Metaconglomerate is a
rock type which originated from
conglomerate after undergoing
metamorphism. Conglomerate is easily identifiable by the pebbles or larger clasts in a
matrix of
sand,
silt, or
clay. Metaconglomerate looks similar to conglomerate, although sometimes the clasts are deformed. The
cement matrix of conglomerate is not as
durable as the grains, and hence when broken, conglomerate breaks around the grains. Metaconglomerate, however, breaks through the grains, as the cement has
recrystallized and may be as durable as the clasts.[1]
Foliated metaconglomerate is created under the same metamorphic conditions that produce
slate or
phyllite, but with the parent rock (
protolith) being conglomerate, rather than clay.[2]
^VALLEY, John W.1, CAVOSIE, A.J., WILDE, S.A., GRANT, M., and LIU, Dunyi, JACK HILLS METACONGLOMERATE: EVIDENCE OF EARLY AND LATE ARCHEAN HYDROSPHERE, The Geological Society of America, 2002 Denver Annual Meeting
http://gsa.confex.com/gsa/2002AM/finalprogram/abstract_39602.htm
^ftp://rock.geosociety.org/pub/reposit/2002/2002034.pdf from: Peck, W.H., Valley, J.W., Wilde, S.A., and Graham, C.M., 2001, Oxygen isotope ratios and rare earth elements in 3.3 to 4.4 ga zircons: Ion microprobe evidence for high δ18O continental crust in the early Archean: Geochimica et Cosmochimica Acta, v. 65, p. 4215-4229.