Chapter 4 Flashcards
______are particles of organic or inorganic matter that accumulate in loose, unconsolidated forms and vary greatly in appearance and size
Sediments
The origin of a sediment can be determined by its ____ and ______.
texture; composition
Sediments can _____ to form sedimentary rock
- lithify
- Additional Info: Cementation, Compaction, or Precipitation
More than half of all rock
exposed on the continents is
sedimentary rock that originally
formed __ __ ______ as sediment
in an ocean
_________ are classified by their _____ and contain clues about:
- Past Climates and Climate Change
- Ocean Circulation Patterns
- Major Extinction Events
- Movement of Tectonic Plates
Marine Sediments;source
The ocean floor is a ______ of different _____ and ______ of sediments
mixture; types; thicknesses
______ marine sediment is a result of ______ and _____ of continental rock
clues; transported to the ocean by Water, Wind, Ice, and Gravity
Lithogenous;weathering;erosion
Lithogenous sediment can be categorized as ____
i.e., near shore) or ____ (i.e., deep ocean
Neritic;Pelagic
_______ marine sediments mostly consist of the macroscopic and microscopic _____ (i.e., shells) of plankton
Biogenous; tests
Biogenous
most tests sink by ______ on ______ and accumulate on the deep ocean floor to form_____(i.e., mud)
Clue: (200 micrometers or 0.008 inches long)
suspension settling; fecal pellets; ooze
______ is composed of shells made of ____ (SiO2) or (SiO2●H20)
Siliceous* Ooze;Silica
(Siliceous Ooze) \_\_\_\_\_ are microscopic Photosynthetic algae * a \_\_\_\_\_\_\_ * result in Siliceous Ooze * can lithify to form \_\_\_\_\_\_\_\_\_\_\_
Diatoms;Phytoplankton; Diatomaceous Earth (i.e., Diatomite)
(Siliceous Ooze) \_\_\_\_\_\_\_ are microscopic single-celled protozoan * a \_\_\_\_ \_\_\_\_ \_\_\_\_\_ * result in Siliceous Ooze (SiO2) * have well-developed symmetry * the "\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ \_\_ \_\_\_ \_\_\_"
Radiolarians; filter feeding plankton; “living snowflakes of the sea”
______ is composed of shells made of _______ (CaCO3)
Calcareous* Ooze;Calcium Carbonate
(Calcareous* Ooze) \_\_\_\_\_\_\_ are single-celled microscopic photosynthetic algae * a \_\_\_\_\_ * result in Calcareous Ooze (CaCO3) * are very small * lithify to form\_\_\_
Coccolithophores; Phytoplankton; Chalk
(Calcareous* Ooze) \_\_\_\_\_\_\_ are microscopic and macroscopic single-celled protozoan * a \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ * result in Calcareous Ooze (CaCO3) * most have a \_\_\_\_\_\_ test
Foraminifera; filter feeding plankton; chambered
Calcareous ooze dissolves below the __________
Calcite Compensation Depth (CCD)
______ marine sediments are pelagic and _____ directly from seawater
Hydrogenous; precipitate
_________ cover a large percentage of the deep ocean floor and remain a mystery
Manganese Nodules
Other hydrogenous sediments include _____, ______, and ______.
Evaporites;Phosphates;Carbonates
________ sediments include ______, _______, and _____
(10% = 300,000 metric tons/year)
*An insignificant proportion of all marine sediments
Cosmogenous*; Meteorites; Space Dust; Tektites
Mineral and organic resources from marine sediments
include…
- Petroleum, Sand and Gravel, Salts,
Phosphate Minerals, Manganese
Nodules, and Gas Hydrates (i.e, _______) such ______
clathrates; Methane Hydrate
1) The type of marine sediment that forms the thickest deposits worldwide is ________.
A) abyssal clay deposits
B) manganese nodule deposits
C) neritic, lithogenous sediment deposits
D) neritic siliceous sediment deposits
E) pelagic biogenous calcareous deposits
neritic, lithogenous sediment deposits
2) Sediments produced because of chemical reactions in seawater are called \_\_\_\_\_\_\_\_. A) cosmogenous B) biogenous C) hydrogenous D) lithogenous E) volcanogenic
hydrogenous
3) Which of the following is a biogenous sediment? A) Evaporites B) Halites C) Manganese nodule D) Phosphates E) Stromatolites
?????Manganese nodule
4) The most likely place to find abundant manganese nodules is on the \_\_\_\_\_\_\_\_. A) abyssal plain far from a continent B) continental rise C) continental shelf D) crest of a mid-ocean ridge E) None of the above
abyssal plain far from a continent
5) Calcium carbonate is most likely to dissolve in water with which characteristics?
A) Low carbon dioxide and warmer temperatures
B) Lots of carbon dioxide and colder temperatures
C) Lots of carbon dioxide and warmer temperatures
D) Low pressure and warmer temperatures
E) Low pressure and colder temperatures
Lots of carbon dioxide and colder temperatures
Students sometimes ask… How are scientists able to identify cosmogenous sediment? I mean, how can they tell that it’s extraterrestrial?
- Structure and composition
- can be either silicate rock or rich in iron (common composition of lithogenous sediment)
- tektites(glassy fragments indicative of melting) are uniquely cosmogenous
- iron-rich spherules
Students sometimes ask… Are there any areas of the ocean floor where no sediment is being deposited?
Very little sediment accumulates:
(1) the South Pacific Bare Zone east of New Zealand, where a combination of factors limit sediment accumulation
(2) along the continental slope, where there is active erosion by turbidity and other deep-ocean currents
(3) along the mid-ocean ridge, where the age of the sea floor is so young (seafloor spreading) and the rates of sediment accumulation far from land are so slow that there hasn’t been enough time for sediment to accumulate.
Students sometimes ask… When will we run out of oil?
- not anytime soon
- (finite resource)not relevant as when production begins to taper off
- countries past peak of their production: USA and Canada (peaked in 1972)
