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climate of the region is the result of the permanent equatorial low-pressure zone (tropical convergence). Changes in sea level are known to have occurred during the last 30,000 years.

Laterally extensive domed peat deposits are forming on the coastal plain and on offshore islands. These deposits form because organic matter is accumulating faster than it can decay. High rainfall and dissolved organic acids inhibit decay and cause leaching of mineral matter, leading to the low concentrations of ash (less than 3 percent) and sulfur (less than 0.5 percent) in the peat. Sand and clay are generally being removed from the vicinity of the peat swamps by tidal currents; sediments are being deposited only in a few places in the estuaries and in the Straits of Malacca. Most sediment is being transported northwest through the Straits to the Andaman Sea.

dized tracts of burrowing marine organisms, which have been eroded from the underlying silty clay. The oxidized burrows record three probable changes in sea level. First, during an earlier period of high sea level (approximately 30,000 years ago), burrowing marine organisms. left tracks and trails in the silty clay bottom sediment. These burrows were mineralized with an iron carbonate mineral known as siderite. Approximately 18,000 years ago, during a lower stand of sea level, this bottom surface was exposed to the atmosphere, which oxidized the iron carbonate to iron oxide. Finally, about 5,000 years ago, sea level rose to its present position. Bottom currents are presently eroding and redepositing the burrows and shell fragments. These sealevel changes combined with the wet tropical climate of the region have

Figure 3. Land area of the continental shelf that was exposed approximately 18,000 years ago during a time of lower sea level.

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West Kalimantan

Phase two was conducted in a coastal setting in West Kalimantan (fig. 2). This study covered an area of approximately 9,300 square miles bounded on the east by the estuary of the Sambas River and on the west by the open water of the South China Sea. This second area was chosen for study because sedimentation is occurring on an open shallow shelf, seaward of a significant peat deposit. Such environments appear to be common in the rock record, but the modern counterpart has not been studied extensively.

Sedimentation is controlled by tidal currents in the Sambas estuary and by tidal and longshore currents along the coast. Like the Sumatra estuaries, the Sambas is erosional except near the mouth where a mouth bar or tidal delta appears to be developing. In contrast to the coastline of Sumatra, the coast in the study area of West Kalimantan may be slowly building seaward, as the result of clay being deposited in the intertidal and near-shore environments and sand forming small beaches and tidal flats. The offshore area is similar to the area offshore of Sumatra; the bottom surface appears to be erosional and highly irregular. The seafloor is covered by a thin veneer of coarse-grained sand and gravel, composed of fragments of shells and the oxi

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resulted in the formation of a thick (more than 26 feet), laterally extensive (approximately 62 square miles) domed peat deposit.

Future Studies

The field area for phase three of the research is expected to be in East Kalimantan (fig. 2). This area has been tentatively selected for study because of the physical contrast with the other two study areas. The area includes an inland basin surrounded by upland areas. One major drainage, the Mahakam River, passes through this basin. In further contrast, the peat in the basin is expected to have a planar rather than a domed upper surface. Therefore, ground and surface water may be the primary source of water, rather than the rainwater source for the other two areas. This area is expected to have marked differences in peat thickness and quality when compared to domed peat deposits.

Many conditions of the three study areas appear to be similar to those that controlled sedimentation, including peat formation, in a number of coal basins in the United States, Indonesia, and other parts of the world. These conditions include a tectonically active basin, a wet tropical climate, and worldwide changes

in sea level. The interactions of these processes have resulted in sedimentary systems that have little sediment input so that thick, high-quality, laterally continuous peat deposits can form. Such conditions appear to be responsible for the formation of coal deposits of known or inferred tropical or subtropical origins. These studies in Indonesia are expected to help answer remaining questions about the geologic processes that control the occurrence and quality of coal in the rock record. The answers will lead to more efficient and cost-effective methods in coal-resource assessment, exploration, and development.

Other International
Program Activities

The strengthening of earth-science institutions in foreign countries, training of foreign nationals, and exchange of scientists are activities integral to all international programs. During fiscal year 1988, 54 nationals from 22 countries received training in the United States; 41 visiting scientists from 17 countries conducted research at the USGS or at other facilities arranged by the USGS. Survey personnel trained more than 121

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foreign-national scientists and technicians either individually in-country or collectively in groups at scheduled regional training sessions. Examples include the marine geology course in Chile (15 participants), the hazards course in Italy (20), the cartography course in Bangladesh (22), and the deformation monitoring volcano hazards evaluations in Colombia (30), Peru (6), and Guatemala (5). Eighteen countries benefited from these USGS overseas training efforts.

Activities with the countries listed below were conducted by the USGS in fiscal year 1988 under bilateral agreements sanctioned by the Departments of State and of the Interior:

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Argentina

Mapping with satellite imagery. Bangladesh

Strengthening the Geological Survey of Bangladesh.

Bolivia

Evaluation of SPOT/Landsat images and map revision at 1:50,000 scale; mineral deposits modeling workshop on gold and silver.

Canada

Marine geology; geophysics; ore-deposit models; water resources; platinum-group elements; Great Lakes seismicity; Arctic research; mapping data exchange; border digital mapping; atmospheric deposition. Chile

Seismic zoning; improved earthquakeresistant designs; marine-geology training

course.

China

Surveying and mapping-cartographic applications of remote sensing and development of geographic information systems. Earth sciences-pyrophyllite deposits; comparative geochemical anomalies in Xinjiang and southwestern United States; modeling for Bayan Obo iron-niobium-rare earth deposit in inner Mongolia; comparative geology of southern China and western U.S. Surface water-sediment transport; hydrologic equipment and measurements; hydrologic extremes; analytical techniques; cold-regions hydrology; hydrologic data exchange. Earthquakes-deep crustal structures in fault zones; premonitory phenomena; crustal stress; seismic networks; rock mechanics; intraplate active faults. Dominican Republic

Study of biochemical corrosion of gates of the Sabama Yequa Reservoir.

El Salvador

Geologic hazards assessment; evaluation of seismic hazards and compilation of seismic

risk map.

France

Oceanography; geophysics; radioactive wastes; minerals assessment; borehole geophysics application to water resources; seaice monitoring; remote sensing in Polar regions.

Germany

Marine seismology; radioactive wastes; petroleum resource assessment; Antarctic research; sea-ice monitoring; marine minerals assessment.

Hungary

Petroleum resource potential of the Pannonian Basin; geophysics.

Iceland

Geophysics; geology; hydrology.

India

Multidisciplinary workshops; identification of mutually beneficial joint projects. Indonesia

Volcano monitoring; marine geology; peat swamps as coal field analogs.

Italy

Installation of digital seismographs; earthquake reconstruction; training course on hydrological and landslide hazards; improvement of capability for early warnings of volcanic eruptions.

Japan

Deeply buried mineral deposits; gold deposits; debris flows; sediment transport on continental shelves and in estuaries.

Jordan

Seismic network; remote sensing.

Korea

Sedimentary basin analysis.

Mexico

Border mapping cooperation; color image maps.

A fishing village on a stream draining one of the peat swamps in the coastal plain of central Sumatra. (Photograph by Sandra Neuzil.)

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Digital sonar images data processing; soil genesis and hydrochemical weathering

assessment.

Pakistan

Coal resources exploration and assessment; institutional modernization of Geological Survey of Pakistan.

Panama

Earthquake hazards mitigation.

Papua New Guinea

Mineral resource assessment.

Portugal

Massive sulfide deposits in the Iberian pyrite belt.

Saudi Arabia

Mineral resources assessment and data base; geographic and geologic cartography; geochemistry and geophysics; Landsat image maps; seismic network; strengthening of the earth sciences community. Spain

Ground-water geochemistry and flow systems; remote sensing for mineral deposits; earthquake research; marine geology of continental margins; water-resources management and pollution reduction; goldalunite deposits; hydrochemistry in Canary Islands.

United Arab Emirates

Ground-water resources assessment of Abu Dhabi.

United Kingdom

GLORIA seafloor sonar imaging surveys; Antarctica remote sensing image mapping. USSR

Earthquake prediction; estimation of seismic risk and seismic sources; marine mineral resources; climate changes; cooperative project discussions.

Venezuela

Geologic mapping and mineral resources

assessment of the Guayana shield; erosion rates and sediment composition of the Orinoco River.

Yugoslavia

Agrogeology; soils surveys; geochemical exploration methods; seismology and earthquake hazards; granite metamorphic complexes; remote sensing; coal quality; water and soil sampling.

Programs in which activities were conducted under multilateral agreements in fiscal year 1988 included

Executive briefing on strategic planning to reduce economic impacts of earthquake hazards worldwide in preparation for a forthcoming cooperative program.

• International Strategic Minerals Inventory, cooperative studies by the USGS and the U.S. Bureau of Mines with Australia, Canada, West Germany, South Africa, and the United Kingdom to develop a global assessment of strategic commodities including cobalt, nickel, platinum, and titanium.

⚫ Global Seismic Network, the generation of a comprehensive, unrestricted seismic data base for fundamental earthquake monitoring and research (150 stations in 54 countries).

Famine Early Warning System (FEWS), the application of geographic information systems to target populations at risk of famine in eight sub-Saharan and Horn of Africa countries: Mauritania, Mali, Burkina, Niger, Chad, Sudan, Ethiopia, and Mozambique.

• AGRYMET, identification of remote sensing data requirements to make agricultural, hydrological, and meteorological assessments in nine west African coun

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tries: Mauritania, Senegal, Gambia, Guinea-Bissau, Cape Verde, Mali, Niger, Burkina, and Chad.

• Grasshopper and locust habitat identification and monitoring by remote sensing in Chad, Mali, Mauritania, Niger, and Sudan.

• Antarctic research including acquisition of geodetic data, aerial photography, and satellite imagery to produce base maps and to assess changes in the glaciers and ice sheets composing the margin of Antarctica due to global change; operation of the Scientific Committee on Antarctic Research (SCAR) Library for Cartography and Geodesy; seismology and data telecommunications at the South Pole; ice cap motions, sea-ice monitoring, and low-frequency-radar ice experiments; lakes in dry valleys as related to the global carbon cycle. • Interagency Volcano Early Warning Disaster Assistance, which provides for emergency responses to crises related to volcanic eruptions.

• Advisory consultations, particularly in resource assessment methodologies, to intergovernmental geoscience organizations in eastern Asia; preparation of regional base maps at 1:2,000,000 scale covering approximately 12 million square miles.

Mineral deposit evaluations for the Pacific Trust Territories; assessment work on Guam and Saipan.

• Circum-Pacific Mapping Project, program coordination and the cartographic preparation of about 60 thematic maps. • Comparative earthquake and tsunami potential for zones in the Circum-Pacific.

Southwestern Pacific offshore exploration for petroleum resources.

• Advisory coordination and training in coastal geologic hazards and resources assessments in the western/southwestern Pacific.

Technical expertise provided to agencies of the United Nations as requested: spectrographic analyses (Guyana); geothermal feasibility (Honduras); mineral resources (Mozambique); marine geophysics (China); seismology (Peru); water resources (India); mineral deposit modeling workshop (Chile).

28th International Geological Congress.

For the first time since 1933, the United States played host to the International Geological Congress. The National Academy of Sciences and the USGS were the official hosts for the 28th session of the Congress, held in Washington, D.C., July 9-19, 1989.

The goal of the Congress is to encourage the advancement of fundamental and applied research in the earth sciences worldwide. To achieve this goal, an international congress is organized about every 4 years by scientists in member countries of the International Union of Geological Sciences. The Congress brings together a broad representation of the world's earth scientists for a unique opportunity to exchange scientific information and concepts.

The Congress provides a special forum for new and sustained international exchange of geological knowledge. It is an event with long-term value in the continuing effort to advance worldwide understanding of the Earth and thereby improve our capability to manage its resources wisely.

Members of the 16th International Geological Congress held in Washington, D.C., in 1933.

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