603087

PLATE 1. A, Yukon Valley, looking downstream from international bound-

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ary; B, Yukon River at the mouth of Washington Creek;
C, Panoramic view of the narrows of the Yukon River
at the mouth of Woodchopper Creek----

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2. A, Valley near the headwaters of the Charley River; B, Undif-

ferentiated (possibly upper Silurian) limestone along

the west bank of the Yukon River just above Takoma

Creek...

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3. A, Contorted feldspathic quartzite in Birch Creek schist; B,

Augen gneiss, intrusive into Birch Creek schist___

4. A, Cambrian limestone and associated rocks on the north bank

of the Yukon River just north of Calico Bluff; B, Crinoids

in crystalline limestone of Silurian (?) age from west slope

of Loop Mountain, Yukon Territory...

5. A, Fossiliferous Middle Devonian limestone in Woodchopper

volcanics, as seen along the north bank of the Yukon

River opposite Woodchopper; B, Woodchopper volcanics

along the northeast bank of the Yukon River below the

mouth of Woodchopper Creek...----

6. A, Lower Mississippian chert formation on the east bank of the

Yukon River just below the mouth of Shade Creek; B, El-

lipsoidal greenstone in Woodchopper volcanics on the north

bank of the Yukon River above Woodchopper---

7. A, Undifferentiated Paleozoic greenstone in bluff on the west

side of the Yukon River at the mouth of Mission Creek;

B, Lower Mississippian volcanic rocks along the east bank

of the Yukon River above Circle----

8. A, Vertical beds of chert at north end of bluff on the west side

of the Yukon River below Takoma Creek; B, East side of

Calico Bluff, on the Yukon River below Eagle---

9. Enigmatical fossils in Mississippian or Pennsylvanian transitional

formation...

PLATE 10. A, Anticline and syncline in Tahkandit limestone (Permian) along

northeast bank of the Yukon River just above the mouth

of the Nation River; B, Conglomerate and sandstone of

Nation River formation on the east bank of the Yukon

River a few miles below Eagle...

11. A, Infaulted block of Tahkandit limestone (Permian) in midst

of Woodchopper volcanics (Middle Devonian) on the

south bank of the Yukon River about 1 mile below the

mouth of Coal Creek; B, Lower Cretaceous rocks (Kandik

formation) in bluff on the north side of the Yukon River

a few miles above the mouth of the Kandik River_.

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In pocket.

12. Geologic map of the Eagle-Circle district_-_.

FIGURE 1. Index map showing location of area covered by this report__-

2. Diagrammatic sketch showing structure of rocks in the fault

zone on the north bank of the Yukon River 3 miles above

Eagle....

3. Index to localities of fossils collected along the international

boundary by the Canada Geological Survey, as listed by

Cairnes...

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4. Geologic section from Takoma Creek northward along the

west bank of the Yukon River...

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5. Sketch of south side of Calico Bluff, Yukon River....

6. Section along the southwest bank of the Yukon River opposite

the mouth of the Nation River...

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