Geologic map of the north half of the Lake Walcott 30'×60' quadrangle, Idaho

Scientific Investigations Map 3405
Prepared in cooperation with the National Park Service and the Bureau of Land Management
By: , and 



The geologic map of the northern half of the Lake Walcott 30ʹ×60ʹ quadrangle shows the volcanic geology of the southern part of the Craters of the Moon lava field, the complex geologic features of the Holocene Kings Bowl and Wapi lava fields, and the southern part of the Great Rift volcanic rift zone. The long extent and distribution of skylights in lava-tube systems of the Horse Butte and Wapi Park lava fields are depicted on this map. 40Ar/39Ar and K/Ar age determinations give detail to the Holocene, late Pleistocene, and late middle Pleistocene volcanic lava fields in this quadrangle. Most of the younger basalt eruptions (less than 150 thousand years [ka]) have occurred along the Great Rift volcanic rift zone, but two of the younger lava fields are located in the western part of the quadrangle. Kimama Butte, a shield volcano, is 87±11 ka, and Shale Butte is dated at 11±6 ka. Paleomagnetic studies have shown that the Horse Butte-Inferno Chasm eruptive fissure system has at least five paleomagnetic-correlative lava fields, the Claasen vent complex consists of at least seven correlative lava fields, and the Streifling-Flat Top vent complex includes at least four correlative lava fields.

This map provides geologic, geochronologic, and paleomagnetic data for Holocene lava fields along the southern part of the Great Rift, and for late Pleistocene and late middle Pleistocene lava fields in the central and western parts of the quadrangle. These data can contribute to wise management and preservation of the Craters of the Moon National Monument and for broad-scale understanding of the basaltic-volcanic evolution of the eastern Snake River Plain.

Suggested Citation

Kuntz, M.A., Champion, D.E., Turrin, B.R., Gans, P.B., Covington, H.R., and VanSistine, D.P., 2018, Geologic map of the north half of the Lake Walcott 30'×60' quadrangle, Idaho: U.S. Geological Survey Scientific Investigations Report 3405, pamphlet 25 p., scale 1:100,000,

ISSN: 2329-132X (online)

Study Area

Table of Contents

  • Introduction
  • Evolution, Purpose, and Use of this Map
  • Rock Nomenclature, Petrologic Descriptions, and Notes on Rock Names, Descriptions, and Thickness of Lava Flows
  • Geochronology
  • Description of Map Units
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Geologic map of the north half of the Lake Walcott 30'×60' quadrangle, Idaho
Series title Scientific Investigations Map
Series number 3405
DOI 10.3133/sim3405
Year Published 2018
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Geosciences and Environmental Change Science Center
Description Report: v, 25 p.; Sheet: 49.75 x 34.00 inches; Read Me; Data Release
Country United States
State Idaho
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details