anthropogenic (created by humans) landscape, into horse-drawn carts and carried away, In EVERYTHING YOU Indeed, it was the steep-sidedness and irregu- contrast, the continuous use of Mount Hope as WANTED TO KNOW larity of the area that probably led to its use as a cemetery since 1838 has also preserved an a burial ground; it was picturesque, and, after incomparable glacial landscape, ABOUT THE GEOLOGY some initial gravel quarrying, it apparently OF MOUNT wasn't good for anything else, The former St, Mount Hope Cemetery was built on the eastem HOPE CEMETERY Patrick's Cemetery on Pinnacle Hill was quarter of a row of hills called the Pinnacle apparently built on its site for similar reasons, Range, In a city where topographic drama is by William Chaisson However, consolidation of the neighborhood elsewhere provided by holes in the ground like Catholic cemeteries to Holy Sepulchre in the the Genesee Gorge, the Irondequoit \'alley, and (Editor's Note. Bill Chaisson is a professor of Here, looking north from Lawn Avenue in the gullies of Durand-Eastman Park, the geology at the University of Rochester. In this Section E, is a conical hill formed by a glacier Pinnacle Range represents the only significant positive relief, The Pinnacle, the tallest hill in article, he takes us through mythological ideas and known in geological terms its a kame, It is about the formation of the earth's surface to the range, lies between South Clinton and formed when a glacier deposits sediment into a the major scientific discoveries that ascertained Monroe avenues and rises 263 feet above the lake in front of the ice sheet. the existence of massive global glaciers that surrounding plain, The knolls of the by created the interesting landscape of Mount Photo Frank A, Gillespie. Irondequoit Valley and Durand-Eastman Park Hope Cemetery and the surrounding area, are incidentally left standing higher as a result These glaciers present a fascinating story, and of running water incising and eroding the sedi- a tale that is true,) ments around them, while the Pinnacle Range late 19th century permitted the resumption of hills were actively built during the latter states The jumble of hills and glens in Mount Hope quarrying at Pinnacle Hill, As a result, much of of the last glacial retreat, Cemetery is a largely natural rather than an the natural shape of Pinnacle Hill has been put HISTORICAL found over much of Europe and North America, In 1840, he published "Etude sur les BACKGROUND Glaciers," wherein he proposed the existence of a global ice age in the geologic past, The Pinnacle Range entered the geological lit- Agassiz was an enthusiastic and tireless lectur- erature in 1843 when James Hall, New York er, and he immediately began a campaign State geologist, published the first description throughout Europe to replace the diluvial theo- of the ridge, He included a sketch of the sedi- ry with the glacial explanation for drift ments revealed by the excavations done to deposits . lower the grade of Monroe Avenue on its way out of the city and into Brighton, At this early In 1846, three years after Hall's initial exami- date, Hall would not have guessed the true nation of the Pinnacle Range, Agassiz moved agent for the construction of hills, From the Sedimentfrom the ice sheet is to the United States and published "Systema 17th half of 19th the to the latter the century, deposited in layers into Glacial Lake Glaciare" ( 1847) on the strength of extensive scientific community generally accepted the Danaforming the kame delta. field work throughout Europe, After 1848, he hypothesis that Noah's Flood was responsible accepted a professorship at Harvard University, for the form and distribution of much of the did more field work in North America, and unconsolidated material found on the Earth's actively introduced the glacial theory to the surface, Because this debris was thought to New World geologic community, Largely have been transported and deposited by water, because of more rigid religious beliefs from it was called "drift." those of their European colleagues, the North American geologists took longer to be won During the Renaissance (15th and 16th cen- over, As late as 1891, prominent Canadian turies), scientific explanations for natural phe- geologist Sir J, William Dawson (1820-1899) nomena began to replace mythological stories, was still actively defending the diluvial theory, The hypotheses to explain the form and opera- The ice sheet retreats a short distance which had long since been abandoned by the tion of Nature became increasingly ambitious from the kame delta and continues to European establishment, in the 17th century . Thomas Burnet (1635- deposit till infront ofit. 1715), royal chaplain to King William III of But through the second half of the 19th centu- England, published his "Telluris Theoria ry, the glacial theory gradually gained more Sacra," or "The Sacred Theory of the Earth" in American adherents . In 1890, geologist 1861, One of Burnet's primary assumptions Charles Dryer noted that the lower half of the was that he was living in a "fallen world." Pinnacle Range was composed of coarse grav- Before the commission of the "original sin," els, while the upper half consisted of fine the world had been a perfectly orderly place, sands, He called the entire ridge a gigantic Burnet sought to explain the erosion, decay, "kame," a term of Scottish origin that refers to and disorder that he saw on the landscape, and layered or stratified sediments that are derived he attributed much to the violence and scale of from a glacier, but deposited into a body of the Noahic flood, Through the 18th century, as The ice sheet re-advances onto water, Two years later, another geologist more field work led to more extensive map- the kame-delta, deposited Warren Upham, impressed by the linear form ping of drift deposits, this "diluvial theory" unlayered and unsorted moraine of the chain of hills, claimed it was a very was gradually refined, It would have been material over the kame sediments. large "esker;" the sediment accumulation in the Hall's assumption, as he sat in the middle of a channel of a sub-lacial river. In 1895, Herman construction site on Monroe Avenue in 1843, LeRoy Fairchild (1850-1943), a geology pro- that he was sketching sediments deposited in a fessor at the University of Rochester, showed global flood, that Dryer was closer to the truth than Upham. In the 1930s, Swiss paleontologist and zoolo- gist Louis Agassiz (1807-1873) began taking walks in the Alps with mountain guides . These were men with little education, but years of experience traveling in the mountains, They showed Agassiz the deposits left on valley ice sheet retreats to latitude floors after glaciers had melted back decades The the of before, The professor was struck by how simi- thepresent shore ofLake Ontario. lar these alpine deposits were to piles of drift Glacial Lake Dawsonforms at a lower that he had observed much further north in level than Dana and the southern Germany, some distance from the kame-moraine is left exposed mountains, Using the premise that similar to erosion. results have similar causes, Agassiz hypothe- sized that the alpine glaciers had been much more extensive in the distant past, Agassiz threw himself into the scientific literature on this new topic and found that drift deposits similar to the alpine glacial sediments could be for hundreds of miles . At the edges of the ice Lake Dana." Most of the glacial lakes were PLEISTOCENE sheet, this load of sediment was disgorged. named for famous geologists. Consequently, GEOLOGY Sediment ejected from a glacier is collectively the lower half of the Pinnacle Range consists referred to as "till," which is essentially syn- of stratified sands and gravels, as described by H. L. Fairchild's major achievement as a onymous with the historical term "drift." Dryer, and is, as he claimed, a kame deposit. It research geologist was his mapping of a series is part of a longer feature that extends west- of glacial lakes that ponded in front of the Ice sheets and glaciers "retreat" when the rate ward, which is sometimes called the retreating continental ice sheet at the close of of melting at their perimeters exceeds the rate "RocHester-A INon moraine." the last glacial cycle, which was between of ice accumulation at their centers. When 18,000 and 9,(X)0 years before the present time these rates are exactly balanced, the edge of Fairchild described the Pinnacle Range as a (B.P.). The topography of western New York the ice sheet will remain in the same place and "hybrid structure" called a "kame-moraine," State rises steadily from the Lake Ontario continue to eject till, building up a long linear because the hills, although stratified at the basin to the Pennsylvania border, which is why pile along the perimeter. Such a pile at the base, have an unstratified "crown" that is in the Genesee River flows north, As the southern maximum extent of an ice sheet is called a many places full of large boulders. Fairchild edge of the ice sheet retreated northward "terminal moraine." Accumulations that are reasoned that the ice sheet must have retreated across the state, the meltwater collected deposited during standstills in the course of thee northward a short distance from the "kame between the towering ice mass to the north and ice sheet's retreat are called "recessional delta" it had built into Glacial Lake Dana. A higher ground to the south in a series of enor- moraine",. brief re-advance of the icefront then reached mous "proglacial" lakes.