geo 1080: uvu chapter 4

The distance of point B from the mid-ocean ridge crest is 1200 km, the average seafloor spreading rate is 1.8 cm/year, and the average sedimentation rate is 1 cm/1000 years. What is the expected thickness of sediment at point B in km? (1 km=100,000 cm)

0.667 km

What is the rate of deposition for course lithogenous sediment?

1 meter every 1000 years

Some locations in the Gulf of Mexico have as much as 18 km of sediment. How long would it take to accumulate that much sediment assuming a rate of 1 meter every 1000 years? (remember, 1000 m in 1 km and Ma=million of years)

18 Ma years

How deep is the CCD on average?

4500 m

Biogenous ooze has an average rate of deposition 1 cm/1000 yrs? How long would it take to accumulate 50 meters of sediment? (100 cm = 1 m and Ma=millions of years)

5 Ma years

Which type of marine sediments include siliceous and calcareous oozes?

Biogenous

Stromatolites are an example of which of the following sediment types?

Biogenous Sediment

Which type of sediment deposit has an average rate of deposition of 1 cm per every 1000 years?

Biogenous ooze

How may calcareous oozes be found in depths greater than the CCD?

Calcareous ooze deposits can be found at depths greater than the CCD if they fromed at more shallow depths and were buried by another sediment before being moved into deeper water.

The CCD (calcite compensation depth) is the depth at which this type of sediment dissolves rapidly.

Calcareous oozes

According to the Wentworth scale, what is the particle name for a sediment that is 64 to 256 millimeters in size?

Cobble

Which of the following sediment types forms from material from space?

Cosmogenous

Tektites are an example of which of the following sediment types?

Cosmogenous Sediment

Which of the following marine resources is used to make wallboard or sheet rock?

Evaporative salts

Which of the following contains calcium carbonate (CaCO3)?

Foraminiferans

Which of the following contains the most organic carbon on Earth?

Gas hydrates

_________________ are solid forms of methane that form in the ocean sediment and may be an important energy source for the future.

Gas hydrates

Which of the following sediment types forms from the dissolved materials in seawater?

Hydrogenous

Rock salt (halite) is an example of which of the following sediment types?

Hydrogenous Sediment

Volcanic ash is considered to be which type of marine sediment?

Lithogenous

Which of the following sediment types forms from pre-existing rock material on continents or islands?

Lithogenous

Calcium carbonate is most likely to dissolve in water with which characteristics?

Lots of carbon dioxide and colder temperatures

Which type of sediment deposit has an average rate of deposition of 0.001 millimeter er every 1000 years?

Manganese nodule

________ deposits are found on continental shelves and in shallow water near islands, whereas, ________ deposits are found in deep-ocean basins and are fine grained.

Neritic pelagic

Which of the following is the major environmental concern regarding the release of methane from the sea floor to the atmosphere?

Release of large quantities of methane from the ocean causes dramatic effects on global climate.

You are on a research cruise in the middle of the Indian Ocean. The water depth is very deep at 6500 meters. You are 5000 km (3000 miles) from land. The surface water is warm. What is the most likely sediment you would expect to find on the sea floor?

Siliceous Ooze

Locate the Gulf of Mexico on the map below. The Mississippi River transports 230 million tons to the Gulf of Mexico each year. The map shows total sediment thickness. How does the Deposition in the Gulf of Mexico from the Mississippi River compare to the rest of the ocean?

The Gulf of Mexico has much higher sedimentation rates than the rest of the ocean.

Sediments that are poorly sorted were most likely deposited by ________.

a glacier

The most likely place to find abundant manganese nodules is on the ________.

abyssal plain far from a continent

In which way(s) does lithogenous sediment travel to the oceans?

all other answers are correct

Which of the following correctly lists lithogenous sediment in order of increasing grain size?

clay, silt, sand, gravel

Stromatolites form from

cyanobacteria that builds up in layers creating mounds.

Generally speaking, the size of lithogenous particles _____________ with increasing distance from the shore.

deceases

All of the following are biogenous sediments except

evaporites

The main energy resources associated with marine sediments are petroleum and ________.

gas hydrates

A turbidite shows _______________,

graded bedding

Dried beans are _____________ in size

gravel

Abyssal clay contains ________.

iron

You are drilling a core sample of marine sediments 90 feet offshore in the Gulf of Mexico. The sediment will most likely be

lithogenous

Cosmogenous sediment consists of two main types of sediment ________.

microscopic spherules and macroscopic meteor debris

Where does the highest concentration of lithogenous sediment occur?

near the coasts

The type of marine sediment that forms the thickest deposits worldwide is ________.

neritic, lithogenous sediment deposits

How is clay carried out to sea for abyssal clays to form?

ocean currents and wind

These sediments are found in deep water, are fine-grained and are deposited slowly.

pelagic

One of the most abundance, chemically stable, and durable minerals in the Earth's crust is ________.

quartz

Which of the following contains silica (SiO2)?

radiolarians

The distance of point D from the mid-ocean ridge crest is 480 km, the average seafloor spreading rate is 3.7 cm/year, and the average sedimentation rate is 1 mm/1000 years. What is the expected thickness of sediment at point D in m? (Remember, there are 100,000 cm in 1 km and 1000 mm in 1 m)

~13 m

Calcite dissolves more readily in seawater that is ________ in temperature and ________ in pressure.

colder; higher

Chemical reactions within seawater cause certain minerals to come out of solution, or precipitate, they change from the ________ state to the ________ state.

dissolved; solid

The image below shows ________________.

stromatolites

Abyssal clays form by which process?

suspension settling

The term referring to the size and shape of sediment particles is ________.

texture

This lithogenous sediment exhibits graded bedding and may from on submarine fans.

turbidite

The microorganism in the photo below is a _______________.

diatom

Which of the following is a biogenous sediment?

diatom ooze