Adam Sedgwick is one of the giants of early geology despite the fact that he was so often wrong.
Born in 1785 in Dent, the son of a Yorkshire vicar, Sedgwick found his life's work rambling around the Yorkshire countryside. Throughout his entire career, he was attatched in some way to Cambridge University. Entering Cambridge's Trinity College as a sizar, he was made a fellow in 1810. After eight years of mindless toil, he was made a professor, taking over the chair of John Woodward.
From there, his effect on the field of geology increased. His lectures were popular (and open to women), the geological collections at Cambridge expanded immnsely as Sedgwick prized apart the sequences of rocks in his travels across England and Wales. He worked to allow women admittance to Cambridge, which earned him a fan in Queen Victoria.
Segdwick's contribution to geology, however, is invariably tied to that of another geologist, his friend and later rival Roderick Impey Murchison. Sedgwick and Murchison began working together in the later 1830's. In 1839, they identified the Devonian period, then went their separate ways trying to work out the "transitional" layer beneath. While Murchison identified the Silurian system, Sedgwick worked out the older Cambrian system, then thought to contain the beginnings of life on Earth.
Unfortnately, Sedgwick's methods weren't the best. He assumed that rock layers were older than ones on top of them, and didn't understand that a recumbent or overturned fold could reverse the sequence. As a consequence of his dating methods, he didn't use fossils to correlate layers of similar age. Murchison began to find that some of his Silurian layers were the same as some of Sedgwick's Cambrian layers. A fight for geological turf (?)ensued, which continued until Sedgwick's death in 1873. At one point, Murchison tried to fold the entire Cambrian into the Silurian, but a compromise was worked out by John Lapworth in 1879, naming the time period of the disputed layers "Ordovician" after a warlike Celtic tribe of northern Wales.
Today, modern cretinsts use Sedgwick's opposition to gradualism and natural selection as an argument for an interpretation of the Bible containing a recent creation of the Earth. Of course, they don't know what they're talking about. Sedgwick was no young Earth creationist. He accepeted the notion of an ancient Earth -- indeed, he was responsible for demonstrating its reality. He accepted Louis Agassiz's theory of Ice Ages as the explanation for Pleistocene deposits and gave up the idea that they were caused by the Biblical Flood. Due to his religious upbringing, he never gave up the idea that the hand of God played a role in the creation of the Earth. But there's nothing wrong with that.
More seriously, Sedgwick was uncomfortable with his former student Charles Darwin's mechanism of evolution by natural selection. Sedgwick claimed it abandoned the inductional methods that science is founded upon, calling it "a pyramid which rested on its apex, and that apex a mathematical point". When Robert Chambers anonymously published an anonymous paper on the transmutation of species (containing many scientific errors) in 1844, Sedgwick responded with a 90-page critique. But in the end, his opposition wasn't scientific. He was afraid that the amoral notion would "brutalize" humanity and "undermine the whole moral and social fabric" of society (which of course misses the point).
In the end, the worst that could be said of Sedgwick was that he was a committed catastrophist, embracing the notions of Georges Cuvier and Agassiz. He probably would have had an affinity with the American school of Neo-Lamarckians who stressed intelligent design and a weird positivist philosophy of "progress" in evolution. One wonders what Sedgwick would think of modern ideas of punctuated equilibrium.