OBJECTID|DescriptionOfMapUnits_ID|Category|Type|Symbol|Label|MapUnit|Name|FullName|Age|AgeType|AgeOldest|AgeYoungest|Description|HierarchyKey|ParagraphStyle|AreaFillRGB|AreaFillPatternDescription|GeoMaterialDictID|GeoMaterial|GeoMaterialConfidence|Notes|DataSourceMethod|DescriptionSourceID|created_user|created_date|last_edited_user|last_edited_date|GlobalID
|1|{D5011562-DAE5-41DB-9BE5-0BA4681CC5C4}|map unit|map unit, generic|*q|*q|IPq|Quadrant Formation|Quadrant Formation|Pennsylvanian|relative|Pennsylvanian|Pennsylvanian|Light gray, pinkish gray, and yellowish gray, medium- to thick-bedded, medium- to fine-grained, well-sorted, quartz sandstone with rounded grains cemented by quartz overgrowths. Very light gray, medium to thick dolomite beds may be present in the lowermost and uppermost parts, interbedded with quartz sandstone. Occurs as brecciated masses associated with complex faulting in the easternmost part of the quadrangle.|03-01|dmu, map unit|161,235,255||{58AA9A01-133F-46B5-A023-A044212E1BD3}|Sandstone|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{D5011562-DAE5-41DB-9BE5-0BA4681CC5C4}
2|{7F7738C1-85D0-4FBF-9A3C-522334A954FC}|map unit|map unit, generic|_f|_f|CBf|Flathead Formation|Flathead Formation|Cambrian|relative|Cambrian|Cambrian|Dense, hard, pink, white, or salmon, medium- to coarse-grained, moderately sorted, thick-bedded, feldspar-poor quartzite with prominent crossbeds, although locally the laminations are faint. Contains massive beds up to 1 m (3 ft) thick. Most grains are rounded to subrounded. Contains rare granules and small rounded pebbles of quartzite, quartz, and red chert. Contains 89–97 percent quartz, no potassium feldspar, 0–3 percent plagioclase, up to 3 percent red chert (?) grains and up to 11 percent interstitial sericite and other unidentified interstitial minerals. Occurs in the northeastern part of the quadrangle where it overlies Swauger Formation or Lawson Creek Formation. Thickness varies from less than 200 m (660 ft) near Jackson to more than 600 m (2,000 ft) on the eastern edge of the quadrangle. While these thicknesses ap-pear atypical for Flathead Formation, in the east adjacent Ermont 7.5′ quadrangle (McDonald and Lonn, in review), it was estimated to be 600 m (2,000 ft) thick, and McDonald (in review) reports an estimated thickness of 305 m (1,000 ft) in nearby areas. The contact with underlying Mesoproterozoic units is a low-angle unconformity that is difficult to pinpoint.|03-08|dmu, map unit|247,140,181||{E6582AD1-79FA-4488-A0F6-E9FB6EBA3291}|Mostly sandstone|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{7F7738C1-85D0-4FBF-9A3C-522334A954FC}
3|{C56FBA1D-280F-4477-A9AC-9320348CF28A}|map unit|map unit, generic|_h|_h|CBh|Hasmark Formation|Hasmark Formation|Cambrian|relative|Cambrian|Cambrian|Light gray to white thinly laminated to massive dolomite with minor magnesium limestone intervals. Weathers very light gray with a smooth, laminated surface. Thickness as much as 100 m (330 ft).|03-05|dmu, map unit|240,189,176||{65F1F2FF-CA4E-498D-87C2-F198FC15ED62}|Dolomite|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{C56FBA1D-280F-4477-A9AC-9320348CF28A}
4|{6CCACB14-D901-4C1F-975D-D5DCF1DA5BC9}|map unit|map unit, generic|_q|_q|CBq|quartzite|quartzite|Cambrian|relative|Cambrian|Cambrian|Dense, white, moderately well-sorted, fine- to medium-grained quartzite. Bedding difficult to see. Contains 96-99% quartz, 1-2% plagioclase, no potassium feldspar and 1% red chert and black hematite grains. Also contains sparse coarse floating grains of well-rounded quartz. Interpreted to lie above or within the upper part of the Silver Hill Formation. Similar quartzite occupies an identical stratigraphic position near Argenta, 10 km (6mi) east of the map area, where it is gradational with underlying micaceous shale that is interpreted as Silver Hill Formation (Katie McDonald and Jeff Lonn, unpublished mapping, 2013).|03-06|dmu, map unit|232,130,199||{58AA9A01-133F-46B5-A023-A044212E1BD3}|Sandstone|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{6CCACB14-D901-4C1F-975D-D5DCF1DA5BC9}
5|{AF486E82-CE1B-4509-9B46-924860D898A8}|map unit|map unit, generic|_rl|_rl|CBrl|Red Lion Formation|Red Lion Formation|Cambrian|relative|Cambrian|Cambrian|Multi-colored and lithologically variable unit that includes red dolomite with thin maroon anastomosing shaly layers, shaly conglomerate containing limestone and mud-chip intraclasts, reddish calcareous silty shale, and calcareous and non-calcareous sandstone and quartzite. Thickness approximately 40 m (130 ft).|03-04|dmu, map unit|250,173,204||{B4F03DC4-7787-49F9-80C4-16E8A1B5E728}|Sedimentary rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{AF486E82-CE1B-4509-9B46-924860D898A8}
6|{F2B570B6-BDB3-4020-879C-DC9CAB1B4055}|map unit|map unit, generic|_sh|_sh|CBsh|Silver Hill Formation|Silver Hill Formation|Cambrian|relative|Cambrian|Cambrian|Lithologically varied unit. Very poorly exposed, but contains brown to greenish brown micaceous shale, distinctive red to maroon argillite and siltite, dark gray limestone with wavy yellow-brown silty seams that impart a “black and gold” color to rock, calcareous sandstone, white, feldspar-poor quartzite, and quartzpebble conglomerate. Thickness as much as 105 m (345 ft).|03-07|dmu, map unit|245,163,191||{B4F03DC4-7787-49F9-80C4-16E8A1B5E728}|Sedimentary rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{F2B570B6-BDB3-4020-879C-DC9CAB1B4055}
7|{EA921138-0C60-48D5-8780-AD204684B0D3}|map unit|map unit, generic|Dj|Dj|Dj|Jefferson Formation|Jefferson Formation|Devonian|relative|Devonian|Devonian|Dark gray, yellow, and white, sugary dolomite and limestone. Commonly bleached and recrystallized to white marble. Dark gray dolomite distinguishes this unit from the lighter-colored Hasmark Formation (unit _h). Strongly deformed, with numerous intraformational faults, abundant tectonic breccia, and tight folds. Deformation makes thickness estimates problematic, but probably more than 300 m (980 ft) thick.|03-03|dmu, map unit|153,153,255||{1D871FE3-5589-442E-B930-589778137872}|Carbonate rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{EA921138-0C60-48D5-8780-AD204684B0D3}
8|{F32CDAE9-3DBB-4F83-BA2E-C15BB38E6255}|map unit|map unit, generic|Kdi|Kdi|Kdi|diorite|diorite|Cretaceous?|absolute|Cretaceous|Cretaceous|Hornblende diorite of the Carmen Creek Stock in the westernmost part of the quadrangle. Composed of 50-75% hornblende along with plagioclase, hypersthene, actinolite, quartz, and opaque minerals, and also contains small hornblende pyroxenite xenoliths (Kilroy, 1981).|05-06|dmu, map unit|253,089,013||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{F32CDAE9-3DBB-4F83-BA2E-C15BB38E6255}
9|{F4350D15-5B17-479C-A363-2A28F53794A3}|map unit|map unit, generic|Kgb|Kgb|Kgb|hornblende gabbro|hornblende gabbro|Cretaceous|absolute|Cretaceous|Cretaceous|Medium to dark gray, medium- to coarse-grained, hypidiomorphic granular hornblende gabbro containing an average 40–45 percent plagioclase, 45–55 percent hornblende after augite, 3–5 percent augite cores in hornblende, and 0–5 percent biotite (Zimbelman, 1984; Pearson and Zen, 1985). Age determined through U-Pb dates is 70–72 Ma (Katie McDonald, written commun.). Thought to be an early border phase of the Pioneer Batholith (Snee, 1982; Zimbelman, 1984).|05-09|dmu, map unit|250,071,069||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{F4350D15-5B17-479C-A363-2A28F53794A3}
10|{16E1E4B3-94D2-4C27-9370-3BC395D87829}|map unit|map unit, generic|Kgd|Kgd|Kgd|granodiorite|granodiorite|Cretaceous|absolute|Cretaceous|Cretaceous|Light gray, massive, medium-grained, hornblende-biotite granodiorite of the Pioneer Batholith in the northeastern part of the quadrangle. Locally contains large potassium feldspar phenocrysts up to 2 cm long (Pearson and Zen, 1985; Zimbelman, 1984). Equivalent to the Uphill Creek granodiorite of Pearson and Zen (1985), the predominant rock type of the Pioneer Batholith. Best age estimate of the unit is an 40Ar/39Ar date of 75 Ma (Snee, 1982).|05-08|dmu, map unit|242,031,041||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{16E1E4B3-94D2-4C27-9370-3BC395D87829}
11|{E29EABFB-C9BF-42DB-9D6F-A2D0FCDA8E6B}|map unit|map unit, generic|Kgdp|Kgdp|Kgdp|granodiorite, porphyritic|granodiorite, porphyritic|Cretaceous|absolute|Cretaceous|Cretaceous|Porphyritic biotite granodiorite of the Pioneer Batholith. Contains phenocrysts of potassium feldspar as large as 6 cm. Hornblende is absent. (After Berger and others, 1983)|05-07|dmu, map unit|235,046,046||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{E29EABFB-C9BF-42DB-9D6F-A2D0FCDA8E6B}
12|{D99AEA05-E7D1-4433-9ADE-5ED3F1301766}|map unit|map unit, generic|Kqd|Kqd|Kqd|quartz diorite|quartz diorite|Cretaceous|absolute|Cretaceous|Cretaceous|Biotite-hornblende quartz diorite of the Carmen Creek stock in the westernmost part of the map area. Composed of 45-55 percent andesine (An40-50) along with hornblende, biotite, quartz, and orthoclase (Kilroy, 1981). Cretaceous age based on 40Ar/39Ar hornblende ages of 81.5 ± 1.6 Ma and 80.3 ± 2.2 Ma that are considered to be the minimum age for this unit (Kilroy, 1981).|05-10|dmu, map unit|232,082,015||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{D99AEA05-E7D1-4433-9ADE-5ED3F1301766}
13|{70A4D755-5548-4DDB-97C9-0E3FC740E0BF}|map unit|map unit, generic|0000|md|md|mine dumps and tailings|mine dumps and tailings|Anthropocene|relative|Anthropocene|Anthropocene|Mining waste|01|dmu, map unit|255,255,255|229-M|{5B6BE598-6C3E-40CD-9082-7EF21AD7BF1D}|"Made" or human-engineered land|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{70A4D755-5548-4DDB-97C9-0E3FC740E0BF}
14|{34BB9D8D-46EE-4A16-822F-3CECB9745B7E}|map unit|map unit, generic|Mm|Mm|Mm|Madison Group|Madison Group|Mississippian|relative|Mississippian|Mississippian|Mostly Mission Canyon Limestone: Gray, microcrystalline, thick-bedded locally fossiliferous limestone with abundant gray, black, olive, and pale yellowish brown lentil-shaped or elongate chert nodules. Includes some Lodgepole Limestone: Dark gray, thin-bedded, microcrystalline limestone, with yellowish brown and grayish orange, thin partings and interbeds of calcareous mudstone. Exposed only on a thrust plate in the easternmost part of the map. Thickness unknown.|03-02|dmu, map unit|168,189,230||{17AAA689-8B7C-40D3-B384-264AAD16094A}|Limestone|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{34BB9D8D-46EE-4A16-822F-3CECB9745B7E}
15|{398D278C-C337-4B71-9157-3BEA696EAA71}|map unit|map unit, generic|Qaf|Qaf|Qaf|alluvial fan deposit|alluvial fan deposit|Holocene and Pleistocene|relative|Pleistocene|Holocene|Subangular to subrounded, poorly sorted, cobble to boulder gravel, silt and sand. Thickness unknown, but probably less than 60 m (200 ft).|02-03|dmu, map unit|247,237,097||{EFF14953-918D-4560-87E8-CB91351003C9}|Alluvial sediment, mostly coarse-grained|high||1|DAS01|||KMCDONALD|2022-06-15 14:30:58|{398D278C-C337-4B71-9157-3BEA696EAA71}
16|{858DE33E-1198-4EF0-95A6-A04706F3700A}|map unit|map unit, generic|Qal|Qal|Qal|alluvium|alluvium|Holocene|relative|Holocene|Holocene|Modern stream and flood plain deposits. As much as 100 m (300 ft) thick.|02-01|dmu, map unit|255,255,214||{EFF14953-918D-4560-87E8-CB91351003C9}|Alluvial sediment, mostly coarse-grained|high||1|DAS01|||KMCDONALD|2022-06-15 14:28:54|{858DE33E-1198-4EF0-95A6-A04706F3700A}
17|{2B9C10B8-D025-4316-875D-322DF7DA9F0B}|map unit|map unit, generic|Qalo|Qalo|Qalo|alluvium, older than Qal|alluvium, older than Qal|Holocene and Pleistocene|relative|Pleistocene|Holocene|Stream and flood plain deposits that are above the modern flood plain. Includes glacial outwash gravels, subrounded to rounded, well-sorted sandy cobble to boulder gravel and sand. Thickness unknown, but probably less than 150 m (500 ft).|02-04|dmu, map unit|237,237,163||{EFF14953-918D-4560-87E8-CB91351003C9}|Alluvial sediment, mostly coarse-grained|high||1|DAS01|||KMCDONALD|2022-06-15 14:31:51|{2B9C10B8-D025-4316-875D-322DF7DA9F0B}
18|{1C33856A-7FFA-48F9-B779-8F27EE2A2DEB}|map unit|map unit, generic|Qc|Qc|Qc|colluvial deposits|colluvial deposits|Holocene and Pleistocene|relative|Pleistocene|Holocene|Mapped separately where so thick it completely masks the underlying deposits.|02-08|dmu, map unit|245,232,000||{F0646F40-5324-404D-B3CA-EA0C8C1E65BB}|Colluvium and other widespread mass-movement sediment|high||1|DAS01|||KMCDONALD|2022-06-15 14:33:04|{1C33856A-7FFA-48F9-B779-8F27EE2A2DEB}
19|{0ED0BECE-CE60-4FFA-AEF2-1BEEA9F52FD3}|map unit|map unit, generic|Qg|Qg|Qg|glacial deposit|glacial deposit|Holocene and Pleistocene|relative|Pleistocene|Holocene|Most is unsorted sandy to clayey boulder to large boulder till with subangular to subrounded clasts. Also includes minor outwash, fan, kame, and esker deposits. Most till is of Pinedale age, but unit also includes younger glacial and periglacial deposits in higher elevations, and older till. Of particular interest are the older partially dissected moraines located just west of Jackson, Montana. As thick as 100 m (330 ft).|02-07|dmu, map unit|245,245,071||{58D27EA4-C3DD-44B3-ABB5-2719231545E1}|Glacial till|high||1|DAS01|||KMCDONALD|2022-06-15 14:32:50|{0ED0BECE-CE60-4FFA-AEF2-1BEEA9F52FD3}
20|{AB1713C4-4105-40B8-A10B-90D6D41163B5}|map unit|map unit, generic|Qgr|Qgr|Qgr|gravel|gravel|Holocene and Pleistocene|relative|Pleistocene|Holocene|Thin pediment gravel deposits.|02-09|dmu, map unit|242,230,074||{EFF14953-918D-4560-87E8-CB91351003C9}|Alluvial sediment, mostly coarse-grained|high||1|DAS01|||KMCDONALD|2022-06-15 14:33:18|{AB1713C4-4105-40B8-A10B-90D6D41163B5}
21|{0811A041-DFF4-4259-AD18-B2796EEC5F58}|map unit|map unit, generic|Qlk|Qlk|Qlk|lake deposits|lake deposits|Holocene and Pleistocene|relative|Pleistocene|Holocene|Silt and sand deposited in standing water. Thickness 1-4 m (3-13 ft).|02-06|dmu, map unit|235,222,171||{35D9ACB4-EFBE-4B4F-995A-3CAF01195712}|Lacustrine sediment, mostly fine-grained|high||1|DAS01|||KMCDONALD|2022-06-15 14:32:04|{0811A041-DFF4-4259-AD18-B2796EEC5F58}
22|{4C688E7B-5BB2-447B-8DB4-9AE234577422}|map unit|map unit, generic|Qls|Qls|Qls|landslide deposit|landslide deposit|Holocene and Pleistocene|relative|Pleistocene|Holocene|Unsorted mixtures of silt, clay, sand, gravel and boulders. Typically characterized by hummocky topography. Not all mass wasting deposits are shown on the map because they are difficult to unambiguously identify.|02-05|dmu, map unit|235,235,077||{743EA93E-C344-4316-A975-A09F39CC0243}|Debris flows, landslides, and other localized mass-movement sediment|high||1|DAS01|||KMCDONALD|2022-06-15 14:31:34|{4C688E7B-5BB2-447B-8DB4-9AE234577422}
23|{E94C1441-1595-42C8-8D66-97C0D52BD338}|map unit|map unit, generic|Qta|Qta|Qta|talus and glacial deposits|talus and glacial deposits|Holocene|relative|Holocene|Holocene|Piles of angular boulders to cobbles on glaciated valley walls and in cirques. Mostly pro-talus ramparts, talus aprons, and slumps derived from moraine remnants and recent frost-wedged quartzite debris. Includes some alluvial fan gravel and young glacial and periglacial deposits. Thickness less than 18 m (60 ft).|02-02|dmu, map unit|245,245,092||{743EA93E-C344-4316-A975-A09F39CC0243}|Debris flows, landslides, and other localized mass-movement sediment|high||1|DAS01|||KMCDONALD|2022-06-15 14:30:40|{E94C1441-1595-42C8-8D66-97C0D52BD338}
24|{067241BA-2225-420F-A82F-B0909EC88B40}|map unit|map unit, generic|QTdf|QTdf|QTdf|alluvial fan and debris flow fan deposit|alluvial fan and debris flow fan deposit|Pleistocene or Pliocene|relative|Pliocene|Pleistocene|Subangular to subrounded, poorly sorted, boulder-cobble gravel, sand, and silt. Perched as much as 60 m (195 ft) above modern streams, but associated with modern drainages. Mapped in the northeastern part of the quadrangle. Thickness unknown.|02-10|dmu, map unit|255,235,000||{743EA93E-C344-4316-A975-A09F39CC0243}|Debris flows, landslides, and other localized mass-movement sediment|high||1|DAS01|||KMCDONALD|2022-06-15 14:33:33|{067241BA-2225-420F-A82F-B0909EC88B40}
25|{C3BCC2FD-46FD-48DF-BD6E-E941F1A786EE}|map unit|map unit, generic|QTgr|QTgr|QTgr|gravel|gravel|Miocene or younger|relative|Miocene|Miocene|Immature, unsorted quartzite cobble gravel that may be colluvium or lag deposit from older gravel. No bedding or primary structures are visible. Forms aprons that slope away from highlands. May be equivalent to the Big Hole River Member of the Sixmile Creek Formation (Fritz and Sears, 1993). Thickness up to 60 m (200 ft).|02-11|dmu, map unit|242,230,077||{EFF14953-918D-4560-87E8-CB91351003C9}|Alluvial sediment, mostly coarse-grained|high||1|DAS01|||KMCDONALD|2022-06-15 14:33:42|{C3BCC2FD-46FD-48DF-BD6E-E941F1A786EE}
26|{BFAC4854-4726-4150-986C-D91A9F3F8D8C}|map unit|map unit, generic|Tba|Tba|Tba|basalt|basalt|Oligocene|absolute|Oligocene|Oligocene|Rusty brown weathering, dark gray, aphanitic, vesicular, and amygdaloidal basalt flows in the eastern part of the quadrangle. Matoush (2002), Kickham (2002), and Jänecke and others (2005) reported four nearly identical 40Ar/39Ar ages of 27–28 Ma for erosional remnants of these basalt flows and shallow intrusions. This valley-filling basalt has impressive colonnades of cooling joints south-west of Bannack, Montana. Some dikes are also present in the underlying Medicine Lodge beds but extrusive masses are more common than intrusive ones. Tba is in the western edge of the 53–17 Ma Dillon Volcanic field of Fritz and others (2007).|05-01|dmu, map unit|222,069,064||{D1F63224-FA24-46BE-813D-EC34C47E7AAE}|Lava flows|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{BFAC4854-4726-4150-986C-D91A9F3F8D8C}
27|{E60E5579-8C3E-4F93-9E9B-6FBBBCAA1AAC}|map unit|map unit, generic|Tbr|Tbr|Tbr|breccia|breccia|Teritary|relative|Teritary|Teritary|Area of angular quartzite clasts from pebble- to boulder-sized. Part of larger breccia field in the adjacent Ermont 7.5′ quadrangle (McDonald and Lonn, in review). Commonly lithified. Map pattern forms a half-circle around Black Mountain located along the border between the Ermont and west-adjacent Polaris 7.5′ quadrangles (Lonn and Lewis, 2012). Interpreted as a sedimentary debris flow or landslide deposit, but could be of tectonic origin. Unknown thickness.|02-12|dmu, map unit|219,168,041|||Debris flows, landslides, and other localized mass-movement sediment|medium||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{E60E5579-8C3E-4F93-9E9B-6FBBBCAA1AAC}
28|{05D3B139-85A0-4F14-926F-15C71084E9D9}|map unit|map unit, generic|Tcl|Tcl|Tcl|silt and clay|silt and clay|Miocene? to Eocene?|relative|Eocene|Miocene|Light yellowish brown, massive silt and clay containing sparse matrix-supported pebbles and boulders. Typically capped by a flat surface of lag deposits containing sub-angular to subrounded cobbles and boulders. Very poorly exposed. Thickness as much as 540 m (1,750 ft). Probably locally equivalent to the upper Medicine Lodge beds (Tml) of Janecke and others (2005) but may correlate with Everson Creek (Tec) or Bannock Pass beds (Tbp).|02-14|dmu, map unit|255,201,005||{1AAFA5FB-97A2-4F94-9FBB-54EB8A9641ED}|Sedimentary material|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{05D3B139-85A0-4F14-926F-15C71084E9D9}
29|{77AAE66B-9487-4D3C-9C49-A3BD10C6CF4F}|map unit|map unit, generic|Tdi|Tdi|Tdi|diorite dikes|diorite dikes|Eocene|absolute|Eocene|Eocene|Dark-colored, fine- to medium-grained hornblende diorite. Mostly occurs as dikes that may be undeformed, have sheared margins, or be strongly foliated. One dike in the Goldstone Pass 7.5′ quadrangle (Lonn and others, 2009) of the central Beaverhead Range has a U-Pb zircon age of 46 Ma (Richard Gaschnig, written commun., 2009). Where deformed, these dikes record Eocene or later faulting.|05-02|dmu, map unit|235,064,079||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{77AAE66B-9487-4D3C-9C49-A3BD10C6CF4F}
30|{2F48A2CB-0BB5-4A89-95C2-4D392CD7F61E}|map unit|map unit, generic|Tec|Tec|Tec|Everson Creek beds|Everson Creek beds|early Miocene to late Oligocene|relative|late Oligocene|early Miocene|Interbedded coarse sand, silt, and clay with minor conglomerate. Generally poorly exposed, but reflected by mottled uneven surfaces visible in aerial photographs. Areas underlain by Tec are oddly mottled and uneven in airphotos, which may reflect mass wasting, but also may reflect variation in lithification within the unit. Well-lithified sandstone and conglomerate channels running through the soft, poorly lithified, muddy sediments that make up the bulk of Tec may also account for the unusual surface features. Distinctive, well-cemented lenses of two-mica-bearing feldspathic sand-stone and conglomerate have trough to planar cross beds and well-developed pebble imbrications. Lenses are interpreted to be fluvial chan-nel deposits within overbank muds (Thomas, 1995; Roe, 2010; Barber, 2013). Vertebrate fos-sils from correlative units in the Everson Creek 7.5′ quadrangle to the south indicate a late early Arikareean age (Nichols and others, 2001; North American Land Mammal age, ca. 29.5–25.0 Ma, after Barnosky and others, 2014).|02-16|dmu, map unit|255,196,036||{1AAFA5FB-97A2-4F94-9FBB-54EB8A9641ED}|Sedimentary material|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{2F48A2CB-0BB5-4A89-95C2-4D392CD7F61E}
31|{9232813B-BC1D-4C17-A8A2-D9B075FF155F}|map unit|map unit, generic|Tgd|Tgd|Tgd|granodiorite|granodiorite|Eocene|absolute|Eocene|Eocene|Hornblende-biotite granodiorite of the Carmen Creek stock in the westernmost part of the quadrangle. Complexly zoned oligoclase (An25-35), quartz, microcline, hornblende, and biotite are the major constituents (MacKenzie, 1949; Anderson, 1959; Kilroy, 1981). Eocene age based on 40Ar/39Ar dating of biotite (47.7 ± 0.6 Ma and 49.4 ± 0.8 Ma) and hornblende (50.5 ± 1.8 Ma) (Kilroy, 1981), and a U-Pb zircon age of 49.2 ± 1.7 Ma (Darin Schwartz, written commun., 2011).|05-03|dmu, map unit|247,043,020||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{9232813B-BC1D-4C17-A8A2-D9B075FF155F}
32|{01EE659A-DEBE-4AEB-A8B6-98C771CDA936}|map unit|map unit, generic|Tgr|Tgr|Tgr|conglomerate|conglomerate|Pliocene? to Eocene?|relative|Eocene|Pliocene|Mature gravel of well-rounded quartzite cobbles interlayered with varying amounts of fine-grained and ashy clastic sediments. Locally expressed as a lag deposit of cobbles. Appears to be the base of the Tertiary section where it rests on bedrock. In other places might be the Big Hole Member of the Sixmile Creek Formation elsewhere in southwest Montana (Fields and others, 1985; Fritz and Sears, 1993). Within the Grasshopper basin, mature gravel is interlayered with fine-grained lithic sandstone, siltstone, reworked tephra and ash, and mudstone that weathers to tan, buff and white, and is generally poorly exposed. Jänecke and others (2005) called these the Bannack (sic) Pass beds. Bed-ding and sedimentary structures are obscured by intense burrowing. Vertebrate fossils from correlative deposits at Bannock Pass in far southwest Montana are early to middle Miocene (M’Gonigle, 1994; Barnosky, 2001, 2007; Har-ris and others, 2017). At Bannock Pass, detailed tephrochronology places the base of Tsc at 21.4 Ma (Harris and others, 2017). Tabrum (in Nichols and others, 2001) identified fossils near Polaris as late Arikareean (North American Land Mammal age, ca. 18.5–23.0 Ma, after Barnosky and others, 2014). Thickness unknown.|02-15|dmu, map unit|237,179,020||{1AAFA5FB-97A2-4F94-9FBB-54EB8A9641ED}|Sedimentary material|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{01EE659A-DEBE-4AEB-A8B6-98C771CDA936}
33|{162B1E48-7E91-4E7E-BE9D-6CC60EE80BBE}|map unit|map unit, generic|TKb|TKb|TKb|Beaverhead Group|Beaverhead Group|Tertiary? and Cretaceous|relative|Cretaceous|Tertiary|Massive boulder-cobble conglomerate containing mostly Proterozoic quartzite and Paleozoic limestone clasts. In contrast to Tertiary conglomerates, it is complexly folded and well-indurated. Occurs in the footwall of a thrust fault along the eastern border of the quadrangle.|02-20|dmu, map unit|122,207,028||{B1E5F115-8FCA-4B05-A257-4AADCD7CCBCD}|Conglomerate|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{162B1E48-7E91-4E7E-BE9D-6CC60EE80BBE}
34|{F607AC82-525E-4668-935D-1A7DAD0A48DD}|map unit|map unit, generic|TKgd|TKgd|TKgd|granodiorite|granodiorite|Tertiary or Cretaceous|relative|Cretaceous|Tertiary|White, equigranular, biotite-hornblende granodiorite. Composition typically 60% plagioclase, 23% quartz, 9% biotite, 3% hornblende, 2% potassium feldspar, and 3% accessory minerals including sphene, apatite, zircon, and pyrite (Coppinger, 1974).|05-04|dmu, map unit|201,000,000||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{F607AC82-525E-4668-935D-1A7DAD0A48DD}
35|{9D4030A5-FBDE-4DA3-9687-F89FCC450990}|map unit|map unit, generic|TKv|TKv|TKv|volcanic rocks, undivided|volcanic rocks, undivided|Tertiary or Cretaceous|absolute|Cretaceous|Tertiary|Gray hornblende porphyry and white to red lithic tuff containing round quartz grains. Poorly exposed in the northeastern corner of the quadrangle. Mosolf (in review) reported late Cretaceous U-Pb zircon ages for similar volcanic rocks in the east-adjacent Bannack 7.5′ quadrangle.|05-05|dmu, map unit|222,143,102||{AD5B795C-23C4-4340-A555-A11D444BF39F}|Intrusive igneous rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{9D4030A5-FBDE-4DA3-9687-F89FCC450990}
36|{30208C9C-CA1B-4CFD-83BC-E089ACBEBE58}|map unit|map unit, generic|Tls|Tls|Tls|Paleolandslide deposits|Paleolandslide deposits|Oligocene and/or Eocene|relative|Eocene|Oligocene|Unsorted hummocky deposits and large slide blocks. Composition typically reflects quartzites of the immediate source area, but locally includes both intact and brecciated masses of Challis Volcanic Group clasts (Janecke and others, 2005). Locally interbedded with Medicine Lodge beds (Tml and Tmlc). Janecke and others (2005) describe slide blocks up to 2 km long, including a large block of maroon quartzite that now makes up Red Butte on Horse Prairie Creek in the southeast corner of the map area. They describe the quartzite as belonging to the Missoula Group of the Belt Supergroup, but it is more likely to be from the Swauger Formation. Janecke and others (2005) interpret Tls deposits as having slid from the west into the Grant protobasin during extension on the shallowly west-dipping Muddy- Grasshopper detachment. However, Lonn interprets these exposures as para-autochthonous bedrock knobs protruding through the Cenozoic deposits, developed by pre- or early Tertiary erosion.|02-17|dmu, map unit|255,204,000||{1AAFA5FB-97A2-4F94-9FBB-54EB8A9641ED}|Sedimentary material|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{30208C9C-CA1B-4CFD-83BC-E089ACBEBE58}
37|{F97907A4-139D-47BA-87BC-E4A2502A57F8}|map unit|map unit, generic|Tml|Tml|Tml|Medicine Lodge beds and equivalents|Medicine Lodge beds and equivalents|late Oligocene to Eocene|relative|Eocene|late Oligocene|Basin fill deposits described in detail by Janecke and others (2005). Includes a wide variety of clastic sediments which grade laterally over short distances from conglomerate to feldspathic and quartzose sandstones, shale, and mudstone. Sediments are commonly tuffaceous. Sandstones are typically lenticular and crossbedded. Fossils and 40Ar/39Ar dates for volcanic components (summarized in table 1 of Janecke and others, 2005) support the conclusion that the Medicine Lodge beds are equivalent in age to the Renova Formation elsewhere in Montana. Thickness over 1,000 m (3,300 ft) in the southeast corner of the map.|02-18|dmu, map unit|212,181,084||{1AAFA5FB-97A2-4F94-9FBB-54EB8A9641ED}|Sedimentary material|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{F97907A4-139D-47BA-87BC-E4A2502A57F8}
38|{AB9BD9DE-D4B2-4895-BF69-74D4185152F3}|map unit|map unit, generic|Tmlc|Tmlc|Tmlc|Medicine Lodge beds conglomerate|Medicine Lodge beds conglomerate|Oligocene to Eocene|relative|Eocene|Oligocene|Angular to rounded, quartzite cobble conglomerate and angular to rounded cobble float that is locally well cemented. Composed of alluvial, fluvial and debris flow deposits generally derived from Proterozoic rocks of adjacent highlands, though conglomerates on the farthest east were derived from Paleozoic and Mesozoic rocks in the footwall of the Muddy-Grasshopper detachment (Janecke and others, 2005). As thick as 550 m (1,800 ft).|02-19|dmu, map unit|212,171,097||{B1E5F115-8FCA-4B05-A257-4AADCD7CCBCD}|Conglomerate|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{AB9BD9DE-D4B2-4895-BF69-74D4185152F3}
39|{2086F7E9-1854-486B-A96B-1A8C3F58F13D}|map unit|map unit, generic|Ts|Ts|Ts|sediment|sediment|Tertiary|relative|Tertiary|Tertiary|Gravel, silt, sand, and clay. Red to pink, crudely bedded, poorly sorted, angular to subangular boulders, cobbles, pebbles and sand appear to overlie finer-grained sediments; otherwise there is no stratigraphic control. Thickness as much as 130 m (430 ft).|02-13|dmu, map unit|255,179,000||{1AAFA5FB-97A2-4F94-9FBB-54EB8A9641ED}|Sedimentary material|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{2086F7E9-1854-486B-A96B-1A8C3F58F13D}
40|{3E32959C-9F4D-4884-B4F6-680C5AC4EDCC}|map unit|map unit, generic|Xgbd|Xgbd|Xgbd|gneiss of Bloody Dick Creek|gneiss of Bloody Dick Creek|Paleoproterozoic|relative|Paleoproterozoic|Paleoproterozoic|Finely layered biotite gneiss with zones of medium-grained augen gneiss, felsic gneiss, and hornblende gneiss. Biotite schist occurs within all gneisses. Primary mineralogy is quartz, plagioclase, biotite, and hornblende, with minor garnet and altered pyroxene (Coppinger, 1974). Pearson and others (2017), using zircon U-Pb and Lu-Hf analysis, postulated a 2,438 Ma protolith was intruded at 1,802 Ma and metamorphosed at 1,759 Ma. They proposed that all rocks had an igneous protolith. Richard Gaschnig (written commun., 2009) reported similar ages: about 1,800 Ma for metamorphism and 1,830 Ma for the youngest non-metamorphic zircons (Sherwin and others, 2017). Numerous centimeter- to meter-thick quartz veins occur throughout the unit and are associated with gold–silver–copper–lead mineralization (Brenner-Younggren and Cox, 2017).|04-06|dmu, map unit|140,117,145||{AD743F1C-B16C-49EA-B248-59D9755580CA}|Medium and high-grade regional metamorphic rock, of unspecified origin|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{3E32959C-9F4D-4884-B4F6-680C5AC4EDCC}
41|{CF8FEC00-69C1-446A-8A1B-F2F856127CE1}|map unit|map unit, generic|Yaj|Yaj|Yaj|Jahnke Lake member, Apple Creek Formation|Jahnke Lake member, informal of Apple Creek Formation of Belt Supergroup|Mesoproterozoic|relative|Mesoproterozoic|Mesoproterozoic|Gray, pale green or light red to pink, thick-bedded, very fine- to medium-grained, well-sorted, very feldspathic quartzite. In the west, bedding is difficult to see, but where visible is commonly defined by dark laminations that are rich in hematite grains. Convolute bedding resulting from soft sediment deformation is common. Thin skins of green argillite commonly separate the meter-scale quartzite beds, and thin mud rip-ups are present but uncommon. Rare chert rip-ups are also present. Toward the east, the rocks are less metamorphosed, bedding is well defined bedding and small red mud chips are locally abundant. Feldspar content ranges from 20% to 50%, with plagioclase more abundant than potassium feldspar in the west, subequal in the east. The unit is correlated with the lowest part of the re-defined Apple Creek Formation in the Lemhi Range to the southwest (Burmester and others, 2013; in review). Best exposed on the ridge north of Jahnke Lake on the Goldstone Pass 7.5' quadrangle (Lonn and others, 2009) with the eastern part incompletely exposed along the Big Hole Divide, southeast of the center of the map. Thickness ranges from 0 m near Jackson in the northeastern part of the quadrangle to 4,300 m (14,000 ft) in the hanging wall of the Eastern Strand of the Beaverhead Divide fault, where the upper contact is not exposed and the lower contact is gradational with the underlying Lawson Creek Formation.|04-01|dmu, map unit|207,204,207||{58AA9A01-133F-46B5-A023-A044212E1BD3}|Sandstone|high||1|DAS01|||KMCDONALD|2022-06-15 14:34:07|{CF8FEC00-69C1-446A-8A1B-F2F856127CE1}
42|{5E9C503A-0C41-4665-8BD5-DE6FB5C9B989}|map unit|map unit, generic|Ygs|Ygs|Ygs|Gunsight Formation|Gunsight Formation of Belt Supergroup|Mesoproterozoic|relative|Mesoproterozoic|Mesoproterozoic|Northeast of the North Fork Thrust, Gunsight Formation is observed in stratigraphic contact with the overlying Swauger Formation. Here, Gunsight is mostly gray, pale green, or light red, moderately well-sorted, fine-grained, very feldspathic quartzite characterized by flat laminations of black hematite; typically weathers into thick (8 cm) plates. Contains some crossbeds and minor thin argillite layers that are commonly mudcracked. Near the top, includes thin layers of coarse, well-rounded quartz grains interpreted to be lag deposits. Feldspar content is 35 to 40 percent, with plagioclase and potassium feldspar in subequal amounts. Upper contact is gradational with the overlying Swauger Formation (Ysw). Only the upper 770 m (2,500 ft) is exposed northeast of the North Fork Thrust. Southwest of the North Fork Thrust, in its hanging wall, Gunsight Formation (labeled Ygs?) is thinner bedded and finer-grained, consisting of interbedded intervals of couplets (centimeter-scale beds) of dark siltite grading up to darker gray to green argillite, and couples (decimeter-scale beds) of white, very fine-grained, very feldspathic quartzite grading up to dark-colored silt. Thicker beds typically have bedding defined by dark millimeter-scale flat laminations. Load casts, convolute lamination, and decimeter-thick stacks of centimeter-scale ripple cross lamination are also common. Coarser, quartzite-rich intervals appear to be laterally discontinuous. Thickness uncertain because of deformation, but a minimum of 2,400 m (7,900 ft) is likely. Unit Ygs? is fault bounded, and therefore its stratigraphic position is unknown. Although originally correlated with Gunsight Formation (Burmester and others, 2016a), recent work outside the quadrangle has called this interpretation into question (Burmester and others, 2017). In addition, a single detrital zircon grain from this unit immediately south of the Salmon quadrangle yielded a 1,373 Ma age (Gillerman, 2008), suggesting the unit is near the top of the Lemhi section (Apple Creek) rather than near the bottom (Gunsight Formation). Unit Ygs? may therefore be correlative with part of the Apple Creek Formation.|04-04|dmu, map unit|150,176,115||{58AA9A01-133F-46B5-A023-A044212E1BD3}|Sandstone|high||1|DAS01|||KMCDONALD|2022-06-15 14:34:59|{5E9C503A-0C41-4665-8BD5-DE6FB5C9B989}
43|{7AE362EE-DADC-4BAE-84A1-2EFDF46338F5}|map unit|map unit, generic|Ylc|Ylc|Ylc|Lawson Creek Formation|Lawson Creek Formation of Belt Supergroup|Mesoproterozoic|relative|Mesoproterozoic|Mesoproterozoic|Characterized by couplets (centimeter-scale alternating beds) and couples (decimeter-scale alternating beds) of fine- to medium-grained white quartzite alternating with purple, black, and green argillite. Lenticular and flaser bedding are common and characteristic. Mud rip-up clasts are locally common, and some are very large, as much as 15 cm in diameter; chert beds and cherty rip-up clasts are less common. The thick section on the eastern part of the quadrangle is dominated by thick intervals of fine- to medium-grained, relatively quartz-rich (up to 90 percent) quartzite separated by thinner argillite-rich intervals. In the western part of the map, the lower contact is placed at the bottom of the thin-bedded, argillite-rich interval that gradationally overlies the coarse-grained Swauger Formation, and the upper contact is placed at the top of the upper-most argillite-rich strata beneath the dominantly thick-bedded, fine-grained quartzite of the Jahnke Lake member of the Apple Creek Formation. In the eastern part of the map, northeast of the Buffalo Creek–Jackson Fault Zone, the lower contact is placed at the lowest occurrence of chert rip-up clasts above the coarse-grained Swauger Formation and the upper contact is not exposed. Not identified along the eastern border of the map where Cambrian sediments overlie Swauger Formation. Thickness where identified varies from 300 m (980 ft) in the Beaverhead Mountains to 2,150 m (7,000 ft) on the east side of the Buffalo Creek–Jackson Fault. The detrital zircon data presented above suggest that the large difference in thicknesses is due to facies changes across the Buffalo Creek–Jackson Fault, with the upper part of the Lawson Creek northeast of the fault being time-correlative with the Jahnke Lake member southwest of the fault. The Lawson Creek Formation is tentatively correlated with the McNamara Formation of the Missoula Group, Belt Supergroup, on the basis of similar lithology and stratigraphic position.|04-02|dmu, map unit|222,222,186||{33F67A5B-8B6D-493B-BD7F-A3241BF3BB13}|Sandstone and mudstone|high||1|DAS01|||KMCDONALD|2022-06-15 14:34:30|{7AE362EE-DADC-4BAE-84A1-2EFDF46338F5}
44|{ED53A70C-082A-4601-9D2F-A3A31CD1C6CC}|map unit|map unit, generic|Ysw|Ysw|Ysw|Swauger Formation|Swauger Formation of Belt Supergroup|Mesoproterozoic|relative|Mesoproterozoic|Mesoproterozoic|Red, pink, and white poorly sorted, medium- to coarse-grained, trough and planar crossbedded quartzite in beds as thick as 2 m. Contains small pebbles, black or purple mudcracked argillite beds as thick as 2 cm, thick black mud rip-up clasts, and coarse, floating, well-rounded quartz grains. Chalky white feldspar grains are obvious in hand sample. Feldspar content ranges from 10 to 40% with potassium feldspar dominant over plagioclase. Lower part is very coarse and contains pebbles as much as 5 cm in diameter of well-rounded quartzite and angular quartz and feldspar. Grades downward into the Gunsight Formation (Ygs), and upward into Lawson Creek Formation (Ylc). Best exposed section is on the ridge north of Miner Creek in the Homer Youngs Peak 7.5’ quadrangle (Lonn and others, 2008) in the Beaverhead Mountains. Thickness varies from 5,500 m (18,000 ft) in the Beaverhead Mountains to 2,770 m (9,100 ft) northeast of the Jackson fault zone. As with the Lawson Creek Formation, this thickness variation could be due to lateral facies changes or to miscorrelation of the argillite-rich intervals that separate the Swauger from the overlying Lawson Creek. The Swauger Formation is tentatively correlated with the Bonner and Mount Shields Formations of the Missoula Group, Belt Supergroup, on the basis of lithologic similarity and stratigraphic position.|04-03|dmu, map unit|173,163,173||{58AA9A01-133F-46B5-A023-A044212E1BD3}|Sandstone|high||1|DAS01|||KMCDONALD|2022-06-15 14:34:49|{ED53A70C-082A-4601-9D2F-A3A31CD1C6CC}
45|{F9C52C5B-5691-4252-8DFD-729824BA5A47}|map unit|map unit, generic|Yyb|Yyb|Yyb|Yellow Lake and Big Creek Formations|Yellow Lake and Big Creek Formations of Belt Supergroup|Mesoproterozoic|relative|Mesoproterozoic|Mesoproterozoic|Quartzite, siltite, and argillite that are commonly carbonate bearing and locally phyllitic. Unit Yyb? occurs in the structural domain between the Freeman and North Fork Thrusts in the Beaverhead Range, where complex internal faulting, folding, and strong cleavage prevent separation of individual formations. Big Creek Formation is mostly greenish, calcareous coarse siltite in meter-thick beds. Yellow Lake Formation gradationally overlies Big Creek, and is mostly phyllitic dark-colored siltite and argillite couplets (centimeter- to millimeter-scale), with locally abundant carbonate and pinch-and-swell bedforms. Complex structure precludes thickness estimates, but together these formations are at least 2,800 m (9,200 ft) thick in their type sections in the Lemhi Range (Ruppel, 1975; Lonn, 2017).  Similar lithologies in the North Fork area northwest of this map (Burmester and others, 2016a) have recently been reinterpreted as the banded siltite member of the Apple Creek Formation because diamictite was observed (Burmester, Lewis, Lonn, unpublished mapping, 2017) and diamictite has been reported only in members of the Apple Creek Formation (Tietbohl, 1986; Connor and Evans, 1986; Tysdal, 2000). Therefore, an alternative interpretation is that this unit (Yyb?) also correlates with the banded siltite member of the Apple Creek Formation.|04-05|dmu, map unit|222,212,232||{BA4AC2E3-4497-4C92-B603-75B4A05BC069}|Mostly mudstone|high||1|DAS01|||KMCDONALD|2022-06-15 14:36:27|{F9C52C5B-5691-4252-8DFD-729824BA5A47}
46|{9E68A09C-7C05-49DA-9545-3ABA0205E17F}|header|header, generic||||QUATERNARY, TERTIARY, AND MESOZOIC|QUATERNARY, TERTIARY, AND MESOZOIC|Quaternary, Tertiary, and Mesozoic|||||02|dmu, header|||{1AAFA5FB-97A2-4F94-9FBB-54EB8A9641ED}|Sedimentary material|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{9E68A09C-7C05-49DA-9545-3ABA0205E17F}
47|{F700D3B5-2C32-43A5-B4B7-F1F1AE79FA97}|header|header, generic||||PALEOZOIC STRATA|PALEOZOIC STRATA|Paleozoic||||A poorly exposed and incomplete Middle Cambrian to Pennsylvanian section is present in the north eastern part and along the central eastern border of the Salmon quadrangle. A fault system at a low angle to bedding omits various Cambrian units. This bedding parallel fault system is very similar to one in the northern Pioneer Mountains that also tectonically thins the lower Paleozoic section (McDonald and others, 2012).|03|dmu, header|||{B4F03DC4-7787-49F9-80C4-16E8A1B5E728}|Sedimentary rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{F700D3B5-2C32-43A5-B4B7-F1F1AE79FA97}
48|{2E0D972F-94DC-46FF-B311-EE843EB8C57D}|header|header, generic||||MESOPROTEROZOIC STRATA|MESOPROTEROZOIC STRATA|Mesoproterozoic||||Our new mapping shows that >4,500 m (14,800 ft) of Mesoproterozoic strata rest on top of the previously described Lemhi Group and overlying Swauger and Lawson Creek Formation (Ruppel, 1975; Hobbs, 1980; Burmester and others., 2013, 2016a; fig. 1). We now refer to the Lemhi Group plus the strata above it—Swauger, Lawson Creek, and Apple Creek Formations—as the Lemhi subbasin strata. These strata, which are sandier than typical Belt units, extend north and northeast into Montana where they grade into the Missoula Group of the upper Belt Supergroup (fig. 2; Lonn, 2014; Lonn and others, 2016a,b). The MBMG-IGS collaborative team now assigns all Proterozoic strata in the Salmon quadrangle to the Lemhi subbasin section (Burmester and others, 2013, 2016a,b, 2017). However, the thicknesses and lithologies of the Swauger Formation, Lawson Creek Formation, and Jahnke Lake member of the Apple Creek Formation change considerably from the western to the eastern and northern sides of the quadrangle. The Jahnke Lake member is unrecognized northeast of the Buffalo Creek–Jackson Fault Zone, where Cambrian strata disconformably overlie a thick section of Law son Creek Formation. Eastward changes in grain size and thicknesses in the Swauger Formation, the Law son Creek Formation, and the Jahnke Lake member (described below) could be the result of facies changes near the eastern margin of the Lemhi subbasin, or they could result from miscorrelation of the argillite-rich intervals used to divide the formations within this immensely thick quartzite succession. The Gunsight Formation is also coarser grained and thicker bedded to the east in the footwall of the Freeman–North Fork Thrust than it is in the hanging wall near the western border of the map. This may be the result of the proximity of the Belt Basin margin immediately east of the map, or it may because the western facies has been miscorrelated (see discussion below).|04|dmu, header|||{E79BBBBA-7CA2-4345-A4BA-F0AC3289E510}|Metasedimentary rock|high||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{2E0D972F-94DC-46FF-B311-EE843EB8C57D}
49|{E80E45CE-F9A2-40DA-A064-77D32FABAEDE}|header|header, generic||||IGNEOUS ROCKS|IGNEOUS ROCKS|||||Intrusive rocks extensively exposed in the north eastern part of the quadrangle are part of the Pioneer Batholith. A smaller composite stock, the Carmen Creek Stock, crops out in the westernmost part of the map area and has apparently intruded an east–west structure interpreted as a down-to-the-south normal fault. Eocene diorite dikes are scattered across the quadrangle and locally intrude fault zones; some are strongly deformed and interpreted to record Eocene or later faulting.|05|dmu, header|||||||1|DAS01|||CELLIOTT|2022-05-18 16:28:42|{E80E45CE-F9A2-40DA-A064-77D32FABAEDE}
