Page 35 - GSATJanuary2020

F F Field Guide 56
Field Guide 56ield Guide 56ield Guide 56

The Gigantic Markagunt and Sevier Gravity Slides

Resulting from Mid-Cenozoic Catastrophic Mega-Scale

Failure of the Marysvale Volcanic Field, Utah, USA

By Robert F. Biek, Peter D. Rowley, and David B. Hacker

The Markagunt and Sevier gravity slides are gigantic landslides that resulted from gravitationally induced cata-
strophic failure of the southern ank of the Oligocene to Miocene Marysvale volcanic eld. Each is nearly 100 km
long with runouts over the former land surface >35 km; together they span 7000 km and rank among Earth’s
2
largest terrestrial landslides. Basal cataclastic layers, injectites, pseudotachylyte, deformed clasts, and a variety of
kinematic indicators demonstrate catastrophic emplacement, which was preceded by slow gravitational spread-
ing of the volcanic eld. This volume offers a history of their discovery, our current understanding of the gravity
slides, and a guide to particularly instructive exposures for which the authors document their conclusions about
the size, age, and signi cant structural features of these newly discovered features.e, age, and signi cant structural features of these newly discovered features.
the siz
FLD056, 121 p., ISBN 9780813700564 | list price $23.00 | member price $16.00

Field Guide 56
The Gigantic Markagunt and Sevier Gravity Slides
M B E
M B E
M B E
M B E
Resulting from Mid-Cenozoic Catastrophic Mega-Scale E E E M B E P R I C •
I C
I C
M B E R R R R R R P R I C
P R I C
I C
Failure of the Marysvale Volcanic Field, Utah, USA
16
16
16
16
16
16
16
16
16
16
16
16
16
16
E
E
E
E
E
E
•
•
•
•
•
By Robert F . Biek, Peter D. Rowley, and David B. Hacker M M M • • • $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ 16 C C C C C C E E E
M
M
M
M
M
M
M
M
M
E
E
E
E R R R R R R I I I I I I
E
E
M
M
M P P P P P P
M
M
M
M B B B E E E R
M
M
R
M
R
M
M
The Gigantic Markagunt and Sevier Gravity Slides Resulting from Mid-Cenozoic Catastrophic Mega-Scale Failure
GSA BOOKS } https://rock.geosociety.org/store/
toll-free 1.800.472.1988 | +1.303.357.1000, option 3 | gsaservice@geosociety.org