Evolution of Quaternary duricrusts in Karinga Creek drainage system, Central Australian groundwater discharge zone

Palaeoenvironmental significance of palustrine carbonates and calcretes in the geological record

“…However, this tenn may include both pedogenic and non-pedo genic types, so the terms groWl dwater or phreatic calcretes are generally preferred. These calcretes delineate the trunk valleys of palaeodrainage channels (Arakel, 1986;Nash and Smith, 1998) and are also common in mudfl at environments of playa lakes that act as outlets for discharge of regional groWl dwater (Arakel, 1991), as well as near the toes of large alluvial fans (Mack et aI., 2000). In all cases, ground water ca1cretes occur in arid to semiarid climates.…”

Desert Crusts and Rock Coatings

“…Although pedogenic and nonpedogenic calcretes share many macromorphological similarities (Wright, 2007), nonpedogenic varieties do not normally exhibit the well-organised profile structure shown in Figure 8.6, and may not go through the same stages of development (e.g. Arakel and McConchie, 1982;Arakel, 1986Arakel, , 1991Jacobson, Arakel and Chen, 1988;Khadkikar et al, 1998;Tandon and Andrews, 2001;Nash and McLaren, 2003). Groundwater and channel calcretes also appear to develop much more rapidly than pedogenic varieties (e.g.…”

“…Khadkikar et al, 1998;Khadkikar, Chamyal and Ramesh, 2000). In Australia, many calcretes have been interpreted as nonpedogenic crusts (Mann and Horwitz, 1979;Arakel, 1986Arakel, , 1991Jacobson, Arakel and Chen, 1988), but pedogenic varieties are also extensive (Warren, 1983;Semeniuk and Searle, 1985;McQueen, Hill and Foster, 1999). The development of both pedogenic and nonpedogenic calcretes often bears little relationship to the materials upon which they accrete.…”

The West Water Formation (Hualapai Plateau, Arizona, USA) as a calcrete-paleosol sequence, and its implications for the Paleogene-Neogene evolution of the southwestern Colorado Plateau

“…As with pedogenic calcrete, evaporation or evapotranspiration may be important mechanisms triggering carbonate precipitation in near-surface sediments, but CO2 degassing associated with a fluctuating water table is likely to be more significant at depth (Nash and McLaren, 2003;Nash and Smith, 2003). Studies of valley calcretes within Australian paleodrainage systems suggest that the thickest calcretes form within the zone of groundwater fluctuation, with their thickness attributed to progressive carbonate accumulation associated with a fluctuating but gradually falling water table (Arakel and McConchie, 1982;Arakel, 1986Arakel, , 1991Jacobson et al, 1988). Valley calcretes may not be uniform in thickness.…”

“…Miller, 1937;Netterberg, 1969;Carlisle et al, 1978;Mann and Horwitz, 1979;Carlisle, 1983;Reeves, 1983;Kaemmerer and Revel, 1991;Butt, 1992;Nash et al, 1994;Nash and McLaren, 2003). The bestdeveloped valley calcretes within Australian and Kalahari paleodrainage systems reach up to 10 km width, 100 km length, and several tens of meters in thickness (Arakel and McConchie, 1982;Arakel, 1986Arakel, , 1991Jacobson et al, 1988;Arakel et al, 1989;Nash et al, 1994).…”