Horlick Mountains

Horlick Mountains. The Horlick Mountains are a major mountain range within the Transantarctic Mountains system of Antarctica. They are situated in the continent's interior, forming a significant barrier between the East Antarctic Ice Sheet and the West Antarctic Ice Sheet. The range is notable for its extensive ice-covered plateaus, rugged peaks, and its critical role in scientific research into Gondwana and past climate change.

Geography and location

The range is positioned in West Antarctica, primarily within the Marie Byrd Land region, and stretches between the Reedy Glacier and the Scott Glacier. This location places the mountains deep within the Antarctic interior, contributing to their extreme isolation and harsh climatic conditions. The terrain significantly influences the flow of the East Antarctic Ice Sheet, with major outlet glaciers like the Reedy Glacier carving through the range. Its remote position has made access challenging, historically reliant on expeditions from McMurdo Station and supported by operations like those of the United States Antarctic Program.

Geology and composition

Geologically, the range is composed primarily of Beacon Supergroup sedimentary rocks, including sandstones and siltstones, which are intruded by Ferrar Dolerite sills. These formations are part of the extensive Transantarctic Mountains geologic province that records the breakup of the supercontinent Gondwana. The presence of coal seams within the Beacon Supergroup provides evidence of Antarctica's warmer, vegetated past. Structural features within the mountains also offer insights into the tectonic activity associated with the West Antarctic Rift System.

Discovery and exploration

The mountains were first sighted in December 1934 by the expedition of Admiral Richard E. Byrd, during his second Antarctic expedition, and were named for William Horlick, a sponsor. Further reconnaissance was conducted during Operation Highjump in the 1946-1947 season. Detailed geological mapping and study were significantly advanced by parties from the United States Antarctic Research Program during the International Geophysical Year. Later traverses by the University of Wisconsin–Madison and surveys supported by the British Antarctic Survey have contributed substantially to the modern understanding of the region.

Subfeatures and ranges

The primary constituent ranges include the Wisconsin Range, the Long Hills, and the Ohio Range. Notable individual features within these subranges encompass Mount Schopf in the Ohio Range, a site of important fossil discoveries, and the Maine Plateau within the Wisconsin Range. Other significant peaks and formations include Mount Glossopteris, Mount Wegener, and the Buckeye Table, each named for their scientific or exploratory significance. These features are often separated by immense glaciers like the Reedy Glacier.

Scientific importance

The range is a globally significant site for studying the Permian-Triassic geological record and the extinct Glossopteris flora, providing key evidence for the existence of Gondwana. Research conducted here, often involving the National Science Foundation and institutions like Ohio State University, has been pivotal for understanding ancient climate change and plate tectonics. The stable ice sheets adjacent to the mountains also serve as critical sites for deep ice core drilling, such as those projects linked to the West Antarctic Ice Sheet Divide, which reveal historical atmospheric data. Ongoing studies focus on geomorphology, paleontology, and the dynamics of the East Antarctic Ice Sheet.

Category:Mountains of Antarctica Category:Transantarctic Mountains Category:Marie Byrd Land