Page 4 - 1052-5173-27-11

P. 4

Classic Geologic Outcrops: Preservation and Future Accessibility

Marjorie A. Chan, Dept. of Geology & Geophysics, University of Utah, Salt Lake City, Utah 84112, USA, marjorie.chan@utah.edu;
Diane L. Kamola, Dept. of Geology, University of Kansas, Lawrence, Kansas 66045, USA, kamola@ku.edu

INTRODUCTION GEOCONSERVATION, ETHICAL Blackhawk Formation (Fig. 2). The scar-
ISSUES, AND CHALLENGES ring is permanent, despite later efforts to
Geologists are privileged to work in fill the drill holes.
some of the most remarkable, beautiful, Geoconservation focuses on recognizing
and remote areas on the Earth. As profes- and preserving unique sites and landscapes Sadly, these are not isolated incidents.
sionals, we must care for important outcrops that have important scientific value and add Great outcrops deserve respect. We must
so they can continue to enlighten and edu- to our quality of life. Some efforts have protect Earth’s library of information; a
cate earth scientists well into the future. resulted in global designations for UNESCO photo is never the same as seeing a geologic
Rock archives of valuable information, Geoparks and World Heritage sites (e.g., feature in outcrop. While modest and dis-
and access to these outcrops, can be O’Halloran et al., 1994; Burek and Prosser, creet sampling of some outcrops is critical
destroyed by a few thoughtless actions. 2008). The U.S. National Park Service pro- to advancing our science, there is no legiti-
Accessible, exemplary geologic sites are tects many beloved landscapes, but other mate reason to deface a classic outcrop.
visited by numerous individuals and field- public-owned lands with remote sites are
trip groups each year. The consequences difficult to manage with limited resources. Numerous classic outcrops on private
of unauthorized access, and the impact of Vandalism of outcrops on public land has land have been accessed by geology groups
rock hammers, painted section numbers, occurred on classic sites, such as the expo- for decades, and are important for teaching
drill plug holes, and other evidence of sure of the Moab fault in Bartlett Wash basic concepts and skills to the geologic
increasing visits to these classic sites has near Moab, Utah, USA (B. Trudgill, 2017, community (Mogk, 2004). A prime exam-
serious consequences. In order to protect pers. comm.). In this instance, people with- ple is the Cretaceous of the northern Book
continued access for students and research- out required permits from the U.S. Bureau Cliffs, near Helper, Utah, USA. Numerous
ers, we, as a geologic community, must act of Land Management (BLM) cut a chunk field trips routinely stop at Gentile Wash
responsibly by getting proper permits where of rock with deformation bands from a (Fig. 3) to observe classic fluvial-dominated
required, conserving and protecting clas- pristine outcrop exposure adjacent to the delta front and shelf turbidites in the Panther
sic localities, and respecting land-use fault, leaving a gaping hole (Fig. 1). Tongue (Newman and Chan, 1991; Van
rules. In the following, we discuss a few Wagoner et al., 1990; Olariu et al., 2010),
examples of the preservation and acces- At another highly visited locality or to see classic wave-dominated para
sibility of classic outcrops we have studied (Tuscher Canyon) in the Book Cliffs, sequences of the Blackhawk Formation
for years, recognizing that similar issues numerous drill holes were cut into world- (Van Wagoner et al., 1990; Kamola and
are prevalent globally. class exposures of hummocky cross- Van Wagoner, 1995). The number of
stratified sandstone of the Cretaceous groups at times makes it seem like you

SW NE

Je Kcm Figure 1. A well-visited exposure
of a splay off the Moab fault near
Moab, Utah, USA. (A) The eolian
Jurassic Slickrock Member of the
Entrada Sandstone (Je) is juxta-
posed against the Cretaceous
Cedar Mountain Formation (Kcm).
Credit: M. Chan. (B) A ~ 60 cm chunk
of slickrock sandstone was cut
and removed in 2011 without
proper permission and BLM per-
mits. Credit: B. Trudgill.

A Footwall Hanging wall B

4 GSA Today | November 2017

1 2 3 4 5 6 7 8 9