The Gruithuisen region in northern Oceanus Procellarum on the Moon contains three distinctive domes interpreted as nonmare volcanic features of Imbrian age. A 4 d extravehicular activity (EVA), four-astronaut sortie mission to explore these enigmatic features and the surrounding terrain provides the opportunity to address key outstanding lunar science questions. The landing site is on the mare south of Gruithuisen 3 (36.22°N, 40.60°W). From this site, diverse geologic terrains and features are accessible, including highlands, dome material, mare basalts, multiple craters, small rilles, and a negative topographic feature of unknown origin. Preliminary mission planning is based on Clementine multispectral data, Lunar Prospector geochemical estimates, and high-resolution (0.5 m/pixel) stereo images from the Lunar Reconnaissance Orbiter Narrow Angle Camera. Science objectives for the mission include: (1) determining the nature of the domes, (2) identifying and measuring the distribution of any potassium, rare earth elements, and phosphorus (KREEP)- and thorium-rich materials, (3) collecting samples for age dating of key units to investigate the evolution of the region, and (4) deploying a passive seismic grid as part of a global lunar network. Satisfying the science objectives requires 7 h, ~20 km round-trip EVAs, and significant time driving on slopes up to ~15°.

The Schrödinger impact basin near the southern pole on the lunar farside (134°E, 75°S) is a young multiring impact basin, and it is well preserved and exposed for scientific study. A crewed sortie-reconnaissance mission to Schrödinger Basin would allow (1) collection of samples in order to obtain an absolute age date for the Schrödinger impact event and to constrain the ages of volcanic events, (2) detailed analysis of pyroclastic materials that mantle the basin's impact melt sheet, (3) study of lunar explosive volcanism mechanics, and (4) installation of a passive seismic array for study of interior activity. The region's diversity of geologic materials and features make it a prime target for human and robotic exploration. A landing site located within the pyroclastic deposit (139.6°E, 75.7°S) allows access to the volcanic vent and inner ring of the basin. Sampling the inner ring, which may be composed of South Pole–Aitken Basin uplift material, would allow absolute dating of the South Pole–Aitken Basin event. Engineering objectives necessary for extending surface stay time for sortie missions or a lunar outpost can be met at this locale. Pyroclastic material is optimal for in situ oxygen production. Demonstrating oxygen production and storage at the landing site would prove technologies for an outpost and leave a cache of consumables for use by future longer-term expeditions. Mission planning is based on Lunar Reconnaissance Orbiter , Lunar Orbiter , Clementine , and SELENE mission data. Extravehicular activities necessary for completing the science objectives require long traverses (24 km and 7.5 h per traverse) for a four-member crew over a 4 d mission.

Abstract Southwest Alaska lies between the Yukon-Koyukuk province to the north, and the Alaska Peninsula to the south (Wahrhaftig, this volume). It includes the southwestern Alaska Range, the Kuskokwim Mountains, the Ahklun Mountains, the Bristol Bay Lowland, and the Minchumina and Holitna basins. It is an area of approximately 175,000 km 2 , and, with the exception of the rugged southwestern Alaska Range and Ahklun Mountains, consists mostly of low rolling hills. The oldest rocks in the region are metamorphic rocks with Early Proterozoic protolith ages that occur as isolated exposures in the central Kuskokwim Mountains, and in fault contact with Mesozoic accretionary rocks of the Bristol Bay region. Precambrian metamorphic rocks also occur in the northern Kuskokwim Mountains and serve as depositional basement for Paleozoic shelf deposits. A nearly continuous sequence of Paleozoic continental margin rocks underlies much of the southwestern Alaska Range and northern Kuskokwim Mountains. The most extensive unit in southwest Alaska is the predominantly Upper Cretaceous Kuskokwim Group, which, in large part, rests unconformably on older rocks of the region. Volcanic rocks of Mesozoic age are common in the Bristol Bay region, and volcanic and plutonic rocks of latest Cretaceous and earliest Tertiary age are common throughout southwest Alaska. Two major northeast-trending faults are known to traverse southwest Alaska, the Denali-Farewell fault system to the south, and the Iditarod-Nixon Fork fault to the north. Latest Cretaceous and Tertiary right-lateral offsets of less than 150 km characterize both faults. The Susulatna lineament (or Poorman fault), north of the Iditarod-Nixon Fork

Abstract Alaska is commonly regarded as one of the frontiers of North America for the discovery of metalliferous mineral deposits. A recurring theme in the history of the state has been “rushes” or “stampedes” to sites of newly discovered deposits. Since about 1965, mining companies have undertaken much exploration for lode and placer mineral deposits. During the same period, because of the considerable interest in federal lands in Alaska and the establishment of new national parks, wildlife refuges, and native corporations, extensive studies of mineral deposits and of the mineral resource potential of Alaska have been conducted by the U.S. Geological Survey, the U.S. Bureau of Mines, and the Alaska Division of Geological and Geophysical Surveys. These studies have resulted in abundant new information on Alaskan mineral deposits. In the same period, substantial new geologic mapping has also been completed with the help of new logistical and technical tools. One result of the geologic mapping and associated geologic studies is the recognition of numerous faultbounded assemblages of rocks designated as tectonostratigraphic (lithotectonic) terranes. This concept indicates that most of Alaska consists of a collage of such terranes (Silberling and others, this volume, Plate 3). The purpose of this report is to summarize the local geology, geologic setting, and metallogenesis of the major metalliferous lode deposits and placer districts of Alaska. The term “major mineral deposit” is defined as a mine, mineral deposit with known reserve, prospect, or occurrence that the authors judged significant for any given geographic region. This report is