Carbon sequence

There is always a terminal CH3 in this four-carbon sequence. From RR CHCOCHRR the products are... 

Yes. The four-carbon sequence has a terminal CHj, and each half has the same sequence of C s. Use RR CHCHO, where R = H and R = CHjCH,. 

No. The formed bond is not part of a four-carbon sequence with a terminal CH, and the two halves do not have the same skeleton of C s one half is branched, the other half is not. 

Figure 7.4. A sedimentation diagram for a hypothetical Devonian-age carbonate sequence. The curve for the sequence gives its inferred position relative to sea level and land surface elevation since the time of its sedimentation. Schematic subsurface isotherms are also presented based on estimates of crustal thickness and hypothetical heat flow values related to plate movements and igneous activity. [Adapted from Siever s (1979) representation of the Esopus Formation.]...

This latter statement is supported by carbon isotope data on limestone samples collected from the Pleistocene carbonate sequences of Barbados Island in... 

More deep bore holes should be drilled in carbonate sequences not directly associated with hydrocarbon accumulations to obtain diagenetic data and information on carbonate composition as a function of geologic age. 

From the data given it follows that for any variations of and fluid composition, siderite cannot be retained at temperatures above 510-530°C and its disappearance indicates the beginning of metamorphism in epidote-amphibolite facies conditions. In this case, in interbedded schist-carbonate sequences, magnetite can be formed either in the absence of excess quartz or in the inner parts of sideritic sequences, where the introduction of water was limited. 

The absence of siderite from normal Archean carbonate sequences indicates that this is a... 

Thus, it appears that the apparent trends in Phanerozoic carbonate mineralogy are related to changes in atmosphere-hydrosphere conditions that are driven in part by plate tectonic mechanisms. However, we are aware that this tentative proposition requires collection of more data on the detailed chemistry and mineralogy of Phanerozoic carbonate sequences worldwide as well as resolution of the problem related to the past production rates of the oceanic lithosphere. 

Wright, V.P. (1994) Paleosols in shallow marine carbonate sequences. Earth-Science Reviews 35, 367-39. 

Table 5. Surface mass fractions of various isotopes in stellar evolution models in the initial mass range 15M0 < Minitiai < 50M (Langer Henkel 1995) at the pre-SN stage. The pre-SN configuration is also indicated, where RSG means red supergiant and WC stands for Wolf-Rayet star of the carbon sequence. The last column gives the initial abundances used in the stellar evolution calculations.

James, W.C. (1992) Sandstone diagenesis in mixed siliciclastic-carbonate sequences Quadrant and Ten-sleep formations (Pennsylvanian), northern Rocky Mountains. J. sediment. Petrol., 62, 810-824. 

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