William B. Clarke, geologist and Church of England clergyman, studied at Jesus College, Cambridge from 1817 and was awarded the degrees Bachelor of Arts (1821), and Master of Arts (1824). He was ordained deacon in 1821 and priest in 1823, and served as a clergyman. Clarke was elected a Fellow of the Geological Society of London in 1826. He made fifteen geological excursions in continental Europe and published numerous scientific papers. These included three papers on meteorites (1833-1836), one on electrical phenomena (1837), two on the geology of Britain (1838), and two on the fall of dust in the Atlantic Ocean. He also wrote poetry, which was published in five volumes between 1819 and 1829.
In 1839 he went to New South Wales, Australia, for health reasons. He must have visited the Cape on his way there, for he wrote a paper, "On the geological phenomena in the vicinity of Cape Town, South Africa", which was published in the Proceedings of the Geological Society of London (1838-1842, Vol. 3, pp. 418-423). A summary of the paper was published in the South African Commercial Advertiser in 1842. Clarke described the physical geography of the Cape to the Hottentots-Holland Mountains, followed by the geology of the coastal area from Green Point to beyond Camp's Bay, and Table Mountain. He recorded several observations which led him to conclude that in comparatively recent times the sea had been much higher than at present, for example, the presence of marine shells in the sands of the Cape Flats. Thus the Cape Peninsula and Table Mountain would have been islands. The paper was written after his arrival in Australia, for he remarked on the general similarity of the geological structure of the Cape and New South Wales.
Clarke continued his geologising in Australia, though he also became headmaster of a school and worked as a cleric until his retirement in 1870. He played a key role in the discovery of gold in the alluvial deposits of the Macquarie River in 1841, and did extensive research on the coal deposits of New South Wales. In 1851 he published a pamphlet on the discovery and working of gold in Australia, and in 1869 another on earthquakes, with special reference to tremors felt in New South Wales. In 1860 he produced a book, Researches in the southern gold fields of New South Wales, which was published in Sydney. His Remarks on the sedimentary formations of New South Wales (1867) was of enough interest to lead to a fourth edition in 1878. In numerous scientific papers he described fossil pines on the Australian east coast, the geology of the island Lifou (New Caledonia) in the south Pacific, Carboniferous plants in New South Wales, Trilobites in New South Wales, the solar eclipse at Paramatta on 1 February 1851, and many other aspects of Australian geology and palaeontoloty. In 1872 he delivered an address on the diamond fields of Brazil, South Africa and Australia, which was published in the Transactions of the Royal Society of New South Wales. In later years his work was used in the compilation of geological maps of New South Wales (1893) and the area around Sydney (1903), by the territory's Department of Mines. He built up a collection of some 4000 geological specimens, which he presented to the Woodwardian Museum, Cambridge, in 1854.
Clarke was active in the Philosphical Society of New South Wales from its foundation in 1856, addressing the society on "Recent geological discoveries in Australia" in November 1861. During 1867-1876 he served as the first vice-president of the Royal Society of New South Wales.