Quaternary stratigraphy and chronology of Mauna Kea, Hawaii: A 380,000-yr record of mid-Pacific volcanism and ice-cap glaciation

Author:

Porter, Stephen C.

Title:

Quaternary stratigraphy and chronology of Mauna Kea, Hawaii: A 380,000-yr record of mid-Pacific volcanism and ice-cap glaciation

Periodical:

Geological Society of America Bulletin, Part II

Year:

1979

Volume:

90

Pages:

980-1093

Subject:

Mauna Kea volcano Glaciation Geochronology

Summary:

Mauna Kea, the highest of five massive shield volcanoes that makes up the island of Hawaii, is where evidence of glaciation exists on the upper slopes of this volcano that is located in the basin of the central Pacific Ocean. Even though this high landmass was built largely during Pleistocene time, Mauna Kea has experienced minor eruptive activity during Holocene time that last occurred approximately 3,600 to 5,000 yr ago. While glaciers do not exist on this mountain today, (since the snowline currently lies above the summit (4,206 meters)), this volcano has supported a succession of small ice caps during the last several glacial ages. This is evidenced by wide spread glacial landforms and numerous stratigraphic sections on the upper slopes. Here, eruptions occurred intermittently during late Pleistocene time, for both lava flows and tephra layers of this age are intercalated with sheets of glacial drift. Since most lava flows and associated pyroclastic cones that lie within the limits of former ice caps can be stratigraphically related to the glacial deposits, this provides a basis for the relative dating of volcanic and glacial events. In addition, certain distinctive volcanic landforms and deposits, which in Hawaii apparently are unique to the upper slopes of Mauna Kea, provide striking evidence of subglacial eruptions. Such volcanic units offer a direct basis for obtaining radiometric ages of several episodes of ice-cap glaciation. Therefore, this is the purpose of this investigation.

Label:

Geology - Glaciation

URL:

http://cletus.uhh.hawaii.edu:2074/10.1130/GSAB-P2-90-980

Collection:

Periodicals