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Image map of Kitchen Creek and its waterfalls in Ricketts Glen State Park, as well as other prominent features. Each label is linked to an article or image. Click here for larger map. |350px|thumb|rightrect 23 473 109 508 Sullivan County, Pennsylvania rect 1 631 88 667 Columbia County, Pennsylvania rect 121 562 206 601 Luzerne County, Pennsylvania rect 182 454 240 512 Pennsylvania Route 487 rect 674 670 792 692 Pennsylvania Route 118 rect 471 596 543 632 Ricketts Glen rect 655 280 780 319 Bowman Creek rect 505 6 646 41 Ricketts Glen State Park rect 477 651 543 690 Kitchen Creek rect 494 750 551 770 Adams Falls rect 366 733 485 753 Kitchen Creek Falls rect 499 546 618 563 Shingle Cabin Falls rect 491 488 632 506 Murray Reynolds Falls rect 487 471 631 488 Sheldon Reynolds Falls rect 480 454 615 470 Harrison Wright Falls rect 413 398 469 437 Waters Meet rect 447 298 494 334 Glen Leigh rect 478 428 556 445 Wyandot Falls rect 483 410 585 427 B. Reynolds Falls rect 485 392 595 408 R. B. Ricketts Falls rect 483 376 539 391 Ozone Falls rect 491 348 545 365 Huron Falls rect 496 326 573 345 Shawnee Falls rect 498 306 604 323 F.L. Ricketts Falls rect 500 287 585 304 Onondaga Falls rect 356 355 421 389 Ganoga Glen rect 427 521 463 538 Erie Falls rect 362 503 447 519 Tuscarora Falls rect 325 487 415 503 Conestoga Falls rect 321 472 394 488 Mohican Falls rect 285 452 367 470 Delaware Falls rect 312 434 377 450 Seneca Falls rect 308 418 373 434 Ganoga Falls rect 286 398 349 414 Cayuga Falls rect 276 383 337 398 Oneida Falls rect 248 365 321 382 Mohawk Falls rect 540 520 705 540 Shingle Cabin Brook rect 306 116 352 156 Lake Jean rect 253 295 344 340 Lake Rose rect 564 165 614 209 Lake Leigh rect 4 234 78 259 Big Run (Fishing Creek tributary) rect 63 0 130 35 Ganoga Lake desc bottom-left There are 24 named waterfalls in Ricketts Glen State Park in the U.S. state of Pennsylvania along Kitchen Creek as it flows in three steep, narrow valleys, or glens. They range in height from 9 feet (2.7 m) to the 94-foot (29 m) Ganoga Falls. Ricketts Glen State Park is named for R. Bruce Ricketts, a colonel in the American Civil War who owned over 80,000 acres (32,000 ha) in the area in the late 19th and early 20th centuries, but spared the old-growth forests in the glens from clearcutting. The park, which opened in 1944, is administered by the Bureau of State Parks of the Pennsylvania Department of Conservation and Natural Resources (DCNR). Nearly all of the waterfalls are visible from the Falls Trail, which Ricketts had built from 1889 to 1893 and which the state park rebuilt in the 1940s and late 1990s. The Falls Trail has been called "the most magnificent hike in the state" and one of "the top hikes in the East".〔Young, p. 66.〕 The waterfalls are on the section of Kitchen Creek that flows down the Allegheny Front, a steep escarpment between the Allegheny Plateau to the north and the Ridge-and-Valley Appalachians to the south. The glens are made of sedimentary rocks from the Huntley Mountain and Catskill Formations that formed up to 370 million years ago in the Devonian and Carboniferous periods. The waterfalls are the result of increased flow in Kitchen Creek from glaciers enlarging its drainage basin during the last Ice Age. Ricketts named 21 of the waterfalls, mostly for Native American tribes and places, and his family and friends. There are ten named falls in Ganoga Glen, eight named falls in Glen Leigh, and between four and six named waterfalls in Ricketts Glen. The DCNR names 22 falls, the United States Geological Survey (USGS) Geographic Names Information System (GNIS) names 23 falls, and Scott E. Brown's 2004 book ''Pennsylvania waterfalls: a guide for hikers and photographers'' names 24. The falls are described in order going upstream along the creek for each of the three glens. ==Geology== The waterfalls in Ricketts Glen State Park are on the Allegheny Front, which is the boundary between the Allegheny Plateau to the north and the Ridge-and-Valley Appalachians to the south. The headwaters of Kitchen Creek are on the dissected plateau, from which the stream drops approximately 1,000 feet (300 m) in 2.25 miles (3.62 km) as it flows down the steep escarpment of the Allegheny Front. Much of this drop occurs in Glen Leigh and Ganoga Glen, two narrow valleys carved by branches of Kitchen Creek, which come together at Waters Meet.〔 The branch in Glen Leigh has eight named waterfalls and lies north of the confluence, while the branch in Ganoga Glen has ten named waterfalls and lies to the northwest. Ricketts Glen lies south of and downstream from Waters Meet; here the terrain becomes less steep, and there are fewer named waterfalls. The DCNR names only four in Ricketts Glen, all on Kitchen Creek;〔 the USGS GNIS names these and one more on the creek,〔 and Brown's book on Pennsylvania waterfalls adds a sixth named falls on a tributary.〔Brown, pp. 50–52.〕 The rocks exposed in the park were formed between 370 and 340 million years ago, when the land was part of the coastline of a shallow sea that covered a great portion of what is now North America. The high mountains to the east of the sea gradually eroded, causing a build-up of sediment made up primarily of clay, sand and gravel. Tremendous pressure on the sediment caused the formation of the rocks that are found in the park and in the Kitchen Creek drainage basin: sandstone, shale, siltstone, and conglomerates.〔 About 300 to 250 million years ago, the Allegheny Plateau, Allegheny Front, and Appalachian Mountains all formed in the Alleghanian orogeny. This happened long after the sedimentary rocks in the park were deposited, when the part of Gondwana that became Africa collided with what became North America, forming Pangaea. In the years since, up to 5,000 feet (1,500 m) of rock has been eroded away by streams and weather. At least three major glaciations in the past million years have been the final factor in shaping the land that makes up the park today.〔〔〔Shultz, pp. 372–374, 391, 399, 818.〕 The effects of glaciation have made Kitchen Creek "unique compared to all other nearby streams that flow down the Allegheny Front", as it is the only one with an "almost continuous series of waterfalls". Prior to the last ice age, Kitchen Creek and Phillips Creek to the east had drainage basins of similar area and slope, and both watersheds were confined to the Allegheny Front. This changed when receding glaciers formed temporary dams on two of Kitchen Creek's neighboring streams on the Allegheny Plateau, South Branch Bowman Creek to the northeast and Big Run, a tributary of Fishing Creek to the northwest. The headwaters of South Branch Bowman Creek were very close to those for the Glen Leigh branch of Kitchen Creek, and the headwaters for Big Run were very close to those for the Ganoga Glen branch.〔 As the glaciers retreated to the northeast about 20,000 years ago, glacial lakes formed. Drainage from the melting glacier and lakes cut a sluiceway, or channel, that diverted the headwaters of South Branch Bowman Creek into the Glen Leigh branch of Kitchen Creek. The retreating glaciers also left deposits of debris 20 to 30 feet (6.1 to 9.1 m) thick, which formed a dam blocking water from draining into Big Run. Instead water from Ganoga Lake and the area that later became Lake Jean was diverted into the Ganoga Glen branch of Kitchen Creek. These diversions added about 7 square miles (18 km²) to the Kitchen Creek drainage basin, increasing it by just over 50 percent to 20.1 square miles (52 km²).〔 The result was increased water flow in Kitchen Creek, which has been cutting the falls in the glens since. The gradient or slope of Kitchen Creek was fairly stable for its flow when it had a much smaller drainage basin, as Phillips Creek still does. The increased basin size means that Kitchen Creek in the glens is too steep for its present amount of water flow. As Kitchen Creek continues to cut into the rock and erode it up the Allegheny Front, the creek's slope will decrease and become less steep. In the future, the creek's flow and slope are predicted to become similar to those of other nearby creeks with similar size drainage basins. This process could take so long that a new glacial period might occur before the transformation is complete.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Waterfalls in Ricketts Glen State Park」の詳細全文を読む スポンサード リンク
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