Dating corals

dating corals

Are there similar U-Th dating systematics for deep-sea corals?

However, similar studies on deep-sea corals are generally lacking Adkins et al 1998, Cheng et al 1995, Goldstein et al 1996, Smith et al 1997, Lomitschka and Mangini 1999. In many respects, one would expect the U-Th dating systematics of deep-sea corals to be similar to those of their surface-dwelling counterparts.

How can you tell how old a coral is?

One way to do this is with radiometric dating. As a coral animal grows, it secretes a hard external skeleton. Radioactive isotopes absorbed from seawater by the animal are incorporated into the skeleton, where they begin to undergo radioactive decay. Radiometric dating will reveal the age of individual corals on the seamount.

How deep can coral live in the ocean?

While reported depth habitats of deep-sea coral range from 60–6000 meters (Cairns and Stanley, 1981), most specimens are found between 500–2000 meters. This depth range makes deep-sea corals ideal for studies of intermediate and upper deep water masses.

What is the TH concentration of fossil corals?

Chemically cleaned fossil corals have 232 Th concentrations ranging from 856 to 4809 ppt, about 30–80% lower than their untreated counterparts.

Are there similar U-Th dating systematics for deep-sea corals?

However, similar studies on deep-sea corals are generally lacking Adkins et al 1998, Cheng et al 1995, Goldstein et al 1996, Smith et al 1997, Lomitschka and Mangini 1999. In many respects, one would expect the U-Th dating systematics of deep-sea corals to be similar to those of their surface-dwelling counterparts.

Can deep-sea corals be used as recorders of changes in ocean temperature?

The growth rates measured here indicate that deep-sea corals may be used as recorders of deep-sea changes at annual to centennial time scales (Smith et al., 1997).

How deep can coral live in the ocean?

While reported depth habitats of deep-sea coral range from 60–6000 meters (Cairns and Stanley, 1981), most specimens are found between 500–2000 meters. This depth range makes deep-sea corals ideal for studies of intermediate and upper deep water masses.

Are foraminifera suitable candidates for uranium-series dating?

For example, foraminifera shells have primary uranium concentrations about 200 times lower than deep-sea corals Delaney and Boyle 1983, Henderson and O’Nions 1995, Ku 1965, Russell et al 1994 . These high uranium contents make deep-sea corals ideal candidates for uranium-series dating.

How can you tell the difference between coral and fossil coral?

Thus, fossil coral specimens may have slightly varying densities depending on the exact mineral concentration. Fossil coral can be mistaken for other types of agate such as moss or dendritic agate, but the pattern and body color of fossil coral is quite distinct. Fossil coral is also much harder than precious coral.

How is fossil coral formed?

Fossil coral is a natural gemstone that is created when prehistoric coral is gradually replaced with agate. Corals are marine animals and it is their skeletons that are fossilized and preserved. The fossil coral forms through hardened deposits left by silica-rich waters. The entire process can take over 20 million years.

What are the characteristics of coral?

Coral color may vary widely within a single stone, depending on weathering, oxidation and the original mineral content. Fossil coral is typically opaque, but some specimens may appear near-translucent. When cut and polished, they have a waxy to dull luster. Fossil coral is often shaped and polished as cabochons.

Where can I find fossil coral?

Almost all fossil coral specimens are found in either Indonesia or the United States (Florida and Georgia). Florida has even declared agatized fossil coral as their official Florida State Rock. Indonesian fossilized coral is considered to be the most desirable and unique.

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