The Chukchi Sea Shelf or Chukchi Shelf is the easternmost part of the Continental shelf of Russia

Continental shelf of Russia

The continental shelf of Russia is a continental shelf adjacent to Russia. Geologically, the extent of the shelf is defined as the entirety of the continental shelves adjacent to Russia's coast...

 and the westernmost part of the Continental shelf of the United States

Continental shelf of the United States

The term continental shelf of the United States has two related meanings. Geologically, it is the total of the continental shelves adjacent to the United States...

. Geologically

Geology

Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

, it includes parts of the continental shelves adjacent to Russia, so that large sections of the seabed and subsoil of the submarine areas of the Chukchi Shelf are under US sovereignty.

The main geological features of the Chukchi Shelf are the Hope Basin

Hope Basin

The Hope Basin is a geological feature of the Chukchi Sea Shelf. It lies off the Chukchi Sea coast of Alaska. Its area extends from the outer continental shelf of the Seward Peninsula for about westwards off the coast of Chukotka towards Wrangel Island....

 and the Herald Thrust, a basement uplift cored by Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 thrust fault

Thrust fault

A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger...

s. The latter is named after Herald Island

Herald Island (Arctic)

Herald Island or Gerald Island is a small, isolated Russian island in the Chukchi Sea, to the east of Wrangel Island. It rises in sheer cliffs, making it quite inaccessible, either by ship or by plane. The only sliver of shoreline is at its northwestern point, where the cliffs have crumbled into...

. Off the northwestern Alaska

Alaska

Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

n coast there is a Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 rift basin, the Hannah Trough. In the north the Chukchi Shelf is limited by the Arctic Ocean

Arctic Ocean

The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...

 geological zone.

The Chukchi Shelf is shared between Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

 and the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 according to the 1990 USA-USSR maritime boundary.