<div style="margin: 12px 0px; font-family: arial; color: #333333; background: #ffffff; border: solid 4px #e5e5e5; width: 100%; clear: left;"><div class="CM_CTB_Content_Wrap" style="margin: 0px; padding: 0px;background-color: #ffffff;"><div style="border-bottom: solid 1px #dcdcdc; white-space: nowrap; margin-bottom: 8px; background-color: #eeeeee ;background-image: url(http://clipmarks.com/images/source-bg.gif); background-repeat: repeat-x; height: 24px; line-height: 24px; vertical-align: middle; padding-bottom: 4px; color: #666666; font-size: 10px;" ><a href="http://clipmarks.com/clip-to-blog/" title="see clips that are hot right now"><img src="http://content.clipmarks.com/blog_embed/01849569-92be-42fc-b85e-a0a645edd855/F7ACB15C-7E29-4B59-B426-B31FBB239E22/" alt="" width="19" height="19" border="0" style="vertical-align: middle; margin: 0px 4px; display: inline; border: none; float:none;" /></a>clipped from <a title="http://en.wikipedia.org/w/index.php?title=Tholeiitic_basalt&oldid=230029302" href="http://en.wikipedia.org/w/index.php?title=Tholeiitic_basalt&oldid=230029302" style="font-size: 11px;">en.wikipedia.org</a></div><blockquote style="text-align: left; padding: 0px 8px; margin: 4px 0px 8px 0px; background: transparent; border: none;" cite="http://en.wikipedia.org/w/index.php?title=Tholeiitic_basalt&oldid=230029302"><P>Basalt magmas are partial melts of <A title="Peridotite" href="http://en.wikipedia.org/wiki/Peridotite">peridotite</A> produced by decompression melting in the <A class="mw-redirect" title="Earth's mantle" href="http://en.wikipedia.org/wiki/Earth%27s_mantle">Earth's mantle</A>, a process described for <A title="Igneous rock" href="http://en.wikipedia.org/wiki/Igneous_rock">igneous rocks</A>. Tholeiitic basalts are the most common <A title="Volcano" href="http://en.wikipedia.org/wiki/Volcano">volcanic</A> rocks on <A title="Earth" href="http://en.wikipedia.org/wiki/Earth">Earth</A>, as they are produced by <A title="Submarine volcano" href="http://en.wikipedia.org/wiki/Submarine_volcano">submarine volcanism</A> at <A title="Mid-ocean ridge" href="http://en.wikipedia.org/wiki/Mid-ocean_ridge">mid-ocean ridges</A> and make up much of the ocean crust. <B>MORB</B>, the acronym for typical <B>m</B>id-<B>o</B>cean-<B>r</B>idge <B>b</B>asalt, is a type of tholeiitic basalt particularly low in <A title="Incompatible element" href="http://en.wikipedia.org/wiki/Incompatible_element">incompatible elements</A>. In contrast, alkali basalt is not typical at ocean ridges, but is erupted on some oceanic islands and on continents, as also is tholeiitic basalt. (AGI, 41), <A rel="nofollow" title="http://micro.magnet.fsu.edu/primer/techniques/polarized/gallery/pages/basalttholeiiticsmall.html" class="external autonumber" href="http://micro.magnet.fsu.edu/primer/techniques/polarized/gallery/pages/basalttholeiiticsmall.html">[2]</A></P></blockquote></div><div style="margin: 0px 6px 6px 4px;"><table style="font-size: 11px;border-spacing: 0px;padding: 0px;" cellpadding="0" cellspacing="0" width="100%"><tr><td style="background:transparent;border-width:0px;padding:0px;">&nbsp;</td><td align="right" style="background:transparent;border-width:0px;padding:0px;width:107px" width="107"><a href="http://clipmarks.com/share/F7ACB15C-7E29-4B59-B426-B31FBB239E22/blog/" title="blog or email this clip"><img src="http://content7.clipmarks.com/images/c2b-foot.png" border="0" alt="blog it" width="107" height="17" style="border-width:0px;padding:0px;margin:0px;" /></a></td></tr></table></div></div>

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