basal conglomerate

American  

noun

1. a conglomerate deposited on an erosion surface and constituting the bottom layer of a stratigraphic series.

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Etymology

Origin of basal conglomerate

First recorded in 1895–1900

Example Sentences

The lowest member is a basal conglomerate composed of pebbles derived from the erosion of the dark crumpled schists beneath,—schists which are supposed to be Archean.

From The Elements of Geology by Norton, William Harmon

The sea encroached on the new land, and spread far and wide a great basal conglomerate and coarse sandstones.

From The Elements of Geology by Norton, William Harmon

The basal conglomerate of the Potsdam formation is shown at the lower right-hand corner, and is overlain by sandstone.

From The Geography of the Region about Devils Lake and the Dalles of the Wisconsin by Atwood, Wallace W.