China
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Supai salt karst features: Holbrook Basin, Arizona
Published in Barry F. Beck, Felicity M. Pearson, Karst Geohazards, 2018
The Supai Salt Basin, AZ, also called the Holbrook Basin, located along the southern border of the Colorado Plateau between the Mogollon Rim on the south and the Defiance uplift on the north, is underlain by some 1200 m (4000 ft) of Paleozoic rocks, including bedded Supai Salt, extending some 6000 km2 (2300 mi2) (Figure 1). The Supai Formation extends well beyond, but contains salt only in this relatively small area around Holbrook. The total formation is nearly 600 m thick, and the upper salt member ranges up to about 150 m (500 ft) thick, with some areas of sylvite concentrations along the northern portion. The thickest Permian sequence in Arizona occurs here, with the deepest portion of the evaporite basin between Snowflake and Holbrook (Mytton, 1973). The Supai Salt is overlain by Coconino Sandstone (100–175 m thick), which is the principal aquifer in the region, and some local exposures of Kaibab Limestone and Moenkopi red-beds. Underlying the Supai are lower Paleozoic Redwall Limestone, Martin Formation, and Tapeats Sandstone (0– 225 m thick), all resting unconformably on the Precambrian crystalline basement.
Lignite Surface Mining and Reclamation
Published in M.H. Wong, J.W.C. Wong, A.J.M. Baker, Remediation and Management of Degraded Lands, 2018
Native soils are derived from geologic materials, from overlying glacial till, or from alluvial or aeolian deposits. The Bemaldo (fine-loamy, siliceous, thermic Glossic paleudalfs) and Freestone (fine-loamy, siliceous, thermic Gossaquic Paleudalfs) series are representative of the better soils of the upland position (DeMent and Cooney, 1992). These soils are very deep, well drained and moderately well drained soils on uplands. Both have a fine sandy loam surface ranging from 20 to 50 cm thick and a loam or clay loam argillic horizon. They are developing in cross-bedded sands, silts, and clays from the Wilcox group of Eocene age. Soils representative of the alluvial valley position include Roetex c (fine, mixed, thermic, Udertic Haplustoll) and Kaufman c (very fine, montmorillonitic, thermic, Typic Pelludert) (Hossner et al., 1992). The Roetex c soil is formed on fine textured alluvium along streams carrying sediments from Permian red beds. The soil ranges from mildly alkaline through moderately alkaline. The Kaufman c soils are extensive and are located on level to gently sloping floodplains of streams draining the Blackland Prairies. They are moderately acid at the surface and calcareous at depths of 60 cm or greater.
Ground subsidence
Published in F.G. Bell, Geological Hazards, 1999
Wassman (1980) described subsidence that resulted from the solution mining of salt in the area around Hengelo in the Netherlands. Cavities have been produced in the salt, and they have subsequently become interconnected. Wassman quoted 1.6 m of subsidence as having taken place in the centre of one subsidence trough, and at Hengelo vertical subsidence amounting to about 50 mm per year is still occurring. Again, certain similarities with subsidence due to coal mining were observed. However, the duration over which the subsidence occurs differs and the area of influence at the surface in relation to depth of cavity is small. Furthermore, Wassman found that some cavities tended to collapse several years after pumping had ceased. In addition, brecciation has taken place in the overlying Red Beds of Bunter age (this claystone or marl loses its strength when wetted). Unfortunately, brine from the cavities in the underlying salt permeates into the marl, rising as a result of capillary action. Eventually this weakened roof material collapses into the cavity. Void migration then takes place and, depending on the bulking factor of the rocks involved, the void may move into the overlying Tertiary clays. Pronounced subsidence occurs when this happens. The subsidence basin in these latter deposits is demarcated by an angle of influence of 45°, which extends upwards from the contact between the Red Beds and Tertiary clays. This explains the relatively small area of influence in relation to the depth of the original cavity. An additional cause of ground movement is attributable to consolidation, which occurs in the brecciated marls. This is responsible for the slowly decreasing but long-lasting subsidence.
Experimental research on applicability of weathered red sandstone soil to roadbed filling
Published in Road Materials and Pavement Design, 2021
Jingrong Zou, Jiayi Li, Runjie Lei, Shuai Wang
Red sandstone strata formed in the late Cretaceous and early Tertiary continental deposits cover many areas of China. These rocks are geologically referred to as the ‘red bed’, since they are red or brown in colour due to the abundance of iron oxides. The red bed covers nearly 25% of the total area of the Hunan Province, and thus road construction frequently encounters subgrade construction issues associated with it. Due to the steep terrain of the red sandstone area, it is difficult to transport subgrade fills all the way from places outside the area. Also, earthwork waste for road cutting has no place for disposal. Given this, for purpose of cost-saving and environmental protection, it is urgent to research the application of weathered red sandstone soil in roadbed filling.
Geomechanical analysis from well log for brownshale hydrocarbon development in the Bengkalis Trough, Central Sumatra Basin, Indonesia
Published in Geosystem Engineering, 2021
Aris Buntoro, C. Prasetyadi, Ricky Adi Wibowo, A. M. Suranto
The Upper Red Bed Formation is produced from the final deposition of the F1 tectonic phase with the basin observed to be fully filled due to an increase in the rate of sedimentation and supply of clastic material, thereby, leading to a fluvial and alluvial sedimentation environment. The formation consists of sandstones, conglomerates, and red-green claystone.