Complete Brief Geologic History of the Denver, Colorado area

1. Geologic History of the Denver Area
MJD 3/2016 1

2. Geologic History of the Denver Area
The Usual and the Unusual
Geology of the Denver Area
By
Michael Delvaux
MJD 3/2016 2

3. Geologic History of the Denver Area
• Disclaimer: This presentation is meant to give an overall top level history (sequence of
events) of the major events that occurred in the Denver area from the beginning of time.
It is not meant to serve any other purpose. The published sources from which many of
the pictures and graphics that were used are listed at the end. There were some
pictures and graphics that were collected from the internet over the years that I do not
have references for. Some of the photographs I have taken myself.
• Due to the uplift of the Rocky Mountains, there are good exposures to a lot of the
geologic history. Unlike other places in the world, there are a number of rather unusual
(not un-natural or un-explainable) things that have occurred here which I have
attempted to point out.
• I have attempted to point out at least one location in the area that contains evidence for
the current theory of these major events.
• For those really interested, I could offer my services up as a guide. Friend me and
message me on my Linkedin site (Public Profilehttps://www.linkedin.com/in/michael-
delvaux-3244052).
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4. Geologic History of the Denver Area
• Introduction
– 3 Classifications and what they mean
IGNEOUS
SEDIMENTARY
METAMORPHIC
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5. Geologic History of the Denver Area
• Introduction
Igneous Classification
Crystals High Content of In Between Low Content of
Orthoclase Feldspar Mixtures Orthoclase Feldspar
Quartz Quartz
Low Content of High Content of
Plagioclase Feldspar Plagioclase Feldspar
Macroscopic Granite Quartz Monzonite Gabbro
Crystals Granodiorite
Diorite
Microscopic Rhyolite Quartz Latite Basalt
Crystals Dacite
Andesite
Extrusive Behavior Extrusive Behavior
Explosive Volcanic Non explosive
Ash most common non viscous thin
Or thick Volcanic lava
Viscous Lava
MJD 3/2016
5

6. Geologic History of the Denver Area
• Introduction
Igneous Rocks – What’s Cool
Different elements and minerals crystalize out of
a cooling magma at different temperatures.
Radioactive Isotope parents
(like U238) crystalize at a
different temperature than their
daughter products (like Pb206).
Since they start at a pure state
they can be used to measure time.
MJD 3/2016 6
Ref: wikipedia

7. Geologic History of the Denver Area
• Introduction
Sedimentary Rocks – What’s Cool
Material is eroded, transported and deposited.
The depositional environments have discernable
recognizable features.
Erosion
Alluvial
fan
Fluvial
Shoreface Marine
MJD 3/2016 7
Picture Ref: Weimer

8. Geologic History of the Denver Area
• Introduction
Sedimentary Rocks – What Else Is Cool
Rock formations below are older than rock
formations above.
 Law of Superposition – Nicoli Steno 1669
Rock formations that reside vertically from one
another were deposited horizontally from one
another
 Walther’s Principle – Johannes Walther 1893 ( first suggested by: Amanz
Gressly 1838)
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9. Geologic History of the Denver Area
• Introduction
Hundreds
Of
Feet
Hundreds of Miles
MJD 3/2016 9
Example of
Walther’s Principle

10. Geologic History of the Denver Area
• Introduction
That’s cool but what could can an amateur
determine?
Stream and
river current
directions
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11. Geologic History of the Denver Area
• Introduction
Flow Direction?
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12. Geologic History of the Denver Area
• Introduction
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13. Geologic History of the Denver Area
• Introduction
Faults
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14. Geologic History of the Denver Area
• Fossils (from Latin fossus, literally "having been dug up") are the
preserved remains or of animals, plants, and other organisms from
the remote past.
• Trace fossils, also called ichnofossils (sg. pronounced /ˈɪknoʊfɒsɨl/, from
Greek: ιχνος ikhnos "trace, track"), are geological records of biological
activity. Trace fossils may be impressions made on the substrate by an
organism: for example, burrows, borings (bioerosion), footprints and feeding
marks, and root cavities.
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15. Geologic History of the Denver Area
• Introduction
– Time Chart
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Picture Ref: Abbott

16. • Our Story Begins
Geologic History of the Denver Area
13Bya
4.5ByaMJD 3/2016 16Now
First there was the Big Bang

17. • Our Story Begins
Geologic History of the Denver Area
Big Bang
13Bya
4.5ByaMJD 3/2016 17Now

18. • Our Story Begins
Geologic History of the Denver Area
Big Bang
13Bya
4.5ByaMJD 3/2016 18
Supernovas create heavy elements
Ref: Wikipedia
Now

19. • Our Story Begins
– Cool Place: Chamberlain Observatory
• Observatory Park, Denver, Colorado
Geologic History of the Denver Area
MJD 3/2016 19
Ref: Wikipedia

20. • Our Story Begins
Geologic History of the Denver Area
Big Bang
13Bya
4.5Bya
Solar Nebula
MJD 3/2016 20Now

21. • Our Story Begins
Geologic History of the Denver Area
13Bya
4.5ByaMJD 3/2016 21
Earth FormationSolar Nebula
Now

22. • Our Story Begins
Geologic History of the Denver Area
Big Bang
13Bya
4.5Bya
Solar Nebula Earth Formation Canadian Shield Begins to form
2.45ByaMJD 3/2016 22
Ref: Abbott, HoffmanPrecambrian
Now

23. Geologic History of the Denver Area
• Amalgamation of Early North America
(Laurentia)
MJD 3/2016
23
Ref: Hoffman, Jones
13Bya
4.5Bya 2.45Bya
Big Bang
Earth Formation
Canadian Shield
Forms
Precambrian
Now

24. Geologic History of the Denver Area
• Yavapai Orogeny
13Bya
4.5Bya 2.45Bya
Big Bang
Earth Formation
Canadian Shield
Forms
1.76Bya
Yavapai Orogeny
Yavapai Orogeny:
Mountain building
as a result of the
accretion of the
Colorado Volcanic
Arc to Laurentia
PrecambrianMJD 3/2016
24
Ref: Abbott, Hoffman,
Now

25. Geologic History of the Denver Area
13Bya
4.5Bya 2.45Bya
Big Bang
Earth Formation
Canadian Shield
Forms
1.76Bya
Yavapai Orogeny
Precambrian
Yavapai Orogeny
Cynobacteria
formed
stromatolites
in the back arc
shallow
environments
MJD 3/2016
25
Ref: Abbott, Hoffman, Snoke,
Knight
Now

26. Geologic History of the Denver Area
• Cool Place: Bioherms (stromatolites) in the
Medicine Bow Mountains of S.Wyoming
MJD 3/2016 26
Ref: Snoke, Knight

27. Geologic History of the Denver Area
• Cool Place: Bioherms (stromatolites) in the
Medicine Bow Mountains of S.Wyoming
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28. Geologic History of the Denver Area
• Denver Area Rocks of Yavapai Orogeny Time
Gneisses and Schists
Volcanic Arc produced thousands of feet of sediment
of which burial pressure and heat metamorphosed.
Boulder Creek Granodiorite (batholith)
Igneous plutonic rock composed of both plagioclase
and orthoclase feldspars due to the melting and
mixing of both the continental crustal granites and
oceanic crustal basalts
Coal Creek Quartzite
Metamorphosed sandstones and conglomerates from
erosion of mountains and continental rocks.
MJD 3/2016 28
Ref: Cole, Kellog

29. Geologic History of the Denver Area
• Denver Area Rocks of Yavapai Orogeny Time
MJD 3/2016 29
Ref: Kellog

30. Geologic History of the Denver Area
• Mazatzal Orogeny
13Bya
4.5Bya 2.45Bya
Big Bang
Earth Formation
Canadian Shield
Forms
1.76Bya
Yavapai Orogeny
Mazatzal Orogeny:
Mountain building
as a result of the
accretion of
succeeding
volcanic arcs.
Precambrian
Mazatzal Orogeny
1.65Bya
MJD 3/2016
30
Ref: Abbott, Hoffman,
Now

31. Geologic History of the Denver Area
• No Denver Area Rocks are from the Mazatzal
Orogeny
Gneisses, Schists, and intrusions at the Royal
Gorge are part of the Salida-Gunnison Volcanic
Arc
Transition zone of overlapping Yavapai and Mazatzal
processes.
MJD 3/2016 31
Ref: Abbott, Hoffman,

32. Geologic History of the Denver Area
• A third stage set of igneous plutonic pulses
occurred in the Arizona, New Mexico, and
Colorado Area
– 1.50 Bya This pulse did not occur in the Denver
Area
– 1.45 to 1.4 Bya This pulse occurred as the Silver
Plume, Mount Evans, and Longs Peak Batholiths
• Largely granite to granodiorite in composition
• Berthoud Plutonic Suite (Berthoud Orogeny)
MJD 10/2016 32
Ref: Hoffman,

33. Geologic History of the Denver Area
• Iron Dike Intrusion
– Dark-gray to black ferrogabbro; weathers dark brown to orange brown with
prominent limonite stains along joint surfaces; very fine grained along dike
margins, and medium grained in centers of thicker dike segments (as wide as 50
ft). Intruded 1,316 ± 50 Ma (Rb-Sr isochron; Braddock and Peterman, 1989). Iron
Dike forms a narrow north-northwest trending swarm that can be traced almost
continuously from eastern margin of Front Range near Boulder, across Estes Park
quadrangle, and beyond into Medicine Bow Range to near Colorado-Wyoming
State line, over a distance of about 95 mi.
– Ferrogabbro composition indicates a deeper mantle source than all previous
igneous intrusions. The cause of this intrusion is unclear.
– Cool location to observe this: Near Boulder and near Estes Park
MJD 3/2016 33
Ref: Kellog

34. • Grenville Orogeny
Geologic History of the Denver Area
13Bya
4.5Bya 2.45Bya
Big Bang
Earth Formation
Canadian Shield
Forms
1.76Bya
Yavapai
Orogeny
Precambrian
Grenville
Orogeny
1.0Bya
Grenville Orogeny:
Mountain building
as a result of the
Collision of many
land masses
forming the first
supercontinent,
Rodinia.
MJD 3/2016
34
Ref: Abbott, Hoffman,
Now

35. • Grenville Orogeny
Geologic History of the Denver Area
13Bya
4.5Bya 2.45Bya
Big Bang
Earth Formation
Canadian Shield
Forms
1.76Bya
Yavapai
Orogeny
Precambrian
Grenville
Orogeny
1.0Bya
Immense collision
forces may have
resulted in
fracturing the crust
and causing rift
zones internal to
the continent
MJD 3/2016
35
Ref: Abbott, Hoffman,
Now

36. Geologic History of the Denver Area
• Pikes Peak Batholith
– 3 Intrusive Centers
• Pikes Peak
• Buffalo Park
• Lost Park
– Other Intrusive
Centers may be
buried
– 7 satellite stocks of
non granite igneous
rock are associated.
MJD 3/2016 36
Ref: Abbott, Epis

37. Geologic History of the Denver Area
• Sandstone Dikes
– Extremely unusual feature that occurs within the
Pikes Peak Granite in more than one geographical
location
– Also occurs in biotite gneiss near Arapahoe Pass
in the Indian Peaks Wilderness Area and is
associated with the Arapahoe Pass Fault.
– Explanations vary, but most likely fault induced
fissures into which unconsolidated sand from
aeolian sand dunes fell.
• Likely occurred in the Precambrian between 1.0 Bya and
0.5 Bya. Possibly at the breakup of Rodinia (0.8 Bya).
• Dunes or dune formation eroded during Precambrian
time leaving no other trace of its existence.
MJD 3/2016 37
Ref: Epis, Siddoway

38. Geologic History of the Denver Area
• Sandstone Dikes (Very Unusual)
– Cool Place: Highway 126 (Pine Valley Rd)
Granite Granite
Sandstone
Dike
MJD 3/2016 38

39. • Cambrian Period
– Explosion of Multicellular Life
– Marks the beginning of the Phanerozoic Eon /
Paleozoic Era
– Earth for the first time had an over abundance
of oxygen which probably lead to the
development of multicellular life
Geologic History of the Denver Area
13Bya
4.5Bya 2.45Bya
Big Bang
Earth Formation
Canadian Shield
Forms
1.76Bya
Yavapai
Orogeny
Precambrian
Grenville
Orogeny
1.0Bya
Cambrian Period
0.54Bya
Phanerozoic
MJD 3/2016 39
Now

40. • Cambrian Period -> Ordovician Period
– Started with no deposition and ended with
flooding by shallow sea in Colorado
• Upper Cambrian Sawatch formation marks the
transgression of the sea.
• Cool Place: Sawatch deposited on Pikes Peak
Granite visible in Manitou Springs.
Geologic History of the Denver Area
MJD 3/2016
40
Ref: Blakey

41. • Ordovician Period -> Silurian Period
– Shallow Sea followed by no deposition in
Colorado.
Geologic History of the Denver Area
MJD 3/2016 41
Ref: Blakey

42. • Silurian Period -> Devonian Period
– Shallow Sea transgression across Colorado.
– Eurasian/African Plate encroaches NA plate.
Geologic History of the Denver Area
MJD 3/2016
42
Ref: Blakey

43. • Kimberlite Diatremes
– Widespread clusters of deep mantle derived volcanic
activity occurred in the West from Very late
Precambrian through Devonian.
– Source is at depths where pressures are great enough
to form diamonds.
– Volcanism was very violent ripping away wall rocks,
some of which were entombed within the diatreme
pipes themselves.
– Captured wall rocks suggest Silurian/Devonian ages
for diatremes near the CO/WY boarder.
– Some diatremes including the one near Boulder are
Late Precambrian or early Cambrian.
Geologic History of the Denver Area
MJD 3/2016 43
Ref: Abbott, Cole Coopersmith, Kellog

44. • Kimberlite Diatremes
Geologic History of the Denver Area
Economics of these diatremes:
0 to 100 carats per 100 tons.
MJD 3/2016 44
Ref: Coopersmith

45. • Kimberlite Diatremes
Geologic History of the Denver Area
Cool Unusual Place near Denver:
Boulder’s Green Mountain Diatreme
MJD 3/2016 45
Ref: Abbott, Nesheim

46. • Devonian Period -> Mississippian Period
– Shallow Sea still across Colorado.
– Eurasian/African Plate encroaches NA plate
Geologic History of the Denver Area
MJD 3/2016 46
Ref: Blakey

47. • Mississippian -> Pennsylvanian Period
Geologic History of the Denver Area
Ancestral
Rockies
Appalachians
Atlas Mtns
MJD 3/2016 47
Ref: Blakey

48. Geologic History of the Denver Area
• The Great Colorado Unconformity
– Uplift of Ancestral Rockies eroded all previously
deposited Sedimentary rocks
– Alluvial deposits (Fountain Formation) on
Precambrian
– Cool Place: Red Rocks Amphitheater
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49. • Pennsylvanian Period -> Permian Period
Geologic History of the Denver Area
MJD 3/2016 49
Ref: Blakey

50. • Permian Period
– Supercontinent Pangea
– Continued erosion of Ancestral Rockies.
– Large scale wind blown Sand dunes and location
dependent fluvial (stream/river) deposits.
– Cool Places: Lyons Formation in Morrison (contains
very large desiccation cracks. Lyons Formation in Red
Rock Canyon Open Space Park, Manitou Springs
(contains large dune crossbedding, also SS quarry for
building stone ).
– Permian Period ends with the largest extinction event
in geologic history.
Geologic History of the Denver Area
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51. • Permian Period
– Mud cracks (Matthews) or freezing/thawing cracks
(Abbott) in Lyons formation in Morrison city limits.
Geologic History of the Denver Area
MJD 3/2016 51
Ref: Matthews, Abbott

52. • Triassic Period
– No trace of Ancestral Rockies remain
– Lykins Formation
• Low lying mudflats with interfingering marine limestones
• Red iron oxidation suggests arid to semi arid conditions
• Cool places: Within Morrison city limits, South Valley Park, and
above NCAR in Boulder
• Limestones contain stromatolite trace fossils.
Geologic History of the Denver Area
MJD 3/2016 52

53. • Jurassic Period
– Breakup of supercontinent Pangea
– Morrison Formation
• Ancient river channel and flood plains deposits
• Red iron oxidation and teal iron reduction in the flood plain /
ancient soils
• Dinosaurs
• Cool place: Dinosaur Ridge (bone site and track site)
Geologic History of the Denver Area
MJD 3/2016 53

54. • Jurassic Period
– Morrison Formation
• Cross Section of current ripples at Dinosaur Ridge
Geologic History of the Denver Area
MJD 3/2016 54

55. • Cretaceous Period
– Dakota Formation
• Cyclical occurrences of ancient river channel deposits
progressing into tidal flat, shoreface and marine deposits.
• Dinosaurs
• Cool place: Dinosaur Ridge
– Track site – dinosaur and crocodile
– Fossil plant material in channel sands
– Small burrows in tidal flat and shallow marine deposits
– Volcanic ash deposits
• Cool Place: Eldorado Canyon near Boulder
– Tidal Flat and shallow marine / delta deposits
Geologic History of the Denver Area
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56. • Cretaceous Period
– Dakota Formation
Geologic History of the Denver Area
Track site
MJD 3/2016
56

57. • Cretaceous Period
– Dakota Formation
Geologic History of the Denver Area
U Shaped burrows in Tidal Flat
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58. • Cretaceous Period
– Cretaceous Interior Seaway
• Over 5000 feet of marine deposits
– Benton, Niabrara, and Pierre Formations
• Cool place:
– Dinosaur Ridge – Benton shale
– City of Morrison (along bike trail under C470) – Benton & Niabrara
– NCAR (Boulder) and Red Canyon Open Space (CO Sprgs) – Niabrara
– Rooney Road – Pierre
Geologic History of the Denver Area
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59. • Cretaceous Period
– Cretaceous Interior Seaway
Geologic History of the Denver Area
Seaway Deposits
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60. • Cretaceous Period
– Cretaceous Interior Seaway
Geologic History of the Denver Area
MJD 11/2016 60
Ref: Blakey, Wikipedia

61. • Cretaceous Period
– Uplift: Retreat of the Seaway and rise of the Rockies
• Compression in the North American plate caused regional
uplift resulting in regression of the sea.
• Further compression caused major thrust faulting
– Faults extended down into the basement crystalline rocks
– This episode is called the Laramide Orogeny
• Cool place:
– Rooney Road – Fox Hills Formation Delta deposits
– Fossil Trace Golden and CSM Golden – dinosaur tracks in Laramie
Formation
– Bear Creek Reservoir Park (Lakewood) and Marshall Open Space
(Boulder) - Fox Hills and Laramie Formations: beach and swamp (coal)
Geologic History of the Denver Area
MJD 3/2016 61

62. • Cretaceous Period
Geologic History of the Denver Area
MJD 3/2016 62
Ref: Abbott

63. • Late Cretaceous Period
Geologic History of the Denver Area
MJD 3/2016 63
Ref: Abbott

64. • Late Cretaceous Period
– KT Boundary
• Most famous extinction event of all (extinction of the
dinosaurs)
• Cool Place: South Table Mountain at about 70 meters below
lava flows on SE side. KT boundary determined from fossil
pollens (clay layer itself is not preserved)
• Cool Place: Clay layer outcrops in Bijou Creek
Geologic History of the Denver Area
MJD 11/2016 64
Ref: Kellog, et. al. , 2004

65. • Paleocene Epoch
– Golden Fault was still active
– Erosion continued into the crystalline basement rocks
and formed a rough but gentle sloping eastward plane
called the Rocky Mountain Erosion Surface (parts still
observable today)
– Front Range Volcanoes emerged creating many lava
flows.
– Most of the lava flows eroded and redeposited as stream
bed conglomerates of the Denver Formation.
Occurrences of fossil plant material. Cool Place: lower
half of Green Mountain.
Geologic History of the Denver Area
MJD 3/2016 65

66. • Paleocene Epoch
Geologic History of the Denver Area
MJD 3/2016 66
Ref: Abbott

67. • Paleocene Epoch
– Cool Place: North and South Table Mountains
• 3 lava flows on North Table Mountain
• 2 lava flows on South Table Mountain
• Composition of the lava is called Shoshonite (a
variation of Latite). Mixture of plagioclase and
orthoclase feldspars.
• Contains mineralization
– Zeolite Group: thomsonite, anaclime, chabazite, aragonite,
and others
• Lava source was Ralston Dike located a few miles
north of North Table Mountain.
Geologic History of the Denver Area
MJD 3/2016 67
Ref: Drewes 2006, Pearl

68. • Paleocene Epoch
Geologic History of the Denver Area
MJD 3/2016 68
Ref: Abbott

69. • Eocene Epoch (58 – 37 mya)
– Front Range Volcanoes went extinct.
– Golden Fault went dormant.
– Major erosion period buries the mountains in
their own debris and removes steep slopes.
– Cool Place: Green Mountain Conglomerate
(contains fossil plant and wood material) on
Green Mountain.
Geologic History of the Denver Area
MJD 3/2016 69

70. • Eocene Epoch
Geologic History of the Denver Area
(Saprolite – intense chemical weathering of gneiss. Current top of Lookout Mountain)
MJD 3/2016 70
Ref: Abbott

71. • Eocene Epoch
– Ignimbrite Flare-up
• One of the most extensive episodes of high-silica volcanism
(high explosive) in the world
• 6 of the 40 worlds largest eruptions of all time anywhere in the
world occurred in Colorado at this time
• Wall Mountain Tuff was the opening volley with an extremely
large pyroclastic flow.
– Volcanic Source 65 miles to the west near Mt. Princeton
– https://www.youtube.com/watch?v=Cvjwt9nnwXY (example)
• Cool place: Wall Mountain Tuff in Rhyolite Park in Castle
Rock. Most of the tuff has been quarried for building material
but some still remains in place.
Geologic History of the Denver Area
MJD 3/2016 71
Ref: Abbott

72. • Eocene Epoch
– Wall Mountain Tuff – Hot incandescent cloud of ash
and gas raced across central Colorado to the vicinity of
Castle Rock in about an hour consuming everything in
its path. As the huge volume of material erupted, the
surface foundered into the magma chamber.
Geologic History of the Denver Area
MJD 3/2016 72
Ref: Matthews

73. • Eocene Epoch
– Wall Mountain Tuff
Geologic History of the Denver Area
Topography was
different than it is
today
MJD 3/2016 73
Ref: Abbott

74. • Eocene Epoch
– Massive Flooding - Castle Rock Conglomerate
• Extensive flooding brought large stones from as far away as
46 miles (pieces from Coal Creek Quartzite)
• Contains blocks of Wall Mountain Tuff, thus younger than the
tuff itself.
• Cool place: Rock Park in Castle Rock and Castlewood
Canyon State Park
Geologic History of the Denver Area
MJD 3/2016 74
Ref: Abbott

75. • Eocene Epoch
– Castle Rock Conglomerate
• Massive flooding carves canyon in
Wall Mountain Tuff.
Geologic History of the Denver Area
Topography was
different than it is
today
MJD 3/2016 75
Ref: Abbott

76. • Eocene Epoch
– Castle Rock Conglomerate
• Massive flooding brings material
from as far away as Boulder CO.
Geologic History of the Denver Area
Topography was
different than it is
today
MJD 3/2016 76
Ref: Abbott

77. • Eocene Epoch
– Florissant Formation
• Guffey Volcanic
eruptions
– After Wall Mountain
– Buries leaves, insects,
and fish in ash
• Lahar ( volcanic mud
and debris flow) buries
Sequoia redwood forest.
• Cool place: Florissant
National Monument
Geologic History of the Denver Area
MJD 3/2016 77
Ref: Abbott

78. • Oligocene, Miocene, and Pliocene Epochs
– Continued regional uplift to 5000 ft
– Erosion: Incision of canyons and valleys in the
mountains
Geologic History of the Denver Area
MJD 3/2016 78
Ref: Abbott

79. • Pleistocene Epoch
– Cool Place: Mount Morrison Slide in Matthews Winters
Park. Massive landslide deposit when the valley floor
was not incised as deep as it is today.
Geologic History of the Denver Area
MJD 3/2016 79
Ref: Drewes 2005

80. • Pleistocene Epoch
– Glaciation in the mountains
– Cool Place: Valleys of Rocky Mountain
National Park
– Cool Place: Lamb Spring (Littleton, CO);
Pleistocene animal remains of mammoths,
camels, horses, sloths, llamas and wolves.
~ 13Kya
Geologic History of the Denver Area
MJD 3/2016 80
Ref: Web Site

81. • Modern Times
– Earliest human inhabitants ~8400 years ago as
evidenced by spear points and bison bones at
Lamb Spring (Littleton, CO)
– Magic Mountain Archeological Site (Apex
Open Space) ~ 5000 years human presence
– Plains Indians
– 1858 first white settlement in Denver
– 1970 skyscraper boom
Geologic History of the Denver Area
MJD 3/2016 81

82. Geologic History of the Denver Area
• References
Abbott,A. and Cook,T. 2012, Geology Underfoot Along Colorado’s Front Range. Mountain Press Publishing Co,
Missoula, MT.
Blakey, Ron, Paleogeography and Geologic Evolution of North America: https://www2.nau.edu/rcb7/nam.html
Cole, J.C., and Braddock, W.A., 2009, Geologic map of the Estes Park 30’ x 60’ quadrangle, north-central
Colorado: USGS Scientific Investigations Map 3039, 1 sheet, scale 1:100,000.
Coopersmith, H., Mitchell, R., Hausel, W., 2003, Kimberlites and Lamproites of Colorado and Wyoming, USA.
Guidebook Prepared for the VIIIth International Kimberlite Conference, Colorado and Wyoming Field Trip 16-21
June2003, Geological Survey of Canada, Ottawa, Ontario.
Drewes, H., Townrow, J., 2005, Trailwalkers Guide To The Dinosaur Ridge, Red Rocks And Green Mountain Area,
Second Edition, Friends of Dinosaur Ridge, Morrison, CO
Drewes, H., 2006, Table Mountain Shoshonite Porphyry Lava Flows and Their Vents, Golden, Colorado, Scientific
Investigations Report 2006-5242, US Geological Survey
Epis, R. and Weimer, R., 1976, Professional Contributions of Colorado School of Mines; Studies in Colorado Field
Geology. Colorado School of Mines, Golden, Colorado.
Hoffman,P. 1988, United Plates of America, The Birth Of A Craton: Early Proterozoic Assembly and Growth of
Laurentia. Annual Review of Earth Planetary Sciences, Vol 16, Palo Alto, CA, Annual Reviews, Inc, p. 543-603.
Jones,D. et at. 2010, New Models for Paleoproterozoic orogenesis in the Cheyenne belt region: Evidence from the
geology and U-Pb geochronology of the Big Creek Gneiss, southeastern Wyoming. GSA Bulletin Vol 122; no.
11/12.
Kellog,K., Bryant,B., and Reed,J., 2004, The Colorado Front Range-Anatomy of a Laramid Uplift, Geological
Society of America Field Guide 5.
Kellog,K., et al, 2008, Geologic Map of the Denver West 30’ x 60’ Quadrangle, North Central Colorado: USGS
Scientific Investigations Map 3000, 1 sheet
MJD 3/2016 82

83. Geologic History of the Denver Area
• References
Knight,S.H., 1968, Precambrian staromatolite bioherms and reefs in the lower half of the Nash Formation, Medicine
Bow Mountains, Wyoming: University of Wyoming Contributions to Geology, University of Wyoming, v. 7, no. 2.
Matthews, Vincent, 2009, Messages in Stone Colorado’s Colorful Geology, Colorado Geological Survey, Denver ,
Colorado, Second Edition.
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Neoproterozoic revealed through detrital zircon provenance analysis. GSA Abstract.
Snoke, Art, August 17, 2013, RMAG Snowy Range, Medicine Bow Mountains, Wyoming Field Trip. University of
Wyoming Unpublished Paper.
Web Site: Lamb Spring Archeological Preserve: http://www.lambspring.org/
Wikipedia, online encyclopedia: https://en.wikipedia.org/wiki/Radiometric_dating
Wikipedia, online encyclopedia: https://en.wikipedia.org/wiki/Supernova
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84. Geologic History of the Denver Area
• Field Trip:
• Bring:
– Water
– Hiking food
– Magnifying glass
– Camera
– Sun Protection (sunscreen, hat, ect)
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85. Geologic History of Denver
– Locations:
• Chamberlain Observatory
• Bioherms – Medicine Bow Mtns
• Iron Dike* - Boulder
• SS Dikes – Pine Junction
• Sawatch – Manitou Spgs
• Kimberlite - Green Mountain Boulder
• Red Rocks Amphitheater – Fountain FM
• Lyons: Desiccation Morrison, quarry CO Sprgs
• Lykins: Morrison, South Valley Park, NCAR
• Eldorado Canyon – Fountain – Dakota FMs
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86. Geologic History of Denver
– Locations:
• Dinosaur Ridge – Morrison FM and Dakota FM
• Benton FM – Morrison
• Niabrara – Morrison, Bear Creek Park, NCAR, Red
Canyon Open Space
• Pierre – Rooney Road,
• Fox Hill, Laramie – CSM, Fossil Trace, Rooney
Road, Bear Creek Park, Marshall Open Space
• Denver Formation – Green Mountain, N and S
Table Mountains
• KT – S Table Mountain, Bijou Creek*
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87. Geologic History of Denver
– Locations:
• Paleocene – N and S Table Mountains
• Wall Mountain Tuff – Castle Rock
• Castle Rock Conglomerate – Castle Rock
• Florissant
• Green Mountain plant and wood material
• Morrison Slide
• Rocky Mountain National Park
• Lamb Spring*
• Apex Site
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* Author has not been to this location as of publication