Editing Basalt (section)

====The Moon====
[[File:Lunar Olivine Basalt 15555 from Apollo 15 in National Museum of Natural History.jpg|thumb|Lunar [[olivine]] basalt collected by [[Apollo 15]] astronauts]]
The dark areas visible on Earth's [[moon]], the [[lunar mare|lunar maria]], are plains of [[flood basalt]]ic lava flows. These rocks were sampled both by the crewed American [[Apollo program]] and the robotic Russian [[Luna program]], and are represented among the [[lunar meteorite]]s.<ref name="lucey-2006">{{cite journal |last1=Lucey |first1=P. |title=Understanding the Lunar Surface and Space-Moon Interactions |journal=Reviews in Mineralogy and Geochemistry |date=1 January 2006 |volume=60 |issue=1 |pages=83–219 |doi=10.2138/rmg.2006.60.2|bibcode=2006RvMG...60...83L }}</ref>

Lunar basalts differ from their Earth counterparts principally in their high iron contents, which typically range from about 17 to 22 wt% FeO. They also possess a wide range of titanium concentrations (present in the mineral [[ilmenite]]),<ref name="NYT-20151228">{{cite news |last=Bhanoo |first=Sindya N. |title=New Type of Rock Is Discovered on Moon |url=https://www.nytimes.com/2015/12/29/science/new-type-of-rock-is-discovered-on-moon.html |date=28 December 2015 |work=[[The New York Times]] |access-date=29 December 2015 }}</ref><ref>{{cite journal |last1=Ling |first1=Zongcheng |last2=Jolliff |first2=Bradley L. |last3=Wang |first3=Alian |last4=Li |first4=Chunlai |last5=Liu |first5=Jianzhong |last6=Zhang |first6=Jiang |last7=Li |first7=Bo |last8=Sun |first8=Lingzhi |last9=Chen |first9=Jian |last10=Xiao |first10=Long |last11=Liu |first11=Jianjun |last12=Ren |first12=Xin |last13=Peng |first13=Wenxi |last14=Wang |first14=Huanyu |last15=Cui |first15=Xingzhu |last16=He |first16=Zhiping |last17=Wang |first17=Jianyu |title=Correlated compositional and mineralogical investigations at the Chang'e-3 landing site |journal=Nature Communications |date=December 2015 |volume=6 |issue=1 |pages=8880 |doi=10.1038/ncomms9880 |pmid=26694712 |pmc=4703877 |bibcode=2015NatCo...6.8880L |doi-access=free }}</ref> ranging from less than 1 wt% TiO<sub>2</sub>, to about 13 wt.%. Traditionally, lunar basalts have been classified according to their titanium content, with classes being named high-Ti, low-Ti, and very-low-Ti. Nevertheless, global geochemical maps of titanium obtained from the [[Clementine mission]] demonstrate that the lunar maria possess a continuum of titanium concentrations, and that the highest concentrations are the least abundant.<ref name="GiguereEtAl2000">{{cite journal |last1=Giguere |first1=Thomas A. |last2=Taylor |first2=G. Jeffrey |last3=Hawke |first3=B. Ray |last4=Lucey |first4=Paul G. |title=The titanium contents of lunar mare basalts |journal=Meteoritics & Planetary Science |date=January 2000 |volume=35 |issue=1 |pages=193–200 |doi=10.1111/j.1945-5100.2000.tb01985.x |bibcode=2000M&PS...35..193G |doi-access=free }}</ref>

Lunar basalts show exotic textures and mineralogy, particularly [[shock metamorphism]], lack of the [[redox|oxidation]] typical of terrestrial basalts, and a complete lack of [[mineral hydration|hydration]].{{sfn|Lucey|2006}} Most of the [[geology of the Moon|Moon]]'s basalts erupted between about 3 and 3.5 billion years ago, but the oldest samples are 4.2 billion years old, and the youngest flows, based on the age dating method of [[crater counting]], are estimated to have erupted only 1.2 billion years ago.<ref name="hiesinger-etal-200">{{cite journal |last1=Hiesinger |first1=Harald |last2=Jaumann |first2=Ralf |last3=Neukum |first3=Gerhard |last4=Head |first4=James W. |title=Ages of mare basalts on the lunar nearside |journal=Journal of Geophysical Research: Planets |date=25 December 2000 |volume=105 |issue=E12 |pages=29239–29275 |doi=10.1029/2000JE001244 |bibcode=2000JGR...10529239H |doi-access=free }}</ref>