What rock type can be described as a mafic volcanic rock that is dark, heavy and appears in hand sample to be hard solid material with abundant tiny crystals of dark minerals that glint and sparkle in strong light?

a. Basalt

b. Pumice

c. Scoria

d. Rhyolite

Select the correct text in the passage. the moving continents affect all subsystems on earth. which sentence identifies a potentially negative consequence of shifting continents? the supercontinent pangaea began to break up about 175 million years ago. [during this process, more coastline was exposed as the landmasses separated]. [the rearrangement and displacement of these huge landmasses resulted in the diversity of plants and animals we see on earth today]. [the movement of the plates sometimes leads to earthquakes and tsunamis]. however, over the long course of earth's history, their effects are usually minimal. in oceans, the plate movements usually lead to seafloor spreading. [seafloor spreading often results in the formation of underwater ranges of mountains].

Over half of the african-american population in the united states live in

Which characteristics of temperature and salinity have the greatest influence on the movement of deep-ocean currentsa. warm and low salinityb. cold and high salinityc. cold and low salinityd. warm and high salinity