Depositional facies and Hohokam settlement patterns on Holocene alluvial fans, north Tucson basin, Arizona

Persistent Link:
http://hdl.handle.net/10150/191342
Title:
Depositional facies and Hohokam settlement patterns on Holocene alluvial fans, north Tucson basin, Arizona
Author:
Field, John J.
Issue Date:
1985
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The distribution of depositional facies on nine Holocene alluvial fans of varying dimensions is used to evaluate prehistoric Hohokam agricultural settlement patterns. Two facies are recognized: channel gravelly sand facies and overbank silty sand facies. No debris flow deposits occur. The channel facies is characterized by relatively well sorted stratified sands and gravels with common heavy mineral laminations. Overbank facies deposits are massive and very poorly sorted due to heavy bioturbation. Lithostratigraphic profiles from backhoe trenches and sediment size analysis document headward migration of depositional facies which results in fining upward sequences. Each sequence is a channel fan lobe with an underlying coarse—grained channel sand which fines to overbank silty sands. Lateral and vertical variations in facies distributions show that depositional processes are affected by drainage basin area and distance from fan head. Gravelly channel sands dominate at the headward portions of the fan and are more pervasive on larger fans; overbank silty sands are ubiquitous at fan toes and approach closer to the fan head of smaller alluvial fans. When depositional facies are considered as records of water flow over an alluvial surface, the farming potential of each fan can be analyzed. Most Hohokam agricultural settlements occur on surfaces dominated by overbank deposits where water evenly wets the entire fan and the need for water diversion or labor intensive irrigation is avoided. Depositional models of alluvial fan sedimentation provide the basis for understanding Hohokam settlement patterns on alluvial surfaces.
Type:
Thesis-Reproduction (electronic); text
LCSH Subjects:
Hydrology.; Facies (Geology) -- Arizona -- Tucson Region.; Alluvial fans -- Arizona -- Tucson Region.; Land settlement patterns -- Arizona -- Tucson Region.; Hohokam culture -- Arizona -- Tucson Region.; Paleohydrology -- Holocene.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Geosciences; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleDepositional facies and Hohokam settlement patterns on Holocene alluvial fans, north Tucson basin, Arizonaen_US
dc.creatorField, John J.en_US
dc.contributor.authorField, John J.en_US
dc.date.issued1985en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe distribution of depositional facies on nine Holocene alluvial fans of varying dimensions is used to evaluate prehistoric Hohokam agricultural settlement patterns. Two facies are recognized: channel gravelly sand facies and overbank silty sand facies. No debris flow deposits occur. The channel facies is characterized by relatively well sorted stratified sands and gravels with common heavy mineral laminations. Overbank facies deposits are massive and very poorly sorted due to heavy bioturbation. Lithostratigraphic profiles from backhoe trenches and sediment size analysis document headward migration of depositional facies which results in fining upward sequences. Each sequence is a channel fan lobe with an underlying coarse—grained channel sand which fines to overbank silty sands. Lateral and vertical variations in facies distributions show that depositional processes are affected by drainage basin area and distance from fan head. Gravelly channel sands dominate at the headward portions of the fan and are more pervasive on larger fans; overbank silty sands are ubiquitous at fan toes and approach closer to the fan head of smaller alluvial fans. When depositional facies are considered as records of water flow over an alluvial surface, the farming potential of each fan can be analyzed. Most Hohokam agricultural settlements occur on surfaces dominated by overbank deposits where water evenly wets the entire fan and the need for water diversion or labor intensive irrigation is avoided. Depositional models of alluvial fan sedimentation provide the basis for understanding Hohokam settlement patterns on alluvial surfaces.en_US
dc.description.notehydrology collectionen_US
dc.typeThesis-Reproduction (electronic)en_US
dc.typetexten_US
dc.subject.lcshHydrology.en_US
dc.subject.lcshFacies (Geology) -- Arizona -- Tucson Region.en_US
dc.subject.lcshAlluvial fans -- Arizona -- Tucson Region.en_US
dc.subject.lcshLand settlement patterns -- Arizona -- Tucson Region.en_US
dc.subject.lcshHohokam culture -- Arizona -- Tucson Region.en_US
dc.subject.lcshPaleohydrology -- Holocene.en_US
thesis.degree.nameM.S.en_US
thesis.degree.levelmastersen_US
thesis.degree.disciplineGeosciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.identifier.oclc213471166en_US
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