marine environment Flashcards
shape and depth of the sea floor
bathymetry
deepest parts of the ocean
trench
transition from continental crust to oceanic crust
continental slope
gentel angle of slope down to the edge of the abyssal plains
continental rise
shallow submarine terrace of continental crust
continental shelf
flat depositional surface of the sea floor
abyssal plains
200 meters water depth
neritic zone
200 - 2000 meters water depth
bathyal
2000 - 5000 meters water depth
abyssal zone
more than 5000 meters water depth
hadal zone
region between mean high water and low water marks of tides
foreshore
region of the shelf between the low tide mark and depth to which waves normally affects the sea bottom
shoreface
the deeper shelf area between the fair weather and storm weather bases
offshore transition zone
region below the storm wave base and extends out to the shelf edge break at around 200 meters depth
offshore zone
the cyclic rising and falling of earth’s ocean surface
tides
bulge of water due to gravity
tidal bulge
at any point of the surface the level of water will rise and fall twice a day as two bulges are passed in each other
diurnal tides
when the sun and moon are aligned, occurs during full and new moon
spring tides
when the sun and moon are at right angles, the tides are not too high or low
neap tides
vertical motion of tides
tidal current
tidal current moves toward the land
flood
tidal current moves away the land
ebbs
the depth to which there is wave influenced motion under normal weather conditions
fair weather wave base
the depth waves reach when the surface waves have higher energy due to stronger winds driving them
storm weather wave base
current driven by the difference of water density (salinity and temp)
thermo-haline current
wind driven currents r
geostrophic currents
a mudrock that contains 1-15% organic carbon
blackshale
gark green mineral that is found quite commonly in marine sediments
glauconite
sed rx erniched with phosphorous
phosphorites
materials distributed on shelves and epicontinental seas by tides, waves, storms and ocean
terrigenous material
consists of rounded mounds of sand on the sea floor a few cm high
hummocky cross stratification
between hummocks lies swales and where concave layers in the are preserved
swaley cross stratification
any shallow marine environment where there is an accumulation of carbonate seds
carbonate platform
platform attached to a continental mass
carbonate shelf
isolated platforms that are surrounded by deep water
carbonate banks
formed above a subsiding volcano
carbonate atoll
gentle slope down deep with no breaks in slope
carbonate ramp
flat-topped with a sharp change in slope at the edge forming a steep margin
rimmed shelf
an accumulation of sediments in the margins of a continent, where wave energy is strong and very present
beach
sediments seperates the open sea from a laggon
barrier
coastal bodies of water that have very limited connection to the open sea
lagoons
sites of fine-grained sedimentation forming layers off carbonate mudstone and wackestone
carbonate lagoons
hot, dry climate, tapos nagka lagoon by influx of water
arid lagoons
lies above the mean high water mark and is only inundated by seawater under exceptional circumstances, such as very high tides sand storm conditions
supratidal carbonate flats
sites of evaporite formations. gypsum and anhydrite grow within the sed while a crust of halite forms at the surface,
arid sabkha flats
deposits of ime mud and shelly mud are subject to subaerial desication at low tide
intertidal deposits
carbonate bodies mainy built by framework-building benthic organisms such as corals
reefs
sed body consisting of structure less fine crystalline carbonate
carbonate mud mounts
transitional environment between marine and terrestrial environment: tall trees, woody
swamp
transitional environment between marine and terrestrial environment: grasses
marsh
transitional environment between marine and terrestrial environment: mosses
bogs
originate from the reef, characterized by a range of fabrics
slump
sand is transported down steep slopes by dispersive pressure
grain flow deposits
poorly sorted clast-rich, muddy deposits here the clasts are transported down slope of buoyancy pressure
debris flow deposits
deposit of a turbidity current
turbidites
fine-grained material derived from the platform and resedimented by suspension into the slope and basinal environment
hemipelagic carbonates
sediment is deposited by slow suspension of material biochemically produced in surface waters
pelagic carbonates
