- Usage in publication:
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- Crystal Peak dolomite
- Modifications:
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- Named
- Dominant lithology:
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- Dolomite
- Sandstone
- AAPG geologic province:
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- Great Basin province
Summary:
Named for exposures at the Crystal Peak section 10 mi southwest of Smooth Canyon, Millard Co, UT in the Great Basin province. No type locality designated. Separates Watson Ranch tongue (first used) of Swan Peak quartzite from the younger Eureka quartzite. Consists of brown, gray to black, usually fine- to medium-grained, but may be coarse-grained, dolomite. Thin (about 6 ft thick) quartz sandstone and siltstone occur about 50 ft from base. Is 85 ft thick in Smooth Canyon. Fossiliferous: orthocone cephalopods, corals. Cross sections, measured sections. Ranges between 61 ft thick in Tule Valley, UT to 92 ft thick in Desert Range Experiment Station, UT. Is 89 ft thick at Crystal Peak. Middle Ordovician age. Crystal Peak equivalent recognized in the Lehman Formation in the Snake Range of NV. Was not specifically identified in adjoining eastern NV.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
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- Crystal Peak Dolomite*
- Modifications:
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- Adopted
- AAPG geologic province:
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- Great Basin province
Summary:
Crystal Peak Dolomite (Webb, 1956) is adopted. Age is Ordovician.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
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- Crystal Peak Dolomite*
- Modifications:
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- Age modified
- Biostratigraphic dating
- AAPG geologic province:
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- Great Basin province
Summary:
Age of the Crystal Peak Dolomite is Middle Ordovician based on fossils [ostracodes].
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
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- Crystal Peak Dolostone*
- Modifications:
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- Redescribed
- Overview
- Dominant lithology:
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- Dolostone
- AAPG geologic province:
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- Great Basin province
Summary:
Is redescribed as dolostone. The name "dolostone" is used for rocks composed predominantly of the mineral "dolomite" on Figure 2 and throughout this chapter, although in the literature it has been common practice to use dolomite rather than dolostone in formal names of dolomitic formations and members. Occurs in stratigraphic column for west-central UT (Great Basin province). Conformably above Watson Ranch Quartzite (Middle Ordovician); conformably below Eureka Quartzite (Middle Ordovician). Assigned to Whiterockian Series (Middle Ordovician).
Uses Blacksmith Dolostone. In fig. 2 and throughout chapter, "dolostone" is used for rocks composed predominantly of the mineral "dolomite." [Although "dolostone" is the proper term, it has not often been applied to dolomitic formations and members; historically, common practice in the literature has been the use of "dolomite."] Blacksmith Dolostone shown in stratigraphic column of north-central Utah (Great Basin province). Overlies Ute Limestone (Middle Cambrian); underlies Bloomington Formation (Middle Cambrian). Age is Middle Cambrian.
Source: GNU records (USGS DDS-6; Denver GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).