Foraminiferal oxygen and carbon isotopic measurements from 5 sites of southern Atlantic and Pacific

The stratigraphy and paleoceanography of the late Miocene and early Pliocene have been examined at six sites in the South Atlantic and southwest Pacific oceans: Deep Sea Drilling Project (DSDP) sites 284, 516A, 519, 588, and 590 and two piston cores from Chain cruise 115. A consistent stratigraphy was developed among sites using graphic correlation, which resulted in age models for all sites that are tied to the revised paleomagnetic time scale of Berggren et al. (1985). Applying these chronologies, we assessed latitudinal and interocean contrasts in the stratigraphic ranges of late Miocene-early Pliocene planktonic foraminiferal and nanno - fossil datums. Salient stratigraphic results include (1) The last appearance datum (LAD) of Globoquadrina dehiscens is a late Miocene (approx. 6.4 Ma) event in the subtropics and is not useful for the placement of the Miocene/Pliocene (M/P) boundary in this biogeographic province. (2) The first appearance datum (FAD) of Globorotalia crassaformis occurred at 5.1 Ma in the South Atlantic near the M/P boundary, suggesting that Gr. crassaformis may have first evolved in the South Atlantic and later migrated to other regions. (3) In the southwest Pacific, the FADs of Gr. margaritae (5.97 Ma), Gr. puncticulata (5.09 Ma), and Gr. crassaformis (4.87 Ma) are significantly time transgressive between temperate and warm subtropical regions. Time lags of 1.0 m.y. were required for these species to adapt to physical and/or biotic conditions peripheral to their endemic biogeographic provinces. (4) Between the subtropics of the South Atlantic and southwest Pacific, many planktonic foraminiferal datums (FAD of Dentogloboquadrina altispira, Gr. cibaoensis, Gr. conomiozea, Gr. margaritae, and Gq. dehiscens and LAD of Gr. cibaoensis) markedly depart from the correlation suggested by magnetostratigraphy, indicating that these datum levels are unreliable for correlation between these ocean basins. (5) In contrast, available calcareous nannofossil datum levels fall on or near the paleomagnetic correlation line, indicating synchroneity of events within the subtropics. (6) Biostratigraphic, magnetic, and 87Sr/86Sr correlation between sites 588 and 519 and the M/P neostratotype at Capo Rossello, Sicily, suggests that the base of the Zanclean stratotype occurs at 5.1-5.0 Ma in the lower reversed subchron of the Gilbert, about 2-3 * 10**5 years above the Gilbert/Chron 5 boundary. Oxygen isotopic results from DSDP sites 284, 519, and CH115 piston cores confirm a prolonged benthic d18O increase in the latest Miocene between 5.6 and 5.0 Ma, as originally proposed by Shackleton and Kennett (1975). At DSDP site 588, the benthic d18O record in the latest Miocene is marked by high-frequency fluctuations with amplitude variations of 0.5per mill, and a long-period wavelength component of 400,000 years. Maximum d18O values, however, occurred during the late Miocene (Kapitean Stage) between 5.5 and 5.1 Ma. The late Miocene d18O changes resulted from mid- and high-latitude cooling and pulses of ice sheet expansion and contraction. Glacial events were most intense during the latest Miocene (Kapitean Stage), and occurred at 5.50-5.35 Ma and at 5.10 Ma. Glacial events are estimated to have lowered sea level by 40 to 60 m and contributed to the isolation and desiccation of the Mediterranean Basin during the late Messinian. Interglacial conditions prevailed at 5.2 Ma and between 5.0 and 4.1 Ma in the early Pliocene. The beginning of the Pliocene was marked by changes in many proxy climatic indicators at all sites, suggesting a prolonged interval of warm, interglacial conditions between 5.0 and 4.1 Ma during the earliest Pliocene.

Distribution of planktonic foraminifera in surface sediments of the Mediterranean Sea

The Mediterranean Sea is a partillay isolated ocean where excess evaporation over precipitation results in large east to west gradients in temperature and salinity. Recent planktonic foraminiferal distributions have been examined in 66 surface sediment samples from the Mediterranean Sea. In addition to mapping the frequency distribution of 16 species, the faunal data has been subjected to cluster analysis, factor analysis and species diversity analysis. The clustering of species yields assemblages that are clearly temperature related. A warm assemblage contains both tropical and subtropical elements, while the cool assemblage can be subdivided into cool-subtropical, transitional and polar-subpolar groupings. Factor analysis is used to delineate the geographic distribution of four faunal assemblages. Factor 1 is a tropical-subtropical assemblage dominated by Globigerinoiden ruber. It has its highest values in the warmer eastern basin. Transitional species (Globorotalia inflata and Globigerina bulloides) dominate factor 2 with highest values occurring in the cooler western basin. Factor 3 reflects the distribution of Neogloboquadrina dutertrei and is considered to be salinity dependent. Subpolar species dominate factor 4 (Neoglobuquadrina pachyderma and G. bulloides), with highest values occurring in the northern part of the western basin where cold bottom water is presently being formed. The Shannon-Weiner index of species diversity shows that high diversity exists over much of the western basin and immediately east of the Strait of Sicily. This region is marked by equitable environmental conditions and relatively even distribution of individuals among the species. Conversely, in areas where temperature and salinity values are more extreme, diversity values are lower and the assemblages are dominated by one or two species.

University of Michigan Football Team, 1901

Top Row: Wesley Winkler, Ralph Drake, Charles Rothschild, Norman Sterry, Kenneth Robinson, Alfred Chadwick, Weldon Fix, Ross Kidston, Les Barkenbus, Harrison Weeks, David Dunlap, George Gregory, Harold Baker, Cecil Gooding, George Sadler

Third Row: student mngr. H.C. Crafts, Edward Dickey(?), David Beardsley, William Snushall, ? Smith, George Davison, Kennedy Potter, ? Clark, Charles Van Valkenberg, Neil Snow, Joseph Horgan, James Forrest, William Foote, Webb Sadler, ? Hayes

Second Row: trainer Keene Fitzpatrick, ? Smith, Samuel Sackett, Everett Sweeley, Herbert Graver, Walter Shaw, Hugh White, Albert Herrnstein, Curtis Redden, Dan McGugin, Ebin Wilson, Bruce Shorts, Arthur Redner, Temple Owens

Front Row: Ralph Husson, Albert Preussman, Arthur Urquhart, Willie Heston, Benjamin Southworth, coach Fielding Yost, Charles Crane, Jerome (mascot), John Lewis, Frank Doty, Frank Belknap

1993 University of Michigan Baseball Team

Back Row: (10) Groundskeeper Erich Keil, Scott Niemiec, Scott Weaver, Mark Temple, Andy Wade, Brian Simmons, John Arvai, Matt Humbles, Student Manager Matt Hyde, Student Trainer Ann Whittenbach.

Middle Row: (12) Volunteer Assistant Coach Ed Turek, Jasen Livingston, Chris Newton, Heath Murray, Nate Holdren, Matt Ferullo, Ray Ricken, Chad Chapman, Sean Coston, Ryan Van Oeveren, Rodney Goble, Trainer Rex Thompson.

Front Row: (11) (from left): Assistant Coach Ace Adams, Toby Brzoznowski, Bryan Santo, Eric Heintschel, Co-Captain Todd Marion, Head Coach Bill Freehan, Co-Captain Scott Timmerman, Scott Winterlee, Matt Copp, Pat Maloney, Assistant Coach Dan O'Brien.

1994 University of Michigan Baseball Team

Back Row: Groundskeeper Erich Keil, Student Manager Matt Hyde, Scott Weaver, Brad Tinkham, Mike Muir, Matt Humbles, Kirk Beermann, Mike Haskell, Mick Kalahar, Assistant Coach Ernie Savas, Trainer Rex Thompson.

Middle Row: Assistant Coach Ace Adams, Kelly Dransfeldt, Brian Simmons, John Arvai, Chad Chapman, Matt Ferullo, Sean Coston, Mark Temple, Andy Wade, Matt Fleury, Assistant Coach Dan O'Brien.

Front Row: Scott Niemiec, Ryan Van Oeveren, Ron Hollis, Jasen Livingston, Kevin Crociata (Captain), Head Coach Bill Freehan, Chris Newton, Aaron Toth, Ray Ricken, Heath Murray, Rodney Goble.

1995 University of Michigan Baseball Team

Back Row: Student Manager Tim Freehan, Groundskeeper Erich Keil, Volunteer Coach Alan Trammell, Dan Sanborn, Brad Schemer, Alex Wozniak, Matt Herr, Chris Hesse, Bryan Besco, Derek Besco, John Papp, Mike Hribernik, Mike Cervenak, Mario Garza Jr., Dan Murphy, Trainer Rex Thompson, Student Trainer Stephanie Rummel. Missing: Chuck Winters.

Middle Row: Assistant Coach Ace Adams, Kirk Beermann, Mike Haskell, Matt Fleury, John Arvai, Kelly Dransfeldt, Tyler Steketee, Brian Steinbach, Andy Wade, Mark Temple, Mike Muir, Brad Tinkham, Mick Kalahar, Assistant Coach Steve Merriman.

Front Row: (From Left): Student Manager Matt Hyde, Brian Simmons, Scott Niemiec, Sean Coston, Jasen Livingston, Co-Captain Ryan Van Oeveren, Head Coach Bill Freehan, Co-Captain Rodney Goble, Aaron Toth, Matt Ferullo, Chad Chapman, Matt Humbles, Scott Weaver.

1996 University of Michigan Baseball Team

Back Row: (17) Manager Andy Galbreath, Manager Jeff Olsen, Groundskeeper Erich Keil, Andy Hood, Quinn DeMarrais, Alex Wozniak, Mike Seestedt, Brian Bush, Brian Kalczynski, Ryan Kelley, Pete Martay, Luke Bonner, Bobby Scales, Jason Alcaraz, Mario Garza Jr., Dan Murphy, Student Trainer Jon Nichols.

Middle Row: Assistant SID Jim Schneider, Mike Cervenak, John Papp, Bryan Besco, Derek Besco, Chuck Taylor, Tyler Steketee, J.J. Putz, Brian Steinbach, Mike Hribernik, Brian Berryman, Chris Hesse, Matt Herr, Brad Scheiner, Mick Kalahar, Trainer Rex Thompson.

Front Row: (13) Kirk Beermann, Marlon Wright, Mike Muir, John Arvai, Assistant Coach Tom Dodge, Assistant Coach Chris Harrison, Head Coach Geoff Zahn, Assistant Coach Ace Adams, Matt Hyde, Mark Temple, Matt Fleury, Kelly Dransfeldt, Mike Haskell.