Peach Springs Research Articles

Peach Springs Tuff: Its Bearing on Structural Evolution of the Colorado Plateau and Development of Cenozoic Drainage in Mohave County, Arizona: Discussion and Reply

Research Article| March 01, 1975 Peach Springs Tuff: Its Bearing on Structural Evolution of the Colorado Plateau and Development of Cenozoic Drainage in Mohave County, Arizona: Discussion and Reply: Discussion EARL M. P. LOVEJOY EARL M. P. LOVEJOY 1Department of Geological Sciences, University of Texas at El Paso, El Paso, Texas 79968 Search for other works by this author on: GSW Google Scholar Author and Article Information EARL M. P. LOVEJOY 1Department of Geological Sciences, University of Texas at El Paso, El Paso, Texas 79968 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1975) 86 (3): 428–429. https://doi.org/10.1130/0016-7606(1975)86<428:PSTIBO>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation EARL M. P. LOVEJOY; Peach Springs Tuff: Its Bearing on Structural Evolution of the Colorado Plateau and Development of Cenozoic Drainage in Mohave County, Arizona: Discussion and Reply: Discussion. GSA Bulletin 1975;; 86 (3): 428–429. doi: https://doi.org/10.1130/0016-7606(1975)86<428:PSTIBO>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract No Abstract Available. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Peach Springs Tuff: Its Bearing on Structural Evolution of the Colorado Plateau and Development of Cenozoic Drainage in Mohave County, Arizona

The Peach Springs Tuff, a welded ash flow of Miocene age, formerly blanketed a minimum area of 2,000 sq mi on both sides of the western edge of the Colorado Plateau in Mohave County, Arizona, and filled northeast-trending, pre–Colorado River canyons cut through the Paleozoic rocks. Paleomagnetic direction, petrography, and field relations indicate that the tuff is a single cooling unit of trachytic composition and normal polarity. It was erupted across the region prior to the last major movement of the plateau marginal faults, the completion of a significant amount of Basin and Range block faulting, and development of the existing topographic relief. A pre-tuff period of uplift and erosion exposed the Precambrian basement rocks directly west of the plateau. Gravel buried in canyons beneath the tuff on the edge of the Hualapai Plateau is evidence of northeast-flowing, incised drainage, in pre-tuff time, which probably continued northward along the Hurricane fault zone across the region where the younger canyon of the Colorado River is now. This ancient drainage system was disrupted by faulting, volcanism, and localized fluvial aggradation, followed by gradual incision of the modern Colorado River drainage. South of the Truxton Valley, there is evidence of a pre–middle Miocene drainage divide along the edge of the present plateau. All geologic evidence points to an early to middle Pliocene age for the modern Colorado River and associated tributary drainage on the Hualapai Plateau west of the Hurricane fault.

Facies Changes in the Cambrian Muav Limestone, Arizona

In the stratigraphic profile of the Muav Limestone from Diamond Creek to Yampai Cliffs, Arizona, every member shows evidence of shoreward facies change in a southerly direction. Facies relationships within Tongue Bright Angel (2) suggest that a southeasterly trending embayment of the Muav sea extended through the Yampai Cliffs area during part of Middle Cambrian time; the axis of this embayment lies along a line connecting Columbine Falls, Bridge Canyon, and Yampai. Within the Peach Springs Member, facies relationships support this interpretation and indicate that the east side of the embayment was controlled by a north-south hinge line located approximately along the Mohave-Yavapai County boundary.

News Reports

AbstractUniversity of Arkansas—The Art Department announces the appointments of David Smith, sculptor, and Edward Millman, painter, as Visiting Artists for the second semester of the academic year 1952–1953.California College of Arts and Crafts—New faculty members added to the staff are: Harry Krell, oil painting and figure drawing; Maurice Lapp, painting; and Arthur Palmer, figure painting and figure drawing. Mr. Krell was educated in Germany. Mr. Lapp received his M.A. at the Chicago Art Institute and spent 1950 in Mexico on a Ryerson Travelling Fellowship. Mr. Palmer is widely known as a portrait painter. College of the Pacific, Pacific Art Center—Mrs. Helen Dooley Hodgins has been granted a year's leave of absence to study Indian culture on the Wallapai Indian Reservation, Peach Springs, Arizona. Miss Margaret St. George has replaced Mrs. Hodgins on the Art Center staff. Miss St. George comes from the University of Minnesota, Duluth Branch. … Mr. Richard Reynolds, Chairman of the Department, has been appointed chairman of the Membership Committee of the National Art Education Association. … There are three fulltime staff members on the art faculty, with three to five others cooperating on part time assignments. The college is considering an expansion in the field of ceramics. Occidental College—In October, the Art Department organized an exhibition of paintings, prints and photographs by former art majors. During November the department exhibited paintings by Mary Finley Fry, Robert Holdeman, and H. W. Kanne, Jr., all members of the California Watercolor Society.