RADI
LARIA
VOLUME 21
JULY 2003
NEWSLETTER OF THE INTERNATIONAL ASSOCIATION OF RADIOLARIAN PALEONTOLOGISTS ISSN: 0297.5270
INTERRAD International Association of Radiolarian Paleontologists A Research Group of the International Paleontological Association
Officers of the Association President
Past President
PETER BAUMBARTNER
JOYCE R. BLUEFORD
Lausanne, Switzerland
[email protected]
California, USA
[email protected]
Secretary
Treasurer
JONATHAN AITCHISON
ELSPETH URQUHART
Department of Earth Sciences University of Hong Kong Pokfulam Road, Hong Kong SAR, CHINA Tel: (852) 2859 8047 Fax: (852) 2517 6912 e-mail:
[email protected]
JOIDES Office Department of Geology and Geophysics University of Miami - RSMAS 4600 Rickenbacker Causeway Miami FL 33149 Florida U.S.A. Tel: 1-305-361-4668 Fax: 1-305-361-4632 Email:
[email protected]
Working Group Chairmen Paleozoic
Cenozoic
PATRICIA, WHALEN, U.S.A.
ANNIKA SANFILIPPO California, U.S.A.
[email protected]
[email protected]
Mesozoic
Recent
RIE S. HORI Matsuyama, JAPAN
DEMETRIO BOLTOVSKOY Buenos Aires, ARGENTINA
[email protected]
[email protected]
INTERRAD is an international non-profit organization for researchers interested in all aspects of radiolarian taxonomy, palaeobiology, morphology, biostratigraphy, biology, ecology and paleoecology. INTERRAD is a Research Group of the International Paleontological Association (IPA). Since 1978 members of INTERRAD meet every three years t o present papers and exchange ideas and materials INTERRAD M EMBERSHIP: The international Association of Radiolarian Paleontologists is open to any one interested on receipt of subscription. The actual fee US $ 15 per year. Membership queries and subscription send to Treasurer. Changes of address can be sent to the Secretary. BIBLIOGRAPHIES: The bibliographies are produced by the Secretary. Any suggestion, reprints of articles and details of omission should be sent to him directly. Please send reprints of any radiolarian article to the Secretary this facilitate the edition of forthcoming bibliographies.
RADIOLARIA Newsletter of the International Association of Radiolarian Paleontologists ISSN: 0297-5270
VOLUME 21
JULY 2003
Editor: Jonathan Aitchison
CONTENTS
EDITORS NOTE .......................................................................................................................2 PLIENSBACHIAN TO AALENIAN WORKING GROUP S. Gorican and E.S. Carter .................................2 EHRENBERG COLLECTION ANNOUNCEMENT
Dave Lazarus .................................3
ODP MICROPLAEONTOLOGY REFERENCE COLLECTION ANNOUNCEMENT .....4 HOT NEWS ITEM INTERRAD X – THIRD CIRCULAR RADIOLARIAN BIBLIOGRAPHY 2002-2003
Demetrio Boltovskoy .................................4 .................................5 Jonathan Aitchison ...............................12
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EDITORS NOTE
Another year has passed since the last issue of RADIOLARIA. Doubtless, many of you are looking forward to our next meeting being organized by Peter and colleagues in Laussanne. I hope to see you all there. Thanks to all of you who contributed copies or details of publications, working group reports and other material to this issue. Without your contributions many would lose touch of what is happening in the rad world. This is be my last time as Secretary of Interrad and Editor of this newsletter. Life moves on and it is time for somebody else to take up this challenge. I wish my successor every success in continuing this tradition. Regards
Jonathan Aitchison
PLIENSBACHIAN TO AALENIAN WORKING GROUP
Spela Gorican and Elizabeth Carter The second meeting of the Pliensbachian – Aalenian Working Group was held in August 2002 in Ljubljana with four members in attendance: Beth Carter, Paulian Dumitrica, Spela Gorican, and Patricia Whalen. The purpose of the group is to produce a catalogue and a zonation (similar to that of Baumgartner et al. 1995) for the Pliensbachian, Toarcian and Aalenian. Zonation of these stages is essential to span the missing interval between the well-established Hettangian to Sinemurian (Carter et al. 1998) and Middle Jurassic to Lower Cretaceous (Baumgartner et al. 1995) radiolarian biozones. The systematics of 280 taxa earlier agreed upon has been expanded to 312 taxa and all will be included in the catalogue. Each taxon will be presented with an up-to-date synonymy, original and subsequent definitions, remarks, and data on geographic distribution. Plates will illustrate the holotype and sufficient other specimens from different paleogeographic realms to clearly illustrate intraspecific variability. The biochronological scale will integrate radiolarian-occurrence data from measured sections in the Circum-Pacific belt (Baja California, Oregon, British Columbia, Japan) and the Tethyan realm (Oman, Turkey, Slovenia, Austria). Jean Guex will be involved in calculating the range chart (protoreferential) using the BioGraph computer program, which is based on the Unitary 2
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Association Method (UA). Calibration for this new zonation will be based on ammonites cooccurring with radiolarians in Queen Charlotte Islands (British Columbia). The first draft of the zonation was presented at the 6th ISJS meeting in Palermo; the advanced version will be shown at INTERRAD X in Lausanne.
LATE CRETACEOUS – EARLY PALEOGENE WORKING GROUP - UPDATE
Members Yoshiaki Aita, Marta Bak, Peter Baumgartner, Kjell Bjørklund, Chuck Blome, Taniel Danelian, Paulian Dumitrica, Valesca Portilla Eilert, John Gregory, Chris Hollis, Donna Hull, Liu Jianbing, Kiyoshi Kawabata, Irina Khokhlova, Hsin Yi Ling, Marta Marcucci, Atsushi Matsuoka, Cathy Nigrini, Akiko Nishimura, Irina Popova, Mensi Rela, Toyasaburo Sakai, Annika Sanfilippo, Tatiana Shikova, Torstein Steiger, Osamu Takahashi, Elspeth Urquhart, Valentina Vishnevskaya. Co-chairs Hollis and Sanfilippo
EHRENBERG COLLECTION ANNOUNCEMENT
The Museum fuer Naturkunde in Berlin is pleased to announce an online ftp archive of Ehrenberg Collection documentation at: http://www.museum.hu-berlin.de:55080/Ehrenberg/. Scanned high resolution images of all of Ehrenberg's ca. 3000 pages of drawings are available, as well as the scanned pages of Clara Ehrenberg's index volumes to the collection. Other items include a fairly comprehensive (if not fully complete) list of Ehrenberg's publications, illustrative images of the collection materials, and a fair number of scanned plates from Ehrenberg's major monographs. This site will be regularly updated with additional materials. All images and information can be freely downloaded and used, although appropriate citation is expected. For futher information or assistance please contact the curator:
[email protected].
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ODP MICROPALEONTOLOGIC REFERENCE CENTER (MRC) ANNOUNCEMENT
The curators of the global MRC project are pleased to announce an online ftp site documenting the MRC collections at: http://www.museum.hu-berlin.de:55080/Ehrenberg/. Available are a downloadable relational database (ca 10,000 records) of the full radiolarian and diatom collections (calcareous microfossil data will be added in the future) and a set of maps showing the global distribution of MRC radiolarian samples by age interval. The database requires the program 4th Dimension v. 6.8 - downloadable versions for both Mac and PC are also available at the Museum's ftp site. A licence to run this software is available for free for academic use from 4D: www.4d.com. Users who are having difficulty obtaining this licence, or need help in using the database, should contact D. Lazarus, curator of the Berlin Radiolarian MRC Collection:
[email protected].
FIRST RECORD OF A BRACKISH POLYCYSTINE RADIOLARIAN HOT NEWS ITEM FROM A RECENTLY SUBMITTED MANUSCRIPT
Plankton samples collected in the Río de La Plata estuary (Atlantic coast of South America at approx. 35°S), and in coastal waters off Mar del Plata (approx. 38°S) yielded up to 394 live cells per liter of a single new nassellarian plagoniid species. In estuarine waters the species was recorded at salinities as low as 15.4≈; densities in excess of 100 cells per liter were found at salinities ranging between 16.9 and 33.2≈. These extremely high concentrations (the highest ever reported in the literature), as well as the fact that over 90% of the individuals recorded are provided with cytoplasm, indicate that these are self-sustaining populations which thrive in the estuary (and in nearshore coastal waters) probably due to plentiful dissolved silica and an abundant food supply. This is the first polycystine brackish-water species described. This finding shows that radiolarian fossils are not unequivocally associated with open-ocean conditions, but may also be useful indicators of coastal and brackish estuarine paleoenvironments. Reported by: Demetrio Boltovskoy, Mariela Kogan, Viviana A. Alder, Hermes Mianzan
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TENTH MEETING OF THE INTERNATIONAL ASSOCIATION OF RADIOLARIAN PALEONTOLOGISTS TO BE HELD AT THE UNIVERSITY OF LAUSANNE, SWITZERLAND, SEPTEMBER 8-12, 2003 THIRD CIRCULAR
DEADLINE FOR REGISTRATION AND SUBMISSION OF ABSTRACTS: APRIL 30, 2003 ********************************************************************** Dear Radiolarian Colleagues, Plans for the upcoming meeting are proceeding nicely. Sorry to be late again. The construction of our web site took more time that we thought. Unfortunately, due to time constraints the premeeting field trip to Spain had to be cancelled. We would like to invite participants of this field trip to subscribe for the field trip to Sicily. T-shirts will be for sale with the INTERRAD-X logo for approximately CHF 25.- We will have a variety of sizes available and it would be appreciated if you could order the number and sizes in advance via e-mail to
[email protected]. If you have any comments or questions, please do not hesitate to contact us
[email protected] We look forward to seeing you in September! Yours Peter O. Baumgartner CONTENTS OF THIS CIRCULAR - Meeting dates and location - Important dates - Fixed costs: Field trips Accommodation Registration fee - Scientific committee - Abstracts - Evening workshops - Scientific theme sessions - Special events ONLINE REGISTRATION PROCEDURES - Registration procedure - Abstract procedure - Personal page ********************************************************************** MEETING DATES: Sept. 7 (Sunday, travel day) - Sept. 13 (Saturday, travel day), 2003
MEETING LOCATION: University of Lausanne, Switzerland. For further information visit http://www.unil.ch/central/bref_en/acces/ ********************************************************************** IMPORTANT DATES: The Web site for on-line registration, payment and submission of abstracts is up and running. http://www-sst.unil.ch/interrad/ Registration for the meeting, field trips, and accommodation until April 30, 2003. Payment of registration fee, field trip costs, and accommodation deposit until April 30, 2003 Submission of abstracts until April 30, 2003 Submission of manuscripts for proceedings of the meeting until January 2004 ********************************************************************** FIXED COSTS: Costs have now been confirmed for the congress. All fees will be due in CHF. 1 CHF = 0.68 Euro or 0.72 US Dollar (March. 2003, be aware of fluctuations) FIELD TRIPS: For more details on the pre- and post-meeting field trips we ask you to contact the organizers listed below. Upon receipt of payment, you will be informed about the detailed logistics of each field trip by the field trip organizers. University mini buses will be used for the pre- and post-meeting field trips. PRE-MEETING FIELD TRIP, SICILY. Wednesday, September 3 to Sunday September 7. Mesozoic and Cenozoic radiolarian biostratigraphy and paleogeography of Sicily. Includes flight Geneva-Palermo-Geneva. Cost: CHF 1000. – Since the other pre-meeting field trip was cancelled, we think that those who were interested in Spain may find Sicily equally interesting! At present there are 16 persons interested in participating. Organizer: Marco Chiari:
[email protected]. MID-MEETING FIELD TRIP, Wednesday, September 10. Field trip to ZERMATT - GORNERGRAT by train. Structural geologists who have worked in the area will led the filed trip, this will allow us to observe a complete transect of the Central Alps. The transportation will be by bus and trains Cost: CHF 120. - Currently there are 34 participants for this trip. Free space ISstill available. It seems as if almost everybady will be going on this trip! Contact:
[email protected] POST-MEETING FIELD TRIP, Saturday, September 13 to Thursday, September 18. Mesozoic radiolarian occurrences in the Southern Alps (Belluno Basin) and Slovenia. Starts and ends in Lausanne. Cost: CHF 500. - At present there are 16 persons interested in participating. Organizer: Spela Gorican and Paola Beccaro:
[email protected]. TRANSPORTATION TO THE MEETING:
Participants should fly preferably to Geneva or alternatively to Zurich International Airports. Direct trains to Lausanne leave every 30 minutes from both airports. It takes 40 minutes from Geneva Airport and costs 26 CHF for an adult second-class one-way ticket and 46 CHF for a return ticket. It takes 3 hours by train from Zurich Airport to Lausanne, and costs 67 CHF for an adult secondclass one-way ticket and 123 CHF for a return ticket. For more information: http://www.rail.ch/index_e.htm The University of Lausanne and the Hotel can be reached within 20 minutes from the train station by public transport. We will provide you with maps and directions. The pre- and post-meeting field trips will start and end in Lausanne, or Geneva Airport respectively. ACCOMMODATION: The cost of accommodation INCLUDING THREE DAYLY MEALS is depending on your choice of room: Double room with shower on the hallway: CHF 90.- per day. Double room with private shower: CHF 100.- per day Single room with private shower: CHF 120.- per day During on-line registration it is possible to request to share rooms. Families traveling with a child: The maximum room size offered is for 2 people, therefore families wanting a small bed for a young child please contact us so we can arrange this for you REGISTRATION FEE: Registration fee: 200 CHF Student (includes undergraduate and graduate students, pre-PhD): 100 CHF REQUESTS FOR TRAVEL SUBSIDIES: We expect to be able to help fund travel and accommodation costs of a few participants who cannot come to the meeting without our help. Please contact us by mail
[email protected] with a preliminary budget and justification of the amount requested. ********************************************************************** SCIENTIFIC COMMITTEE: AITCHISON Jonathan, China BAUMGARTNER, Peter O., Switzerland BLUEFORD, Joyce R., USA BOLTOVSKOY Demetrio, Argentina CARTER Elizabeth, USA DUMITRICA Paulian, Switzerland GORICAN Spela, Slovenia GUEX Jean, Switzerland HORI Rie S., Japan MATSUOKA Atsushi, Japan O’DOGHERTY Luis, Spain
[email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] luis.o'
[email protected]
SANFILIPPO Annika, USA. URQUHART Elspeth, USA WHALEN Patrica, USA.
[email protected] [email protected] [email protected]
********************************************************************** TALKS: No parallel sessions will be held. Sessions will be organized based on the submitted abstracts. A speaker ready room will be set up, and information for the speakers will be mailed to speakers along with abstract acceptance notices. POSTERS: Posters will be hung for the duration of the meeting and specific time will be set-aside for authors to be present at their posters for their discussion and presentation. Maximum poster size is set at A0 (1189 mm x 841 mm). ABSTRACT LIMIT: As usual, each speaker will be limited to one oral presentation and two posters. You may be coauthor on additional abstracts that you are not presenting. Abstracts are to be submitted via the web site (for procedures see below). Abstracts are only accepted in digital format. They may include illustrations. Abstracts will have to fit on two pages of the abstract booklet. Therefore they will be limited to 1,000 words, or 500 words and one page of illustration, etc. Please submit illustrations on the web site as a .gif or .jpg file WITH MAXIMAL QUALITY. Maximum actual document size is limited to 270x170 mm. For further details of submission see below. ********************************************************************** EVENING WORKSHOPS: Please contact us by mail
[email protected], if you would like to propose a theme. To date the following themes are planned: Paleozoic Working Group Triassic-Jurassic Working Group Pliensbachian-Aalenian Working Group Middle Jurassic to Lower Cretaceous Working Group (progress and discussion of the revision of the Atlas) Late Cretaceous- early Paleogene Working Group ********************************************************************** SCIENTIFIC THEME SESSIONS: Technical sessions for INTERRAD 2003 will be plenary sessions, organized by theme. The listed conveners are tentative and incomplete. 1. Radiolarian biology, ecology, genomics. Convener: Atsushi MATSUOKA 2. Radiolarian taxonomy, systematics, and phylogeny. Convener: Paulian DUMITRICA 3. Radiolarian biochronology, quantitative methods, calibration, correlation. Convener: Jean GUEX 4. Radiolaria and Radiolarites as paleoenvironmental indicators. Convener: Patrick DEWEVER 5. Radiolarians in terrain analysis, structure and tectonics. Convener? 6. Development of radiolarian databases and computer tools. Convener: Giuseppe CORTESE 7. Radiolarian biostratigraphy of critical stratigraphic intervals. Several conveeners depending on interval.
Please note: the length of these sessions will be determined by the abstract submissions. Those with little or no interest will be cancelled or combined with other sessions. ********************************************************************** SPECIAL EVENTS: MID-MEETING FIELD TRIP: As has been the tradition at the last few meetings, we have reserved Wednesday, September 10 as a geo-sightseeing day. For those who wish to relax in Lausanne, the shores of Lake Geneva and against the backdrop of the Alps the great historical and cultural city of Lausanne offers its guests a wide variety of points of interest and leisure activities. For more information: http://www.lausanne-tourisme.ch/ For those wishing to sightsee, this year the mid-meeting field trip will be to ZERMATT GORNERGRAT by train. This trip will be led by structural geologists who have worked in the area and will allow us observe a complete transect of the Central Alps, with many panoramic stops and a gentle walk on a Mesozoic ocean floor on the Gornergrat at 3000 m above sea level. We will have a breathtaking view of many glaciers and the highest peaks of the Alps. Mountain boots and warm, waterproof clothing is required. CONGRESS DINNER: The Swiss folk dance evening will take place near the university grounds on the evening of Thursday, September 11. It will include meal and beverages. ********************************************************************** LETTERS OF INVITATION: Anyone who requires a letter of invitation, for either securing a visa or funding, please
[email protected] as soon as possible ********************************************************************** REGISTRATION PROCEDURE: 1. Web site http://www-sst.unil.ch/interrad/ 2. The registration page is a secure page protected by the University of Lausanne. Please fill all your personal details, mandatory fields are indicated. All information you submit at this stage can be changed at a later date using your chosen password to re-access the page. Please make sure you have entered a correct e-mail address, as all confirmation e-mails will be sent to this address. 3. If you are being accompanied please fill the name and surname of the accompanying person, please note an e-mail address for this person is not compulsory. 4. Choose your registration category. Please note that students will be required to present proof of full time enrolment at an accredited university during on-site registration at the beginning of the symposium. 5. Choose your preferred accommodation and how many rooms required. This option is available incase several rooms are required for accompanying persons. If you wish to share your room with a colleague/ accompanying person, please indicate the intended person. 6. Once you press the “Submit” button, you will be given another opportunity to verify your details. Your total bill will be calculated. In order to confirm your registration, payment of your full registration fee, total field trip cost and a 20% hotel room deposit is required.
7. Select your method of payment. If you wish to make a bank transfer, details will appear on the following page and they will also be sent to the e-mail address you entered, in order for you to proceed with your payment. 8. Your personal username is automatically set. Please enter a password. This will allow you to enter details in the abstract submission section. 9. Alternatively, if you prefer to send your payment details by fax, please print the payment page and send it to +41 (0) 21 692 43 05. ********************************************************************** ABSTRACT SUBMISSION PROCEDURE: 1.
Web site http://www-sst.unil.ch/interrad/
2. Enter your given username and chosen password. This was e-mailed to you during the registration process. 3. Enter the abstract title and authors details. If more spaces are required for authors details please click on “more”. Please note that each first author is limited to 3 abstract submissions, one oral presentation and 2 posters. In case you choose the option “I am not the presenting author”, you will be redirected to the list of participants where you can pick the name of the presenting author. If the presenting author is not yet registered, you are considered the presenting author but you will be able to change this information later. 4. Copy and paste your abstract into the space provided. The abstract word limit is 1,000 words maximum, or 500 words and one page of illustration. Important note: Special Characters for Use in Web Submission. When typing your abstract in the space provided, only plain characters can be used. If special features such as boldface, italic, superscript, and subscript are needed, you have to indicate these by the appropriate HTML tags. The use of such tags is not as complicated as it may seem, i.e. Stylosphaera hispida Before the word(s) After the word(s) Boldface Italics Superscript Subscript 5. Please submit illustrations to the web site as a .gif or .jpg file WITH MAXIMUM QUALITY. Maximum actual document size is limited to 17 x 25 cm. Click “Browse” to select the image from your hard drive. 6. Using the pull down menus chose your first and second preferred sessions to present your oral presentation/ poster. 7. Select the type of presentation, either oral or poster, and before you click on the submit button, be sure you have verified the information on this page. ********************************************************************** PERSONAL PAGE:
Once you have registered you have a personal page. This will allow you to make any desired changes to your abstract submission and your registration details. To access your personal page, please enter your user name and password hat was e-mail to you during registration. https://wwwdbunil.unil.ch/interrad/?MIval=scm_infoC **********************************************************************
Bibliography 2002-2003
Radiolaria 21
BIBLIOGRAPHY 2002-2003 Jonathan Aitchison
This compilation contains 153 references, mostly covering the 2002-2003 period. This list of publications includes pretty much anything that mentions the word radiolarian somewhere. Compilation has been possible thanks to the collaboration of colleagues who have sent their articles and I am grateful to all who have done this. AL-RIYAMI K., DANELIAN T. & ROBERTSON A.H.F. 2001. Radiolarian biochronology of Mesozoic deep-water successions in NW Syria and Cyprus!: implications for south-Tethyan evolution Terra Nova, 14, 271-280.
Neotethyan spreading axis. More probably, they originated near the south margin of the Northern Neotethys, but reached their position by out-of-sequence thrusting. Formation within a southerly strand of the Northern Neotethys (Inner Tauride ocean) is more probable than within the main Northern Neotethys further north.
New radiolarian biostratigraphical data have shed light on the Mesozoic tectonic evolution of South-Tethys in the Baer-Bassit region of NW Syria. Radiolarian assemblages of Late Triassic, Middle Jurassic and Early Cretaceous age were extracted from radiolarites in five measured sections. The results are compared with published radiolarian ages from the Mamonia Complex, western Cyprus. These two areas are interpreted as preserved fragments of the conjugate margins of a small South Tethyan oceanic basin formed by Triassic rifting. In the southerly (i.e. Arabian) margin proximal successions were dominated by shallow-water-derived carbonate, whereas distal successions reveal seamount-type alkaline/peralkaline volcanism, dated as both Late Triassic and Middle JurassicEarly Cretaceous. Along the northern margin (i.e. western Cyprus) proximal successions are dominantly terrigenous, whereas distal settings include Late Triassic oceanic crust and seamount-type lavas.
APEL, M., KIESSLING, W., BÖHM, F. AND LAZARUS, D. 2001. Radiolarian Faunal Characteristics in Oligocene Sediments of the Kerguelen Plateau, Leg 183, Site 1138. At: http://www-odp.tamu.edu/publications/ 183_SR/002/002.htm. Three sites from Ocean Drilling Program (ODP) Leg 183 (Kerguelen Plateau) have been analyzed to document faunal change in high-latitude radiolarians and to compare the faunal change to Eocene-Oligocene climatic deterioration. Radiolarians are not preserved in Eocene sediments. In Oligocene sediments, radiolarian preservation improves in a stepwise manner toward the Miocene. A total of 115 species were found in lower Oligocene samples from Site 1138; all are documented herein. Radiolarian preservation is presumably linked to productivity triggered by climatic cooling during the early Oligocene. Similar patterns of improving preservation through the Eocene/Oligocene boundary are documented from several Deep Sea Drilling Project and ODP sites in the Southern Ocean, indicating a general pattern. In contrast to the Southern Kerguelen Plateau, however, proxies for productivity are more divergent at Site 1138 (Central Kerguelen Plateau). Whereas carbonate dissolution, as indicated by poor preservation of foraminifers and common hiatuses, is very pronounced in the upper Eocene-lowermost Oligocene, the quality of radiolarian and diatom preservation does not significantly increase until the uppermost lower Oligocene. Multiple measures of radiolarian diversity in the Oligocene from Site 1138 closely parallel radiolarian preservation, indicating that preserved radiolarian diversity is controlled by productivity.
ANDREW, T. & ROBERTSON, A. H. F. 2002. The Beysehir-Hoyran-Hadim nappes; genesis and emplacement of Mesozoic marginal and oceanic units of the northern Neotethys in southern Turkey. Journal of the Geological Society of London 159 (Part 5), 529-543. The Beysehir-Hoyran-Hadim Nappes crop out over 700 km from NW to SE. Above a regionally autochthonous Tauride carbonate platform the Beysehir-Hoyran Nappes begin with a thrust sheet (c. 400 m) of mainly redeposited carbonates, quartzose sandstones and mudstones of Mid-Late Triassic age, interpreted as a proximal slope-base-of-slope succession. Above is a thrust sheet (c. 1 km) of Middle-Upper Triassic intermediate-acidic extrusive rocks, volcaniclastic rocks and minor pelagic carbonates, interpreted as a continental rift. Thin ( 100 m) nassellarian species. Spongaster tetras tetras, a surface water radiolarian species, exhibited its preference for high SST and moderate salinity conditions during the pre-monsoon season (March May). Radiolarian fluxes responded to seasonal changes in SST and salinity variations due to the monsoonal precipitation, and the freshwater runoff from the Indian rivers causing a hyposaline condition in the Bay of Bengal. Results imply that the radiolarian assemblages in the down core data may reveal the monsoonal history in the geological past.
G U , S. & FE N G , Q. 2002. Uppermost Permian radiolarian biostratigraphy of southern Guizhou, Southwest China. Journal of China University of Geosciences 13 (1), 44-47. With abundant deep-water upper Permian sediments, Guizhou is an ideal place for the research of radiolarian biostratigraphy of Upper Permian. The sections of Sidazhai and Lekang in southern Guizhou Province are studied. Lithology and biostratigraphy of the siliceous rock sequence of uppermost Permian in the two sections are introduced. Radiolarian assemblage zones, Neoalbaillella optima assemblage zone and Klaengspongus spinosus assemblage zone in ascending order are established for the topmost Permian of southern Guizhou. The Klaengspongus spinosus zone has been the topmost radiolarian assemblage zone of Permian, which is also correlated with former ones in a considerable depth.
HABIB, L. H. & EL R I C K , M. B. 2002. Early silicification of Upper Ordovician deep-water chert-limestone rhythmites, central Nevada. In: (ANONYMOUS eds). Geological Society of America, 2002 annual meeting abstracts. Geological Society of America (GSA). Boulder, CO, United States. 2002.
GUPTA, S. M. 2002. Pyloniid stratigraphy; a new tool to date tropical radiolarian ooze from the central tropical Indian Ocean. Marine Geology 184 (1-2), 85-93.
The Upper Ordovician Hanson Creek Formation of central Nevada is composed of 250 m of deep- to shallow-water carbonates, fine siliciclastics, and chert. The uppermost 40 m is characterized by thin, rhythmically interbedded, deep-water limestone and replacement chert (rhythmites). Limestonechert couplets average 20 cm thick and layers are laterally extensive over 100's m. Limestone layers ( approximately 10 cm) are composed of dark, laminated, pelletal microspar with sparse siliceous sponge spicules; chert layers ( approximately 10 cm) are composed of laminated, organic-rich, dolomitic, calcitic chert with abundant sponge spicules and sparse radiolarians. The rhythmites were deposited below storm-wave base during a global sea-level rise related to melting of Late Ordovician glaciers and immediately after the Late Ordovician global mass extinction. The interbedding between limestone and chert layers is interpreted to represent short-term (millennial-scale) fluctuations in upwelling. Increased intensity of upwelling provided the silica for fossil-rich chert layers. Evidence for very early silicification of limestone includes: limestone compaction around chert beds/nodules, only minor radiolarian compaction in cherts, and chert breccia fragments in submarine debris flow deposits lying 8 m above the rhythmites. Within chert layers approximately 50% of spicules and radiolarians are preserved as silica; the remaining are partially replaced by calcite with some silica preserved in fossil centers. At the scale of SEM observations, siliceous fossils are poorly preserved and are variably composed of silica, calcite or dolomite. Combined field and microscope observations suggest that during rhythmite deposition there were short-time intervals when there were more siliceous sponge spicules being deposited (now chert layers). Soon after deposition of sponge spicule-rich layers either: 1) many spicules dissolved and reprecipitated locally within layers as siliceous cement, while the carbonate in spicule-rich layers dissolved and reprecipitated in adjacent spicule-poor layers (now limestone) as calcite cement; or 2) many spicules dissolved and reprecipitated locally within layers as siliceous cement, while the carbonate matrix in the spicule-rich layers recrystallized locally or partially replaced the originally siliceous fossils.
Pyloniid stratigraphy, a faunal abundance-variation stratigraphic tool, similar to Cycladophora davisiana stratigraphy employed at high latitudes, is found to work well for tropical radiolarian ooze. The relationship between the spatial distribution of 25 modern radiolarian groups in surface sediments and monsoonal surface salinity from the central Indian Ocean is analyzed. Among them, Pyloniids exhibit the potential to serve in the same way as the C. davisiana stratigraphy. Down-core (temporal) variation of % Pyloniids in a sediment core is compared with (i) the sum of the Earth's orbital eccentricity, axial tilt and precession (ETP), (ii) solar insolation at the core site (8°S) and 65°N, and (iii) the SPECMAP-delta18O stratigraphy. The multi-taper (MTM) spectral analysis of Pyloniids for the last 485 ka in a core (AAS 2/3) reveals significant climatic cycles at the eccentricity (100 ka), tilt (41 ka) and precession (23 ka) bands. Cross-spectral analyses suggest coherent (>90%) Pyloniid cycles lag both the ETP and June insolation (65°N) by
