In general, the sequence of faunas is consistent with those found in the measured sections. All collections from unit Ml₄ can be correlated with the upper Alapah faunas. Collections 133, 147 and 59ACu15 represent the "Chester"-type assemblage, also found in collection 55 of the measured section. It would appear that 59ACu15 may be correlated too high in the unit.

Collection 138 seems to be out of place. The distinctive Spirifer that occurs in abundance in this collection is found in the central Brooks Range in rocks of Wachsmuth age.

The group of collections that were listed as either Ml₃ or Ml₁ probably should be assigned to Ml₁. The fossil assemblage of 59ACr 19-20 is very like that of 119 which characterizes Ml₁ in the measured section.

Collection 15 contains a Wachsmuth age assemblage and therefore contributes evidence for the Wachsmuth equivalence of unit Ml₂. In the measured sequence, Ml₂ did not contain definitive fossils but was bracketed by upper Wachsmuth fossil assemblages in Ml₁ and lower Ml₃.

Collections 162 and 154 present a problem. The corals in these collections suggest a higher position in the section than indicated on the transmittal sheets. Faberophyllum? was found in collection 27 and may tie that collection to 162. On the other hand, the brachiopods suggest a lower correlation. Collection 154 may correlate with the levels of collections 8 or 1 in the measured section. These two collections (162 and 154) seem to have been collected at the place where I made extensive collections and measured a section in 1951. It was my opinion, at the time, that the sequence in that area should be correlated much higher (perhaps with your unit Ml₄). The coral-bearing beds are overlain by quite a thickness of dolomites. What I consider good evidence of faulting would explain the juxtaposition over beds equivalent to your Ml₁.

In this report we have labeled the larger animal groups where any confusion might exist. In this, as well as earlier reports, the fossils are listed in systematic order.

Collection part of scattered localities, statigraphic position determined by field-mapping correlations (from faunal list given on Table 2, pp. 8-9 in Campbell, 1967)

Fossil locality shown on Plate 1.

The Nasorak Formation (Campell, 1965a) is a limestone sequence named from typical exposures in sea cliffs near the mouth of Nasorak Creek (pl. 2B), where nearly 1,800 feet of the upper part of the formation are nearly continuously exposed with relatively little structural complexity. (from Campbell, 1967, p. 7)

Fossils are relatively abundant. The identifiable forms are chiefly Bryozoa (predominately fenestrate), brachiopods, horn corals, lithostrotionoid corals, and a few endothyroid Foraminifera. The megafossils were examined by J.T. Dutro, Jr., and Helen M. Duncan, of the Geological Survey, who conclude (written commun., 1961) that collection from the upper 1,500 feet of the Nasorak Formation (table 2) indicate equivalence to the lower part of the Alapah Limestone (Upper Mississippian) of the central and eastern Brooks Range, and those from the lower approximately 500 feet indicate correlation with the upper part of the Wachsmuth Limestone (Lower Mississippian). They also conclude that the basal 165 feet of the Nasorak contains fossils that correlate with those of the Utukok Formation (Lower Mississippian) of the western DeLong Mountains (Sable and Dutro, 1961, p. 591-592) and that the fossils of the remaining 1,935 feet of the Nasorak are equivalent to those in part of the Kogruk Formation (Lower and Upper Mississippian) of the western DeLong Mountains (Sable and Dutro, 1961, p. 592). Apparently, then, the beds of the Nasorak Formation represent continuous deposition from Lower Mississippian at the base to Upper Mississippian at the top. The formation is accordingly assigned an Early and Late Mississippian age; the lower member and Cape Thompson Member are included in the Lower Mississippian part, and the boundary betweeen the Lower and Upper Mississippian lies in the lower part of the upper member. (from Campbell, 1957, p. 14)