university of iowa - cresco elevation protivin …...iowa department of natural resources annual...
TRANSCRIPT
Dai
ly G
eolo
gy:
The
ride
toda
y ov
er th
e Io
wan
Su
rfac
e m
ay n
ot s
eem
all
that
ex
citin
g, b
ut s
omet
hing
qui
te
inte
rest
ing
shou
ld ju
mp
out a
t you
on
the
geol
ogic
cro
ss-s
ectio
n to
the
righ
t. Th
e be
droc
k ha
s lo
ts o
f dee
p va
lleys
cut
into
it. T
his
regi
on w
as
exte
nsiv
ely
carv
ed b
y an
cien
t riv
ers
prio
r to
cont
inen
tal g
laci
atio
n be
gini
ng a
roun
d 2.
6 m
illio
n ye
ars
ago.
The
dee
pest
bed
rock
val
ley
is m
ore
than
250
feet
dee
p! S
ome
of th
ese
valle
ys c
ut a
ll th
e w
ay
thro
ugh
the
Dev
onia
n ag
e be
droc
k an
d in
to th
e O
rdov
icia
n ag
e (~
445
mill
ion
year
s ol
d) M
aquo
keta
Fo
rmat
ion.
Dolom
ite(~4
50 m
illion
yrs. o
ld)
Till
(0.5-2
.6 mi
llion y
rs. ol
d)
Limes
tone
,Dolo
mite
& Sha
le
Shale
& Lim
eston
e
(443-4
50 m
illion
yrs. o
ld)
Ceda
rRiv
er
(385-3
95 m
illion
yrs. o
ld)
Ceda
rRiv
er
Waps
ipinic
onRiv
er
Little
Turke
yRiv
er
Turke
yRiv
er
Little
Waps
iRiv
er
As you bike across the state of Iowa you will primarily be riding on paved roads, but what are they paved with? Some are paved with concrete and some with asphalt. What is the difference? Well, both are composed mostly of aggregate, fragments of crushed limestone or dolomite and sand. It is the material that glues these fragments together that is the primary difference. Concrete (the white or light gray road surface) uses Portland cement to glue the aggregate together. Portland cement is made by firing a finely crushed mixture of limestone, sand, clay, and other materials to 2,600° F in a kiln to produce a clinker that is mixed with gypsum and crushed to a fine powder to make the cement. The cement is mixed with water and the aggregate and applied to the road base to create a concrete roadway. Asphalt is a viscous petroleum product that is heated, mixed with aggregate and applied to the road base to create an asphalt roadway. 94% of asphalt and 80% of concrete is made up from aggregate.
RAGBRAIDay 5
2017Thursday, July 27
The Science of Roads
* Cover photo: Chickasaw County Park is a former quarry. This location was designated by IGS geologists as the “type section” for the Devonian age (~385 mil-lion years old) Chickasaw Shale and Bassett members. Photo courtesy of Ryan Clark (IGS).
Protivin
Cresco
LawlerCharles City
1381 ft.
974 ft.
Elevation
Ionia
New Hampton
Little Cedar River
Cedar River
Parks and preserves
Cities and towns
USGS streamflow station
While thousands of RAGBRAI participants experience Iowa each July from the seat of their bike, hundreds of Iowans spend their July vacation from the seat of a canoe, getting their feet wet and muddy on a river cleanup event called Project AWARE. Project AWARE (A Watershed Awareness River Expedition) is the Iowa Department of Natural Resources annual volunteer weeklong river cleanup. Since 2003, more than 4,000 participants have cleaned up over 1,080 river miles across Iowa and removed 377 tons of trash, of which 76% has been recycled. Earlier this month, Project AWARE celebrated its 15th year, with more than 300 volunteers removing garbage from a 55-mile stretch of the Cedar River in north-central Iowa. Volunteers camped along the banks of the Cedar River in Charles City for two nights. As part of Project AWARE, volunteers clean up a different Iowa river each year. People come together on this annual adventure to paddle and learn about the river. Although canoes and kayaks were filled with trash each day, and rivers look better by the end of the event, the true impact of AWARE lies in the environmental education, understanding, and empowerment of the volunteers to protect, preserve, and cherish Iowa’s natural resources.
Just 12 feet downstream from the bridge crossing the Cedar River on the left bank is another USGS stream gage. All 8,000+ stream gages across the nation are a part of the USGS WaterAlert program. By subscribing to the WaterAlert service, you can receive instant, customized updates about water conditions as reported by any of the sites across the country. Whether you are watching for floods, interested in recreational activities or concerned about the quality of water in your well, you can receive updates about current conditions in rivers, lakes and groundwater when those conditions match the parameters you select. Information will be sent to you hourly or daily by text or email – you choose! Sign up at http://water.usgs.gov/wateralert.
Since 1993 the Iowa Geological Survey has conducted geologic mapping in selected areas of Iowa. In 2016, maps were made of the surficial (below) and bedrock (right) geology of the Charles City Quadrangle. Subsurface information from the drilling of water wells and other borings provide valuable information to geologists. Bedrock exposures along rivers and in quarries are also utilized to better understand what the geology is beneath our feet. Maps like these can help decision makers regulate groundwater resources, plan future urban developments, identify limestone deposits for aggregate, as well as improve understanding of watersheds and flooding hazards.
Project AWARE STATEMAP
USGS WaterAlert