Heise volcanic field

Heise volcanic field
Kbh3rd · Public domain · source
Name	Heise volcanic field
Location	Idaho, United States
Coordinates	43°30′N 111°00′W
Elevation	1,800–2,500 m
Type	volcanic field
Age	Pleistocene
Last eruption	~14,000 BP

Heise volcanic field is a Pleistocene volcanic province in eastern Idaho within the Yellowstone hotspot track. The field lies near the western margin of the Snake River Plain and is part of a chain of Cenozoic volcanic centers that record interaction between mantle plume activity and continental lithosphere. The area contains lava flows, tuff beds, and cinder cones that are interleaved with glacial and lacustrine deposits from the Bonneville Flood region.

Geography and setting

The volcanic field occupies terrain across Jefferson County, Clark County, and Bingham County adjacent to the Snake River and Southeastern Idaho. It is situated down-ice and downflow from the Yellowstone Plateau and lies northwest of the Craters of the Moon National Monument and Preserve and southwest of the Teton Range. Topography includes mesa-like plateaus, scoria cones, and basaltic plains; land management falls under Bureau of Land Management jurisdiction with nearby access via U.S. Route 20 and Interstate 15. The setting connects to the larger Columbia River Basalt Group province to the west and the Owyhee Uplands to the southwest and is hydrologically linked to the Snake River Plain aquifer.

Geology and petrology

The field records alkaline to tholeiitic magmatism related to passage of the Yellowstone hotspot beneath continental lithosphere modified by Proterozoic basement. Bedrock includes basalt, andesite, and volcaniclastics emplaced on basaltic-andesitic substrates. Regional structural controls involve the Lost River Fault system and other Basin and Range–style normal faults that facilitated magma ascent and eruption. Petrologic studies show phenocryst assemblages of olivine, plagioclase, and clinopyroxene with groundmasses exhibiting microlitic textures; trace-element patterns indicate enrichment in incompatible elements consistent with plume-derived melts metasomatized by lithospheric mantle. Geochemical comparisons draw links to compositions reported for Snake River Plain basalts, Columbia River Basalt Group, and Steens Basalt sequences.

Eruptive history and chronology

Eruptive activity primarily occurred during the late Pleistocene with ages clustering between ~16,000 and ~12,000 radiocarbon years before present, contemporaneous with regional events such as the Bonneville Flood and the late stages of Glacial Lake Bonneville. Stratigraphic relationships place Heise lavas above some Pinedale Glaciation deposits but below late-Holocene alluvium in parts. Radiometric dating using argon–argon dating and radiocarbon dating on interbedded charcoal has refined eruption ages; tephrochronology correlates Heise tephras with distal ash layers found in Yellowstone National Park and Great Salt Lake cores. Paleomagnetic signatures help to correlate flows across the plain and to the regional Bridgerian–Holocene transition.

Volcano types and morphology

Morphologies include low-profile ʻaʻā and pāhoehoe lava flows, spatter cones, scoria cones, and maar-like explosion craters where magma interacted with groundwater. Shield-like edifices and fissure-fed lava fields resemble features mapped in the Lava Beds National Monument and the Craters of the Moon area. Cone dimensions range from small scoria mounds to systems producing long lava flows extending several kilometers across sagebrush steppe and irrigated farmland. Structural mapping documents vent alignments parallel to regional extensional trends characteristic of the Basin and Range Province.

Paleoclimate and environmental impact

Eruptions unfolded during climatic shifts tied to the terminal phases of the Last Glacial Maximum and the desiccation of Lake Bonneville. Volcanic ash and aerosols from Heise eruptions contributed to short-term atmospheric perturbations that are recorded in pollen sequences from limnology cores and in oxygen isotope excursions in lake sediments from Bear Lake and the Great Salt Lake basins. Tephra layers provide time-synchronous markers for reconstructing paleohydrology during the Younger Dryas–Bølling–Allerød intervals. Local ecology responded to ash deposition and lava emplacement with succession patterns evident in fossil pollen of sagebrush steppe and in vertebrate assemblages preserved in lacustrine and alluvial deposits.

Human history and research

Indigenous occupancy of the region by Shoshone people and Bannock people predates scientific investigation; cultural landscapes include archeological sites adjacent to volcanic features and traditional travel corridors of the Shoshone-Bannock Tribes. Euro-American exploration and mapping by the U.S. Geological Survey and early geologists such as Hiram M. Chittenden led to initial descriptions; later detailed studies were conducted by researchers affiliated with Idaho State University, University of Idaho, and the U.S. Geological Survey. Contemporary research integrates field mapping, geochemical analysis at laboratories like Los Alamos National Laboratory and University of California, Berkeley petrology labs, and remote sensing from NASA platforms. Conservation, geotourism, and land-use planning involve collaborations with the Bureau of Land Management, the National Park Service for nearby units, and tribal governments of the Shoshone-Bannock Tribes.

Category:Volcanic fields of the United States Category:Geology of Idaho Category:Pleistocene volcanism