Limestone, Chert, or Limestone? [2013225_fieldtrip]
-
Upload
geotom123 -
Category
Art & Photos
-
view
674 -
download
4
description
Transcript of Limestone, Chert, or Limestone? [2013225_fieldtrip]
Limestone, Chert, or Limestone?
ByThomas Liner
The Mystery Rock
Zero Mountain Outcrop #1
Zero Mountain Outcrop #2
Hammer Time [HT]
Beav-O-Rama [BR]
Northern Section [NBR]
• Interbedded Chert & Limestone
• Tripolitic chert prominent in the form of one large bed
Middle Section [MBR]
• Interbeded Limestone & Chert
• Penecontemporaneous Chert & Tripolitic Chert
Southern Section [SBR]
• Massive Limestone
• Chert becomes less prominent
• ~100 yds South of [MBR]
Southern Face
• Inter-bedded things!
• Interbedded Chert and Crinoid beds.
• Crinoid beds exhibit upward thinning
• Transgressions or Turbidity Flows?
Graded Crinoid Bed
• Thins Upward
• TOP= Fine-Grained Bryzoan Packstone
• BOTTOM= Coarse Crinoidal Grainstone
What does it mean?• "The Boone Formation appears to be cyclic in some
areas throughout most of its lower interval."
• "They may represent turbidity flows in which shallower water sediment is periodically brought into the deeper water setting."
• "These cycles may also be related to fluctuations in early Mississippian shoreline where the orientation changed frequently in areas."
• Source: Proceedings Arkansas Academy of Science, Vol. XXXX, 1986
Western Face [BRW]
Conglomerate?