This article reports the radiocarbon age measurements made at the Lamont Geological Observatory between February 1957 and July 1958. For convenience the sample ages have been classified into the following categories:

1. Table I Geologic Samples—North American glacial geology

2. Table II Geologic Samples—Pluvial lake levels

3. Table III Geologic Samples-Relative sealevel changes

4. Table IV Geologic Samples-Oceanography

5. Table V Geologic Samples-Miscellaneous

6. Table VI Archaeologic Samples

7. Table VII Check Samples

Ages are presented for 17 late-Pleistocene peat samples from sections that range from Karluk on Kodiak Island, Alaska to Port Orford, Oregon. Pollen and peat stratigraphy of the sections is used to interpret the environments prevailing at and since the time of sample deposition. The late-glacial at more southerly Pacific coastal Alaskan sites is dated at ca. 10,800 b.p. and the postglacial at ca. 10,000 b.p. At northerly coastal sites these intervals begin somewhat later. Regression rates for sealevel are given for a number of sites along this coast. Sample ages from two Oregon lakes suggest eustatic transgression ca. 5000 b.p. during the Hypsithermal interval.

This paper is a list of the radiocarbon datings of geologic and archaeologic samples made during 1958 after the dating apparatus had been installed at the Geological Survey. It is a direct continuation of the first dating list (Östlund, 1957a). Some of the results of geophysical interest, measurements of a few sea water samples, have been published separately (Fonselius and Östlund, 1959); others will follow.

The radiocarbon laboratory at the University of Pennsylvania is sponsored jointly by the University Museum and the Physics Department. In this laboratory our primary function is to date archaeologic samples from those four regions of the world in which the University Museum studies are concentrated, namely, the Near East, South America, Central America, and the Arctic. Dates for sites in the first two regions are included in this list, and a long series of temple lintels from Tikal, Guatamala is now being processed. Dates for the Arctic were obtained intermittently from 1953 through 1955 (with solid-carbon counting); others, more recently. The materials for many of the Arctic dates, however, were not reliable; that is, they were physically contaminated before processing in the laboratory. We hope that better samples can be found for future Arctic dating. Our Arctic dates which now furnish tentative age ranges for Punuk, Birnirk, Kachemak Bay III, Okvik, Old Bering Sea, Ipiutak, Norton, Dorset, Kachemak Bay I, Choris, Firth River (Early Mountain Phase), Sarqaq, and Denbigh Flint Complex Periods have been submitted to American Antiquity (Rainey and Ralph, in press) along with detailed discussions of possible contaminations.

The radiocarbon age measurements reported on in this article were made during a period from May, 1957, through May, 1958. During this time the laboratory was operated by the Department of Anthropology, under the direction of Dr. Emil W. Haury. On July 1, 1958, the Carbon-14 laboratory, under the supervision of Dr. Paul E. Damon with Dick Shutler, Jr. as laboratory technician, was transferred to the Geochronology Laboratories.

The dates given have been obtained up to the end of December, 1958. They have been made with carbon dioxide at 2 atmospheres pressure in a proportional counter of about 2-liter volume. For further details of construction and procedure, see Godwin, Walker, and Willis, 1957. The establishment of the project was made possible by a grant from the Trustees of the Nuffield Foundation, whom we are most happy to thank along with the Imperial Smelting Corporation who have lent us the zinc shielding for the gas-counter.

The C14-dating Laboratory in Trondheim has now been working for one year and a half. The present dating list covers the period from July 1957 to September 1958. The rather small number of datings made during this period is due to a lot of background experiments which have been carried out in the last half-year.

With a few exceptions the datings done before the period mentioned have been previously published (Marstrander, 1956–1957; Nydal and Sigmond, 1957; Skjelsvik and others, 1957–1958).

The first series of radiocarbon dating measurements made at the British Museum Research Laboratory are reported in the following list. The report covers a period during which two instances of radioactive contamination occurred to interrupt dating work, and is consequently a short one.

The following list covers the samples measured at the Uppsala radiocarbon laboratory during 1957, when the measurements started, and 1958. Two samples of sediments have been excluded, as the origin of the material was doubtful.

About three years ago a laboratory was set up in Pisa for the study of geologic and paleontologic problems with the help of modern nuclear techniques. The two main items of the first program were the construction of a mass spectrometer for paleotemperature measurements and of a carbon-14 dating apparatus.

In contrast to previous radiocarbon measurement lists, this list contains only known-age samples, most of which formed during the past ten years. The measurements were made largely in order to gain an understanding of the distribution of radiocarbon within the dynamic carbon reservoir both today and at times in the past. Since all materials forming in this reservoir today do not have the same C14/C12 ratio, such an understanding is necessary in order to arrive at the most accurate possible estimate of the age of samples submitted for dating. This is particularly important when high accuracy (i.e., <100 years error) is required on subaerially grown samples and also when attempting to extend the method to samples which formed in reservoirs other than the atmosphere (for example, the ocean and freshwater systems).

This list covers the measurements made at the University of Bern up until summer 1958. The low-level apparatus is described by Houtermans and Oeschger (1958).

Dates obtained since our last date list (Yale III∗), and up to the end of 1958, are given here. All are based on duplicate measurements of CO2 in a proportional counter. Grateful acknowledgment is made to the National Science Foundation, which has supported our work through grant no. G-2278. Participation of Väinö Hoffren during 1956–1957 was made possible through an arrangement with the Geological Survey of Finland. The technical assistance of Julius Kovats has been invaluable.

The following is a list of radiocarbon dates obtained since the time of the preparation of Michigan list III.∗ The description of the essential features of our method of measurement as given in the introduction to list III applies to this list. The modern standards used were obtained from hardwood logs, and were of various ages from 75 to 150 years by ring count. These standards were sufficiently old so that no correction for the recent dilution of the atmospheric C14 is believed to be necessary in the dates reported here. The ages of carbonate sample are also calculated from modern wood as a reference standard, without any correction for isotope fractionation.

The scope of the problems which are involved in the determination of radiocarbon dates renders complete, or detailed, classification of the published results of the research most complicated. In assembling this bibliography several such classifications were discarded before the present simplified one emerged. It was found, for example, that in a detailed classification of subject titles a large number of papers would have to be listed under several, sometimes as many as four, different headings. This complicated and lengthened the listing and also materially increased the chance of inaccurately locating a title. In such an event it would be “lost” to all but the most meticulous searcher. The reduction in the number of subject headings is open to criticism. We suspect, however, that these are answered by the simplicity of the present outline.