sands interbedded with mud from suspension.
Difference: organisms and habitats
