Earth & Environmental Sciences
accretion
23%
alluvial plain
67%
Archean
15%
basin
19%
breccia
27%
crystal
17%
dating
25%
dike
23%
explosive
31%
explosive volcanism
36%
fragmentation
22%
Gondwana
25%
graben
25%
history
15%
hot spot
54%
ignimbrite
96%
lamprophyre
33%
magmatism
29%
mantle
30%
Miocene
60%
monocline
32%
nepheline syenite
35%
paleomagnetism
30%
planet
22%
platinum
28%
river
17%
solar system
17%
stable isotope
21%
subsidence
42%
tuff
25%
volcanic ash
28%
volcanic eruption
74%
Medicine & Life Sciences
Artifacts
22%
Chronology
36%
Crystallization
30%
Fossils
51%
Hominidae
100%
Indonesia
65%
Islands
20%
Mars
38%
Occupations
25%
Oceans and Seas
29%
Uranium
20%
zircon
46%