Vol. 5, No. 11 November 1995 INSIDE • Science in National Parks, p. 216 • North-Central Section Meeting, GSA TODAY p. 225 A Publication of the Geological Society of America • Southeastern Section Meeting, p. 227 Evidence of Collisional Processes Associated with Ophiolite Obduction in the Eastern Mediterranean: Results from Ocean Drilling Program Leg 160 Scientific Participants of Leg 160: A. H. F. Robertson* and K.-C. Emeis (Co-Chief Scientists), C. Richter (Staff Scientist), M.-M. Blanc-Valleron, I. Bouloubassi, H.-J. Brumsack, A. Cramp, G. J. De Lange, E. Di Stefano, R. Flecker, E. Frankel, M. W. Howell, T. R. Janecek, M-J. Jurado-Rodriguez, A. E. S. Kemp, I. Koizumi, A. Kopf, C. O. Major, Y. Mart, D. F. C. Pribnow, A. Rabaute, A. P. Roberts, J. H. Rüllkotter, T. Sakamoto, S. Spezzaferri, T. S. Staerker, J. S. Stoner, B. M. Whiting, J. M. Woodside Figure 1. JOIDES Resolution at Marseilles, France, prior to departing on Leg 160. ABSTRACT driving force was tectonic loading by longer active (e.g., the Upper Creta- sional settings on land to the east to Recent drilling in the eastern the Eurasian plate. In this area the ceous Oman ophiolite). However, the areas of incipient collision on the Mediterranean Sea south of Cyprus leading edge is represented by the Troodos is an example of an ophiolite Mediterranean Ridge in the west (Cita has revealed important insights into Troodos ophiolite. The breakup and that is undergoing active emplacement and Camerlenghi, l990). One such area fundamental tectonic processes asso- subsidence history of the Eratos- today, in an area that is easily accessi- of incipient collision includes the ciated with continental collision and thenes Seamount, as revealed by ble and geologically well known. Much Eratosthenes Seamount, south of ophiolite emplacement. A transect drilling during Leg 160, is clearly of the evidence for this emplacement is Cyprus. Previous geophysical studies of four sites was drilled across the linked with the emplacement of the recorded beneath the sea to the south (Woodside, l977, l991; Krasheninnikov Africa-Eurasia plate boundary. The Troodos ophiolite. This underwent of Cyprus, along the boundary between et al., l994) suggest that the Eratos- results show that the African plate, strong surface uplift during active the African and Eurasian plates. This thenes Seamount is a fragment of con- represented by the Eratosthenes tectonic emplacement, associated area was a target of drilling during Leg tinental (or transitional-type) crust that Seamount, underwent rapid with collision of the seamount with 160 in March and April l995 (Figs. 1 is undergoing subsidence and breakup subsidence and related faulting the Cyprus margin. and 2). in a zone of incipient collision between in Pliocene-Pleistocene time. The The eastern Mediterranean Sea the African and Eurasian plates (Robert- INTRODUCTION (Fig. 3) is a remnant of the Mesozoic son, l990; Kempler, l993; Limonov et Tethys ocean (Dercourt et al., l993). al., l994; Robertson et al., l994, l995). *Corresponding author—Alastair Robertson, Many ophiolites were emplaced Different areas record various stages of Department of Geology and Geophysics, Uni- long ago by processes that are no versity of Edinburgh, Edinburgh, EH9 3JW, UK. Tethys closure, ranging from fully colli- Obduction continued on p. 219 ABCD E Figure 2. Core photographs illustrating stages in the tectonic-sedimentary evolution of the Eratosthenes Seamount and the adjacent Cyprus margin. A: Oncolites (algal balls) that accumulated on a shallow-water carbonate platform in Miocene time (Site 966, Core 17R, Section 1, 45–65 cm). B: Limestone (Miocene?) composed of various types of clasts, reflecting current reworking in a shal- low-water shelf setting (Site 966, Core 13R, Section 1, 1–21 cm). C: Debris flow composed of clasts of altered shallow-water limestone in a matrix of muddy nannofossil ooze of early Pliocene age (Site 966, Core 8H, Section 1, 1-23 cm). D: Clast-rich nannofossil ooze of Pliocene age showing slumping and color banding. The slumping is related to collapse of the Eratosthenes Seamount (Site 965, Core 3H, Section 3, 35–58 cm). E: Calcareous silty mud with detrital gypsum of Messinian(?) age, possibly deposited in a saline lake located at the foot of the Cyprus slope (Site 968, Core 25X, Section 2, 108–132 cm). A Year-End Message from the President Council, and others will explore the IN THIS ISSUE issues of whether and how a broader Evidence of Collisional Processes percentage of membership (sharehold- Associated with Ophiolite Obduc- Investments Come in More Forms ers) can become more active in GSA via tion in the Eastern Mediterranean: some form of empowerment action. Results from Ocean Drilling than Merely Stocks and Bonds Program Leg 160 .................. 213 Annual Report Message from the President ............. 214 David A. Stephenson This past year did not start out to In Memoriam .......................... 214 look very promising for the geosciences Memorial Preprints ..................... 214 community. The very existence of sev- eral venerated institutions—in particu- GSA on the Web ........................ 214 For all of you who dabble, or time allocated to GSA activities. The lar, the U.S. Geological Survey and the Washington Report ..................... 215 dream of dabbling, in the stock mar- actual funds that GSA generates are U.S. Bureau of Mines—was threatened. ket, to know the cost and the value of broken down as shown on p. 215. Research and Public Education GSA representatives took the position your investment is paramount. By The true value of your invested in the National Park System ............. 216 that the majority of its membership your membership in this Society, you time and money in GSA has far-reach- 1996 Annual Meeting—Denver .......... 222 would support activity to preserve the have become a “shareholder”—with a ing effects both for you professionally USGS and USBM. Thus, GSA joined GSAF Update ........................... 224 vested interest in the success and divi- and for the geoscience community as with others in the American Geological North-Central Section Meeting dends of GSA. As in any corporation, a whole. GSA’s existence has been cen- Institute to talk to U.S. representatives Preliminary Announcement .............. 225 you, the shareholder, are asked annu- tered on publications and the opportu- and senators, and their staffs, in an Southeastern Section Meeting ally to elect the board of directors— nity for its membership to enter scien- effort to avert abolishment. Our goal Final Announcement .................... 227 who in turn are responsible to the tific discussions. Can GSA be more, do was to encourage maintenance of shareholders. (The function of the GSA more, for its membership? For exam- Geologic Division Reduction in Force ..... 229 strong agency programs while conced- Executive Committee and Council is ple, can GSA become a unified voice Book Reviews ........................... 230 ing that some changes could and similar to that of a board of directors, on resource-related issues affecting the Calendar ............................... 232 should be made. Within reason, that and GSA’s president and executive general public? What GSA is or could goal was attained. A continuing goal Rock Stars—T. Wayland Vaughan ......... 233 director function collectively very be—what its value could be—for its will be to reduce the gap between what GSA Annual Meetings ................... 234 much like a CEO/corporate president.) membership must continuously evolve. is known by geoscientists and what is Therefore, as shareholders of this cor- GSA’s leadership—and, most impor- Classifieds .............................. 234 used by governments and by individu- poration, you rightfully would expect tantly, its membership—are urged to 1996 GeoVentures ...................... 236 als. (1) some return (the value) on your identify new directions and participate Other 1995 milestones for GSA investment (the cost) of time and in realizing the integration of these have included: November money, and (2) some communication ideas. GSA TODAY • Newly appointed Executive Director Vol. 5, No. 11 1995 of how the firm has performed. In attempting to zero in on ways Donald M. Davidson, Jr. became to increase the true worth and effec- immersed in developing and manag- GSA TODAY (ISSN 1052-5173) is published monthly Cost and Value tiveness of this organization, GSA’s ing headquarters staff and functions; by The Geological Society of America, Inc., with offices at long-range planning group will be 3300 Penrose Place, Boulder, Colorado. Mailing address: Costs associated with membership • The GSA annual budget was brought reviewing the Society’s operations; in P.O. Box 9140, Boulder, CO 80301-9140, U.S.A. Second- in GSA include dues (required), publi- within Council-directed guidelines class postage paid at Boulder, Colorado, and at additional particular, should and could more mailing offices. 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