Marine Biology Lab Report

“Radiometric dating is the determination of age by using radioactivity, has become geology’s best tool for establishing absolute geologic time” (Shipman, Todd, & Wilson 704). The atomic nuclei that decay of their own accord are said to be radioactive. The decay product—or daughter nucleus, as it is commonly called—may be stable. If so, the transformation reaches completion in a single step. However, the daughter nuclei of many naturally occurring isotopes are themselves radioactive and hence undergo further decay”

Approximately 60 to 80 percent of the Earth’s upper mantle is composed of a mineral called Olivine. When this mineral is exposed to carbon dioxide under conditions of extreme pressure and heat it reacts to form carbonate minerals. In the past, olivine was extracted from the ground, ground up into fine powder, mixed with water, and combined with carbon dioxide in large pressure tanks at power plants to attempt to lower their carbon emissions. Unfortunately, this method is not very efficient in terms of cost and energy. Researchers have now turned their focus on more efficient methods of utilizing this olivine and its carbon sequestering properties. Due to the abundance of olivine in the upper mantle and the difficulty in extracting large amounts, researchers have attempted to invent techniques in which the olivine can be left in the ground (in situ) and the carbon dioxide can be brought to it. The most promising method for accomplishing this involves the oceanic thermohaline circulation of carbon-laden water and the relative thinness of oceanic crust. Using this process, machines would drill boreholes through the crust of the ocean floor and into the mantle where the carbon absorbing rock is located and there is sufficient heat and pressure to provide the proper conditions for the carbonation of the olivine. Once

However, it was not until the second half of the 20th century that three major discoveries began to suggest how this might be possible. In 1948, a survey of the floor of the Atlantic Ocean revealed a continuous ridge running largely north to south. IT was around 1,000km wide and reaching heights of 2.5km. It was composed of volcanic rocks. Similar submarine mountain ranges were later found in the Pacific Ocean extending for over 5,000km. Magnetic surveys of the ocean floor in the 1950’s showed surprisingly regular patterns of palaeomagnetic striping about the ridges. When lavas erupt on the ocean floor, magnetic domains within iron-rich minerals in the lava are aligned with the magnetic field of the earth. This is fixed as the lava cools, and unless the rocks undergo major disturbance, they continue to record the earth’s polarity at the time of their cooling. However, as the earth’s polarity reverses around every 400,000 years, bands or stripes of normal and reverse polarity rocks are mirrored on either side of the mid-ocean ridges. This suggests that new rocks are being added equally on either side.

G., Cong-Qiang, L., WeiDong, Z., Minella, M., Vione, D., Kunshan, G., & ... Hiroshi, S. (2016). Reviews and Syntheses: Ocean acidification and its potential impacts on marine ecosystems. Biogeosciences, 13(6), 1767. doi:10.5194/bg-13-1767-2016

ocean is made up of different layers of varying densities and chemical compositions. During the

Sections 12.1 and 12.2 of the text discuss the origin and composition of the world ocean’s seawater.

Increased terrestrial influx could have served as nutrients for algae and plankton and stimulated high bioproductivity at surface water. The oxygen in surface water would have been over-consumed by respiration and decaying of marine organisms, which was thought to trigger marine anoxia (Algeo et al., 1995). In this process, lighter isotope of carbon was preferentially taken up by aquatic organisms and therefore removed from the system, producing heavy carbon anomalies (Wang et al., 1996). Consequently, positive excursions in δ13C values were observed across the F-F boundary (Figure 2). In addition, higher bioproductivity would bring about elevated burial rate of organic carbon (Wang et al., 1996; Chen et al., 2002)

Phosphorous contained in these shallow ocean sediments can either flow through ocean food webs or can become incorporated into deep ocean sediments which will eventually be uplifted by plate tectonics and start the phosphorous cycle all over again. As previously mentioned, the phosphorus cycle has no atmospheric component. Since phosphorus has no stable atmospheric gas phase, unlike the case for other nutrients such as nitrogen and carbon, ecosystems have to depend primarily on aqueous transfer of this critical nutrient6. Similar to on land, phosphorous is a regulatory element for plant growth in aquatic systems. Dissolved marine phosphorous is a limiting element for biological productivity6, 7, 8 and is probably the most critical regulator of ocean productivity throughout geologic history6, 8. Following the nutrient profile in the world’s oceans, phosphorous concentrations are approach zero in surface waters while phosphate concentrations increase in deep water. The carrying of eroded soils by rivers delivers phosphorous to the oceans. This riverine phosphorous is usually in particulate forms and dissolved forms. Most particulate phosphorous is fixed within mineral lattice thus is unavailable to the active cycle. Consequently, most of the phosphorous weathered from Earth’s continental crust travels to the oceans remaining unaltered. However, the outcome of organic phosphorous

This research piqued my attention among the rest as it matches my desire to learn more about the components of the Earth, more particularly with their chemical components. As I read the abstract of this study, a sense of motivation and determination in searching for further answers and discovering more about this topic. Also, I found this research helpful to everyone because further study related with this topic might help in solving the problem in nutrient distribution in the ocean floor.

The significant variations of metal content in species of the same and different trophic levels (Table 3.2) imply that species, more than the trophic category, was the factor which best explained the variability observed in the concentration of metals in terrestrial organisms. This may be bound up their species-specific ability of active excretion of heavy metal ions and/or their ecological characteristics (Van Straalen and Van Wensem 1986; Grodziniska et al. 1987). This find is conforming to Mackay et al. (1997), who stated that “it may be the physiology of an organism, and not the trophic level which determines the internal concentration of heavy metals”. Likewise, this find, to some extent, accords with the observations of Hernández et

Accumulation of sediments / Fossil as we look at these deposits- burned fossils and sediments, we will see older and older fossils as we move further and further from the mid- oceanic ridge as the results we will see greatest proportion of extinct species. Also sediments much deposit on the older part of the sea floor for longer than new parts around the mid oceanic ridge. Different sediments tend to accumulate on different parts of oceanic floor if the ocean floor stayed still then the other things being equal, we would expect same deposit of the sediments from any particular place on sea –floor to be pretty much the same all the way down. Sea

These deposits of marine hematite and quartz represent a precipitation of dissolved iron from sea water as the dissolved oxygen content of the water increased. After 1800 mya, Banded iron formations are rare, but terrestrial red beds are common for the first time suggesting that iron is being oxidised and precipitated in soils and rocks on land in the source area of sediments instead of being dissolved and carried into the oceans in its unoxidised form. Thus, it has been reasoned that the BIF-red bed transition marks the rise of atmospheric oxygen. Complimentary information comes from detrital uraninite in Archean and earliest Proterozoic alluvial rocks. Because this uranium mineral can survive prolonged transport only in media containing little or no oxygen, the lack of detrital uraninite deposits younger than 2300 ma also points towards a significant environmental transition (Roscoe,1969).

According to Hazen, Over the past four and a half billion years Earth has passed through series of stages in which more and more minerals developed. Here, Evolution of Earth and its minerals has been analyzed, which are divided into stages – Making of Earth, Black Earth, Red Earth, White Earth, Green Earth. Let’s start with Making of Earth- This happened around 4.5 billions years ago, when number of planetesimals (dust, rock materials, gas in solar system) collided to form Earth. These

Few of the outcrop samples were subjected forRock-Eval pyrolysis because most of them with low TOC values. The average S2(mg HC/g rock ) and hydrogen index (mg HC/g TOC) values of the examined well samples is 4.22and 202 respectively. These values and thecross plot of hydrogen index (HI)versus Tmax and S2 versus TOC (Fig.2 and 3)indicate that the kerogen contained in these rocksis mixed II-III. This result is supported by organic petrological study, which indicated that the organic matter is mixed of marine and terrestrial origin; marine organic matter is dominated by alginite and bituminite, whereas the terrestrial organic matter is dominated by sporinite with minor amounts of vitrinite (Alkhafaji, 2017).

In recent years, technological advancement in analytical geochemistry has offered a new suite of non-traditional geochemical proxies developed from trace metals (e.g., Sr/Ca, Mg/Ca, Ba/Ca, B/Ca) (Lea and Spero, 1992, 1994; Nurnberg et al., 1996; Rosenthal et al., 1997; Lea et al., 1999; Lear et al., 2000; Martin et al., 2002; Billups and Schrag, 2003, 2004; Honisch and Hemming, 2004; Yu and Elderfield, 2007; Foster, 2008; Allen et al., 2009) and isotopic compositions (e.g., 87Sr/86Sr, δ11B, δ44/40Ca, and δ26Mg) of foraminiferal calcite (DePaolo and Ingram, 1985; De La Rocha and DePaolo, 2000; DePaolo, 2004; Fantle and DePaolo, 2005; Fantle, 2010; Hodell et al., 2007; Higgins and Schrag, 2012; Fantle and Tipper, 2014; Pogge von Strandmanss et al., 2014) that are complementary to the traditional foraminifera-based isotopic proxies. Moreover, the emerging metal isotopic proxies have potential to reconstruct past variability in seawater chemistry and thereby contribute strongly to understanding the long-term variation in metal cycling (e.g. Ca, Sr, Mg) that are directly linked to the global carbon cycle (Richter et al., 1992; Zhu and Macdougall, 1998; de La Rocha and DePaolo, 2000; Fantle and DePaolo, 2005; Hodell et al., 2007; Griffith et al., 2008; Higgins and Schrag, 2010; Higgins and Schrag, 2012, Fantle and Tipper, 2014; Pogge von Strandmanss et al., 2014). However, due to