E. M. Kindle — Port Clarence Limestone. 335 



Art. XXXVII. — The Faunal Succession in the Port Clarence 

 Limestone, Alaska /* by Edward M. Kindle. 



Introduction. — The faunas under discussion in this paper 

 represent the nearest geographic approach of American fossil 

 faunas to those of Asia. The limestones holding them are 

 typically developed in the western part of the Seward Penin- 

 sula, which extends westward to within 60 miles of eastern 

 Asia. Reconnaissance surveys which were begun by Brooks 

 and Shrader in 1899, and continued by various members of the 

 Alaskan Division of the U. S. Geological Survey, furnished in 

 1908 a preliminary geological map of the major portion of the 

 Seward Peninsula. f P. S. Smith:}: has recently published a 

 summary of the geology of the Peninsula and a general map 

 showing the geology of a considerable area to the eastward of 

 that covered by the earlier map. The only beds which have 

 yielded well-preserved fossils in the Seward Peninsula are 

 included in a single cartographic unit called the Port Clarence 

 limestone on the map published in 1908. A portion of this 

 map is here reproduced. (See fig. 1.) 



The writer's field work was confined almost entirely to the 

 limestones which have been referred to the Port Clarence. 

 Nearly all the other sedimentary beds in this region have 

 undergone severe metamorphism. The collections which were 

 made from these limestones in different parts of the Peninsula 

 demonstrate the composite character of the beds which have 

 been referred to this formation. The beds which have been 

 mapped as Port Clarence limestone include horizons ranging 

 in age from Cambrian to Devonian or Carboniferous. The 

 determination of the thicknesses and relationships of the sev- 

 eral terranes which have been included under the name of the 

 Port Clarence limestone, must await the completion of much 

 detailed work on the stratigraphy and faunas of the region. 

 The present paper will attempt to give only the order of succes- 

 sion and correlation of the several faunas which are known in 

 it, and preliminary lists of the species represented. 



The material representing the various horizons varies con- 

 siderably in quality and completeness. The younger of these 

 faunas are very imperfectly known owing to the metamorph- 



* Published with the permission of the Director of the IT. S. Geological 

 Survey. 



f Collier, Hess, Smith and Brooks, The gold placers of parts of the Seward 

 Peninsula, Alaska : Bull. TJ. S. Geol. Survey No. 328, pis. X-XI, pp. 61-110, 

 1908. '* ^ 



X Smith, P. S., Geology and mineral resources of the Solomon and Cassa- 

 dapaga quadrangles, Seward Peninsula, Alaska : Bull. IT. S. Geol. Survey 

 No. 433, pp. 19-30, pi. II, 1910. 



