GEOLOGIC MAP 53 Idaho Geological Survey BLAKE AND OTHERS Moscow-Boise-Pocatello WWW.IDAHOGEOLOGY.ORG PLATE 1

This Geologic Map is a reproduction of independent mapping. Its

116 15’ 12’30” 10’ 116 07’30” content, quality, and format may not conform to IGS standards.

 

44 

35  25 22 51 

40 

33 

48  58 

 54 KPvr   

37 44 42 39 JPpm 78 Tcbu

29  Pam 38 KPt   40

38 Pam 72

 

 Ksc

28  36 56 

 

26 

34 

35 

30  22  34 

 42

32 21 34  25 KPt 

  31

32 30 

22  28 25 21 37

   41

32  

  25  34

38  

 14 27 

31  24  32

35  

30  EOLOGIC AP OF THE IGGINS OT PRINGS

  

 23 23 06 G M R H S 25

51 

 22 

 19 31  

36 

16 28 20 Allison Creek- 31 

 24

34  

 89 

39 45  09 13 37

 

 Dairy Mountain

 22 

39 24  41 15

1211 

 20

 22 

40  39 34 15 13 66 20

 normal fault 16  QUADRANGLE AND ADJACENT AREAS,

38  28  27

26 17

 

 26 Pam

19 

 28 KPkr

36 41  18

Not Mapped 16   21 26 29 53   89

20

55  36  21   IDAHO COUNTY, IDAHO 32 27 11

  22 28 21 20   25  50  12 Qas    Ksc

35 08 

 31 18  KPt

66 41 26

  45  29

27 42 32

 23 

36  60 Tcbu Plate 1   45 Pam 41

45 

KPt

JPpm David E. Blake, Michelle L.Bruce and Dawn N.Reed

45 30’

45 30’   Department of Earth and Ocean Sciences

18 Not Mapped

57 27  86  University of North Carolina Wilmington KPt  23 80 

35

 88  Pf  26

78  2016

JPfc  65 24 Qas    KPt

DEB497A  DEB497C

62 58 

  36  KPvr

61 40

76 61     34  55 85 60 66 

78 70  58  44

52  88   KPkr

77 55 77  53

DEB1136B

 34  

DEB471A 32 45  72 52

63 75  41

 80 DEB473  48  67

KPt   68 42  34

 37  

 83   38   77  64 35 63 30

36   66  

Pam 55 

82  62 60  27 75

 34  64  54   81   

33 31 55    80

84  Pam 

  65   62 

32  32 30  61 54 Ksc

75 

45

 40 56 58 CORRELATION OF MAP UNITS

85 63 28 

 

67  50

  68    76

75 41 35 57  40 

  57  72 35

 DEB1186B 79

 31 

47 

54 48 

64 

 42 38 32 74 

   33 64   35 

66   76

28 32 DEB1114F Sedimentary and

39 28 48   Volcanic and Subvolcanic Rocks

50   59 Pam 34 37 41 47 DEB1187C DEB1187D  72

44   72  Mass Movement Deposits

 83 

 44

 79 65

 67 64 35  50   

70  36  DEB1189 DEB1113B

58 40  44 77 64   32  Alluvial Mass Movement

70 70   31 

65 43   71 49 Deposits Deposits

  87  60  47  36 62

 

  56

 85 40 45 62  Qam

72 75 KPt  47  Qaf 

 

  Holocene   40 45 67

 53 73  60 Qamo Qas

18 17  59  

76 66  

 81

72 74 25 52  58 61

 64 66 54  

   

 74  21 65

69  80  Sr <0.704

Pf  25 21  40 75 Sr >0.706

72 53 86

 

49   86

52  69 

50  26 59 74 50    Qls

62  73 Sr/

66  Sr/

54 61 Tcbu 87 65   20  65 34 87

76   40 QUATERNARY

 KPt 41 40 71 Pleistocene

 55

Qas   42

JPfc 15 48 Pam    initial initial  80 38 70 64

 

  

70 KPt 39 18 37 35  68

Tcbu   67  43 D U   73

   

32 

 21

73  57 60 72 62

34  

 39  68 

46 30  60 

 34 85 CENOZOIC

71 33  66  

63     29  35 31   77 u n c o n f o r m i t y 49  65 47

46  39  28 DEB1642B 66 

 78 48

 25   43  70  Columbia River Group

   JPpm 86 

 30  35 68  56 32 38  84 38 58 79 Undivided

55 KPkr DEB1640   Zskm

   63 76 67 49 Tcbu

 89 55  45  30 38  Miocene

  

  36 83 69

46 48 27  69 KPvr

65   30

 67 74

70  27

 

  Other Volcanic Rocks   KPvr

75 78 62 61 DEB1412B 84 TERTIARY

Pam  

 33 Oligocene

65 75 44 38 

54 Pam  70  67 28 

    48

 54 42 53 23 30  5873 

 Pgda 34   65 45 45

 37   59 DEB1071  Tbp Ta Eocene Pgda 

70 53 48 55 40  47

53 61 52  43 DEB1070I

  KPt   82 80

 66    35 D U 65 

  73  36 40 30 79  81 67 38   Paleocene Pf Pf 58  67  71 42 78 78 44

KPt  74   69  57 u n c o n f o r m i t y  42  62 

 64 Tcbu  38

31 47 70   Kpc 

   67 

 84 62 51   83  66  65  49

74 57 60  63 37  43 71 55

84   72 65 30 DEB1593 

  46  65 60 Rapid River Lake Creek Pollock Mountain Chair Point Igneous North American

  Cat Creek Meta-Plutonic

 79 73  32  82 78 65 71 

56   31 58  56   

47   77 70

  71 71  60 Thrust Plate Thrust Plate Thrust Plate Thrust Plate Complex and Plutonic Rocks Rocks

85  68  55 38 3153   74  74  78   

 75 47 52 79  69

67  36 76  

42  40   56  78 48  75 57

 JPcs 

79 82   38   60 50

78 78  50 36  33  58 67  60   37 

80   74 65  70 72 67 

 83 Pam   50  67 58 78

 88  81   Ksc Kbl   Kpc Klg Kcp  37 60

 36    47 88 CRETACEOUS  

82  60 49 35 56  33

   85  28 

 74 59  83 71  67    63

88 76 82  38   42  82   70

  55 61 55   56

27’30”    62 54 44 61   79 27’30”

35   Ksc 80 65 73  77 

 50     

85  65 82 26 80 49

 52    51 60 DEB879A  KPvr

  56 58 59 

55 81  JPfc  65  76 37  69

72 

 71  36   

 82 56 75   

82 75  80 85 80

 75  72 

 D U 70  68

85  DEB872 85 41 82

  JPpm  JURASSIC MESOZOIC

78 79  83   80

59  77 83  

 75 78  46  81 60   75  43   79 60   

Pgda 79   41  83 79

77 75  24 33 73 46

 69 77

Pam 74 22    48

   54 KPkr 80 Zskm KPkr KPt KPvr

 66 JPpm

 77   69  48     70   DEB1498B 65

70 72 65 81

 61 80  31

  36  

60  81   Klg

61   53 76

JPfc 

76 44  73 69   80  

  42  60 

32 75  41 51  72 77 82 48  JPsc JPbc JPlc JPfc JPef JPwf JPcs JPpm TRIASSIC    

Pf 78 87  55 46 34  54    72 73   84 47 DEB1347 73   69   64 KPt  76 51

66 66 71   40

 78 76 

56 79 KPt  44 39 49    84 72

 74 

12 59  76  Qas 66

 60  75  

  80  73 52   64  41 42 Little Slate Creek  69 63  74 80    57 40

72 81 45 55 JPcs  47  31 85 

   80 24  normal fault 72 68

84  46  80   43  Pgda 36 44 

    56 80

60     78 78  53 72  82 64 71 74   DEB1353 53 DEB1346 Pcc Pdm Pf Pgda Pam PERMIAN PALEOZOIC 72   32

  65 68 DEB1041

77 32  76   79    52 

61 66 67  80 69 69 85

JPfc  DEB1416  79   77  59

 53    DEB1356B  

72 63  21 52

85 79 KPt 54  52 80  76 66  55 57  Domain of Downslope 62  73 70 79 60 55  55  47  86   61 63 45 Tcbu Lithology and Foliation 73 41  82  67

  64 70

 Pgda

 78 66  85 76  40  60 

 80 87 73

Creep    

59 Pf   67  DEB1093 Zmkm

80  86  

  84  62 65  85 77 31   67  

78 31 66    66  

75 JPlc JPcs 41  63 DEB1097 76 PROTEROZOIC PRECAMBRIAN  

 50 70 28   68

  

55 74  43 81

 58   86  75   80 33

   

 80

44  39  78 Zskm 

 

25  85  47

  

  85

 75 69

70 43 DEB1483 JPpm  DEB1050

  59    76 70 50  34 47 77 86 DEB1369B 78 60   54 65  20  DEB1011 DEB1341

62  61  54 75   35 38 61  39  73 80 76  54

79    65 32 84  61 

  75  46 83  58

81  85  27    Kpc 

 54 61   83 78 67

64 75 70   39    68  84

  30  79  72 69  DEB11722A DEB1722B 48 KPvr 80 

60 62  59  80

Pam 73 43   53 52 52 21   75 84  58

 

 38 75 53 

 62 80  44 28  76  66 

 52 55 62 57    76  70

68 54 35   

    26 72  75 57   62  77   Zskm 55 71 DEB1363 61  74 

 60 52 46 42 51 77 

65  71 74 40  63 74

   62  75  DEB1364  70 42     64 43   78  63

62 72 37 35 43  63   72 DEB1020   46 71 73

   74 87  DEB1017  81

 64    75 76 36 DEB1727  40  DEB1734  82 85  68 Klg 39 JPfc  38  69  68

    63 

62 54 41 78 68 85 85 77 

 29  64 75  65 49 53 Qas     58  

42 31  83 73 D U  47

 71  85  82 72  51

  78 Ta  69 DEB1205C  43  MAP UNITS

 KPt 15   83 82 84 79   37  48

60  75   56  73   64 54

33 34 79  79 71   40 Unit descriptions on accompanying plate  

 33   88 74 86     86  76 68   67 79

50 53  87  65 

 

 64  83 84  65   67 55 70

46 88    D U    67 55 

 86  74  66   79

36  85 44

 45 87 72   

 46  71 84  84  88  52 53

54   72  83 

40  KPkr 88 68 

47 29 JPpm  44  68       

45   72 71  53  

KPt  86 61

  81 64

72 40   78 74  70  48 SEDIMENTARY AND

62  85  44  85 83 82     81  51 56 Klg

44 70  88     

JPfc 74  76 51

 77  75  

   78 75  68 43

DEB1493 58 Ksc  80 78 80   68 65   52 MASS MOVEMENT DEPOSITS

81 73 

63  81  69 80   47

 56  76   DEB791B 85 73   64   46 54   74 70  87  

 65 77 67     55

 49 51   84  66 72     DEB760A DEB760C 67 78 61 56 A’  38   82  70  87 62  

62 86 79 65  85 89 81 70  43  55

 89  88  75   85  80  56 Qam Alluvium of the Salmon River (late Holocene)   85  68

77 85 85 54  62  75 82

A   v 65   78 88 79  82 81 78 74 77  JPlc 87   81         84  40 48 71 58

 77  86 81  70  

 55 61 73  59     78 75  78 73   63  51 

JPef   43  68  86  

  87

 74 Qamo

88 68 86 85  52  69  Older alluvium of the Salmon River (Holocene)   47 88   62 80 61 

35  27 57 88  87  69  Zskm

59 25   70 83  DEB851A DEB1322 72 66   

43 87 75 61 57

69 47 45  89 48 85     40    74 48

 56 43 43 64 Qaf Qaf Qam   73 59  DEB857   Qas Channel and flood-plain deposits (Holocene to Pleistocene)

  76  77

 37 44 63 63 73 65  48  75 88

 57  64

77  48 42   75 Qaf    

88  27 DEB691A 81 70

    72   Klg  78

80 52 34   67  55   28 

  64 36 Qam 65

  21  34 63 53  KPvr 51 Qaf Alluvial fan deposits (Holocene to Pleistocene)

 

84 

JPfc 38 78 80

28    34

63 

60 60 30  

 61  70 54  

23  D U   75 

85  40  

67 50 62   89 82 87  57 74

30  76 57 44     

33

  40 35 37  84 43  

79 73  84

 Qas     Qls

55  57 82 88 76 82 74 Landslide deposits (Holocene to Pleistocene) 

55 65 80     54 75 76

36 47  86

 65

JPfc 37  Zskm  36 Zmkm 66

 42 49  47 74 87   76 77 73 74

 62  77  

JPlc  

  

31 

75   65  72  86 

  77 68 80   79

65    74 71 73 65 29  72 56

   65

 80

60   47 39 66    55  58

   71 74  67 73 64 75   49

32 36    70  83   83 85  63 54 43

65 41 JPbc  79 30  

45  78 25 80 VOLCANIC AND SUBVOLCANIC ROCKS

  59 

  JPpm  Qamo 

65   

 40  82 78  76

 41  78

 73 24   74  44 80 68 53 71 47  44  56 

   87   71 53  50

36  76  87  28  62 66

 42 66 80 61 

 41

63  51

47  Tbp  81   DEB1243 Qls

41 61  76  64  67 71 44 Qamo 62 Tcbu    79    Columbia River basalt undivided (Miocene)

 31  25 Qamo 67   Qls

51  48 59  78 77 57 62 80 55 55 70  

20 44 75 85   DEB1661B 85 80  

 43 35    

35  75  56 56  Zskm 53 

    72 Kpc

JPlc   78 

82 56 62 48  85 56 Tbp Biotite of Riggins Hot Springs (Eocene)

20    80 

40 49   60 JPpm 71 75

31 72 56  56

80   63  35  Qam Qaf 

 38 51 51 

 50 48 

  57 68

50  64 

65  69  Zmkm 55 80 Ta (Oligocene to Paleocene) Qaf   70 73   42  57 

75 60 32 40 35 72 45  65 Qam    81 55

  68 82 60 62  61 84 71 76   68 

25’  72 66 54 71 34   87  45 74  25’ 

  80 45    25 

 Qam

74 72 43  36 47 61 70 58  62 

 JPlc 77   

  44 65 

  50 55 40 59  74 77 64 67 44 83 Zskm

Tcbu   68    61 67 74 KPkr   60    42

 64 58 

65 Qaf  INTRUSIVE ROCKS

 66  73 Qaf 78 64 72

77  60    

 36 50

  80 65 JPbc 43   78 

 72 60  JPef 77 30  59

Qamo  70 54  40 53  

85  71   Ksc 22 Not shown

    65 

27 18 Qls  Qls 52 23  54  80 on map Salmon River intrusive suite (Cretaceous)

 65 23   71 

85  43 45 JPfc   52 31   Zskm

48 88 30 76 88   64  

42  63    34 

Qam 85 58 68  Ksc

77 63 68  70 41  67 69 Spring Creek (Cretaceous)

80  52 

76  

   75 

 38 52 Qaf 64   70  

 Klg 66 

 53 77

    64 

32  62 67 68  58   

72 66  63 64  85

65  47 72 68  50 38  56 72 KPvr  57  62    Van Ridge gneiss (Cretaceous to Permian )

 88 80 65   53 65  82  70 86  72

48 51 JPbc 46 54 45 Qls  79 61 

   55

30  50 35 52   52 

    46    84  58 56 50 50 70 72

50 65 53  63 58 65  53 70  56 Kpc

     Partridge Creek gneiss (Cretaceous)   53 86

 JPfc  

30 53  64    81 64

  53 55  Tcbu  65 

 JPbc  62 Qam 57 85 

32 60   66  46 80

40    57

  Zskm 

 Qamo 75 51    84 62 70  KPkr  Qaf 

15 Pcc  70 76 78 51 61  Kbl

   55 Qaf 63  Broken Leg (Cretaceous) 45  53 65  80  

 65 50 

54  39 60 77 73 56 70

50 48  58  76  74   52  60   

31 18 37      69

28  64  66 81

49 24 88 75 72  45 KPvr 80 60 Kcp 72 62 72 Klg

 20   60 60   80  69 Looking Glass tonalite (Late Cretaceous) 18 

   57 59 Pollock KPkr 74 75   68 

79  42 63 21   76  66

Qaf 74   61  Qls 

32 78  12  62

28    65 46  58 Mountain  71  Kpc  80 74 Kcp

 50  64  Crevice pluton (late Early Cretaceous)

49 21  72 DEB885B 70  

 

  32   

 77

  Qaf

80  52 JPfc 57 thrust 69 12 85 

 77  69 79  52   

68  72

18  15 JPlc  50  62  

72  44 51 61 fault  22

    

30  88  58 81  78

 45 

15  60 JPlc 5150   23 Qam 80  45 56 45

10  45  55  75 

75 65 62  57 40  78 73

50 18   48 Klg 86   

25 Qaf   80 METAMORPHIC ROCKS OF THE CAT CREEK, RAPID RIVER,  70 Qas 67

 88 77 59  55  Qam  72 24 65    75   44

25 57 Qam   12 31 64 65 70 Qam 

 37 80 67

 60 54  53  57  44  65 Ksc Qls Zskm  LAKE CREEK, AND POLLOCK MOUNTAIN THRUST PLATES

 54   67  69  DEB780A

54  40 

 78   56 54 B’

   

20   53 25 76 

77 76   Zskm

50 31 52  54 60  36

 80  53  JPbc 54

JPbc 68 78 

 

70 46   72 38  65  JPsc   47  

  67 76

33 70 84 77  60  51 45 40  Squaw Creek Schist (Jurassic to Permian) 

   

  69 50   

   32

 

 80  54 46 70 83  28 60  65   42

73 

55  53 76 55 65 

50 58 60  62  80 84  62 50 Pcc 53    67 Meta-ultramafic rocks of Cat Creek (Permian)

 60    

49  44 62

 67 65   35 39 40   76   50   18 65 64 60 JPpm  62    52

42 30 80  34 33 13 89 36

JPsc Cat 74 86 45  80 Ta 25 Kcp JPbc Berg Creek Amphibolite (Jurassic to Permian)

  35 33 

 

18  Tcbu 24

  

Creek JPfc 62 31 ?  

56   

59 

37 76  Qas 51

 

56 45  65 31 

thrust    36  Klg JPlc

49 22  89 55  Lightning Creek Schist (Jurassic to Permian) 

30 49    56

22 85  34  

40   

57 42  59

 

  fault 38 

 

 38 50 58

59  45  35 35 80 25 

 28

 

 70  50 62 73 

21 54 JPlc   

35 50  JPfc

40 63   75

55 25   Fiddle Creek Schist (Jurassic to Permian)

JPlc 65  43 36 25   

20 38 

31  35 41   79  87 65 56  

32   51  56   D U 45 

  55 77 55 76 

17 81 80  34 41  65

 63 65

55   JPef  rocks of East Fork (Permian)  

 44 49  52 79  45 Tcbu 35

80 30 18 32  

 70

  

89 Pollock 27  31 50 49

 JPwf

 31  West Fork schist (Jurassic to Permian)  KPvr

Mountain  25 JPbc JPbc 53

36 32  34 Kpc ? 

30  

 48

35 

thrust 

 55 54

36  

 

11  Pdm

 Dogtown Mountain igneous complex (Permian)

35  fault  49 42 Qas

33  72  56

45 32 40  70  45  28 Allison Creek- 48  

  54    

49    63

33 51   34

 

47 9 20  50 41 29

 45 56 68 ? Kbl 

  36 JPcs

65 32  55   37 Calc-silicate gneiss (Jurassic to Permian)

  66  

  37 Dairy Mountain

49   60 50 45 39 35

10 64 

  56 38 39

  59

JPsc 

  

  47 50

60 20 90  

 48 56  80  37

 46  29

  40 

69   

  

 55

40  normal fault 42 78 JPpm

  45 44 35 Pollock Mountain Amphibolite (Jurassic to Permian)

61 50 25 

35 71 66  50 42  78 

44  55   40  85  64

   50   22  61 49 54  ? Zskm  50

60 65  81

Pdm  42

40 

 74 81

41 44  38 61 49 45 52

32 60  32 KPkr

 32 KPkr

 Zskm Keating Ridge gneiss (Cretaceous to Permian)

71  

60  84  

89 25  42 66 50  54  52  

  60

 

 

64  

   

66 40  47

20 45  36 45 

 74 

40 

65   

54 50

 66 51 49  

 32 45 

 42   Qas 86  55  55

 37 54 45  50 JPpm 56  67 18

60  52 44

 50 32

19 89  50 39 61 50 ROCKS OF THE CHAIR POINT 60 

 50   54 60  35 19  50 39 46 54

75 08  

61 63 62  35

 

 60 Not Mapped 

 84  JPbc 45 28  

60 46   IGNEOUS COMPLEX

23 49  60  14 

B   65 55 58  36

 60 

74 JPpm  46  54   58   80 53 

  59 55  Ksc 50

50 65  60 

64 47   62

48 38 64 56  54 46 55 55 Tcbu KPt

 Trondhjemite and tonalite of Chair Point (Cretaceous to Permian)    

68  

 47  

 JPsc 29 60 55   80

60 62 38 57 30 50  Lake  50  44 55 40    Pf 38  69 30 D U 76  45 Felsite (Permian) 37 Creek Pollock 36 31

66  KPvr 75

Pdm  Mountain

thrust  

 35 Pgda

  -hornblendite, and amphibolite (Permian)

 thrust 70

fault 60 60  Klg  75 

 31

48 45 50   fault 68  

 

45 25 Pam

70 Amphibolite and hornblende gneiss (Permian) 54 65

42  Kpc  48  41     JPwf 74 36

40  50  

40 50 60 30 40   54 45 22’30”   87 28 57 43 43  70

Qas   81 

30 50  35  78 

45 22’30”  78 JPpm 35 METAMORPHIC ROCKS OF THE  36 80  Zskm

 42 65   NORTH AMERICAN CONTINENTAL MARGIN 85  68 74 45 50 38 34  57

JPwf  48 Kbl  Tcbu 54  Zmkm

  63  Marble of Kelly Mountain (Proterozoic)

29  82 15

 58 

43 

 

 Zskm Schist of Kelly Mountain (Proterozoic)  46   70 55 45 40 Zskm 28 60   75 40 28  44  76 52 Little Slate Creek

44 82    33 normal fault

 40  45  KPkr 51 50  81 Tcbu

 Qas

40   52 50

 55 MAP AND CROSS-SECTION SYMBOLS

 D U Lake  51  JPwf  55 Creek KPkr 49

42 41

thrust   64 60 Contact: control based upon number of structural attitudes.

fault Sr <0.704 66 Sr >0.706 86

86 /

Sr

Sr/ 87 Normal fault: ball and bar on downthrown side; control based  87 Kpc Klg Zskm  40 72 Ksc KPvr Kbl on number of fabric attitudes.

initial JPwf initial Thrust fault: teeth on upper plate; control based on number of fabric attitudes. 116 15’ 12’30” 10’ 116 07’30” D High-angle contractional fault: control based on number of fabric attitudes. 117°03' U Y Field work conducted between 1987-1990 (DEB), Base map digitally reproduced from 1:24,000-scale E SCALE 1:24,000 A N D C 49°00' E N MN IL N TIA E USGS Riggins Hot Springs, Kelly Mountain, C H N R 1995-1996 (MLB), 2000-2005 (DNR), and 1999-2006 (DEB). U O U Dextral fault: control based on number of fabric attitudes. O GN L J O L 1 0.5 0 1 M F Patrick Butte, and John Day Mountain quadrangles. MILE Control by USGS, USC&GS, and U.S. Forest Service Digital representation by Dawn N. Reed, David B. Parnell, F 2 fold hinge; arrow indicates direction of plunge; dashed where inferred. 20 S G N N Y IN and David E. Blake. I Topography by photogrammetric methods from aerial 1000 0 1000 2000 3000 4000 5000 6000 7000 S L A 0 35' N R L T P E N 356 MILS IGGI S K R U photographys taken 1959. Field checked by the USGS 1964. FEET IGGI O R OT M 10 MILS 111 °03' H Macroscale Lake Creek antiform. Polyconic projection. 1927 North American datum 1 0.5 0 1 The IGS does not guarantee this map or digital data to be free of errors nor

10,000-foot grid based on Idaho coordinate system west zone. KILOMETER 14 assume liability for interpretations made from this map or digital data, or  K Strike and dip of flow layering in basaltic rocks. K IC R T T RSHEY decisions based thereon. CONTOUR INTERVAL 40 FEET A E IDAHO P BUTTE H POIN POLLOC 60 UTM GRID AND 1964 MAGNETIC NORTH  Strike and dip of fracture surface in the Chair Point igneous complex. DECLINATION AT CENTER OF SHEET 42°00' QUADRANGLE ADJOINING 81 Strike and dip of S foliation. LOCATION QUADRANGLES 1

Strike of vertical S 1 foliation. SALMON RIVER SUTURE ZONE 29 Trend and plunge of L 1 mineral lineation in the S 1 foliation. WESTERN IDAHO SHEAR ZONE 75 Strike and dip of S axial surfaces to mesoscale F fold hinges. ISLAND-ARC METASEDIMENTARY, CONTINENTAL METASEDIMENTARY, 1 1

METAPLUTONIC, AND PLUTONIC ROCKS METAPLUTONIC, AND PLUTONIC ROCKS Strike and dip of vertical S 1 axial surfaces to mesoscale F1 fold hinges.

RAPID RIVER THRUST PLATE POLLOCK MOUNTAIN THRUST PLATE 15 Trend and plunge of F1 fold hinge.

86 Strike and dip of S2 axial surfaces and mylonitic foliation in the Crevice pluton. 

67 Trend and plunge of F2 fold hinges having S 2 axial surfaces.  Trend and plunge of crenulation lineation in the S foliation. Blue Mountains island arc- 42 1 North American continent boundary A A’ 78 Strike and dip of local S3 extensional shear surfaces. Lake Creek Berg Pollock Mountain Sr >0.706 Sr <0.704 Zone of highly fractured and silicified and cataclasite; Looking Glass tonalite

6000 86 6000

Mountain 86 / antiform thrust fault / ? Sr Domain of Downslope Sr and Partridge Creek gneiss. 87 Lithology and Foliation Allison Creek-Dairy Mountain 87 Little Slate Creek Kelly initial initial Mountain 5000 Creep normal fault normal fault 5000 Domain of creep; western Allison Creek.1

Rooney Domain of multiple, mesoscale Columbia River Basalt Group dikes; Basin west side of Partridge Creek. 4000 4000 Berg East JPef Keating Van Zmkm Ridge Ridge Headwall scarp of landslide; ticks on downslope side.

Creek Fork Feet Allison Spring Van Kelly Pam Creek 3000 Creek Creek Creek 3000 Limit of historic placer mining.

Feet Qas

A - A’ Line of cross section. 2000 2000 JPfc JPef JPfc KPt JPlc JPbc JPpm KPkr Ksc KPvr KPvr Zskm Kpc Klg Zskm Klg DEB1483 Geochemical sample location and number. 1000 Pam 1000 Zmkm Pam Structural form surface lines of the S 1 foliation in cross section.

0 0 Structural form surface lines of the S1 and S 3 foliations in cross section. No Vertical Exaggeration Lake Creek antiform Macroscale contractional fault zones in cross section.

Macroscale extensional fault zones in cross section.

Lake Creek Blue Mountains island arc- Inferred macroscale dextral fault zone in cross section. Pollock Mountain thrust fault B Allison Creek-Dairy Mountain North American continent boundary thrust fault normal fault B’ Dogtown Mountain Sr >0.706 Sr <0.704 86 86 / / Sr 6000 Sr 87 6000 87 initial Pdm Cat Creek Warm Springs “Carlson” initial thrust fault Ridge Little Slate Creek 5000 Ridge 5000 ACKNOWLEDGMEN TS JPwf normal fault Lava We appreciate permission from the Carlson and Walters Families to access JPpm Warm Springs Ridge 4000 4000 their lands adjacent to the Nez Perce National Forest. The Sigma Xi Scientific Creek Qls Society, Geological Society of America, and University of North Carolina Zskm F Wilmington Cahill Grant and Summer Initiative Programs funded this work. t Partridge

e e Lake e Perry Berry, Cal Callaghan, Robert George, Neil Roberson, David Parnell, e Creek 3000 Creek Salmon 3000 t F Qas Chris Haugstad, and Diana Pietrolungo provided crucial field assistance. Todd Qas River LaMaskin, Reed Lewis, and Mark Carter offered invaluable peer reviews. Ksc 2000 JPsc JPbc JPlc JPbc JPpm KPkr KPvr Zskm Kpc Klg Kcp Zskm 2000

1000 1000 Kbl JPbc Tcbu 0 0 No Vertical Exaggeration JPlc JPbc GEOLOGIC MAP 53 IDAHO GEOLOGICAL SURVEY BLAKE AND OTHERS MOSCOW-BOISE-POCATELLO WWW.IDAHOGEOLOGY.ORG PLATE 2

206 328 descriptions and LA−ICP−MS Pb/ U zircon analyses yielding 105.3 ± 3.0 within the Fiddle Creek Schist. It is exposed as a large block or folded rock composed of ~75% to 95% actinolite occur along the Berg Creek and Map units define macroscale S0 compositional layers that were highly and 103.9 ± 2.7 Ma ages for the stock. It may correlate with compositional layer in the hinge of the Lake Creek antiform on the southwest Pollock Mountain Amphibolite contact. They may represent or transposed during amphibolite facies, syn-kinematic strain in the fold-thrust orthogneiss of the Little Goose Creek complex in the McCall region to the flank of Berg Mountain. Its correlation with other units is not clear, although underpinnings to the Pollock Mountain Amphibolite, or belt and WISZ. Inclusion trails in poikiloblastic garnet define an S1i foliation GEOLOGIC MAP OF THE RIGGINS HOT SPRINGS south that has a similar age (Manduca, 1988; Giorgis and others, 2008; Gray it may be an outlier of the Chair Point igneous complex or mafic substrate allochthonous horses along the west-directed Pollock Mountain thrust. Unit that is oblique to external, regional S1r foliation. The S1r gneissosity or and others, 2012). upon which the Fiddle Creek Schist was deposited. inferred to be metamorphosed mafic volcanic and volcanogenic sedimentary schistosity transposes all map units. Composite S1r foliation, dynamic rocks. Mapped northward into Cretaceous to Permian gneiss and schist of the recrystallization, disharmonic folding and boudins, and meta-ultramafic rocks QUADRANGLE AND ADJACENT AREAS, Kbl Broken Leg granodiorite (late Early Cretaceous)—White to pinkish-gray North Fork Assemblage of Lewis and others (2011b). mark the Squaw Creek Schist−Berg Creek Amphibolite contact as the Cat leucocratic (CI = 5–10) medium crystalline to megacrystic K-feldspar biotite Metasedimentary and Meta-Igneous Rocks Creek thrust; abrupt lithologic change, composite S1r, dynamic granodiorite and granodiorite orthogneiss. Most megacrysts range in length of the Lake Creek and Pollock Mountain Thrust Plate recrystallization, disharmonic folds and boudins, and meta- between 10 and 15 cm, but locally crystals up to 20 cm have been observed in Chair Point Igneous Complex characterize the Lake Creek thrust at the West Fork schist−Pollock Mountain IDAHO COUNTY, IDAHO a xenomorphic quartz, plagioclase, and K-feldspar matrix. The pluton contains In the west-central portion of the map area, an eastward increase in Amphibolite contact (Bruce, 1998). They are separated by the intensely local domains of biotite foliation and down-dip lineation in protomylonitic metamorphic grade reaches the middle amphibolite facies (biotite-kyanite- rocks of the Chair Point igneous complex in the northwestern part of foliated, folded, and intercalated lower contact of the Pollock Mountain and mylonitic orthogneiss. The pluton shares lithologic and textural garnet-clinopyroxene zone) and overprints hanging wall rocks of the Lake the map area were recently reported to be Permian in age by U-Pb zircon ages Amphibolite at the Pollock Mountain thrust. It crosscuts Lake Creek, Cat similarities with the Crevice pluton and may be its lateral equivalent. It Creek and Pollock Mountain plates. These thrust plates are included in the in the John Day Mountain quadrangle (K. Lund, personal communication in Creek, and Rapid River plate rocks, and the Cat Creek and Lake Creek thrust extends southward along lithologic strike on Lava Ridge and may correlate eastern portion of the eastern Salmon River thrust belt of Gray and Oldow Lewis and others, 2011a). Some portions of the complex may be related to faults. These last two faults may have been an earlier, single thrust fault. Plate 2 with Little Goose Creek complex granodiorite orthogneiss on Lava Butte (2005). Mapped units are potentially Cretaceous to Permian in age based upon tonalite and trondhjemite of the late Early Cretaceous Hazard Creek complex West Fork schist may be a down-thrust, higher-grade equivalent of the Squaw (Giorgis and others, 2008). along-strike correlations with Aliberti (1988), Manduca (1988), and Lewis exposed along strike to the south near McCall (Manduca, 1988; Blake, 1991; Creek Schist. Regional kinematics and timing of S1r relative to faulting along and others (2011a, 2011b), but they are poorly dated and any stratigraphic Manduca and others, 1993). Fine-crystalline felsite (Pf) and coarse-crystalline these contacts are equivocal, but S1r seems to be syn-kinematic in the western Kpc Partridge Creek gneiss (Cretaceous)—Gray, tan, and white, hololeucocratic to facing directions are not known. The Pollock Mountain thrust fault separates biotite tonalite-trondhjemite (KPt) form the bulk of the complex. They are portion of the map area. In the WISZ, contact and fabric elements marking leucocratic (CI = 0–10), fine- to medium-crystalline garnet biotite granodiorite the Lake Creek and Pollock Mountain plates from the underlying Cat Creek associated with a mixed lithologic unit of metamorphosed gabbro and lesser the Pollock Mountain thrust are transposed into the steep east-dipping S1r. and tonalite to trondhjemite orthogneiss. Unit is exposed in the western slopes and Rapid River plates along and across the western boundary of the hornblendite, garnet diorite, amphibolite, and locally tonalite (Pgda), although of Kelly Mountain and Hershey Point Ridge as tabular sills hundreds of Cretaceous western Idaho shear zone (Blake and others, 2009). To the contact relationships are not clear. Felsic rocks partially surround large S1r symmetrically wraps porphyroblasts and porphyroclasts in a flattening- meters long and smaller discontinuous layers tens of meters long. They are southwest, the Pollock Mountain thrust fault crosses Dogtown and Indian domains of well-foliated garnet amphibolite, while amphibolite enclaves and type structure. Intensity and steepness increases eastward into the WISZ David E. Blake, Michelle L.Bruce and Dawn N.Reed oriented along strike as a complex, yet continuous intrusive unit. Thickness of Mountains and extends into the Little Salmon River in the Riggins and possibly deformed dikes (Pam) are common in tonalite. Contact relationships interior. L1 mineral elongation, aggregate and shape lineation along with individual sills and layers is quite variable. Rocks of lower CI generally Pollock Quadrangles (Aliberti, 1988). From structurally highest to lowest, the with the Lightning Creek and Fiddle Creek Schists are also not clear. Biotite down-dip boudinage of granitoid and orthogneiss dikes and sills define a Department of Earth and Ocean Sciences crosscut rocks having higher CI. Granitoid orthogneiss has a fine- to medium- map units are listed below based upon their positions within the thrust plates. tonalite-trondhjemite (KPt) appears to crosscut the Pollock Mountain thrust major stretch component in S1r. L1 plunges also steepen eastward into the crystalline, granoblastic mylonitic fabric. The biotite foliation and down-dip The informal West Fork schist (JPwf) in the Lake Creek plate may be a higher and Rapid River and Pollock Mountain plates. Many contacts are highly WISZ, becoming a tabular domain of Cretaceous plutons. L1 plunges match University of North Carolina Wilmington mineral stretch lineation are penetrative. Granitoid sills, dikes, and dikelets grade equivalent of the Squaw Creek Schist (Bruce, 1998). The Dogtown foliated. Lewis and others (2011a, 2011b) suggest that similarity in age and reclined, tight-to-isoclinal southeast-plunging F1 folds that deform S0 and have may display complex single-layer fold geometries. K-feldspar, from several Mountain igneous complex (Pdm) may correlate along strike with the Chair composition may indicate that the Chair Point igneous complex is correlative S1r as their axial surface. Open to tight, concentric-, similar- and chevron-style mm up to 1-2 cm, is porphyroclastic. Locally, subidioblastic garnet Point igneous complex described below. It may also be a block within the with Wallowa terrane and Seven Devils Group basement units such as the F2 folds overprint S0, S1r, and L1. S2 is their geometric axial surface. Biotite porphyroblasts range up to 5 mm. Darker, variably crystalline tonalitic gneiss West Fork schist similar to the meta-ultramafic rocks of Cat Creek within the Cougar Creek complex to the west in Hells Canyon. locally defines S2 in mesoscale fold hinges. The Lake Creek antiform is an F2 2016 hosts crosscutting lighter granitoids. Biotite and hornblende record a down- Squaw Creek Schist. Keating Ridge gneiss (KPkr), calc-silicate gneiss (JPcs), fold. S0 lithodemes, lithologic and structural contacts, and S1 strikes are NW dip stretch lineation. Some biotite-rich interlayers preserve small and Pollock Mountain Amphibolite (JPpm) in the Pollock Mountain plate KPt Trondhjemite and tonalite of Chair Point (Cretaceous to Permian)—Blue- and NE across its southeast-plunging hinge and match with moderate SW to porphyroclasts of feldspar, but appear to be metasedimentary rocks having a correlate along strike to the southwest with similar lithologies on the Little gray leucocratic (CI - 5-10), medium- to coarse-crystalline granitoid and its steep E-SE dips on its limbs. The macroscale fold corresponds with the small component of felsic leucosomes. Correlation of the Partridge Creek Salmon River and top of Pollock Mountain (Hamilton, 1963, 1969; Onasch, orthogneiss equivalent. Relatively equal abundance and granularity of quartz transition from moderately dipping Cat Creek, Rapid River, Lake Creek, and gneiss with other regional plutons is unclear. Intermediate portions may be 1977; 1987; Aliberti, 1988; Selverstone and others, 1992; Bruce, 1998). and plagioclase produce a sugary texture. Biotite ± hornblende and epidote Pollock Mountain thrust plate rocks to the steeply dipping WISZ. Gray and equivalent to the western orthogneiss of the Little Goose Creek complex; gneissosity and streaky, down-dip mineral lineation form along its eastern others (2012) report a shallowly east-dipping and tops-west S2 mylonitic granodioritic gneiss may be equivalent to porphyritic orthogneiss in that margin and in localized zones within the pluton. Interior more weakly foliation in the Crevice pluton that has a 105 Ma age. Timing between fold S2 CORRELATION OF MAP UNITS and mylonitic S is not clear. Steeply east-dipping chlorite- and quartz-fiber complex (Manduca, 1988; Manduca and others, 1993). Lake Creek Thrust Plate foliated to nonfoliated and mafic minerals of lesser volume as compared to 2 pluton margins. Disk-like aggregates of quartz flattened in the foliation. rich or grain-size reduced zones are S3 extensional shear bands and shear zones along the Allison Creek-Dairy Mountain and Little Slate Creek normal Ksc Spring Creek tonalite (Cretaceous)—Medium-tan to gray, mesocratic (CI = 30- JPwf West Fork schist (Jurassic to Permian)—Golden brown, friable, fine- to Abundant at pluton margins, amphibolite and biotite schist enclaves form Sedimentary and Volcanic and Subvolcanic Rocks 40), medium- to coarse-crystalline and locally porphyritic tonalite orthogneiss. small, thin tabular layers parallel to foliation, and become blocky in shape faults, as well as the Van Ridge gneiss and Kelly Mountain schist contact. medium- crystalline pelitic biotite schist, and ribboned quartzite and East-side-down normal faults place Columbia River against pre- Mass Movement Deposits Coarse-grained porphyroclasts of epidote, plagioclase, biotite, and hornblende amphibolite horizons. Thin (2−10 mm), semi-continuous quartz- westward across the pluton. Fine crystalline and pegmatitic dikes attributed to in a quartz-plagioclase matrix are keys to identifying this relatively thin and the Salmon River intrusive suite crosscut the pluton. Correlates with foliated Tertiary rocks and may represent reactivated contractional-transpressional Alluvial Mass Movement plagioclase layers alternate with thinner, 2−mm biotite layers as a faults and foliations. Deposits Deposits very tabular pluton. Hornblende and biotite define a subvertical foliation and variably developed schistosity. Locally, fine-grained, dark-gray, and nonfoliated plutons of Lund (1984, 2004) and Lund and others (1997) down-dip mineral stretch lineation. The pluton intrudes both the Keating northward at Southwest Butte and Dead Point. Mapped northward into biotite Qam ribboned quartzite appears similar to the base of the Squaw Creek Qaf Holocene Ridge and Van Ridge gneiss units. Coarse-grained, transposed layers of trondhjemite of Lewis and others (2011b). Geochemical analyses (Blake, Qamo Qas Schist at the Cat Creek thrust fault. Green, medium-crystalline foliated porphyritic orthogneiss interlayer with Van Ridge gneiss along their mutual amphibolite is interlayered with the ribboned quartzite. Quartzite- 1991) suggest it may correlate with the Hazard Creek complex near McCall. REFERENCES contact. Its contact with the Keating Ridge gneiss is more abrupt. Salmon amphibolite outcrops are discontinuous mesoscale interlayers or large River intrusive suite sills and dikes are pervasive. The pluton is mapped Pf Felsite (Permian)—Light-gray to brownish-tan, leucocratic (CI < 10) fine- Qls isolated blocks within the biotite schist. Platy subidioblastic biotite QUATERNARY northward into eastern portions of the Cretaceous hornblende-biotite tonalite crystalline, massive to foliated felsite. Brown Fe-oxide or Fe-hydroxide Aliberti, E.A., 1988, A structural, petrographic, and isotopic study of the Rapid River area, and Pleistocene porphyroblasts form a down-dip lineation. Gentle to open folds with (Khto) of Lewis and others (2011b). It may be correlative with epidote- amplitudes from 10s to 100s of meters deform the schistosity. Cm- mineralization, fine-crystal size, and domains that are biotite- or hornblende- selected mafic complexes in the northwestern United States; Implications for the evolution bearing plutons of the Hazard Creek complex of Manduca (1988) and scale discordant quartz veins and granitoid dikes, as well as isolated bearing and lack layering are diagnostic. May be a hypabyssal - of an abrupt island arc-continent boundary: Cambridge, Harvard University, Ph.D. dissertation, 194 p. Manduca and others (1993) near McCall. lenses and blocks are abundant in the schist. Highly strained and trondhjemite pluton. Contact relationship with Fiddle Creek Schist to west is Barker, F., 1979, Trondhjemite: definition, environment, and hypotheses of origin, in F. lithologically diverse lower contact inferred to be the Lake Creek unclear. Permian age based on zircon U-Pb dating in the John Day Mountain CENOZOIC KPvr Van Ridge gneiss (Cretaceous to Permian)—Dark-gray to black, melanocratic quadrangle (K. Lund, personal communication in Lewis et al., 2011b). Barker, ed., Trondhjemites, , and Related Rocks: Elsevier, New York, p. 1-12. u n c o n f o r m i t y thrust (Bruce, 1998). The unit may be a structurally exhumed and Blake, D.E., 1991, Geology of the western Idaho suture zone in the Salmon River gorge, west- to mesocratic (CI > 50), fine- to medium-crystalline hornblende biotite Columbia River Basalt Group higher-grade schist equivalent to the Squaw Creek Schist after thrust central Idaho: Pullman, Washington State University, Ph. D. dissertation, 330 p. tonalite orthogneiss. Crystal size increases from west to east. Crystal size and displacement on the Lake Creek thrust fault. Pam Amphibolite and hornblende gneiss (Permian)—Medium- to dark-green to Undivided black mesocratic, fine- to medium-crystalline amphibolite. Hornblende, Blake, D.E., K.D. Gray, S. Giorgis, and B. Tikoff, 2009, A tectonic transect through the percentage variations delineate mesoscale layering and multiple tonalite Salmon River suture zone along the Salmon River Canyon in the Riggins region of west- Tcbu Miocene chlorite and localized garnet vary with plagioclase content to produce more and injections. High-strain zones reduce relict plutonic and Pdmc Dogtown Mountain igneous complex (Permian)—Green-black to gray-green to central Idaho, in O Connor, J.E., Dorsey, R.J., and Madin, I.P., eds., Volcanoes to protomylonitic crystal sizes. Differential weathering of penetrative, white melanocratic to mesocratic, lens-shaped ultramafic-mafic meta-plutonic dioritic hornblende gneiss interlayers. Hornblendite and calc-silicate gneiss Vineyards: Geologic Field Trips through the Dynamic Landscape of the Pacific Northwest: Other Volcanic Rocks TERTIARY horizons are subparallel to a hornblende-biotite foliation. Down-dip mineral Oligocene subvertical biotite and hornblende foliation produces knife-edge canyon complex. Contains fine- to medium-crystalline, chlorite-actinolite-talc schist Geological Society of America Field Guide 15, p. 345–372. ridges. Crystalloblastic biotite, hornblende, and plagioclase and quartz in the northern and structurally lowest portion of the complex in high-strain lineation in northern portion of map area. The Salmon River intrusive suite Bruce, M.L., 1998, Geology across the western boundary of the western Idaho suture zone, stripes the mafic rocks. Exposed as a large mafic domain on the southern Tbp Ta Eocene aggregates define a down-dip mineral stretch lineation. Biotite symmetrically contact with the Squaw Creek Schist. Foliated and lineated amphibolite and Lake Creek area, Riggins, Idaho Wilmington, University of North Carolina Wilmington, wraps felsic porphyroclast trains and individual feldspar augen that primarily hornblendite define its central portion. Relatively undeformed porphyritic and contact of the Chair Point tonalite. Map-scale and mesoscale amphibolite MS thesis, 142 p. Paleocene have an orthorhombic shape fabric. Locally, porphyroclasts have monoclinic megacrystic hornblende diorite mark its structurally highest and southern blocks are enclaves in either tonalite or its orthogneiss equivalent. Correlates Getty, S., J. Selverstone, B. Wernicke, S. Jacobsen, E. Aliberti, and D.R. Lux, 1993, Sm-Nd with Cretaceous to Permian mafic schist (KPmsc) and mafic schist and gneiss u n c o n f o r m i t y shape fabric and inconsistent strike-parallel and dip-parallel asymmetries. portion adjacent to a sharp contact with West Fork schist. Cm-scale xenoliths dating of multiple garnet growth events in an arc-continent collision zone, northwestern Epidote may have allanite cores. Hornblendite and hornblende-diopside gneiss of hornblendite and medium-crystalline diorite occur locally in coarser diorite. (KPmsg) of Lewis and others (2011a,b) to the north. U.S. Cordillera: Contributions to Mineralogy and Petrology, v. 115, p. 45-57. Giorgis, S., B. Tikoff, P. Kelso, and M. Markley, 2006, The role of material anisotropy in the Cat Creek Rapid River Lake Creek Pollock Mountain Chair Point Igneous Meta-Plutonic North American interlayers, selvages, and elongate pods may represent metamorphosed The complex may be a peridotite-pyroxenite and gabbro-diorite plutonic block Pgda Thrust Plate Thrust Plate Thrust Plate Thrust Plate Complex and Plutonic Rocks Rocks ultramafic plutonic cumulate or mafic enclaves. Local domains of coarse within the West Fork schist. It may also correlate with Permian-aged plutonic Gabbro-hornblendite, diorite, and amphibolite (Permian)—Dark-green to neotectonic extension of the western Idaho shear zone, McCall, Idaho: Geological Society of America Bulletin, v. 118, p. 259–273. porphyroblastic garnet biotite hornblende schist share lithologic affinities with rocks to the north in the Chair Point igneous complex described below. Both black, melanocratic to mesocratic (CI > 50), medium- to coarse-crystalline, Giorgis, S., W. McClelland, A. Fayon, B. Singer, and B. Tikoff, 2008, Timing of deformation mafic metavolcanic or metasedimentary rocks in the Pollock Mountain and complexes are exposed at similar elevations on opposing sides of the Salmon massive and highly foliated ultramafic, mafic and intermediate rocks. Relict Rapid River plates to the west. The Salmon River intrusive suite produces a mineral assemblages and phaneritic textures mark plutonic rocks. Massive and exhumation in the western Idaho shear zone, McCall, Idaho: Geological Society of Ksc Kpc Kbl Klg Kcp CRETACEOUS River Canyon. The lower, deformed contact of this unit marks the intersection America Bulletin, v. 120, p. 1119–1133 complexly intruded, striped, and lit-par-lit appearance in exposures of this coarse crystalline garnet-hornblende-plagioclase diorite is common. Some of the Lake Creek and Pollock Mountain thrust faults (Bruce, 1998). Hamilton, W.B., 1963, Metamorphism in the Riggins region, western Idaho: U.S. Geological unit. It is mapped northward into eastern portions of the Cretaceous hornblende prisms exceed 5 cm. Grain-size reduction convert rocks into amphibolite, garnet amphibolite, and hornblende gneiss in shear zones. Fiddle Survey Professional Paper 436, 95 p. hornblende-biotite tonalite (Khto) of Lewis and others (2011b). Major and Gray, K.D., and J.S. Oldow, 2005, Contrasting structural histories of the Salmon River belt Creek Schist along the western contact of this unit contains relict selected trace element petrogenetic plots (Blake, 1991) suggest the pluton Pollock Mountain Thrust Plate and Wallowa terrane: Implications for terrane accretion in northeastern Oregon and west- JURASSIC MESOZOIC correlates with tonalite orthogneiss in the eastern Hazard Creek complex or conglomerate horizons, especially west of Deep and Squaw Saddles. central Idaho: Geological Society of America Bulletin, v. 117, p. 687–706. western tonalite orthogneiss of the Little Goose Creek complex near McCall KPkr Keating Ridge gneiss (Cretaceous to Permian)—Variably colored, mesocratic, Gray, K.D., Watkinson, A.J., Gaschnig, R. M., and Isakson, V.H., 2012, Age and structure of KPkr KPt KPvr (Manduca, 1988; Manduca and others, 1993). medium- to coarse-crystalline biotite-hornblende gneiss and schist. the Crevice pluton: overlapping orogens in west-central Idaho? Canadian Journal of Earth Heterogeneously interlayered with garnet-bearing biotite-hornblende gneiss, LAURENTIAN CONTINENTAL ROCKS Sciences, V. 49, no. 6, p. 709-731. Hamilton, W.B., 1963, Metamorphism in the Riggins region, western Idaho: U.S. Geological JPsc JPbc JPlc JPfc JPef JPwf JPcs JPpm TRIASSIC felsic ± epidote-hornblende orthogneiss, calc-silicate gneiss, amphibolite, and Metasedimentary and Meta-Igneous Rocks local biotite ± kyanite gneiss and schist east of more lithologically uniform Rocks of North American continental affinity underlie the eastern portion of Survey Professional Paper 436, 95 p. of the Cat Creek and Rapid River Thrust Plates Pollock Mountain Amphibolite. Homogeneous biotite-hornblende tonalite the map area. Dominant biotite schist and subordinate quartzite, marble and Hamilton, W.B., 1969, Reconnaissance geologic map of the Riggins quadrangle, west-central orthogneiss is common. Dikes and sills of dioritic, tonalitic, trondhjemitic, and calc-silicate gneiss are equivalent in geographic position and metamorphic Idaho: U.S. Geological Survey Map I-579, scale 1:125,000. In the western portion of the map area, an eastward increase in metamorphic granodioritic orthogneiss of the Salmon River intrusive suite adds to its mineral assemblages to the Proterozoic eastern metasedimentary terrane of Hoover, A.L., 1986, Transect across the Salmon River Suture, South Fork of the Clearwater, River, western Idaho-rare earth element, geochemical, structural, and metamorphic study: Pcc Pdm Pf Pgda Pam PERMIAN PALEOZOIC grade from the lower amphibolite facies (chlorite-biotite-garnet-hornblende layered character. Mesoscale intrusions, and mafic and calc-silicate layers Lund (1984), eastern terrane of Hoover (1986), and metasedimentary zone) to the middle amphibolite facies (biotite-kyanite-garnet zone) overprints supracrustal rocks of Manduca (1988) and Manduca and others (1993). Corvallis, Oregon State University, MS thesis: 138 p. define complex, local isoclinal and intrafolial isoclinal folds whose attenuated Le Maitre, R.W., ed., 2002, Igneous Rocks: A Classification and Glossary of Terms: hanging wall rocks of the Cat Creek and Rapid River plates. These thrust limbs and hinges show down-dip stretch into boudins and pinch-and-swell Recommendations of the International Union of Geological Sciences (IUGS) plates are included in the eastern portion of the eastern Salmon River thrust texture. Folds are common between intruded orthogneiss bodies indicating a Zmkm Ma rble of Kelly Mountain (Proterozoic)—Gray-white to green, fine- to medium-crystalline, generally pure marble. Granoblastic layers are typically Subcommission on the Systematics of Igneous Rocks: Cambridge, Cambridge University Zmkm belt of Gray and Oldow (2005). All mapped units are potentially Jurassic to progressive, multi-injection deformation history. Allanite-cored epidote Press, 252 p. nonfoliated, although distinct partings develop in some outcrops. Calc-silicate PROTEROZOIC PRECAMBRIAN Permian in age based upon along-strike correlations with Lewis and others porphyroclasts are common. Transitional unit of mixed supracrustal-plutonic Lewis, R.S., K.L. Schmidt, K.L. Othberg, D.E. Stewart, and J.D. Kauffman, 2011a, Geologic (2011a, 2011b), but they are poorly dated and their stratigraphic facing affinity within the eastern portion of the Pollock Mountain plate highlighted gneiss contains granoblastic calcite, tremolite, diopside, garnet, and scapolite. map of the Lucile quadrangle, Idaho County, Idaho: Idaho Geological Survey Digital Web Zskm directions are not known. The Pollock Mountain thrust fault truncates the two by 1) a mafic, felsic, pelitic, and minor calcareous multi-lithologic, highly Calc-silicate xenoliths in the Looking Glass tonalite contain calcite, grossular Map 126, scale 1:24,000. plates at their eastern extent along the western boundary of the western Idaho layered and strained character; 2) intrusive relationships preserved locally garnet, diopside, and sphene. A large marble layer outlines the southeastern Lewis, R.S., K.L. Schmidt, D.E. Stewart, K.L. Othberg, J.D. Kauffman, and E.D. Stewart, , shear zone (Blake and others, 2009). This Cretaceous transpressional fault along the western contact with the Pollock Mountain Amphibolite; and 3) tonalite contact. This layer and garnet sillimanite-biotite schist are complexly 2011b, Geologic map of the John Day Mountain quadrangle, Idaho County, Idaho: Idaho overprints the Salmon River suture zone, the western boundary of cratonic medium−to−coarse epidote porphyroclasts locally preserved in intermediate folded adjacent to this contact. Van Ridge gneiss, calc-silicate gneiss, and Geological Survey Digital Web Map 128, scale 1:24,000. North America, and the eastern boundary of Blue Mountains province island- orthogneiss and phyllonitic schist having relict plutonic textures. Multiple biotite ± garnet ± sillimanite schist of Kelly Mountain are also complexly Lund, K., 1984, Tectonic history of a continent-island arc boundary-west-central Idaho: arc terranes. From structurally highest to lowest, the map units are listed magmatic injections were a controlling factor in unit construction. layered along their mutual contacts and transposed into the steep foliation. University Park, Pennsylvania State University, Ph. D. dissertation, 207 p. Lund, K., 2004, Geology of the Payette National Forest and vicinity, west-central Idaho: U.S. below based upon their positions within the thrust plates. Most lithologies Amphibolite, schist, and calc-silicate gneiss reflect the country rock to the INTRODUCTION MASS MOVEMENT DEPOSITS correlate along strike to the west with rocks of the Riggins Group (Hamilton, orthogneiss. Biotite schist and chlorite schist contain fabric relationships that Zskm Schist of Kelly Mountain (Proterozoic)—Grayish-white to brownish-black to Geological Survey Professional Paper 1666, 89p. 1969; Onasch, 1977, 1987), including massive to strongly foliated meta- indicate the unit has, in part, a ductile-brittle fault origin. Chlorite selectively violet, fine- to medium-crystalline, garnet ± fibrolitic sillimanite-biotite schist. Lund, K., W.F. McCollough, and E.H. Price, 1993, Geologic map of the Slate Creek-John Day Qls Landslide deposits (Holocene and Pleistocene)—Poorly sorted and poorly ultramafic rocks, greenstone, garnet-zoisite amphibolite, and hornblende recrystallizes in mafic layers as a retrograde metamorphic overprint, Forms macroscale interlayer between Van Ridge and Partridge Creek area, Idaho County, Idaho: U.S. Geological Survey Miscellaneous Investigations Series Map I-2299, scale 1:50,000. The geologic map and cross sections of the Riggins Hot Springs quadrangle stratified angular to subrounded pebbles, cobbles and boulders mixed with silt biotite diorite gneiss, mafic, felsic, and pelitic schist, and quartzite and especially across from Riggins Hot Springs on the Big Salmon River Road. gneisses, and country rock for the Looking Glass tonalite and Crevice pluton. Lund, K., M.A. Kuntz, C.A. Manduca, C.H. Gammons, K.V. Evans, R.G. Tysdal, G.R. and surrounding areas on Plate 1 depict rock units exposed at the surface or and clay. Locally deposited by slumps, slides, and debris flows. Landslides metaconglomerate. The Cat Creek thrust plate contains the Squaw Creek Presence of fibrolitic sillimanite, finer phyllosilicate sizes, and violet color Chlorite-rich fault zone rocks correspond with the regional-scale, Allison Winkler, and J.J. Connor, 1997, Geologic map of the western Salmon River Mountains, underlying thin surficial cover of soil, saprolite, or colluvium. Surficial range in age from ancient movements that are relatively stable features to Schist (JPsc) and a layered block of meta-ultramafic rocks at Cat Creek (Pcc). caused by sillimanite and vitreous biotite schistosity distinguish these rocks Creek normal fault that is traced along Allison Creek and Warm Springs Valley and Idaho Counties, west-central Idaho: U.S. Geological Survey Miscellaneous those that are more recent and potentially less stable. Three large slide areas from coarser schists of the Riggins Group. Contains only subordinate white alluvial and landslide deposits are shown where they mask or modify This block appears to correlate along strike with meta-ultramafic rocks at Creek to Goose Lake and the USFS Last Chance Campground near McCall Investigations Series Map I-2599, scale 1:100,000. lie north of Ruby Rapids and both north and south of Partridge Creek Bridge. underlying rocks as mappable units. The map is the result of field work Time Zone Bridge on the Salmon River just north of Riggins, Idaho (Hamilton, 1969; Manduca, 1988; Giorgis and others, 2006). It links with the mica and chlorite. Fibrolite size increases adjacent to Cretaceous plutons. Manduca, C.A., 1988, Geology and of the oceanic arc-continent boundary in the undertaken between 1995 and 2006 as a continuation of an investigation (Hamilton, 1969). Structurally below this Cat Creek plate, the Berg Mountain Dairy Mountain fault of Lewis and others (2011b). Location of Riggins Hot Biotite and fibrolite porphyroblasts define a schistosity and down-dip western Idaho batholith near McCall: Pasadena, California Institute of Technology, Ph.D. begun in the Riggins Hot Springs, Kelly Mountain, and John Day Mountain Amphibolite (JPbc), Lightning Creek and Fiddle Creek Schists (JPlc; JPfc), Springs appears fault controlled. Unit includes mafic and intermediate rocks lineation crosscut by shear bands. Schistosity symmetrically wraps VOLCANIC AND SUBVOLCANIC ROCKS dissertation, 272 p. Quadrangles by Blake (1991). It includes the work of Bruce (1998) and Reed and mafic rocks of East Fork (JPef) are units within the Rapid River plate. of the Warms Springs Point gneiss (Bruce, 1998). Unit extends north into xenoblastic to subidioblastic garnet porphyroblasts. Mesoscale felsic Manduca, C.A., M.A. Kuntz, and L.T. Silver, 1993, Emplacement and deformation history of and Blake (2006) that spans the northern boundary of the Patrick Butte western portions of the Cretaceous tonalite (Khto) of Lewis and others leucosomes, veins, and dikelets are prolific, producing a migmatitic aspect. the western margin of the Idaho batholith near McCall, Idaho; influence of a major terrane Quadrangle, and builds upon the regional mapping and lithologic descriptions Columbia River Basalt Group (2011b). Its tonalite appears to be geochemically similar to epidote- and Salmon River intrusive suite gives the unit a multiply injected appearance. boundary: Geological Society of America Bulletin, v. 105, p. 749-765. of Hamilton (1963, 1969), Onasch (1977, 1987), Lund (1984, 2004), and Cat Creek Thrust Plate garnet-bearing plutons of the Hazard Creek complex (Manduca, 1988; Blake, Felsic layers deformed into complex fold patterns and porphyroclast Onasch, C.M., 1977, Structural evolution of the western margin of the Idaho batholith in the Tcbu Columbia River Basalt undivided (Miocene)—Black to brownish-black, Lund and others (1993, 1997). Only the structural attitudes of fabric elements 1991; Manduca and others, 1993). relationships. Thin, discontinuous biotite-bearing quartzite is interlayered Riggins, Idaho area: University Park, Pennsylvania State University, Ph.D. dissertation, mesocratic aphyric and more commonly plagioclase ± olivine phyric basalt. and structures from the mapping of Blake (1991), Bruce (1998), and Reed JPsc Squaw Creek Schist (Jurassic to Permian)—Invariably medium blue gray, fine- with and gradational into biotite schist. 296 p. Plagioclase phenocrysts generally 0.5-2 cm, but some are as large as 3 cm. (unpublished results) are included on the four-quadrangle compilation. This to medium-crystalline pelitic biotite schist. Biotite porphyroblasts form JPcs Calc-silicate gneiss (Jurassic to Permian)—Pale-green to white, fine- to Onasch, C.M., 1987, Temporal and spatial relations between folding, intrusion, Local dikes and sills weather to a sooty brown to reddish brown granular work augments the mapping of Lewis and others (2011a, 2011b) in the Lucile clusters of conspicuous black spots on the foliation surface. Rare actinolite, medium-crystalline and granoblastic calc-silicate diopside-calcite-actinolite- metamorphism, and thrust folding in the Riggins area, west-central Idaho, in Vallier, T.L., detritus or rounded to angular rubble fields. Tend to be poorly exposed except and John Day Mountain Quadrangles northwest and north of the map area, zoisite, and retrograde chlorite plates form locally. Crude laminations of plagioclase-sphene gneiss. Contains minor garnet, scapolite, zoisite or STRUCTURE and Brooks, H.C., eds., Geology of the Blue Mountains region of Oregon, Idaho, and in roadside cuts. Abundant in eastern-facing slopes of the informally named respectively. Plate 2 provides descriptions of lithologies and structures quartz-calcite and obscure mm- to cm-scale layering are suggestive of relict epidote, biotite or chlorite, and quartz. Local layers are tens of meters long Washington; the Idaho Batholith and its border zone: U.S. Geological Survey Professional Carlson Ridge along Partridge Creek where intermediate gneiss is laced with Paper 1436, p. 139-150. encountered and major and trace element analyses of units in Table 1. bedding. Biotite schistosity is oriented subparallel to layers except in local and vary in thickness from mm to tens of meters. Deformed into pinch-and- variably sized bodies (See Symbols). Steep slope outcrops on mountain peaks Reed, D.N., and D.E. Blake, 2006, Testing the role of ductile extension along the western fold hinges. Biotite down-dip lineation is common. Highly weathered and swell texture and boudins extended down dip. Protolith inferred to be Map area deformation is complex and long lived. Structures lie within the preserve entablatures and colonnades. Form tiered cliffs, especially north of Idaho shear zone in the Salmon River suture zone east of Riggins, Idaho: Geological The map area lies within the Salmon River suture zone, a lithospheric friable surfaces characterize many exposures. sedimentary carbonate horizons within the Pollock Mountain Amphibolite. Salmon River suture zone, a poly-deformed oceanic−cratonic plate boundary. Chair Point, along Van Ridge east of Nut Basin, and on the southern reaches Society of America Abstracts with Programs, v. 38, no. 3, p. 75. boundary that juxtaposes Blue Mountain province island-arc and back-arc It 1) separates Paleozoic-Mesozoic Blue Mountains province island-arc Selverstone, J., B.P. Wernicke, and E.A. Aliberti, 1992, Intracontinental subduction and of Carlson Ridge. JPpm basin(?) rocks against North American cratonic units (Blake and others, Pcc M eta-ultramafic rocks of Cat Creek (Permian)—Pale greenish white Pollock Mountain Amphibolite (Jurassic to Permian)—Dark-green to black to terranes to the west and western North American Proterozoic cratonic rocks to hinged unroofing along the Salmon River suture zone, west-central Idaho: Tectonics, v. 11, 2009). To the west, crystalline rocks define lower to middle amphibolite holomelanocratic fine- to medium-crystalline, southeast-dipping layered dark blue gray, melanocratic to mesocratic, medium-crystalline, well-foliated the east, and 2) records the progressive evolution of an oblique, late Mesozoic p. 124-144. facies sedimentary, volcanic and plutonic units in the: (1) Jurassic to Permian Subvolcanic Rocks sequence of talc schist, actinolite-chlorite ± plagioclase rock, talc-actinolite and lineated garnet ± diopside-biotite amphibolite. Discontinuous interlayers arc-continent transpressional collision margin. The Salmon River suture zone Riggins Group in the Cat Creek and Rapid River plates, and (2) Permian to Tbp Biotite porphyry of Riggins Hot Springs (Eocene)—Black to brownish-black serpentinite, and talc schist. Southwest-dipping composite, mica-fish of garnet-biotite schist, biotite-poor quartzitic gneiss, garnet- and biotite-poor is partitioned into a 1) western amphibolite facies, moderate-to-steeply Cretaceous-age Lake Creek and Pollock Mountain plates. The Pollock schistosity (buttons) is well developed in lower talc schist layer at Berg Creek felsic gneiss, and amphibole-bearing biotite gneiss are tens of mm to meters in east-dipping and west-vergent Cretaceous to Jurassic fold-thrust belt marked melanocratic biotite phyric basaltic andesite or alkaline subvolcanic rock. Mountain thrust fault separates the Cat Creek and Rapid River plates from the Subidiomorphic biotite phenocrysts up to 5 mm in width. Crops out as a Amphibolite contact. Sharp contact with overlying Squaw Creek Schist may thickness. Dikes and sills of the Salmon River intrusive suite produce a by the Cat Creek, Rapid River, Lake Creek, and Pollock Mountain thrust Lake Creek and Pollock Mountain plates. Single-stage garnet identifies the mesoscale dike and its sill apophyses on the Big Salmon River Road (County be correlative with other meta-ultramafic block-in-matrix bodies common in striped, migmatitic appearance. Red orange, 1–5 mm idioblastic to xenoblastic plates; and 2) eastern amphibolite facies, steeply east-dipping and Rapid River thrust plate; two-stage garnet occurs in the Pollock Mountain Road 1614) across from the Riggins Hot Springs Bridge in intermediate this lithodeme (Hamilton, 1969; Onasch, 1977), including the meta-ultramafic two-stage garnet porphyroblasts readily distinguishes the unit from Berg magmatically dominated domain that is the Cretaceous western Idaho shear thrust plate (Aliberti, 1988; Selverstone and others, 1992; Getty and others, gneiss. Eocene age based upon 40Ar/39Ar date of 46.8 Ma (Basil Tikoff, body and Berg Creek Amphibolite contact along strike on the northeast side of Creek Amphibolite and its dark red garnet dodecahedra to the west, and zone (WISZ). Western thrust plates and the WISZ share 1) macroscale-to- 1993; Blake and others, 2009; Gray and others, 2012). Middle to upper personal communication, 2010). Time Zone Bridge on U.S. 95 north of Riggins. coarser epidote-hornblende-biotite tonalite orthogneiss of the Keating Ridge mesoscale southeast-plunging folds, and east-southeast-dipping and tops-to- amphibolite facies, Cretaceous to Proterozoic-age sedimentary and plutonic gneiss to the east. Inclusion-trail-rich core garnet and poikloblastic exterior the-west thrusts; and 2) northeast-striking and southeast-trending, planar and units of North American and Idaho batholith affinity underlie its eastern Ta Andesite (Oligocene to Paleocene)—Medium-gray, mesocratic aphyric andesite. rim garnet preserves two distinct growth periods (Selverstone and others, linear fabric elements. Cenozoic north-striking, tops-down-east ductile-brittle portion (Lund, 2004; Gray and Oldow, 2005; Blake and others, 2009; Gray Jointed, flaggy shaped cobble outcrops of dikes along the Van Ridge and Lava Rapid River Thrust Plate 1992; Getty and others, 1993). Layers of zoisite- or chlorite-bearing actinolite normal faults overprint most units and the Columbia River Basalt Group. and others, 2012). Cretaceous to Permian calc-alkaline metaplutonic and Ridge pack trails. May correlate with regional Eocene andesite magmatism. plutonic units intrude into and separate arc- from continental-affinity units in JPbc Berg Creek Amphibolite (Jurassic to Permian)—Dark-black green or gray the central portion of the map area. The Cretaceous western Idaho shear zone green, melanocratic to mesocratic, fine- to medium-crystalline porphyroblastic Table 1. Major element oxide and select trace element analyses of samples collected in the Salmon River Canyon-Allison Creek area, Riggins Hot Springs and Kelly Mountain quadrangles, Idaho County, Idaho. Sills overprints these metaplutonic rocks, as well as the Blue Mountains province PRE-TERTIARY ROCKS garnet-zoisite hornblende amphibolite. Contains thin, discontinuous cm- to and dikes of the Salmon River intrusive suite, and K-feldspar granitoids in the schist of Kelly Mountain and Partridge Creek gneiss are too small to be shown as indivdiual units on the map and cross sections. and continental margin rocks. Columbia River Basalt Group units, likely mm-scale layers of plagioclase-quartz-hornblende ± calcite amphibolite, Imnaha Basalt and small areas of overlying Grande Ronde Basalt based upon medium- to coarse-crystalline hornblendite, and coarse-crystalline Major elements in weight percent Trace elements in parts per million Rocks older than the Columbia River Basalt are exposed over much of the Sample Map regional correlation with the Lucile and John Day Mountain Quadrangles hornblende-zoisite rock. Biotite granitoid sills and dikes of the Salmon River Ni Cr Sc V Ba Rb Sr Zr Y Nb Ga Cu Zn Pb La Ce Th map area. The Jurassic to Permian amphibolite facies Cat Creek, Rapid River, Unit Name Si02 Al 203 Ti02 FeO * MnO CaO MgO K20 Na20 P205 (Lewis and others, 2011a,b), cap the folded and faulted basement rocks. Lava intrusive suite give the unit a conspicuous striped appearance. White zoisite Number Unit Lake Creek, and Pollock Mountain thrust plates are exposed in its western flows are faulted and tilted by normal fault reactivation of older basement prisms, isolated or concentrated in discontinuous layers tens of mm in length DEB 473 Chair Point pluton KPt 77.44 12.14 0.30 1.96 0.06 2.01 0.60 1.01 4.42 0.06 8 0 7 11 232 18 109 106 25 5 10 8 17 0 4 2 1 portion west of the Spring Creek tonalite. Proterozoic amphibolite facies structures. In addition to modern alluvium, older Salmon River deposits form and several mm thick, and deep red subidioblastic to idioblastic garnet DEB 497A Chair Point pluton rocks underlie the eastern portion of the map area east of the Van Ridge KPt 75.16 13.20 0.34 2.26 0.06 2.68 0.69 1.01 4.53 0.07 6 1 15 31 283 18 179 120 26 4.7 12 7 28 3 7 25 2 terrace remnants. Pleistocene and recent alluvial deposits, both stream porphyroblasts up to 4 mm in diameter are diagnostic. Zoisite and pargasitic gneiss. The thrust plates are parts of the Mesozoic−Permian Blue Mountains DEB 1136B Chair Point pluton KPt 76.16 13.24 0.23 1.45 0.05 2.13 0.33 2.03 4.34 0.04 6 2 4 8 553 26 173 113 16 4.5 13 3 15 3 1 29 3 sediments and fan deposits, are related to the Salmon River and its tributaries. hornblende may be randomly oriented or define a down-dip stretch lineation province to the west. The Proterozoic metasedimentary rocks are a part of the DEB 1483 Chair Point pluton The map also shows three landslide deposits in lower levels of the canyon. that increases in plunge eastward. Garnet contains random plagioclase-quartz KPt 75.73 12.77 0.40 2.49 0.06 2.04 0.70 1.01 4.73 0.08 6 1 15 32 249 20 149 153 37 7.4 13 8 34 2 20 45 2 western North American margin to the east. Multiple units of metaplutonic inclusions that suggest a single-stage porphyroblast growth. Boudinaged DEB 1493 Chair Point pluton KPt 75.35 13.20 0.43 2.28 0.03 2.21 0.57 0.76 5.09 0.08 9 2 10 23 255 16 134 157 42 8 13 12 17 3 21 40 2 and plutonic rocks of probable Cretaceous age, including the Spring Creek layers of zoisite-plagioclase-garnet are symmetrically wrapped by zoisite and DEB 1640 Keating Ridge gneiss and Van Ridge units, intrude into and separate these arc- and continent- KPkr 62.81 19.60 0.59 3.64 0.06 5.66 0.97 0.96 5.45 0.26 4 0 13 44 537 17 1098 199 13 8.1 18 19 53 4 37 72 1 hornblende and show down-dip stretch. Discontinuous layers of ribboned DESCRIPTION OF MAP UNITS affinity rocks. Much of the high strain superposed on the mapped units is DEB 1722B Keating Ridge gneiss KPkr 66.07 15.35 0.36 5.55 0.12 6.00 2.14 0.68 3.69 0.06 6 8 24 154 182 9 206 62 27 4.2 12 12 66 4 12 20 2 quartzite, marble, felsic gneiss, and meta-ultramafic rocks in the Squaw Creek attributed to the Cretaceous western Idaho shear zone within the Salmon River DEB 1187C Spring Creek tonalite Schist mark the upper contact of the amphibolite at the Cat Creek thrust fault KPsc 62.20 17.67 0.65 5.43 0.11 5.04 2.38 2.13 4.14 0.25 12 10 21 94 816 54 640 118 14 15.9 18 27 80 6 21 59 5 suture zone. Some metagranitoids may be related to the western border of the (Bruce, 1998). Marble interlayers (Onasch, 1977) and rhythmic mm- to cm- DEB 1734 Spring Creek tonalite KPsc 62.22 18.54 0.50 4.43 0.09 6.06 2.04 1. 41 4.49 0.21 10 5 12 126 631 31 788 97 12 7.7 17 45 61 5 0 17 1 The classification of metavolcanic, metaplutonic and plutonic rocks on Plate 2 Tertiary−Cretaceous Idaho batholith (Manduca and others, 1993). uses normalized values on a modal quartz (Q), alkali feldspar (A), and scale layering (Bruce, 1998) suggests local sedimentary protoliths. Unit is in DEB 857 Looking Glass tonalite Klgt 58.64 18.50 0.80 5.88 0.12 6.92 3.46 1.72 3.75 0.22 3 24 21 114 693 51 673 137 18 13.3 19 4 88 8 6 39 2 part correlative with metamorphosed basaltic to basaltic andesite or fine- plagioclase (P) diagram. Rock names follow the nomenclature of the Plutonic Rocks DEB 1205C Looking Glass tonalite Klgt 62.67 18.29 0.76 4.59 0.08 5.11 2.22 2.04 4.01 0.23 6 8 8 100 989 71 694 211 10 14.6 24 4 84 9 31 38 3 International Union of Geological Sciences (IUGS) Subcommission on the grained tuff of Hamilton (1963) in the Riggins Group. DEB 1322 Looking Glass tonalite Klgt 68.68 16.30 0.62 3.11 0.05 4.12 1.83 1. 72 3.48 0.11 7 8 5 71 771 63 587 132 3 11.3 14 4 53 10 23 0 4 Systematics of Igneous Rocks (Le Maitre, 2002). Relict igneous textures, Not shown Salmon River intrusive suite (Late Cretaceous)—Biotite ± hornblende on map JPlc Lightning Creek Schist (Jurassic to Permian)—Dark gray, mesocratic, fine- to DEB 1341 Looking Glass tonalite Klgt 66.19 17.74 0.58 3.22 0.06 4.53 1.27 1.53 4.68 0.21 6 3 1 47 765 47 900 215 12 16.4 21 5 74 7 46 66 5 modal mineral assemblages, or normalized mineral assemblages, when whole- granitoid orthogneiss, granitoid, and pegmatitic sills and dikes. While medium-crystalline and lithologically heterogeneous garnet-biotite schist and DEB 1346 Looking Glass tonalite rock geochemical data are available, guide the naming of individual map units mesoscale intrusions are too numerous and small scale to depict on the map or Klgt 65.42 18.21 0.67 3.14 0.05 4.95 1.15 1.51 4.69 0.21 4 0 10 44 713 47 975 230 14 15.3 22 5 73 10 32 90 6 gneiss. At Lake Creek Bridge, basal portion contains relict clasts of where dynamic recrystallization overprints most lithologies. A preliminary cross sections, they are a significant and ubiquitous plutonic component of all DEB 1347 Looking Glass tonalite Klgt 70.57 15.86 0.38 2.06 0.04 2.91 0.67 3.60 3.79 0.13 6 0 4 32 1356 81 683 173 7 10.6 18 7 49 13 28 46 8 amphibolite, biotite gneiss, and garnet felsic gneiss in a biotite schist matrix. lithodemic designation is developed here following Articles 31-42 of the map units. The intrusions (CI = 5-15) are subdivided into (1) K-feldspar-poor DEB 1353 Looking Glass tonalite The lithic clasts range from tens of cm to mm in length. Above this basal Klgt 65.07 18.13 0.65 3.24 0.06 4.87 1.27 1. 95 4.56 0.21 6 0 9 44 1029 51 912 219 13 18.6 21 5 77 12 39 83 4 North American Stratigraphic Code. Metaplutonic units, as well as trondhjemite, diorite to tonalite, and granodiorite and their orthogneiss polymictic metaconglomerate, discontinuous layers of medium- to coarse- DEB 1356B Looking Glass tonalite Klgt 66.22 17.84 0.55 3.11 0.06 4.30 1.14 2.31 4.27 0.21 6 0 6 49 1272 57 846 203 12 13.6 21 4 74 11 41 61 6 metavolcanic and metasedimentary units that lack geochronologic data and equivalents; and 2) K-feldspar-rich granite and its orthogneiss equivalent. Sills crystalline garnet-chlorite-biotite schist, porphyroblastic biotite-white mica DEB 1363 Looking Glass tonalite stratigraphic facing directions warrant this designation. The normative and dikes commonly preserve a penetrative foliation, down-dip mineral Klgt 64.68 17 .21 0.59 4.25 0.08 5.02 2.09 2.29 3.61 0.19 5 6 14 79 824 71 595 158 15 13.3 18 4 73 12 14 40 7 schist, epidote-hornblende gneiss, biotite quartzite, and coarse-crystalline, feldspar classification scheme (Barker, 1979) provides the basis to distinguish stretch lineation, and dynamic recrystallization microstructures. Many are DEB 1364 Looking Glass tonalite Klgt 65.57 17.79 0.62 3.36 0.05 4.62 1.29 2.07 4.42 0.21 4 0 13 47 1385 50 947 210 7 6.1 21 5 76 8 78 83 8 porphyroblastic chlorite ± white mica ± staurolite ± kyanite ± garnet-biotite tonalite from trondhjemite. Miocene Columbia River Basalt Group contains also undeformed. Sills may be symmetrically and locally asymmetrically DEB 885B Crevice granite pluton schist are common. Textural relationships among garnet porphyroblasts Kcg 72.47 15.82 0.16 1.10 0.04 2.18 0.23 3.34 4.62 0.04 7 0 0 1 1276 92 526 108 12 15.9 21 3 45 16 26 26 10 basalt, basaltic andesite, and andesite, but the term basalt is applied here as it boudinaged down dip. Large, relict plagioclase and K-feldspar megacrysts suggest single-stage metamorphic growth, analogous to garnet porphyroblasts DEB 1243 Crevice granite pluton Kcg 72.34 15.52 0.21 1.40 0.07 2.14 0.36 3.81 4.07 0.08 8 0 4 6 1030 121 473 125 15 19.3 19 5 40 24 13 24 4 has been historically. In these descriptions and discussions, we use the metric form isolated or trains of symmetrical to local asymmetrical winged in the Berg Creek Amphibolite (Selverstone and others, 1992). Kyanite, DEB 471A Salmon River Intrusive Suite: K-feldspar-poor granitoid system to describe sizes of minerals or lithic clasts in map units, structures, porphyroclasts. Dikes are often ptygmatically folded. Locally, reverse or KPt 71. 65 17.07 0.12 0.77 0.03 2.97 0.17 0.90 6.28 0.04 6 2 2 0 208 13 645 96 8 2.7 16 8 23 4 0 0 1 biotite, and felsic aggregates form a penetrative schistosity and down-dip and fabric elements relationships. However, we use the English system for normal sense of fault slip overprints the mesoscale intrusions. Correlation of DEB 497C Salmon River Intrusive Suite: K-feldspar-poor granitoid KPt 72.16 16.46 0.15 0.94 0.03 2.91 0.24 0.71 6.35 0.05 8 0 6 13 350 11 618 109 4 2 14 10 30 5 1 26 0 lineation. Retrograde chlorite forms topotaxial to pseudomorphic overgrowths thicknesss and distances because that system is used on the base map. the Salmon River intrusive suite to specific plutons is complex due to their DEB 760C Salmon River Intrusive Suite: K-feldspar-poor granitoid on biotite, garnet, and staurolite. Increase in porphyroblast sizes from west to KPvr 69.14 17.85 0.26 1.49 0.04 3.57 0.34 1.29 5.95 0.08 7 0 4 17 701 22 1159 167 4 3.6 15 17 51 6 22 39 2 small scale and wide range in bulk compositions. Major and select trace east along the unit. Garnet and kyanite and less commonly staurolite have DEB 872 Salmon River Intrusive Suite: K-feldspar-poor granitoid KPvr 69.00 15.99 0.42 3.14 0.08 3.99 1.33 1.55 4.41 0.09 12 9 12 59 584 31 446 104 11 4.4 15 10 52 6 9 16 4 element petrogenetic plots suggest a similarity among K-feldspar-poor sills diameters and lengths from 1 to 20 mm; local garnet porphyroblasts are 40 DEB 879A Salmon River Intrusive Suite: K-feldspar-poor granitoid SEDIMENTARY AND and dikes and arc-affinity plutons both locally and to the south near McCall; KPvr 65.68 18.65 0.41 2.69 0.07 5.74 0.63 0.89 5.11 0.13 6 0 12 30 385 13 897 160 12 7.8 18 26 61 7 19 43 1 mm across in the eastern portion of the unit above Allison Creek and the K-feldspar-rich intrusions may relate to granitoid units having Idaho batholith DEB 1070I Salmon River Intrusive Suite: K-feldspar-poor granitoid KPvr 68.96 17.77 0.24 1.71 0.05 3.92 0.29 1. 72 5.25 0.08 7 0 7 16 1141 30 843 159 7 11.4 17 8 50 10 0 27 3 MASS MOVEMENT DEPOSITS Carlson Ranch. Discontinuous polymictic metaconglomerate layers occur on affinities (Blake, 1991). The Salmon River intrusive suite may reflect DEB 1114F Salmon River Intrusive Suite: K-feldspar-poor granitoid the eastern slopes of Berg Mountain within the high-strain western Idaho KPvr 72.31 16.61 0.12 0.68 0.01 3.30 0.21 1.19 5.52 0.06 8 1 2 6 460 20 934 117 2 3 14 10 18 9 9 4 0 complex feeders to regional tabular plutons. Alluvial Deposits shear zone. Clasts are difficult to distinguish there due to metamorphic DEB 1187D Salmon River Intrusive Suite: K-feldspar-poor granitoid KPsc 71.37 17.36 0.14 0.75 0.02 3.12 0.08 1.19 5.90 0.06 5 0 1 9 614 21 807 110 4 2.7 11 15 23 9 0 10 0 coarsening of the matrix and penetrative structural transposition. Where DEB 1189 Salmon River Intrusive Suite: K-feldspar-poor granitoid Klg Looking Glass tonalite (Late Cretaceous)—Dark blue-green gray mesocratic KPsc 71. 24 17.32 0.10 0.56 0.02 3.46 0.10 1. 79 5.36 0.05 6 0 3 5 1238 22 837 107 4 3.2 16 14 14 11 0 10 3 Qam Alluvium of the Salmon River (late Holocene)—Channel and flood-plain apparent, relict felsic lithic clast shapes in biotite schist matrix are commonly (CI = 30-35), medium- to coarse-crystalline tonalite or tonalitic orthogneiss DEB 1412B Salmon River Intrusive Suite: K-feldspar-poor granitoid KPkr 71.00 14.21 0.33 4.03 0.11 4.98 1.24 0.28 3.76 0.07 6 0 22 89 56 5 143 80 33 2.5 13 15 47 4 0 0 0 deposits that are part of the present river system. Two grain-size suites are oriented in the down-dip direction. Unit is correlative with Lightning Creek with hornblende, biotite, plagioclase, quartz, and sphene. Crystal size DEB 1661B Salmon River Intrusive Suite: K-feldspar-poor granitoid typically present: coarse sand in thin shoreline deposits, and well-sorted and Schist sedimentary protoliths of Hamilton (1963) due to relict conglomeratic KPkr 73.10 13.98 0.26 2.84 0.05 3.50 1.34 1.11 3.76 0.05 10 17 12 21 412 29 227 96 6 2.3 13 31 39 1 0 10 1 variations impart a relict, inequigranular, xenomorphic texture at the rounded pebble to boulder gravel in river bars and islands. Gravel clasts clasts and pelitic metamorphic mineral assemblages. DEB 1722A Salmon River Intrusive Suite: K-feldspar-poor granitoid KPkr 74.27 14.64 0.17 1. 62 0.03 2.87 0.46 0.70 5.22 0.04 7 0 9 26 293 11 201 88 4 2.8 12 10 19 2 0 l = 0 mesoscale. On its southwestern margin, alignment of biotite and hornblende, include volcanic, plutonic, and metamorphic rocks of highly variable, local DEB 1727 Salmon River Intrusive Suite: K-feldspar-poor granitoid wispy country rock layers, and elongate to blocky enclaves of KPkr 73.54 14.45 0.35 2.26 0.09 3.17 0.63 0.91 4.51 0.09 6 0 13 27 531 17 221 81 22 11.5 14 6 40 4 0 15 1 and upsteam lithologies. Age is late Holocene to present. JPfc Fiddle Creek Schist (Jurassic to Permian)—Variably gray to gray green, metasedimentary schist and calc-silicate gneiss produce a moderate foliation DEB 1498B Salmon River Intrusive Suite: K-feldspar-poor granitoid KPvr 70.45 17.21 0.23 1.58 0.06 3.47 0.36 0.97 5.57 0.09 6 0 3 19 670 18 650 118 14 17 .2 20 15 32 10 4 20 0 leucocratic to mesocratic, fine- to coarse-crystalline, well-foliated and and down-dip mineral stretch lineation in the pluton. In the northeastern part DEB 1593 Salmon River Intrusive Suite: K-feldspar-poor granitoid Qamo Older alluvium of the Salmon River (Holocene)—Primarily stratified sand and interlayered garnet-white mica-biotite to kyanite garnet white mica biotite KPvr 70.58 15.50 0.33 2.63 0.08 3.69 0.94 1.58 4.58 0.09 8 3 4 30 398 35 405 99 8 11.1 16 11 51 8 0 3 1 of the map area, foliated tonalite grades eastward into mesocratic (CI = 25) well-rounded pebble to boulder gravel. Forms first terrace above the river, schist, metaconglomerate, fine-grained quartz white mica ± garnet ± DEB 691A Salmon River Intrusive Suite: K-feldspar-rich granitoid KPvr 73.17 15.26 0.07 0.66 0.08 1. 91 0.09 4.73 3.98 0.03 5 0 1 11 1382 78 486 72 8 18.5 13 6 25 16 0 7 0 nonfoliated, subporphyritic hornblende-bearing biotite tonalitic orthogneiss, which is significantly higher than the average prehistoric peak flow of the amphibole ± biotite schist, garnet-bearing biotite felsic gneiss, quartzite, DEB 760A Salmon River Intrusive Suite: K-feldspar-rich granitoid leucocratic (CI = 15) nonfoliated hornblende-free biotite granodiorite and then KPvr 72.71 14.98 0.19 1.19 0.04 1.54 0.30 5.56 3.43 0.07 7 0 7 2 1863 76 469 76 6 19.3 18 11 35 14 4 0 4 Salmon River. Maximum age probably middle to early Holocene (see garnet chlorite schist and garnet hornblende gneiss and amphibolite. White Idaho batholith granite. Foliated orthogneiss and nonfoliated tonalite are DEB 791B Salmon River Intrusive Suite: K-feldspar-rich granitoid KPvr 71.08 16.54 0.24 1.31 0.03 2.54 0.26 3.06 4.82 0.11 5 0 5 8 2237 39 770 159 5 15 18 9 35 12 21 42 2 Schmidt and others, 2009). Gravel clast lithology similar to “Qam.” May be mica and quartzitic matrix in much of the unit separates it from the Lightning considered to be mesocratic border facies to the batholith. Gray and others DEB 1071 Salmon River Intrusive Suite: K-feldspar-rich granitoid capped by thin loess and eolian sand. Height above present river level Creek Schist, which has more biotite and chlorite. Isolated to clustered, KPvr 73.93 14.65 0.15 1.11 0.02 1.43 0.18 4.58 3.92 0.04 7 0 1 4 1966 69 428 116 3 16.8 16 9 77 15 8 30 4 (2012) report an LA−ICP−MS 206Pb/328U zircon age of 91.7 ± 2.4 Ma for the averages 25 feet. Represents the first of a sequence of terraces. Interfingers xenoblastic to idioblastic garnet porphyroblasts have white diffusion halos DEB 1113B Salmon River Intrusive Suite: K-feldspar-rich granitoid KPvr 69.66 17 .09 0.21 1.44 0.04 2.57 0.30 3.49 5.13 0.07 6 0 3 15 2181 51 981 145 4 9.6 19 7 47 11 22 18 1 tonalite. It is similar to the 91.5 ± 1.1 Ma date for tonalite near McCall with or is capped by colluvium and alluvial-fan deposits at toe of canyon several mm thick and elongated in the down-dip direction of the schistosity. In DEB 1186B Salmon River Intrusive Suite: K-feldspar-rich granitoid (Giorgis and others, 2008). Major and selected trace element petrogenetic KPsc 71.81 15.45 0.30 1.48 0.03 2.11 0.41 4.64 3.68 0.10 7 0 0 11 3472 51 507 144 4 6.3 12 10 29 10 0 0 0 slopes. Remnants of gold placer mines common, especially northwest of Lake the upper, west-facing reaches of Chair Point, it is difficult to distinguish plots (Blake, 1991) suggest the pluton correlates with the Payette River DEB 1416 Salmon River Intrusive Suite: K-feldspar-rich granitoid KPsc 72.47 15.60 0.25 1.50 0.05 2.25 0.31 2.83 4.66 0.09 8 0 4 3 1071 56 543 129 11 13.6 17 10 63 12 21 45 7 Creek Bridge, at Music Bar, north and south of Partridge Creek Bridge, and between Fiddle Creek and Lightening Creek Schist due to the middle tonalite of Manduca and others (1993) near McCall. It may correlate with the northeast of Manning Bridge (see Symbols). amphibolite facies metamorphic conditions, as well as an increase in biotite DEB 1642B Salmon River Intrusive Suite: K-feldspar-rich granitoid KPkr 73.57 15.17 0.11 0.75 0.03 1.69 0.13 3.83 4.68 0.04 5 0 3 8 1004 56 333 76 3 9.2 17 28 33 21 0 8 1 Rocky Bluff tonalite in upper Slate Creek (Jane Hammarstrom, personal to white mica content and structural transposition. Locally, hornblende forms DEB 1041 K-feldspar-poor granitoid, Kelly Mountain schist Zskm 70.63 16.66 0.30 1. 60 0.04 2.85 0.33 2.66 4.86 0.08 7 0 7 0 1789 39 838 168 8 36 20 15 57 15 27 21 communication, 1988). 1 Qas Channel and floodplain deposits (Holocene and Pleistocene)—Moderately garbenschiefer clusters in intermediate schist. Mesoscale garnet-hornblende DEB 1097 K-feldspar-poor granitoid, Kelly Mountain schist Zskm 69.03 18.24 0.22 1.22 0.03 3.56 0.28 1. 70 5.63 0.08 6 0 4 16 1234 26 904 124 5 13.4 18 8 34 7 6 0 1 sorted, stratified to massive, subangular to rounded pebble to boulder gravel in gneiss and amphibolite are variable in their crystal size and garnet percentage. Crevice pluton (late Early Cretaceous)—Gray-tan leucocratic (CI = 10; color DEB 780A K-feldspar-rich granitoid, Kelly Mountain schist Zskm 75.10 13.90 0.20 0.83 0.01 1.23 0.16 5.76 2.77 0.05 8 1 4 5 1740 107 367 136 5 7.1 14 13 18 26 28 41 16 channels, flood plains, and low terraces of Lake Creek, Allison Creek, Kcp Discordant to concordant mafic interlayers may be hypabyssal basaltic to index), medium-crystalline, biotite-poor, granodiorite and granite stock. The Partridge Creeks. Smaller unmappable horizons are common along all gabbroic dikes or possibly interlayered basaltic flows. Hamilton (1963, 1969) DEB 1093 K-feldspar-rich granitoid, Kelly Mountain schist Zskm 73.79 15.34 0.07 0.42 0.02 1.58 0.08 4.09 4.58 0.03 6 0 2 0 761 50 325 68 5 9.9 21 20 20 18 6 18 4 pluton intrudes metasedimentary schist. Massive rock domains have tributaries to these drainages and the Salmon River. Includes finer grained considered the schist to be largely intermediate to felsic tuff, perhaps dacite. DEB 1011 K-feldspar-poor granitoid, Partridge Creek gneiss KPpc 70.24 16.57 0.31 2.15 0.08 2.84 0.56 2.04 5.11 0.11 5 0 7 28 859 50 769 136 5 39.9 20 9 85 8 16 9 equigranular quartz, plagioclase, and locally porphyritic K-feldspar in its 2 alluvium immediately upstream of landslide toes. Locally includes poorly The unit is mapped northward towards John Day Mountain where Lewis and DEB 1369B K-feldspar-poor granitoid, Partridge Creek gneiss western portions. Central portions have a weak-to-strong penetrative biotite KPpc 71. 01 16.99 0.17 0.86 0.02 2.96 0.32 2.31 5.27 0.07 9 0 6 11 826 34 740 118 4 4.6 16 8 29 12 0 0 2 sorted debris-flow deposits. others (2011a, 2011b) infer the unit to be largely metasedimentary. foliation. In its eastern portion, especially north and south of Manning Bridge, DEB 1020 K-feldspar-poor granitoid, Partridge Creek gneiss KPpc 68.67 17.44 0.35 1. 98 0.06 3.56 0.68 1.43 5.70 0.13 6 0 10 28 503 40 765 131 8 16.6 19 6 69 6 8 27 3 composite biotite gneissic foliation marks protomylonitic and mylonitic high- JPef Mafic rocks of East Fork (Jurassic to Permian)—Dark green to black, DEB 1017 K-feldspar-rich granitoid, Partridge Creek gneiss Qaf Alluvial-fan deposits (Holocene and Pleistocene)—Crudely bedded, poorly KPpc 73.65 15.03 0.16 1.02 0.04 1.71 0.16 3.62 4.55 0.05 8 0 5 17 996 44 393 116 5 14.1 16 10 39 17 16 13 1 strain zones. Foliation is stronger at stock margins and xenoblastic to melanocratic to mesocratic, fine- to medium-crystalline, massive to well- sorted brown muddy gravel derived from basalt and basement-rock colluvium DEB 1050 K-feldspar-rich granitoid, Partridge Creek gneiss KPpc 75.13 14.76 0.08 0.42 0.02 1.60 0.01 3.46 4.52 0.02 14 0 5 0 1721 46 450 65 3 8.9 14 13 17 18 12 9 3 subidioblastic garnet is preserved locally. Locally contains elongate schist and on steep canyon slopes. Subangular and angular pebbles, cobbles, and foliated greenstone, metagabbro, amphibolite, and hornblende-biotite gneiss. calc-silicate gneiss enclaves that are oriented subparallel with foliation. In DEB 851A K-feldspar-rich granitoid, Partridge Creek gneiss KPpc 73.30 15.38 0.15 0.88 0.02 2.12 0.16 3.71 4.24 0.04 9 0 5 4 1484 65 569 104 5 12.9 20 3 48 18 34 8 6 boulders in a matrix of granules, sand, silt, and clay. Locally white spotted with relict plagioclase phenocryts, small clasts, or small cliffs along the Salmon River, subvertical joints produce a slabby exfoliation amygdaloidal domains. May contain small xenoblastic garnet porphyroblasts. *Major elements are normalized on a volatile-free basis; total Fe expressed as FeO. structure in the pluton. Gray and others (2012) provide fabric element Unit is in sharp contact with gray biotite gneiss and biotite-white mica schist All analyses performed in 1989 at the Washington State University GeoAnalytical Laboratory, Pullman, Washington.