Deep Water Flashcards
(33 cards)
What are the three parts of deep water environment?
continental slope, continental rise, abyssal plain
The edge of a continental slope is stable/unstable.
Unstable
How might something like an earthquake affect a continental slope?
Since there is a lot of sediment, and it is unstable, any kind of ground shaking will trigger a flow.
How does sediment get to the abyssal plain?
Wind carried dust, plankton/skeletal material from organisms dying a sinking to the bottom.
What are olistholiths?
Massive sized objects that can slide down the slope
What is a mass flow deposit?
It’s a deposit from something like a debris flow. Mud and larger pieces that slid down the continental slope
Most common in the rock record in terms of deep water environment deposits, involves a chaotic flow with a lot of mixing of different size sediment sizes.
turbidite
What are the 5 common transport processes in deep sea environments?
rockfall, sliding, slumping, mass flow (debris flow), turbidity current.
What is brecciola?
Blocks made of pelletal and skeletal limestones.
__________ planes can be found in slump deposits. It’s where the rock broke off from its original location and is planar.
Shear
What kind of banding do you see in turbidities?
Sand/mud banding. You’ll also see this in storm deposits.
What are the five kinds of turbidity event types?
debris flows, co-genetic flows, slurry flows, high-density turbidity current (HDT), low-density turbidity current (LDT)
What are the behaviors and deposit names of the five different kinds of turbidity events?
debris flow - debrite deposit, laminar flow
Co-genetic flows - “linked debrite”, mix of laminar and turbulent flow
Slurry flow - “banded” sandstone, mix of laminar and turbulent flow
High-density turbidity current - HDT, turbulent flow
Low-density turbidity current - LDT, turbulent flow
On the continental slope you would see more ________-sized sediment, and on the rise you would see more of a __________-sized mix
sand, mud
As the turbidity current slows, largest particles settle followed by the smaller particles. You would call this a ____________ graded bed.
normally
Study this image of a deep sea fan turbidite
How would you tell the difference between a submarine fan and an alluvial fan?
The alluvial fan mostly has big sediment sizes. Submarine fans are mostly mud.
Proximal deep sea fan turbidities are _________-dominated. Distal deep sea fan turbidities are _________-dominated.
sand, mud
What does pelagic mean?
Deep marine. So pelagic mud means deep marine mud.
What can submarine channels be infilled by?
slope muds, mass flow conglomerates, grain flow sands, or turbidite sands
What can submarine fans be infilled by?
Composed of turbidite sands and pelagic muds
What structures would you look for in a turbidite that has been eroded?
In particular you would look for flute marks and tool marks.
(Also scour and fill.)
What structures would you look for in a turbidite deposit?
graded bedding lamination. Micro-crosslamination
What structures would you look for in a turbidite that has been deformed?
loadcasts (in particular). Also slumps, slide pullaparts, sand dikes, sand volcanoes
