摘要:

Cover. (a) Filtered gravity map of the 48 contiguous states. Produced by Hildenbrand, Simpson, Godsen, and Kane as USGS Map GP‐953(A). (b) The map cut and recorrelated. Gravity signatures of the following major features are aligned. (1) Central North American Rift System, Hartville Uplift; (2) Precambrian/Early Paleozoic Rift Passive Margin underneath the Appalachians, Precambrian/Early Paleozoic Rift Passive Margin underneath the Quachitas. Though this offset was independently recognized by the author, it is similar to that proposed by S. W. Carey (The Expanding Earth, Dev. in Geotonics, vol. 10, pp. 378–380, Elsevier, New York, 1976). These alignments are interpreted to indicate that a strike‐slip fault system (transform fault?) offset these features probably concurrent with rift passive margin formation leaving the Palezoic Iapetian Eastern‐Southern continental margin bounded as follows: rift passive margin—transform passive margin—rift passive margin. Late Palezoic continental collision resulted in major overthrusting of the margin forming the Appalachians; lesser overthrusting, because of relatively recessed position, forming the Quachita's and minor thrusting with considerable shearing, because of the orientation of the transform boundary with respect to the closing vector, forming the buried Appalachian‐Quachita connection in Mississippi and Alabama (G. L. Kinsland, Transcontinental strike‐slip fault across North America, paper presented at the 5th International Conference on Basement Tectonics, Oct. 1983). Features south and east of the rift passive margins were not in place at the time faulting occurred and would not a priori be expected to correlate in (b). The small features which do correlate in (b) from north Louisiana northeast along the Atlantic coast are believed to be signatures of portions of collapsed Late Palezoic island arc complexes which correlate due to similar structural relationships to the rift passive margins. Florida does not correlate with southern Mississippi and Louisiana. At this time, no reason for extending the cut through Florida other than necessity to illustrate the other correlations is given. A signature similar to the rift passive margin signatures is noted in southern Mississippi, southern Louisiana, and coastal Texas and is interpreted as the Mesozoic Gulf Coast rift passive margin signature (G. L. Kinsland, Basement Structure of the Gulf Coast: Interpretation of gravity anmalies supported with structural, magnetic and seismic data, Trans. Gulf Coast Assoc. Geol. Soc,

ISSN:0002-8606    

DOI:10.1029/EO065i035p00489

年代:1984

数据来源: WILEY

ISSN:0002-8606    

DOI:10.1029/EO065i035p00490

年代:1984

数据来源: WILEY

摘要:

Here is a list of congressional committees that have direct jurisdiction in geophysics, general science, and science education. Chairmen and ranking minority members listed are for committees of the 98th Congress.Eoswill update this list after committee assignments are made for the 99th Congress, which begins in January 1985.

ISSN:0002-8606    

DOI:10.1029/EO065i035p00491

年代:1984

数据来源: WILEY

摘要:

Roughly 125,000 years ago, the earth underwent a climatic warming trend [Bergen and Van Couvering, 1979] called the Sangamon. This occurred more than 1 million years after the commencement of the Pleistocene time of great glacial advances which brought ice sheets of continental proportions to North America, northern Europe, and Siberia. That interglacial warming trend is the most pronounced climatic warming that we know during the period of the Ice Ages [Mitchell, 1977]. The Sangamon was followed, however, by a time of lower worldwide temperatures when the glaciers advanced once more and until a new warming trend commenced some 20,000–30,000 years ago. Earth's glaciers and ice sheets then began to retreat again, and about 10,000 years ago the last vestiges of these northern continental ice sheets withdrew as the latest warm interglacial, the Holocene, began. The Holocene continues today. Earth's atmospheric and oceanic temperatures rose in this time, well after Neanderthal and Cro‐Magnon men lived in Asia and in Europe. The Holocene warming has been synchronous in both hemispheres and led to a worldwide climatic optimum, called the Hypsithermal interval, between 9,000 and 2,500 years ago [Deevey, 1957]. The Hypsithermal interval was the warmest part of the Holocene to date, and it largely preceded the Bronze Age, which commenced about 3,000 years ago. While the continental ice sheets of North America, Europe, and Asia disintegrated with the approach of the Holocene, the great ice sheets that cover Greenland and Antartica remained stable and largely unchanged at least since the warm Sangamon interglacial of 125,000 years

ISSN:0002-8606    

DOI:10.1029/EO065i035p00493

年代:1984

数据来源: WILEY

摘要:

AGU's membership grew by 7% in 1982 and an additional 9.4% in 1983. This pheonomenal growth is due largely to the ever increasing numbers of students who are joining AGU and to the increase in non‐U.S. membership that has been promoted over the past couple years and is continuing. Student membership was 13.1% of the total membership in 1983 and 15.1% in 1984. Non‐U.S. membership, which was steady at 19–20% in the 1970s, had dropped to 18% in 1982 and is now back a

ISSN:0002-8606    

DOI:10.1029/EO065i035p00515-01

年代:1984

数据来源: WILEY

摘要:

The term of Meetings Chairman has been changed at the recommendation of the Meetings Committee to a 3‐year term. Frank Eden, who began his term with the 1983 Spring Meeting, will continue through the 1985 Fall Meeting. A new chairman will be named next spring and will begin learning the ropes at the 1985 Fall Meeting. This is a very important postion in AGU. The entire responsibility for the quality of the national meeting scheduling and especially the Union and Frontiers sessions rests with this individual. Exceptionally good reports on the meetings have been received during Frank Eden's term, and the Union should be pleased that he is continuin

ISSN:0002-8606    

DOI:10.1029/EO065i035p00518

年代:1984

数据来源: WILEY

摘要:

At its meeting in May 1984, the Council approved two new awards, the Harry Hess Medal for outstanding achievements in research on the form and dynamics of the earth and planets. In addition, they approved the Fleming Medal as an annual award.

ISSN:0002-8606    

DOI:10.1029/EO065i035p00519-02

年代:1984

数据来源: WILEY

摘要:

A Fellow of the American Geophysical Union shall be a scientist who has attained acknowledged eminence in a branch of geophysics. The total number of Fellows elected each shall not exceed 0.1% of the total membership at the time of election. Recipients of AGU medals and awards are also accorded Fellowship in the Union.

ISSN:0002-8606    

DOI:10.1029/EO065i035p00524-01

年代:1984

数据来源: WILEY

摘要:

The purpose of this guide is to assist AGU members in communicating with legislators and government agency officials and to delineate some of the constraints under which AGU must operate when undertaking activities in this area.

ISSN:0002-8606    

DOI:10.1029/EO065i035p00669

年代:1984

数据来源: WILEY

摘要:

The American Geophysical Union, which was established in 1919 by the National Research Council and for more than 50 years operated as an unincorporated affiliate of the National Academy of Sciences, is now a corporation chartered under the laws of the District of Columbia. The Union is dedicated to the furtherance of the sciences of geophysics through the individual efforts of its Members and in cooperation with other national and international scientific organizations.

ISSN:0002-8606    

DOI:10.1029/EO065i035p00674

年代:1984

数据来源: WILEY