Derric L. Iles South Dakota State Geologist - South Dakota School of ...

Derric L. Iles
South Dakota State Geologist

Purpose:
To create, compile, and disseminate
information having the potential to aid
economic development in South Dakota
related to the exploration and
development of oil and gas resources.
To increase interest, exploration, development, and production

Bedrock
geologic
map of
eastern
South Dakota
1:500,000 scale

A building block of the eastern
South Dakota bedrock map
Lincoln County Bedrock Geology
1:100,000 scale

34,241 test holes and wells in the Geological Survey’s Lithologic
Logs database (>22,737 drilled by Geological Survey Program)

Example of
output from
the Geological
Survey Program’s
lithologic logs
database

62,245 test holes and wells in the Water Rights Program’s
water well completion reports database

Example of output from
the Water Rights
Program’s water well
completion reports
database

1,883 test holes and wells in the Minerals and Mining Program’s
oil and gas database

Example of output from
the Minerals and Mining
Program’s database

Stratigraphic
correlation
chart
Areas delineated on the
correlation chart:
• Eastern Powder River
Basin – Western Black Hills
• Black Hills
• Williston Basin
• Chadron Arch
• Kennedy Basin
• Sioux Ridge
• Forest City Basin
• Canadian Shield

Cross sections showing geophysical logs of Phanerozoic rocks in South Dakota
(16 statewide cross sections)
Listing of geologic units and their
depths on the cross section

Elevation map of the Precambrian surface - 1961

Elevation map of the Precambrian surface - 2010

7,523 test holes and wells used to construct the
elevation map of the Precambrian surface

4,829 test holes and wells encountered the
Precambrian surface

Precambrian Basement Terrane of South Dakota - 2010

Influence of basement structure on surface drainage
(Keya Paha fault versus Keya Paha River)

Basement is approximately 3,000 feet deep along the Keya Paha River/Fault

Structure-contour and Isopach maps – in progress
• Database of test hole and well information is being built
• Geologic units presently targeted for maps of this type:
Eagle/Shannon Sandstone – Pierre Shale
Niobrara Formation
Greenhorn Limestone
Dakota Formation/Newcastle Sandstone
Inyan Kara Group
Minnekahta Limestone
Minnelusa Group
Red marker shale within the Minnelusa Group
Madison Group
Three Forks Shale
Red River Formation
Winnipeg Shale
Deadwood Formation

Geophysical logs have been
scanned and we are working
to make them available online
• Geological Survey Program files:
Logs from approx. 5,340 locations
• Minerals and Mining Program files:
Logs from approx. 1,883 locations

Records of drilling
Approx. 34,241 logs from the
files of the Geological
Survey Program
Approx. 62,245 logs from the
files of the Water
Rights Program
Approx. 1,883 logs from the
files of the Minerals
and Mining Program

Online databases – Geological Survey Program web site
Reports, maps, and data available for free download

We will continue to produce and disseminate
report, maps, and databases

Unexplored/under-explored
potential

Pahasapa/Madison Limestone

North
Dakota
limestone, dolomite
Thickness of the
Madison Group

6,487’
5,426’
4,700’
4,548’
5,430’
4,150’
4,070’
5,960’
4,278’
limestone, dolomite
Depth of the
Madison Group
3,250’
4,292’
2,735’
4,170’
2,515’
2,250’

Outcrop on the west side of Rapid City
Newcastle Sandstone
Core from Amerada No. 1 in southwest Harding County

44’
51’
Wyoming
66’
69’
172’
25’
346’
20’
45’
260’
395’
Thickness of the
Newcastle/Dakota Sandstone
75’
110’
220’
325’
223’
132’
344’
250’
siltstone, claystone, sandy shale, sandstone, shale
243’
197’
320’ 69’
278’
220’
370’
192’
205’
495’

3,876’
3,159’
2,464’
Depth of the
Newcastle/Dakota Sandstone
1,779’
1,980’
3,605’
1,958’
3,945’
2,825’
2,510’
2,700’
1,620’
2,715’
2,180’
1,795’
2,150’
1,712’
1,540’
1,100’
1,713’
1,680’
1,732’
1,130’
801’
1,295’
siltstone, claystone, sandy shale, sandstone, shale
865’
746’
1,370’
900’
1,224’
255’

Pierre Gas Field
Pierre Gas
Field

Pierre Gas Field / Paleozoic subcrop
Pierre Gas
Field
Paleozoic
Subcrop
Paleozoic
Subcrop

Minnelusa Formation
sandstone, siltstone, shale, limestone

Wyoming
sandstone, siltstone, shale, limestone
700’
Thickness of the
Minnelusa Formation
500’

5,920’ 5,260’
4,817’
3,464’
4,720’
3,802’
Depth of the
Minnelusa Formation
3,570’
3,360’
3,470’
3,630’
2,820’
2,245’
2,200’
2,700’
2,309’
3,700’ 2,570’
sandstone, siltstone, shale, limestone
2,340’
1,690’

Niobrara Formation

Ranges in thickness from 0 to 308 feet
Niobrara Formation
chalk, marl, and shale
Ranges in depth from 0 to 2,625 feet

Gas tests drilled
in 2007
Niobrara Formation gas tests
Gas test drilled
in 2004
Niobrara
Formation
Cretaceous
undifferentiated

Dakota Sandstone/Niobrara
Gas tests drilled in 2005 & 2007
Gas tests
drilled in 2007
Cretaceous on
Precambrian
Gas test drilled
in 2004

Methane (CH 4) in air in a well completed in a
glacial outwash aquifer
Geology: 0 – 142 feet Till
142 – 160 feet Outwash
160 – 189 feet Till
189 feet Quartzite

Three Forks Shale in South Dakota

Three Forks Shale
Reinterpretation of part
of cross section A-A’
(west-east)

Three Forks Shale
Reinterpretation of part
of cross section K-K’
(south-north)

There has not been enough drilling, testing, and analysis
regarding oil and gas resources in South Dakota
for the full potential to be realized

Questions?
www.sdgs.usd.edu