Reconnaissance map and description of the Chetaslina volcanic debris flow (new name), southeastern Copper River basin and adjacent areas, south-central Alaska

After analysing the catastrophic debris flows on August 18, 2012, and on July 9, 2013, in Jushui River basin, An County, the Wenchuan Earthquake seriously striken areas, it was found that they were characterized by the clay soil content of 0.1~1.2%, the density of 1.68~2.03 t/m3, the discharges of 62.2 m3/s to 552.5 m3/s, and the sediment delivery modulus of 1.0~9.4 × 104 m3/km2. Due to intense rainstorm, many large debris flows produced hazard chain, involved in flash flood, debris flow, dammed lake, and outburst flood, and rose Jushui River channel about 1~4 m as well as amplified flood. The hazards and losses mainly originated from the burying and scouring of debris flows, flood inundating, and river channel rise. The prevention of debris flows is facing the intractable problems including potential hazard identification, overstandard debris flow control, control constructions destructing, and river channel rapid rise. Therefore, the prevention measures for the basin, including hazard identification and risk assessment, inhabitants relocating, monitoring and alarming network establishing, emergency plans founding, and river channel renovating, and the integrated control mode for watershed based on regulating the process of debris flow discharge, were recommended for mitigation.

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Soil Development as a Function of Time in the Rouge River Basin, South-Central Ontario

Géographie physique et Quaternaire ◽

10.7202/032640ar ◽

2007 ◽

Vol 40 (2) ◽

pp. 207-216 ◽

Cited By ~ 3

Author(s):

William C. Mahaney ◽

Kalmia Sanmugadas

Keyword(s):

River Basin ◽

Soil Formation ◽

Exchange Capacity ◽

Early Holocene ◽

Soil Thickness ◽

South Central ◽

Rouge River ◽

Extractable Iron ◽

Over Time ◽

Changes In Soil Properties

ABSTRACT Three soils of postglacial age, representing a chronosequence in the Rouge River Basin of south-central Ontario, were studied to determine variations in morphological, physical, chemical, and mineralogical properties. These soils, forming in alluvium of mixed mineralogy represent the Late HoIocene (Entisol), Middle Holocene (lnceptisol),and Early Holocene (lnceptisol) surfaces. Horizon differentiation and soil thickness increase with greater age, while pH drops slightly in the sola of the older profiles. Cation exchange capacity (CEC) and organic matter in the surface horizons increases slightly with age, while, for the most part, CaCO3 and Ca/ Mg ratio decrease. Significant changes occur over time, especially with an increase of dithionite-extractable iron with age (from ~ 0.20 in the Late Holocene soil to ~ 0.70 in the Middle to Early Holocene profiles). Illite and illite-smectite tend to decrease with age, being replaced by small amounts of chlorite and vermiculite. In spite of some variability in parent materials due to stratification and preweathering, and minor changes in species composition, the changes in soil properties are attributed to processes of soil formation acting over time.

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Little Copper Formation: New Name for Lowest Formation of Mississippian Copper Basin Group, Pioneer Mountains, South-Central Idaho: GEOLOGIC NOTES

AAPG Bulletin ◽

10.1306/c1ea3c44-16c9-11d7-8645000102c1865d ◽

1977 ◽

Vol 61 ◽

Author(s):

R. A. Paull (2), David P. Gruber (3

Keyword(s):

New Name ◽

South Central ◽

Central Idaho

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Palynostratigraphic zonation of Paleocene strata in the central and south-central Alberta Plains

Canadian Journal of Earth Sciences ◽

10.1139/e90-136 ◽

1990 ◽

Vol 27 (10) ◽

pp. 1263-1269 ◽

Cited By ~ 34

Author(s):

Thomas D. Demchuk

Keyword(s):

Coal Seam ◽

River Basin ◽

Red Deer ◽

River Valley ◽

Lower Portion ◽

Wind River Basin ◽

South Central

Paleocene strata of the Scollard and Paskapoo formations in the central and south-central Alberta Plains can be subdivided into five formal biostratigraphic zones, based in part on a Momipites–Caryapollenites palynofloral lineage. A similar zonation previously identified from strata of the Wind River basin in Wyoming displays similar palynomorph occurrences. However, differences that are present are likely a result of latitudinal climatic zonation between Alberta and Wyoming during Paleocene time.Lowermost Paleocene strata of Alberta (Wodehouseia fimbriata Zone) are barren of Momipites species, which subsequently first appear in the Momipites wyomingensis Zone. These two zones include strata from the Cretaceous–Tertiary boundary (Nevis coal seam) to the top of the Scollard Formation. A diverse assemblage of Momipites spp. plus Aquilapollenites spinulosus, Caryapollenites prodromus, and Tiliaepollenites danei are present in the Aquilapollenites spinulosus Zone within the lowermost Paskapoo Formation. Two more species of Caryapollenites appear in the Caryapollenites wodehousei Zone. The Pistillipollenites mcgregorii Zone is characterized by the presence of Pistillipollenites mcgregorii, Insulapollenites rugulatus, and Caryapollenites inelegans. Momipites leffingwellii is absent from the lower portion of this zone, with Momipites waltmanensis, Momipites actinus, and Momipites triorbicularis absent from the upper portion. Lower P. mcgregorii Zone strata are the youngest strata encountered in the vicinity of the Red Deer River valley. Upper P. mcgregorii Zone strata include strata of the Obed–Marsh coal zone within the uppermost part of the Paskapoo Formation adjacent to the Alberta Foothills.

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