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Claire Carter

Publications and source records attributed to Claire Carter.

10 recordsLinked to original sources
USGS2022

Graptolite succession across the Ordovician–Silurian boundary in south-eastern Alaska

The first discovery in North America of a succession of graptolite faunas across the Ordovician–Silurian boundary has been made on Esquibel Island, in south-eastern Alaska, where five graptolite zones are represented in an 18 m interval of shale in the Descon Formation. Despite the thinness of the graptolite zones, no stratigraphical breaks can be inferred from more complete graptolite successions known elsewhere. The Alaskan faunas can be closely correlated with those of the standard British zones—the Dicellograptus anceps Zone (uppermost Ordovician), the Glyptograptus persculptus Zone (lowermost Silurian) and the immediately overlying Akidograptus acuminatus, Orthograptus vesiculosus and Monograptus cyphus Zones of the Lower Silurian. They thus give evidence of the cosmopolitan distribution of graptolite faunas during latest Ordovician and earliest Silurian time.

Alaska↗
USGS1997

Ostracodes in Owens Lake core OL-92: Alteration of saline and freshwater forms through time

Ostracode species’ geographic distributions are limited by parameters such as water temperature, salinity, and dissolved-ion composition. Because these parameters are, in part, determined by climate, ostracode biogeographic distributions serve as proxies for past climates. Therefore, the ostracodes in Core OL-92 from Owens Lake, southeast California, reveal climatic oscillations during the past 800,000 yr. The climatic history of the Owens Lake area, as indicated by the fossil ostracode record, reflects a number of high-latitude glacial and interglacial episodes in which glacial-period terminations fall at approximately 120 ka (Termination II), 225 ka (Termination III), 340 ka (Termination IV), and 438 ka (Termination V). A plot of saline versus freshwater ostracodes over time agrees quite well with a number of other geochemical and biological climatic indicators from the Owens Lake core.

California↗
USGS1995

Correlation of Ordovician rocks of northern Alaska

The Ordovician sequences presented in this report were chosen to cover a range of depositional and structural settings found in northern Alaska. Consequently, the quality of lithostratigraphic, paleontologic, and sedimentologic data is variable. Until 1982, Ordovician rocks in northern Alaska were known only from a few, widely separated localities. Since then, several hundred Ordovician conodont collections were obtained during geologic mapping of chiefly metacarbonate rocks; some are from measured sections that contain a succession of pelagic and (or) warm, shallow-water index species, but others are isolated, single collections that merely contain species that are long-ranging, within the Ordovician. Graptolite collections are fewer than conodont collections, but they provide invaluable ties between carbonate and siliciclastic sequences. New macrofossil localities are rare. All these collections have increased the known areal extent of Ordovician rocks in northern Alaska (Fig. 1) at least thirtyfold. Faunal assemblages from carbonate rocks in northern Alaska indicate that this area was situated in low latitudes during the Ordovician.

Alaska↗
USGS1974

United States Geological Survey Alaska program, 1974

This report on the Alaskan activities of the U.S. Geological Survey contains up-to-date accounts of recent results and summaries of plans for the summer of 1974. It is organized in six parts: (1) responsibilities and services of the Geological Survey; (2) organization of the U.S. Geological Survey; (3} Alaskan field activities for 1974; (4) cooperative programs with state and federal agencies; (5) summary of important results of geological and geophysical research in 1973, and (6) reports published by Survey authors in 1973.

Circular↗