ocean systems quiz

How old are the oldest sediments preserved in the Pacific Ocean basin?

See Figure 5.25 in the textbook. The oldest sediments on the seafloor are preserved above the oldest oceanic crust (basalts) - these are found in the Western Pacific, where 180 million year old basalts have been discovered.

Manganese nodules are currently an economic resource and are actively mined

See discussion of Manganese nodules on page 163 in the textbook. While common, these deposits are found in deep water. This makes them very difficult and expensive to extract - so at this time they are not economic.

Which of the following techniques is not used to sample the sediment at or below the sea floor:

165-166

Hydrogenous (or authigenic) sediments form through:

5.2

Biogenous sediments form through

Biogenous sediments are derived mainly from the skeletal material of marine organisms, especially of marine plankton (floating, mainly tiny organisms). There are three major kinds of minerals secreted by organisms: Silica (SiO2), Calcite/Aragonite (CaCO3) and Apatite Ca10(PO4)6(OH)2. Siliceous, biogenous sediments are mainly secreted by two types of plankton: radiolarians (tiny, animal-like, single-celled creatures) and diatoms

Terrigenous sediments are composed of (select all that apply):

Clays and silicate minerals are the dominant materials in terrigenous sediments. One important silicate mineral is Quartz.

Which of the following are important economic resources derived from marine sediments? (select all that apply)

Coals are formed from ancient land-swamp deposits. Lithium is found in special types of granite. Neither resource are derived from marine sediments.

In which part of the ocean basin, should you expect to see the thickest average sediment accumulations

Continental rises are there because they are underlain by thick accumulations of sediment.

Diatoms are one of the major generators of calcareous oozes.

Diatoms have tiny shells made up of silica. They form an important part of silicate ooze, but not of carbonate ooze

Oil and Natural Gas are significant resources derived in part from marine sediments.

Oil and Natural Gas are common resources found on the coastal shelf and continental slope, for example -- the Gulf of Mexico.

Manganese nodules are currently an economic resource and are actively mined.

See discussion of Manganese nodules on page 163 in the textbook. While common, these deposits are found in deep water. This makes them very difficult and expensive to extract - so at this time they are not economic.

Terrigenous sediments are generated by animals

Terrigenous sediments are derived from terrestrial materials through weathering of pre-existing rocks

Terrigenous sediments are generated by animals.

Terrigenous sediments are derived from terrestrial materials through weathering of pre-existing rocks.

In a profile from the beach environment to deep-water, what general trend characterizes the sediments?

The general trend is a decrease in sediment particle diameter. In shallow water environments, the wave energy is higher and only larger particles are deposited. In deeper waters, the wave energy is lower and finer-sized particles can be deposited. Deep water has the lowest energy and the finest-grained particles.

Calcareous and siliceous oozes are ________ sediments

biogenous

The four major grain size classes are:

clay, silt, sand, and gravel

which of the following are important economic reesources derived from marine sediments

oil, natural gas, evaoprites like salt...

Which of the following techniques is not used to sample the sediment at or below the sea floor:

gous to the "soundings" described in Chapter 4, most of our information about the sea floor came from shallow dredging of parts of the continental shelf especially in and around harbors and ports. The steam winch aided in the process of sampling sediments. Now researchers use a device called the clamshell sampler, which collects a relatively undisturbed sample, to collect sediment samples from the seafloorAnother method that is often used to sample the seafloor is the piston corer, a device that punches into the sediment and collects a plug of material representing 25 meters of sediment in a continuous sample. A third technique is to use rotary drilling, a technique first used on land in oil and gas exploration. This technique generates a core sample of rock that is cylindrical in shape and provides a nearly continuous record of the rock that the drill cut through. Western Michigan Universit