The Project Gutenberg eBook ofDrainage Modifications and Glaciation in the Danbury Region ConnecticutThis ebook is for the use of anyone anywhere in the United States and most other parts of the world at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this ebook or online atwww.gutenberg.org. If you are not located in the United States, you will have to check the laws of the country where you are located before using this eBook.Title: Drainage Modifications and Glaciation in the Danbury Region ConnecticutAuthor: Ruth Sawyer HarveyRelease date: July 3, 2010 [eBook #33050]Language: EnglishCredits: Produced by Charlene Taylor, Tom Cos and the OnlineDistributed Proofreading Team at http://www.pgdp.net (Thisfile was produced from images generously made availableby The Internet Archive/American Libraries.)*** START OF THE PROJECT GUTENBERG EBOOK DRAINAGE MODIFICATIONS AND GLACIATION IN THE DANBURY REGION CONNECTICUT ***
This ebook is for the use of anyone anywhere in the United States and most other parts of the world at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this ebook or online atwww.gutenberg.org. If you are not located in the United States, you will have to check the laws of the country where you are located before using this eBook.
Title: Drainage Modifications and Glaciation in the Danbury Region ConnecticutAuthor: Ruth Sawyer HarveyRelease date: July 3, 2010 [eBook #33050]Language: EnglishCredits: Produced by Charlene Taylor, Tom Cos and the OnlineDistributed Proofreading Team at http://www.pgdp.net (Thisfile was produced from images generously made availableby The Internet Archive/American Libraries.)
Title: Drainage Modifications and Glaciation in the Danbury Region Connecticut
Author: Ruth Sawyer Harvey
Author: Ruth Sawyer Harvey
Release date: July 3, 2010 [eBook #33050]
Language: English
Credits: Produced by Charlene Taylor, Tom Cos and the OnlineDistributed Proofreading Team at http://www.pgdp.net (Thisfile was produced from images generously made availableby The Internet Archive/American Libraries.)
*** START OF THE PROJECT GUTENBERG EBOOK DRAINAGE MODIFICATIONS AND GLACIATION IN THE DANBURY REGION CONNECTICUT ***
Transcriber's Notes:With the following exceptions, the text presented here is that obtained through scanned images from an original copy of the manuscript.Possible Typographic Errors CorrectedPg. 32 occuying =>occupyingPLATE II A."of" was repeated
With the following exceptions, the text presented here is that obtained through scanned images from an original copy of the manuscript.
Pg. 32 occuying =>occupying
PLATE II A."of" was repeated
Drainage Modifications and Glaciation in the Danbury Region Connecticut, by Ruth Sawyer Harvey
Bulletins 1, 9, 12, 17, 21, 25, 27, and 28 are merely administrative reports containing no scientific matter. The other bulletins may be classified as follows:
Geology: Bulletins 4, 6, 7, 8, 13, 18, 23, 24, 29, 36.
Botany: Bulletins 3, 5, 10, 11, 14, 15.
Zoölogy: Bulletins 2, 16, 19, 20, 22, 26, 31.
These bulletins are sold and otherwise distributed by the State Librarian. Postage, when bulletins are sent by mail, is as follows:
The prices when the bulletins are sold are as follows, postpaid:
A part of the edition of these Bulletins have been assembled in volumes substantially bound in cloth, plainly lettered, and sell for the following prices, postpaid:
It is intended to follow a liberal policy in gratuitously distributing these publications to public libraries, colleges, andscientific institutions, and to scientific men, teachers, and others who require particular bulletins for their work, especially to those who are citizens of Connecticut.
Applications or inquiries should be addressed to
George S. Godard,
State Librarian,
Hartford, Conn.
In addition to the bulletins above named, published by the State survey, attention is called to three publications of the United States Geological Survey prepared in co-operation with the Geological and Natural Survey of Connecticut. These are the following:
Bulletin 484. The Granites of Connecticut: by T. Nelson Dale and Herbert E. Gregory.
Water-Supply Paper 374. Ground Water in the Hartford, Stamford, Salisbury, Willimantic and Saybrook Areas, Connecticut: by Herbert E. Gregory and Arthur J. Ellis.
Water-Supply Paper 397. Ground Water in the Waterbury Area, Connecticut: by Arthur J. Ellis, under the direction of Herbert E. Gregory.
These papers may be obtained from the Director of the United States Geological Survey at Washington.
Connecticut.State geological and natural history survey.
Bulletin no. 30. Drainage Modifications and Glaciation in the Danbury Region, Connecticut. By Ruth S. Harvey, Ph.D. Hartford, 1920.
59 pp., 5 pls., 10 fig., 25cm.
Harvey, Ruth Sawyer, Ph.D.
Drainage Modification and Glaciation in the Danbury Region, Connecticut. By Ruth S. Harvey, Ph.D. Hartford, 1920.
59 pp., 5 pls., 10 figs., 25cm.
Geology.
Harvey, Ruth S. Drainage Modifications and Glaciation in the Danbury Region, Connecticut. Hartford, 1920.
59 pp., 5 pls., 10 figs., 25
cm
.
State of ConnecticutPUBLIC DOCUMENT No. 47State Geological and NaturalHistory SurveyHERBERT E. GREGORY, SUPERINTENDENTBULLETIN No. 30HartfordPrinted by the State Geological and Natural History Survey1920
Hartford
Marcus H. Holcomb
, Governor of Connecticut
Arthur Twining Hadley
, President of Yale University
William Arnold Shanklin
, President of Wesleyan University
Remsen Brickerhoff Ogilby
, President of Trinity College
Charles Lewis Beach
, President of Connecticut Agricultural College
Benjamin Tinkham Marshall
, President of Connecticut College for Women
Herbert E. Gregory
Publication Approved by the Board of Control
Drainage Modifications and Glaciationin the Danbury RegionConnecticutByRUTH SAWYER HARVEY, Ph. D.HartfordPrinted by the State Geological and Natural History Survey1920
Hartford
The Danbury region of Connecticut presents many features of geographic and geologic interest. It may be regarded as a type area, for the history of its streams and the effects of glaciation are representative of those of the entire State. With this idea in mind, the field work on which this study is based included a traverse of each stream valley and an examination of minor features, as well as a consideration of the broader regional problems. Much detailed and local description, therefore, is included in the text.
The matter in the present bulletin formed the main theme of a thesis on "Drainage and Glaciation in the Central Housatonic Basin" which was submitted in partial fulfillment of the requirements for the degree of doctor of philosophy at Yale University.
The field work was done in 1907 and 1908 under the direction of Professor Herbert E. Gregory. I am also indebted to the late Professor Joseph Barrell and to Dr. Isaiah Bowman for helpful cooperation in the preparation of the original thesis, and to Dr. H. H. Robinson for assistance in preparing this paper for publication.
The region discussed in this bulletin is situated in western Connecticut and is approximately 8 miles wide and 18 miles long in a north-south direction, as shown onfig. 1.[1]Throughout, the rocks are crystalline and include gneiss, schist, and marble--the metamorphosed equivalents of a large variety of ancient sedimentary and igneous rocks.
For the purposes of this report, the geologic history may be said to begin with the regional uplift which marked the close of the Mesozoic. By that time the mountains formed by Triassic and Jurassic folding and faulting had been worn down to a peneplain, now much dissected but still recognizable in the accordant level of the mountain tops.
Erosion during Cretaceous time resulted in the construction of a piedmont plain extending from an undetermined line 30 to 55 miles north of the present Connecticut shore to a point south of Long Island.[2]This plain is thought to have been built up of unconsolidated sands, clays, and gravels, the débris of the Jurassic mountains. Inland the material consisted of river-made or land deposits; outwardly it merged into coastal plain deposits. When the plain was uplifted, these loose gravels were swept away. In New York, Pennsylvania, and New Jersey, however, portions of the Cretaceous deposits are still to be found. Such deposits are present, also, on the north shore of Long Island, and a well drilled at Barren Island on the south shore revealed not less than 500 feet of Cretaceous strata.[3]The existence of such thick deposits within 30 miles of the Connecticut shore and certain peculiarities in the drainage have led to the inference that the Cretaceous cover extended over the southern part of Connecticut.
A general uplift of the region brought this period of deposition to a close. As the peneplain, probably with a mantle of Cretaceous deposits, was raised to its present elevation, the larger streams kept pace with the uplift by incising their valleys. The position of the smaller streams, however, was greatly modified in the development of the new drainage system stimulated by the uplift. The modern drainage system may be assumed to have been at first consequent, that is, dependent for its direction on the slope of the uplifted plain, but it was not long before the effect of geologic structure began to make itself felt. In the time when all the region was near baselevel, the harder rocks had no advantage over the softer ones, and streams wandered where they pleased. But after uplift, the streams began to cut into the plain, and those flowing over limestone or schist deepened, then widened their valleys much faster than could the streams which flowed over the resistant granite and gneiss. By a system of stream piracy and shifting, similar to that which has taken place throughout the Newer Appalachians, the smaller streams in time became well adjusted to the structure. They are of the class called subsequents; on the other hand, the Housatonic, which dates at least from the beginning of the uplift if not from the earlier period of peneplanation, is an antecedent stream.
The complex rock surface of western Connecticut had reached a stage of mature dissection when the region was invaded by glaciers.[4]The ice sheet scraped off and redistributed the mantle of decayed rock which covered the surface and in places gouged out the bedrock. The resulting changes were of a minor order, for the main features of the landscape and the principal drainage lines were the same in preglacial time as they are today. It is thus seen that the history of the smaller streams like those considered in this report involves three factors: (1) the normal tendencies of stream development, (2) the influence of geologic structure, and (3) the effect of glaciation.
The cover of glacial deposits is generally thin, but marked variations exist. The fields are overspread with coarse till containing pebbles 6 inches in diameter to huge boulders of 12 feet or more. The abundance, size, and composition of the boulders in the till of a given locality is well represented by the stone fences which border fields.
Present drainage of the Danbury region.Fig. 1.Present drainage of the Danbury region.
The regional depression which marked the close of the glacial period slackened the speed of many rivers and caused them to deposit great quantities of modified or assorted drift. Since glacial time, these deposits have been dissected and formed into the terraces which are characteristic of the rivers of the region. A form of terrace even more common than the river-made terrace is the kame terrace found along borders of the lowlands. Eskers in the Danbury region have not the elongated snake-like form by which they are distinguished in some parts of the country, notably Maine; on the contrary, they are characteristically short and broad, many having numerous branches at the southern end like the distributaries of an aggrading river. The material of the eskers ranges from coarse sand to pebbles four inches in diameter, the average size being from one to two inches. No exposures were observed which showed a regular diminution in the coarseness of the material toward their southern end. The clean-washed esker gravels afford little encouragement to plant growth, and the rain water drains away rapidly through the porous gravel. Consequently, accumulations of stratified drift are commonly barren places. A desert vegetation of coarse grasses, a kind of wiry moss, and "everlastings" (Gnaphalius decurrens) are the principal growth. Rattlebox (Crotolaria sagittalis), steeplebush (Spiraea tomentosa), sweet fern (Comptonia asplenifolia), and on the more fertile eskers--especially on the lower, wetter part of the slope--golden rod, ox-eyed daisy, birch, and poplar are also present. All the eskers observed were found to be similar: they ranged in breadth across the top from 100 to 150 feet and the side slopes were about 20 degrees. Only a single heavily wooded esker was found, and this ran through a forest region.
The accumulations of stratified drift are distinguished from other features in the landscape by their smoother and rounder outlines, by their habit of lying unconformably on the bedrock without reference to old erosion lines, and by a slightly different tone in the color of the vegetation covering the water-laid material. The difference in color, which is due to the unique elements in the flora of these areas, may cause a hill of stratified drift in summer to present a lighter green color than that of surrounding hills of boulder clay or of the original rock slopes; in winter the piles of stratified drift stand out because of the uniform light tawny red of the dried grass.
[1]The streams and other topographic features of the Danbury region are shown in detail on the Danbury and the New Milford sheets of the United States Topographic Atlas. These sheets may be obtained from the Director of the United States Geological Survey, Washington, D. C.[2]It was probably not less than 30 miles, for that is the distance from the mouth of Still River, where the Housatonic enters a gorge in the crystallines, to the sea. Fifty-five miles is the distance to the sea from the probable old head of Housatonic River on Wassaic Creek, near Amenia, New York.[3]Veatch, A. C., Slichter, C. S., Bowman, Isaiah, Crosby, W. O., and Horton. R. E., Underground water resources of Long Island: U. S. G. S., PP. 44, p. 188 and fig. 24, 1906.[4]This stage of glaciation is presumably Wisconsin. No definite indication of any older glacial deposits was found.
[1]The streams and other topographic features of the Danbury region are shown in detail on the Danbury and the New Milford sheets of the United States Topographic Atlas. These sheets may be obtained from the Director of the United States Geological Survey, Washington, D. C.
[2]It was probably not less than 30 miles, for that is the distance from the mouth of Still River, where the Housatonic enters a gorge in the crystallines, to the sea. Fifty-five miles is the distance to the sea from the probable old head of Housatonic River on Wassaic Creek, near Amenia, New York.
[3]Veatch, A. C., Slichter, C. S., Bowman, Isaiah, Crosby, W. O., and Horton. R. E., Underground water resources of Long Island: U. S. G. S., PP. 44, p. 188 and fig. 24, 1906.
[4]This stage of glaciation is presumably Wisconsin. No definite indication of any older glacial deposits was found.
View south on the highland northeast of Neversink Pond. The base of a ridge in which rock is exposed is seen at the left; a crescent-shaped lateral moraine bordering the valley lies at the right.
Rocky River begins its course as a rapid mountain brook in a rough highland, where the mantle of till in many places is insufficient to conceal the rock ledges (fig. 1). Near Sherman, about four miles from its source, it enters a broad flood plain and meanders over a flat, swampy floor which is somewhat encumbered with deposits of stratified drift and till. Rocky hills border the valley and rise abruptly from the lowland. The few tributaries of the river in this part of its course are normal in direction.
About six miles below Sherman, Rocky River enters Wood Creek Swamp, which is 5½ miles long by about one mile wide and completely covers the valley floor, extending even into tributary valleys. Within the swamp the river is joined by Squantz Pond Brook and Wood Creek. Tributaries to Wood Creek include Mountain Brook and the stream passing through Barses Pond and Neversink Pond. The head of Barses Pond is separated from the swamp only by a low ridge of till. Neversink Pond with its inlet gorge and its long southern tributary record significant drainage modifications, as described in the section entitled "The Neversink-Danbury Valley."
Within and along the margin of Wood Creek Swamp, also east of Wood Creek and at Barses Pond, are rounded, elongated ridges of till, some of which might be called drumlins. East of Neversink Pond is the lateral moraine shown inPl. I. From the mouth of Wood Creek to Jerusalem, Rocky River is a quiet stream wandering between low banks through flat meadows, which are generally swampy almost to the foot of the bordering hills.
Near Jerusalem bridge two small branches enter Rocky River. Immediately north of the bridge is a level swampy area about one-half mile in length. Where the valley closes in again, bedrock is exposed near the stream, and beginning at a point one-half mile below (north of) Jerusalem, Rocky River--a swift torrent choked by boulders of great size--deserves its name.In spite of its rapid current, however, the river is unable to move these boulders, and for nearly three miles one can walk dry-shod on those that lie in midstream.
At two or three places below Jerusalem, in quiet reaches above rapids, the river has taken its first step toward making a flood plain by building tiny beaches. One-half mile above the mouth of the river the valley widens and on the gently rising south bank there are several well-marked terraces about three feet in height and shaped out of glacial material. A delta and group of small islands at the mouth of Rocky River indicate the transporting power of the stream and the relative weakness of the slow-moving Housatonic.