Conference Reports 117 deposit lies a mixture of slumped/convoluted marine sand and coarse, angular debris- Sea level changes and coastal evolution flow/rock-avalanche gravel (Figure 2). Abundant shallow marine shells, having (INQUA) and Neotectonics (INQUA) lived in a water depth of 5-50 m (identified by H.W. Chen of the Central Geological Sur- vey, R.O.C.), are included in the deformed Taipei, China, October 17–24, 2001 sand body. They are dated around 8.9 and 9.2 ka (unpublished data by M.Y. Hsu). Wood The international meeting on both Sea level zone. The middle and southern portions of fragments are commonly incorporated in the changes and coastal evolution (INQUA) and eastern coast have a high uplift rate. debris-flow deposits; they are dated 8-9 ka. Neotectonics (INQUA) was held in Taiwan Holocene transgression deposits reach more These debris-flow gravel and deformed sand on 17–24 October 2001. Participants came than 50 m amsl or more. There are com- deposits (maximum thickness 20 m) are trun- from more than 10 countries including mem- monly 3–4 flights of Holocene terraces. The cated and overlain by beach (and fluvial) bers of these two commissions of INQUA flight with altitude 37~40 m amsl in the mid- gravel, which inclines shoreward and con- and scientists who were interested in these dle portion of the eastern coast is dated as 5 nects the modern beach at the easternmost topics. This meeting includes two days pre- ka—the age corresponding to the maximum part of the terrace. At the western part of the sentation and four days field excursion to the Holocene transgression around Taiwan. Fan terrace, abundant pottery fragments are very rapid uplift of eastern coast and the deposits superposed on marine deposits of found within this beach gravel. The pottery (at level of 42–46 m in elevation) belongs to 1999 earthquake fault of Taiwan. People terrace is common in this high relief coastal the culture that probably ranges from 4000 to experienced the topography and geological zone. This photo of Tulan Terrace in south- 3500 years ago (Liu and Yen, 2000), and that features under very dynamic natural forces, ern portion of the eastern coast shows tec- yields an uplift rate of at least 1 cm/yr. internal and external. Internal (tectonic) tonic uplift and debris—flow events from Walk to the sea cliff, almost all types of forces coming from the continuous collision deglacial fan-delta sequence. marine sediments on the coast can be of Philippine Sea plate with Eurasian plate The Tulan terrace (Figure 1) is one of observed. Look at the spectacular outcrop on since late Miocene results in the very high the two largest emergent fan-deltas on the the sea cliff and try to imagine what hap- uplift rate of this mountain belt especially eastern coast. The terrace is underlain by a pened to the coast 8000–9000 years ago and eastern coast and large part of southern Tai- mudstone platform which slopes to and even- since then. wan. External forces may be partly due to the tually submerges beneath the sea. This plat- high precipitation during summer in this form is overlain by well-sorted nearshore island—the frontal belt of Asian monsoon sand, which increases landward in height and Ping-Mei Liew and Meng-Long Hsieh situation. Both erosion and deposition thickness. Marine shell fragments in this Department of Geosciences process intensively. deposit are dated 12–15 ka (Pirazzoli et al., National Taiwan University Eastern coast of Taiwan is situated on 1993; Yamaguchi and Ota, 2001), which 245 Choushan Rd., Taipei the accreted arc and proximal to the collision yields uplift rate of 6–9 mm/yr. Above this TAIWAN, CHINA Figure 2 Debris-flow and slump deposits exposed on the Tulan sea cliff (25–30m in height). (a) – A view to the southwest. The more resistant tuffaceous debris-flow gravel (white colored) (T) forms precipitous cliffs. In contrast, the negative topography between these cliffs is composed of slumping and convoluted marine sand (S). These disorganized deposits are underlain by well-stratified shallow marine sand (N), which overlies a shoreward-sloping mudstone platform (M). The top of the debris-flow and slumping deposits is truncated and covered by beach gravel and sand dunes. (b) and (c) – Close view of the Figure 1 Morphology of the coast around Tulan. tuffaceous-gravel blocks (T) and deformed marine sand (S). Episodes, Vol. 25, no. 2 118 Polar regions of the earth: geology, tectonics, resource value, natural environment St. Petersburg, Russia, November 1–3, 2001 The international conference Polar Regions general geological knowledge and tectonic of the Earth: Geology, Tectonics, Resource interpretations, and systematic production of Value, Natural Environment was held in St. GIS-based State Geological Map Series of Petersburg, Russia, on November 1–3, 2001 the Russian continental shelf. G. Grikurov at the premises of All-Russia Research Insti- presented evolution of views on tectonic tute for Geology and Mineral Resources of structure and history of Antarctica in context the World Ocean "VNIIOkeangeologia" of modern isotopic and geochemical analyti- (Ministry of Natural Resources of the Russ- cal data from bedrock geology on land , and ian Federation/Russian Academy of Sci- new geophysical evidence from submarine ences) and Arctic and Antarctic Research continental margin. A. Danilov and V. Institute (Federal Survey for Hydrometeorol- Lipenkov spoke about present-day and pale- ogy and Environmental Monitoring). It was oclimate changes in the Polar regions with an EUROPROBE program in the Arctic, and A. an immediate continuation of the 7th Zonen- emphasis on comparative studies of Arctic Opekunov concluded the session by address- shain Conference on plate tectonics that had and Antarctic records. I. Gramberg gave a ing the environmental geology aspects of assembled during the three preceding days in comprehensive overview of oil and gas exploration and development of the Arctic Moscow. Both events were jointly arranged potential of the Arctic Ocean and adjacent subsurface resources. by the same organizing committee that lands and stressed the outstanding impor- During two subsequent days the main agreed on presentation of most Arctic and tance of this region as a global energy source themes outlined in the plenary session were Antarctic contributions at the St. Petersburg in the third millennium. A. Dodin argued for elaborated in seven parallel oral/poster ses- meeting. a similar value of the Arctic hard minerals sions. Speakers in a half-day Session 1 The conference in St. Petersburg was and the existence in the Arctic of a circum- "Deep-sea Basins, Oceanic Ridges and Rises dedicated to 100-years anniversary of two polar and a transpolar metallogenic belts rich of the Arctic Ocean" concentrated mainly on prominent Arctic scientists, Nikolai Gedroitz in variety of ore deposits. A. Grantz summa- the Eurasian Basin and its immediate conti- and Yakov Gakkel, both born in 1901. The rized concepts on geologic framework and nental flanks. O. Engen showed distribution former was the first of polar explorers who tectonic evolution of the Arctic Ocean Basin and focal mechanisms of earthquakes along foresaw enormous hydrocarbon potential of shared by the majority of western geologists the Gakkel Ridge plate boundary; V. Pease the Arctic region and attracted attention of who believe that, with the exception of the discussed the results of isotopic dating of earth scientists to oil and gas exploration in Lomonosov Ridge and the Chukchi Border- detrital zircons derived from the Lomonosov the Russian North, including the shelf basins land, the crust beneath the entire Arctic deep Ridge bedrock; V. Poselov and B. Kim in on Eurasian continental margin. Ya. Gakkel seabed was formed by Cretaceous and Ceno- separate presentations stressed the peculiar was famous for diversity of his scientific zoic spreading processes. Yu. Pogrebitsky features of sediment distribution in the Eura- interests that covered a variety of Arctic presented an alternative concept of an essen- sia Basin and on the Lomonosov Ridge and research disciplines and enabled him to theo- tially epicontinental evolution of the considered the limitations imposed by those retically predict the existence of submarine Amerasian Basin, and A. Zatzepin supported features on commonly accepted models of ridges in the central Arctic Ocean; one of this view by demonstrating the results of the Eurasia Basin evolution by ocean floor such ridges was named after Gakkel and has geophysical and geological studies carried spreading. I. Gramberg recognized in the his- since become a major focus of modern geo- out in 2000 on the Mendeleev Rise and inter- tory of the Eurasian Basin a rifting stage (late logical and geophysical exploration and a preted in terms of a continental nature of this Cretaceous to Eocene) and a spreading stage site of many recent exciting discoveries. major bathymetric high. Contrasting views (Oligocene to Recent); he also interpreted the The attendance of the polar conference on geodynamic evolution of the Polar elevated Barents-Kara Seas margin and the exceeded 200 participants who contributed regions were also presented by several next Lomonosov Ridge as structural highs that over 150 oral and poster presentations. All speakers. R. Kurinin explained the observed compensated the deepening of the Eurasian oral sessions were conducted in Russian and satellite gravity anomalies by advective Basin in the course of rifting and spreading English languages and equipped with simul- forces in the mantle that cause long-term processes. A. Pavlenkin talked about general taneous translation. The conference started changes in the lithosphere; S. Kostyuchenko characterization of passive margin to ocean with one day-long (1st November ) plenary used the results of deep seismic profiling to transition in the Arctic and the Atlantic, and session that included welcoming and intro- highlight the specific features of sedimentary M.
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