Passive margin

Pitman, W. C. Ill (1978). Relationship between eustacy and stratigraphic sequences of passive margins. Geol. Soc. Am. Bull. 89,1389-1403. 

On passive margins, seep flows are caused by (1) the escape of petroleum and natural gas driven by salt tectonics (Figure 19.21b), (2) artesian flows, (3) catastrophic erosion of sediments, and (4) submarine slides. 

The Rose Run Sandstone is the best characterized of the Cambrian sandstones because it is also an oil and gas reservoir (Fig. 3). It is also the only one of the Cambrian sandstones that is known to retain its sandstone composition in the eastern part of the state rather than passing laterally into carbonate. The Rose Run Sandstone is a sandy layer in the middle of the Knox Dolomite (Fig. 4), which across much of eastern Ohio lies at depths suitable for injection of supercritical C02 (Fig. 3). The Rose Run Sandstone was deposited in a passive margin phase of the Appalachian Basin and consists of interbedded layers of carbonate, primarily dolos-tone, and sandstone (Fig. 5). The sandstone is compositionally mature, consisting largely of quartz. Subordinate reactive minerals are the alkali feldspars and locally abundant glauconite (Fig. 5). Dolomite and quartz are the dominant cements (Janssens 1973 Riley et al. 1993). 

Kastens KA, Mascle J, et al. (1988) ODP Leg 107 in the Tyrrhenian Sea insights into passive margin and back-arc basin evolution. Bull Geol Soc Am 100 1140-1156... 

Figure 10.27. The preservation ("survival") rate of Phanerozoic sedimentary carbonate expressed as 1021 g CO2 per million years as a function of age. The sedimentary carbonate mass has been divided into the pelagic, passive margin slope plus rise and continental realms. (Modified from Hay, 1985.)...

Passive margin continental margin that is not along a plate boundary. 

Oceanic arc -Forearc -On-craton Passive margin -Ocean island -Abyssal Ophiolite Coot- intraplate Massif Cont- arc -Cont- rift Pre-ocecmic margin -PUM -... 

Oceanic arc Forearc On-craton Passive margin Ocean island Abyssal Ophiolite Cent- intraplate Massif Cent- arc Cent- rift Pre-oceanic margin... 

Figure 5 Preservation probabilities for major global tectonic realms. AMB = active margin basins, OB = oceanic intraplate basins, OC = oceanic crust, PMB = passive margin basins, lOB = immature orogenic belts. Rates were derived on the assumption that all deviations from the ideal pattern of the type I age distributions were a consequence of the poor quaUty of the available database (after Veizer, 1988b).

The present-day mass of global sediments is 2.7 X g (Ronov, 1982 Hay et al, 2001). Of these, 72.6% are situated within the confines of the present-day continents (orogenic belts 51.9%, platforms 20.7%), 12.9% at passive margin basins, 5.5% at active margin basins, and the sediments covering the ocean floor account for 8.3% of the total (Ronov, 1982 Gregor, 1985 Veizer and Jansen, 1985). 

Figure 6 The mass/age distribution of preserved sedimentary mass deposited on continental crust (vertical lines), basin of passive margins (black), and on the oceanic floor (cross-hatched) (courtesy of W. W. Hay).

Figure 15 Th/Sc versus Zr/Sc for modem turbidites from active and passive margin setting (after McLennan et al., 2003).

First modern-style sediment-rich passive margin sequences, e.g. Huronian Supergroup, southern margin of Superior craton 2.48-2.2 Ga e.g. Young et a/. 2001... 

The first is stratigraphic in nature and involves the relative abundance, particularly compared with sedimentary rocks, of mafic and ultramafic lavas piled in sequences of 1-10 km thickness, or sometimes multiple sequences, on pre-existing felsic crust. Modern flood basalts, related to mantle plumes, rifts, or both, are the closest analogue but are not nearly as dominant in the modern world relative to sediment-dominated cover sequences and passive margins. 

Robertson, A. 1987. The transition from a passive margin to an Upper Cretaceous foreland basin related to ophiolite emplacement in the Oman Mountains. Geological Society of America Bulletin, 99, 633-653. 

Widdowson, M. (1997b) Tertiary palaeosurfaces of the SW Deccan, Western India implications for passive margin uplift. In Widdowson, M. (Ed.) Palaeosurfaces Recognition, Reconstruction and Palaeoenvironmental Interpretation. Geological Society Special Publication 120. Bath Geological Society Publishing House, pp. 221-248. 

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