Sorry (not really) to contradict so many people, but yes, Uranus does have lava, discovered by Voyager 2
Here's the first Google page on a "Uranus lava" search":
Oberon : color photometry from Voyager and its geological implications Lava flows ; Uranus ; Crater ; Craters ; Lava flows ; Satellite ; Satellites ; Uranus ; Lava flows ; Uranus ; Impactite ; Crater ; Craters ; Erosion ; Ice ...
cat.inist.fr/?aModele=afficheN&cpsidt=19728631 - Similar pages
PSRD: Uranus and Neptune: Late BloomersAug 21, 2001 ... The tardy formation of Uranus and Neptune might have caused the intense ... The Imbrium basin is older than the non-mare lava flows of the ...
www.psrd.hawaii.edu/Aug01/bombardment.html - 29k - Cached - Similar pages
Uranus - Google Books Resultby Seymour Simon - 1990 - Juvenile Nonfiction - 32 pages
The Voyager 2 photograph shows a tall mountain and many craters on its icy surface. The larger craters were once flooded by lava that has now become dark ...
books.google.com/books?isbn=0688099297...
Re: Does Miranda(Uranus Moon)have lava flows?Re: Does Miranda(Uranus Moon)have lava flows? Date: Mon May 1 20:34:52 2000. Posted By: Max Wahrhaftig, None Area of science: Astronomy ID: 955484775.As ...
www.madsci.org/posts/archives/2000-05/957260391.As.r.html - 6k - Cached - Similar pages
Uranus - Discovery of the planet, Voyager 2 mission to uranusUranus, the seventh planet from the Sun, was probably struck by a large object at some ... such as lava flows and the shifting of regions of lunar crust. ...
www.scienceclarified.com/Ti-Vi/Uranus.html - 16k - Cached - Similar pages
Internet Archive Search: subject:"Uranus"The Ugly Ducklings: The Composition of Uranus and Neptune - Alice Enevoldsen ... An investigation of the orbit of Uranus, with general tables of its motion ...
www.archive.org/search.php?query=subject%3A%22Uranus%22 - 44k - Cached - Similar pages
WikiAnswers - What special features are about UranusFive of Uranus's moons have icy, cratered surfaces. The craters show that the moons have been hit by rocks from space. Uranus's moons also have lava flows ...
wiki.answers.com/Q/What_special_features_are_about_Uranus - 46k - Cached - Similar pages
Uranus (Greek mythology) -- Britannica Online EncyclopediaFrom Gaea's subsequent union with Uranus were born the Titans, ... similar to earthquakes and volcanic eruptions, though of icy materials rather than lava. ...
www.britannica.com/EBchecked/topic/619280/Uranus - 52k - Cached - Similar pages
ASP: The topsy-turveying of planets, stars, and lava lampsMiranda, one of the moons of Uranus, appears to have a mantle made of ice ... Lava lamps work on the same principle. Heat causes blobs to form and float up. ...
www.astrosociety.org/education/publications/tnl/28/convection3.html - 13k - Cached - Similar pages
Lava FlowsEarth's Volcanos Video: Lava Flows. ... URANUS ... Lava flows are formed by molten rock that erupts in fountains like these, or pours across the ground from ...
http://www.solarviews.com/cap/index/uranus.html
Implying that a planet can't have lava because it is a gas giant doesn't make logical sense. ALL planetary bodies, even comets, have a rock core, whether or not it is still liquid or has solidified like the moon's core has solidified.