Post on 23-May-2020
Mesa Antero, Chaffee County, Colorado Upper Arkansas River Valley
Geologic Setting c/o Mesa Antero Water Assoc. (MAWA)
Jay C. Close Nathrop, Colorado
Presentation to MAWA Board and Members January 3, 2014
Objectives / Background
• Provide an overview of Upper Arkansas River Basin, Colorado geology, with specific reference to MAWA geologic setting – Utilize selected technical references from publicly available
literature / Internet resources
• Basic understanding of MAWA geology may impact the Board’s actions regarding future water supply – Water utilization considerations are here to stay – Serve as background for water rights questions / investigations – May impact future system maintenance / upgrades – Unforeseen circumstances?
2
Observations / Conclusions
• Upper Arkansas Valley geologic setting – northern Rio Grande Rift (down-dropped fault valley) occupied by
structurally-controlled Arkansas River – Flanked by mountain range uplifts (Sawatch to west; Mosquito to east)
split by the Rift, from which geologically very young glacial outwash / alluvium and underlying basin fill were sourced
• MAWA water supply – Aquifer: glacial outwash gravels; secondarily from deeper basin fill? – Chemistry: sodium bicarbonate fresh water; total dissolved solids very
low (TDS often <250 mg/liter) – Primary water source: surface infiltration; seasonal water table levels
highest after snow melts – Apparent age: variable; some water younger than 1953, some older;
time- and location-specific
3
Central Colorado topography: reflection of geologic setting
Upper Arkansas
Valley
http
s://
map
s.go
ogle
.com
/
4
http
://e
n.w
ikip
edia
.org
/wik
i/Rio
_Gra
nde_
Rift
Upper Arkansas
Valley South Park
Wet Mtn. Valley
San Luis Valley
5
Colorado Plateau: flanked by Rio Grande Rift to east
Centers of igneous activity
San Juan Mtns
http
://w
ww
2.na
ture
.nps
.gov
/geo
logy
/edu
catio
n/fo
os/p
late
au.p
df
Upper Arkansas
Valley
6
Central Colorado topography: influence of Colorado Plateau / Rio Grande Rift on geologic setting
South Park
Northern Rio Grande
Rift (San Luis Valley)
Upper Ark.
Valley
San Juan Mtns
Volcanic Field
Gunnison Plateau
http
s://
map
s.go
ogle
.com
/
Wet Mtn
Valley
Raton Basin
San Juan Basin
Piceance Basin
39 Mile Volcanic
Field
Denver Julesburg
Basin
7
Geologic Time Scale, Cenozoic Era ht
tp:/
/pub
s.us
gs.g
ov/f
s/20
07/3
015/
fs20
07-3
015.
Ma = millions of yrs
8
Fault locations/ages-central Chaffee County, Colorado ht
tp:/
/dnr
web
map
gdev
.sta
te.c
o.us
/cgs
onlin
e/ BV
Nathrop
Salida
Mesa Antero
ka = thousands of yrs
9
central Chaffee County topography ht
tps:
//m
aps.
goog
le.c
om/
Mesa Antero
Salida
Nathrop
Centerville
10
Mt Princeton Chalk Cliffs adjacent to northern Sawatch fault zones
Kaolinite-white clay weathering from white granite •Chalk Cliffs formed by geothermal waters
migrating up along / near Sawatch fault zones: Mt Princeton Hot Springs ! Late Sept 2013 photo, view ~NW
http
://g
eosu
rvey
.sta
te.c
o.us
/Site
Colle
ctio
nDoc
umen
ts/E
nerg
yRes
ourc
es/G
eoth
erm
al/L
oRes
_Pla
te1_
Inte
rpre
titiv
e_Ge
othe
rmal
_Hea
t_Fl
ow_M
ap.p
df
11
Mesa Antero topographic detail
http
://w
ww
.usg
s.go
v/pu
bpro
d/
~1 mi
T51N R8E
12
Geologic Map, Mesa Antero area ht
tp:/
/ngm
db.u
sgs.
gov/
Prod
esc/
prod
desc
_378
4.ht
m
Centerville
Quaternary Qpo: Pinedale glacial outwash Qi: Illinoisan(?) glacial outwash Qn: Nebraskan(?) glacial alluvium Tertiary Td: Dry Union Fm.
~1 mi
Roadcut on switchback eastern end
of 261P (Ouray): excellent example
of Qn underlain
by Td
13
Mesa Antero area geologic setting: Quaternary alluvium / glacial
outwash underlain by Tertiary Dry Union Fm basin fill
Mesa Antero
http
s://
map
s.go
ogle
.com
/
14
Mesa Antero geologic setting
Aug 2013 photo, view ~W From Aspen Ridge
Dry Union Fm.
Sawatch fault zone
Mesa Antero
Dry Union Fm. badlands
NW of Salida
15
US Geological Survey Upper Arkansas River water report
http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf 17
http
://p
ubs.u
sgs.
gov/
sir/2
005/
5179
/SIR
2005
-517
9.pd
f
BV
Nathrop
Generalized surface geology Water table altitude/configuration, Sept 2003
Mesa Antero
18
Cross section of ground water flow, northwest of Salida ht
tp:/
/pub
s.usg
s.go
v/sir
/200
5/51
79/p
df/S
IR20
05-5
179.
19
Water level / water quality monitors, selected stream gauges ht
tp:/
/pub
s.us
gs.g
ov/s
ir/20
05/5
179/
pdf/
SIR2
005-
5179
Mesa Antero
20
Aquifer Characteristics, Upper Arkansas Valley
http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf 21
Depth to Water, Sept 2003
Mesa Antero
http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf 22
Historic Water Well Levels
http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf 23
Water Level Changes, July 2002-July 2003
http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf
Mesa Antero
24
Water Quality, alluvium/outwash, Sept-Oct 2001 ht
tp:/
/pub
s.usg
s.go
v/sir
/200
5/51
79/p
df/S
IR20
05-5
179.
25
Ground Water Ages via Tritium Analyses
• Tritium: hydrogen isotope • Above-ground nuclear weapons testing in 1950’s-1960’s
greatly increased atmospheric tritium concentrations, hence currently provide an excellent chronological marker for geologically extremely young systems
• Tritium half-life ≈ 12.32 yrs • Ground water age estimation via tritium concentrations in
specially collected samples • Qualitative ages: pre-modern <1953, post-modern ≥1953 • Quantitative ages via half-life techniques
http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf 26
Water level and water quality sample wells http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf
27
Apparent Mean Ages (tritium reference) of Ground Water Recharge, Browns Creek – Chalk Creek area
‘Because water level altitudes at wells 55, 58, and 59 were high than the altitude of Browns Creek, the stream reach is probably a gaining reach and the ground water
recharge is likely from precipitation.’ ‘The range in ages of ground water recharge for wells 55, 58 and 59 was not definitive…’
‘…it is likely that the shallow ground water (wells 58 and 59) was recharged more recently than the deeper ground water (well 55).’
http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf p. 37 28
Selected References Upper Arkansas Valley, Colorado geology
• Hydrogeology and Quality of Ground Water in the Upper Arkansas River Basin from Buena Vista to Salida, Colorado, 2000-2003 http://pubs.usgs.gov/sir/2005/5179/pdf/SIR2005-5179.pdf
• Roadside Geology of Colorado (2nd ed.) http://mountain-press.com/item_detail.php?item_key=34
• Geology and Mineral Deposits of the Poncha Springs SE Quadrangle, Chaffee County, Colorado http://pubs.usgs.gov/pp/0829/report.pdf
• Geologic Map of the Poncha Springs Quadrangle, Chaffee County, Colorado http://ngmdb.usgs.gov/Prodesc/proddesc_3784.htm
• Geologic Map of the Poncha Springs NE Quadrangle, Chaffee County, Colorado http://pubs.usgs.gov/pp/0626/report.pdf
• Reconnaissance Geologic Map of the Buena Vista Quadrangle, Chaffee and Park Counties, Colorado http://pubs.er.usgs.gov/publication/mf657
• Geologic Map of the Buena Vista East Quadrangle, Chaffee County, Colorado http://geosurveystore.state.co.us/p-612-buena-vista-east-quadrangle-chaffee-county.aspx http://www.geohaz.com/downloads/GEOLOGIC%20MAPS/COLORADO/BUENA%20VISTA%20East/OF%2004-4%20Buena%20Vista%20East%20Booklet.pdf
• Road and Riverside Geology of the Upper Arkansas Valley….Leadville to Cañon City Tom Karnuta, Salida, Colorado. http://cozine.com/1995-august/geology-of-the-upper-arkansas-valley-by-tom-karnuta/
• High Plains to Rio Grande Rift: Late Cenozoic Evolution of Central Colorado http://fieldguides.gsapubs.org/content/3/59.full
• Insights Into the Structural Development of the Upper Arkansas Valley: The Influence of Pre-Existing Structure and Implications of Basin Geomorphology. Richard Smith, Nathrop, Colorado. https://gsa.confex.com/gsa/2013AM/webprogram/Paper230081.html
• Mt. Princeton Geothermal Presents Energy Plan. Fred Henderson III, Mt Princeton Geothermal LLC. http://www.themountainmail.com/news/article_88772894-29df-11e3-99af-001a4bcf6878.html
• Analysis of Borehole Temperature Data from the Mt. Princeton Hot Springs Area, Chaffee County, Colorado http://www.searchanddiscovery.com/documents/2013/80327morgan/ndx_morgan.pdf
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