Aeolian sediments

Lancaster, N. 2002. Flux of aeolian sediment in the McMurdo Dry Valleys, Antarctica a preliminary assessment. Arctic, Antarctic, and Alpine Research, 34, 318-323. 

O-MIF is present in many atmospheric molecules and aeolian sediments, and is nearly always a result of interactions with atmospheric ozone [6]. It is believed that MIF in O3 results from the non-statistical randomization of energy in vibra-tionally excited O3 during the O3 formation reaction, O -F O2 O3, in a manner that depends on the symmetry of the O3 isotopomer [7]. The source of O-MIF in primitive meteorites is unknown but has been attributed to self-shielding during photodissociation of CO in the solar nebula [3,8-10], and also to ozone-like non-statistical reactions on mineral grain surfaces [11], a hypothesis not yet verified in the laboratory. 

The Bone Chamber sediments have mass susceptibilities of 500-1000 x 10 m kg, greater than those for pristine aeolian sediments such as the Chinese loesses, which typically have mass susceptibilities of the order of 10-100 x 10" m kg (e.g., Heller and Liu, 1984 Chen et al., 1999). Palaeosols developed within loess sequences, however. 

McLaren, S.J. (1995a) Early diagenetic fabrics in the rhizosphere of Late Pleistocene aeolian sediments. Journal of the Geological Society, London 152, 173-181. 

Facies associations (Miall, 1990) were defined from a detailed analysis of lithofacies in the study area (Table 1 Fig. 4). The classification used for fluvial sediments is from Miall (1990) and Davis et al. (1993). The terms facies and facies/lithofacies association are also used to define aeolian sediments and sedimentary characteristics (Kocurek, 1981 Kocurek Dott, 1981 Porter, 1987 Chan, 1989). The symbols used for fluvial and aeolian facies associations (e.g. CH, OF, EC, ES in Table 1 and Fig. 4) were developed for this study. Palaeosol... 

The Permo-Triassic Cooper basin of central Australia (Fig. 1) is Australia s largest onshore hydrocarbon province, containing about 6 TCF of recoverable gas and 300 MMSTB of oil and gas liquids (Heath, 1989 Laws, 1989). The basin consists dominantly of lacustrine-fluvial deposits with local glaciofluvial and rare paraglacial aeolian sediments (see Kapel, 1966, 1972 Gatehouse, 1972 ... 

Fig. 51. The lanthanide abundance patterns for the aeolian sediment, loess, from China, New Zealand and USA are parallel to that of average upper crust so reflecting the composition of the upper continental crustal material, (Data are from table 31.)...

Nickling, W. G. and McKenna-Neuman, C. 2009. Aeolian sediment transport. In Parsons, A. and Abrahams, A.D. (eds.) Desert Geomorphology, 2nd ed. Berlin Springer, 760pp. 

Walker, I.J. 2005. Physical and logistical considerations of using ultrasonic anemometers in aeolian sediment transport research. Geomorphology 68(l-2) 57-76. 

Wiggs, G.F.S., Bullard, J.E., Garvey, B., and Castro, I. 2002. Interactions between airflow and valley topography with implications for aeolian sediment transport. Physical Geography 23(5) 366-380. 

Loess is a well-sorted, usually calcareous, non-stratified, yellowish-grey, aeolian clastic sediment. It consists predominantly of silt-sized particles (2-50 mm), and contains normally less than 20 percent clay and less than 15 percent sand. It covers the land surface as a blanket, which is less than 8 meters thick in the Netherlands (exceptionally 17 meters) but can reach up to 40 meters in Eastern Europe and 330 meters in China. 

Sediments of Tertiary and Quaternary age, including volcanic ash and aeolian materials, make up the parent material of the soils. In the more arid parts of the Andean System (the coastal plain of Peru and Chile, and the Altiplano of Bolivia) the topography is level. The Altiplano is a very large closed basin with numerous salt flats. In northwestern Argentina, the planar topography is broken by mountains composed of Precambrian rocks and Quaternary sediments. 

The micrometeorites that melt during passage through Earth s atmosphere tend to solidify as spheres. These are termed cosmic spherules. The mineralogy of these spherules is given in Table 13.2. Their high iron and nickel content make them much denser (3 to 6g/cm ) than continental rock ( 2.7g/cm ). Like aeolian particles, cosmic dust deposited on the sea surface eventually settles to the seafloor via pelagic sedimentation. 

The clay minerals of aeolian origin comprise 25 to 75% of the mass of pelagic sediments. The large range in composition reflects the latitudinal nature of the dust belt as well as dilution by other locally important particle types such as clay minerals of volcanogenic origin and biogenic hard parts (calcite and opaline silica). 

A global map of quartz abundance is given in Figure 14.12. In this case, the contribution of quartz is presented as the contribution to the bulk sediment from which biogenic carbonate and silica have been removed. This map is very similar to the global distribution of dust presented in Figure 11.4, reflecting the importance of aeolian transport for this detrital silicate. 

On the early Earth, ions were mobilized from volcanic rocks by chemical weathering. Rivers and hydrothermal emissions transported these chemicals into the ocean, making seawater salty. These salts are now recycled within the crustal-ocean-atmosphere fectory via incorporation into sediments followed by deep burial, metamorphosis into sedimentary rock, uplift, and weathering. The last process remobilizes the salts, enabling their redelivery to the ocean via river runoff and aeolian transport. In the case of sodium and chlorine, evaporites are the single most important sedimentary sink. This sedimentary rock is also a significant sink for magnesium, sulfate, potassium, and calcium. 

The abyssal clays are composed primarily of clay-sized clay minerals, quartz, and feldspar transported to the siuface ocean by aeolian transport. Since the winds that pick up these terrigenous particles travel in latitudinal bands (i.e., the Trades, Westerlies, and Polar Easterlies), the clays can be transported out over the ocean. When the winds weaken, the particles fell to the sea siufece and eventually settle to the seafloor. Since the particles are small, they can take thousands of years to reach the seafloor. A minor fraction of the abyssal clays are of riverine origin, carried seaward by geostrophic currents. Despite slow sedimentation rates (millimeters per thousand years), clay minerals, feldspar, and quartz are the dominant particles composing the surface sediments of the abyssal plains that lie below the CCD. Since a sediment must contain at least 70% by mass lithogenous particles to be classified as an abyssal clay, lithogenous particles can still be the major particle type in a biogenous ooze. 

In the South Pacific, the CCD is deep enough to permit the preservation of calcareous oozes except in the center of the basin, which as a result is covered by abyssal clays. The relatively rapid supply of hydrogenous sediments prevents the accumulation of calcareous oozes on the East Pacific Rise. In the North Pacific, abyssal clays dominate as this is the location where the CCD is shallowest. Aeolian transport is the source of the clay minerals that make up these deposits. 

Some component of the terrestrial POM must be extremely nonreactive to enable a higher burial efficiency as compared to autochthonous POM. A possible candidate for this nonreactive terrestrial POM is black carbon. This material is a carbon-rich residue produced by biomass burning and fossil fuel combustion. Some black carbon also appears to be derived from graphite weathered from rocks. It is widely distributed in marine sediments and possibly carried to the open ocean via aeolian transport. 

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