|
Reference
|
| Title: |
Report on Referred Fossils
,
1972
(11/22)
|
|
In summation, fossils of age significance in dating the Bowser Formation and equivalent beds were found last summer in an area about two miles west of Tuxedni Bay, in the high saddle west of Boulder Creek, and along a tributary that drains southeast from the high saddle into Boulder Creek. It seems evident a number of days could be spent profitably doing field work from a camp located on that tributary near the place where Arctocephalites was found. It should be possible to relate the occurrence of Arctocephalites to faunules in adjoining beds and to explore beds equivalent to the Bowser Formation along a number of nearby gulleys. Undoubtedly other areas of Bathonian rocks will be found when the Anchorage (D-3) and (D-4) quadrangles are mapped. One area in the Boulder Creek area that should be investigated is about three miles southwest of localities 30271-73 in the D-4 quadrangle and 3.2 miles up a creek that drains southward into Boulder Creek just north of the extreme west end of Anthracite Ridge. At this place (Mes. loc. 8567) were obtained many late Bajocian age or a mixture of ammonites of that age with others of late middle Bajocian age. The evidence for a late Bajocian age consists of the presence of Leptosphinctes (see PP 418-B, p. B54, pl. 28, figs. 4-6) and Prorsisphinctes (not described). Along with these are Stammatoceras, Normannites and Chondroceras which in Europe occur mostly in the upper middle Bajocian beds but do range as high as lower upper Bajocian beds. |
| Report by: |
Ralph W. Imlay
|
| Referred by: |
Robert L. Detterman
|
|
|
|
| | Age: | Callovian |
| Formation: | Chinitna Formation - Tonnie Siltstone Member (Tonnie Siltstone Member) |
|
|
|
|
|
| Comment: | The lower part of the Chinitna Formation is represented by one collection (Mes. loc. 30255) from the Tuxedni Bay area west of Cook Inlet and by four collections (locs. 30282-85) from the Little Nelchina area in the Talkeetna Mountains. When the last mentioned collections were made last summer we assumed that we were collecting from beds equivalent to the Bowser Formation, although Art Grantz had collected previously in the same gulch (locs. 24804, 24805). The presence of Kheraiceras? intermidius Imlay (loc. 30282) is evidence for a correlation with the basal part of the Tonnie Siltstone Member west of Cook Inlet. The presence of Kheraiceras? chinitnensis n. sp. is evidence for a correlation with the middle part of that member. Please note that the species included under Kheraiceras are being redescribed under new generic names in a paper just submitted to critics. |
|