SEISMIC STUDY OF CRUSTAL STRUCTURE IN THE SOUTHERN ROCKY MOUNTAINS.

Abstract

Two underground mining blasts of 25,500 pounds and 416,235 pounds of explosives, detonated at Climax, Colo., on May 21 and 23, 1964, were recorded at 17 locations in the Front Range uplift of the Southern Rocky Mountains at distances ranging from 25 to 360 km north of the shotpoint. Strong secondary events recorded at distances ranging from 119 to 192 km from the shotpoint were identified as reflections from the Mohorovicic discontinuity and from an intermediate layer in the crust. An analysis of both reflected and refracted events suggests that the crustal thickness north of Climax is approximately 54 km and that it decreases abruptly by about 15 km in the area directly east of the Uinta Mountains. Comparison of crustal models in the different geologic and physiographic provinces of the Far West indicates that isostatic compensation is related primarily to density variations in the upper mantle and only secondarily to variations in crustal thickness. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 26, 1966
Accession Number
AD0628163

Entities

People

  • L. C. Pakiser
  • W. H. Jackson

Tags

DTIC Thesaurus Topics

  • Compensation
  • Discontinuities
  • Explosives
  • Landforms
  • Mohorovicic Discontinuity
  • Mountains
  • Reflection
  • Rocky Mountains
  • Thickness

Fields of Study

  • Geology

Readers

  • Mathematics or Statistics
  • Seismology