Extending the flood record on the Middle Gila River with Holocene stratigraphy

Conference · Thu Apr 01 00:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5023705

Huckleberry, G ^[1]

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1. Univ. of Arizona, Tucson, AZ (United States). Dept. of Geosciences

Historical changes in flood frequency and magnitude are correlated to changes in channel geometry for the Middle Gila River (MGR) in south-central Arizona. The author has attempted to reconstruct the frequency of large floods on the MGR for the last 1,000 years by looking at the stratigraphic record with the purpose of modeling channel changes during a period of significant local cultural change, i.e., the Hohokam-Pima cultural transition. After distinguishing and mapping geological surfaces in the eastern part of the Gila River Indian Community. The author placed a series of backhoe trenches on late Holocene MGR terraces. He interprets lithological discontinuities within overbank deposits as boundaries separating temporally discrete floods. Detrital charcoal from within the stratigraphy was submitted to the National Science Foundation-University of Arizona AMS facility for radiocarbon analysis. The stratigraphic record indicates that a minimum of four large floods have occurred on the MGR since A.D. 1300. Three of these floods may correspond to large historical floods in 1833, 1868, and 1905. If so, then it appears that MGR flood frequency increased after A.D. 1800. There is no evidence for increased flood frequency and channel transformations during the cultural decline of the Hohokam in the 15th century.

• OSTI ID: 5023705
• Report Number(s): CONF-9305259-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 25:5; Conference: 89. annual meeting of the Cordilleran Section and the 46th annual meeting of the Rocky Mountain Section of the Geological Society of America (GSA), Reno, NV (United States), 19-21 May 1993; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ALLUVIAL DEPOSITS
ISOTOPE DATING
STRATIGRAPHY
ARIZONA
FLOODS
FREQUENCY ANALYSIS
CARBON 14
GEOLOGIC HISTORY
MORPHOLOGY
QUATERNARY PERIOD
RIVERS
AGE ESTIMATION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON ISOTOPES
CENOZOIC ERA
DEVELOPED COUNTRIES
DISASTERS
EVEN-EVEN NUCLEI
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
ISOTOPES
LIGHT NUCLEI
NORTH AMERICA
NUCLEI
RADIOISOTOPES
STREAMS
SURFACE WATERS
USA
YEARS LIVING RADIOISOTOPES
580000* - Geosciences