All Maps

In 1976, L.B. Magoon, W.L. Adkinson, and R.M. Egbert published a major geologic map of the Cook Inlet region, which has served well as a compilation of existing information and a guide for future research and mapping. The map in this report updates Magoon and others (1976) and incorporates new and additional mapping and interpretation. This map is also a revision of areas of overlap with...

Map showing the extent of lava flows erupted during Kīlauea’s ongoing east rift zone eruption and labeled with the years in which they were active.

Mesa Verde National Park in southwestern Colorado was established in 1906 to preserve and protect the artifacts and dwelling sites, including the famous cliff dwellings, of the Ancestral Puebloan people who lived in the area from about A.D. 550 to A.D. 1300. In 1978, the United Nations designated the park as a World Heritage Site. The geology of the park played a key role in the lives of...

Map showing the extent of lava flows erupted during Kīlauea's ongoing east rift zone eruption and labeled with the years in which they were active.

The north polar region of Mars occurs within the central and lowest part of the vast northern plains of Mars and is dominated by the roughly circular north polar plateau, Planum Boreum. The northern plains formed very early in Martian time and have collected volcanic flows and sedimentary materials shed from highland sources. Planum Boreum has resulted from the accumulation of water ice...

Map showing the extent of lava flows erupted during Kīlauea’s ongoing east rift zone eruption and labeled with the years in which they were active.

The Issaquah area includes several of the most outstanding geologic features of the eastern Puget Lowland region. Folds have warped thousands of meters of Tertiary sedimentary and volcanic rocks. Several hundred meters of both glacial and postglacial sediment have accumulated in a deep glacial trough, which is now partly occupied by Lake Sammamish but which was previously the conduit for...

Lago Garzas is located in west-central Puerto Rico, about 3.5 kilometers southwest of the town of Adjuntas, in the confluence of the Río Vacas and three other unnamed tributaries (fig. 1). The dam is owned and operated by the Puerto Rico Electric Power Authority (PREPA), and was constructed in 1943 for hydroelectric power generation and municipal water use along the southern coast. The...

Map showing the extent of lava flows erupted during Kīlauea's ongoing east rift zone eruption and labeled with the years in which they were active.

The San Juan Mountains in southwestern Colorado have long been known as a site of exceptionally voluminous mid-Tertiary volcanism, including at least 22 major ignimbrite sheets (each 150-5,000 km3) and associated caldera structures active at 33-23 Ma. Recent volcanologic and petrologic studies in the San Juan region have focused mainly on several ignimbrite-caldera systems: the...

The north polar region of Mars is dominated by Planum Boreum, a roughly circular, domical plateau that rises >2,500 m above the surrounding lowland. Planum Boreum is >1,500 km in diameter, contains deep, curvilinear troughs and chasmata, isolated cavi, and marginal scarps and slopes. The north polar plateau is surrounded by low-lying and nearly horizontal plains of various surface...

The Snegurochka Planitia region is a predominantly low-lying terrain that covers the north polar region of Venus, extending from lat 75° N. to 90° N. and from long 0° E. to 360° E. The plains associated with Snegurochka Planitia abut the highlands of Metis Mons to the south from approximately long 240° E. to 300° E. (V–6) and the highlands of Ishtar Terra to the south from approximately...