Conglomerate

Conglomerate magnetic

Conglomerate

Lithogenous sedimentary rock.
This rock has the common appearance of stream river terrace deposit (a caliche deposit) from near mountain source area rich in ultramafic rocks (igneous and metamorphic rocks). This alluvial conglomerate that bears enough magnetite sand to be magnetic.
This same came from a consolidated alluvial fan deposit downstream from ultramafic bedrock area in the Diablo Range near Clear Creek BLM area, San Benito County, California.
https://gotbooks.miracosta.edu/rocks/sedimentary/35.html 2/2/2021