Google  DNR Home     About the DNR     DNR News     Contact Us     DNR Site Map
Introduction to IGS
Home
About
Welcome
Vision & Mission
Organization & Staff
Location of IGS Main office
Oakdale Research Facility
  and Repository
History
IGS Web site
Browse Area
Information Services
Educational Materials and
   Activities
Earth Science Information
  Sources
General Geology
Geologic Hazards
Groundwater Resources
Mineral Resources
Oil, Gas, and Metallic
  minerals Regulatory
   Information
Publications, Maps, and
  Images
Topographic Maps
List of Publications
Database and Applications
GEOSAM
Natural Resources GIS
  Library
IaStoret
Mapping (GIS Interactive)
Popular Browsing Subjects
Flood of 1993
Geology of State Parks
Geology & Archaeology
Glaciers in Iowa's Past
Iowa-Portrait of the Land
Land Use in Iowa
Loess Hills Region
Mapping Iowa's Geology
Meteorites
Mineral Resources
Miscellaneous Items
Structural Activity
Water Resources
Wetlands
Geology
Economic Geology
Environmental Geology and
  Hydrology
Mapping
Paleontology
State Map
Stratigraphy
Structural Geology
Water
Ambient Water Monitoring
  Program
Drinking Water Protection
  Programs
Geologic Studies and Water
  Programs
Hydrogeology
Iowa STORET Database
IOWATER Volunteer Water
  Quality Monitoring
Water Resources Management program
Other Links
NRCS: Natural Resources Conservation Service
State of Iowa
US EPA
US Fish & Wildlife
Iowa Groundwater Association
Iowa Children`s Water Festival
Geological Society of Iowa
WebManager

Iowa Geological Survey
109 Trowbridge Hall
Iowa City, IA 52242
(319) 335-1575
FAX (319) 335-2754

CORE PHOTOGRAPH

Red ball iconMANSON IMPACT STRUCTURE CORE PHOTOGRAPH

Core  

Crystalline-Clast Breccia
with Melt-Matrix

M-1 core - 423 feet

The light clast is a graphic granite clast that recrystallized from impact melt to fine-grained quartz and sanidine (a similar clast yielded the 74 Ma impact age). The graphic nature of the clast was preserved. Gray clasts are gneiss and the matrix is dominated by melt-rock with abundant quartz and minor crystalline rock lithic clasts.

core is NX (1 7/8" diameter)

     
  return to Manson Impact Structure