18 Geological Reports 07i the State of New York. 



storms and high tides, fresh inroads are made. The beach between 

 Kidd's Point and Sands' Point covers a part of the marsh, the ooze and 

 marine peat of which, may be seen at the foot of the beach at ebb tide. 

 This indicates that high land, or else a beach, was once farther seaward, 

 to aiford protection for the formation of that part of the marsh. Only a 

 few acres of high land remain at Kidd's Point, and if it should continue 

 to be washed away as heretofore, (and much expense would be necessary 

 to prevent it,) a century or two would be sufficient to effect its entire re- 

 moval. 



" Kidd's Rock, as it is called, is a remarkable erratic block which was 

 imbedded in the loam of the tertiary formation. It has been undermined 

 by the action of the sea, and has slid down to the shore and cracked in 

 many large fragments. Viewing it from a little distance, one does not 

 realize its magnitade, but by climbing over and wandering among its 

 fragments at low water, it seems to grow upon the imagination. Its 

 fragments probably weigh at least 2,000 tons, and several sloop loads of 

 it have been shipped to New York for building stone. It is hornblendic 

 gneiss, and some of its masses abound in epidote. It is a durable stone, 

 and will stand any exposure unchanged." 



Coney island is washing away, as is the high bank near 

 Brown's point, on Staten Island. " Here a bank of shells, about 

 two feet thick, is exposed, within eight or ten inches of the natu- 

 ral surface of the ground." Mr. Mather attributes them to the 

 natives ; if our impressions are different, they are founded on sim- 

 ilar facts which we have observed elsewhere, as in Nantucket, 

 where a stratum of shells, but a little under the surface, extends 

 apparently through the Island, and must have been an oceanic 

 deposit, the last work of the tertiary epoch of that region. 



Beaches are universal on the shores of Long Island, and spits 

 are numerous. 



" The beaches and spits are trifling in extent and importance, when 

 compared with the Great South Beach of Long Island. This is a line of 

 alluvial sand and shingle, extending from Nepeague, in East Hampton, 

 to the mouth of New York Bay, a distance of 104 miles, and having a 

 direction of about W. S. W. It is not continuous, but is divided by in- 

 lets communicating with the bays which are situated between this and 

 Long Island, and through these inlets the tide ebbs and flows. AtQ,uogue, 

 and several places east of this, Long Island communicates with the 

 beach, either by marshes or by the upland ; but westward, for about 70 

 miles, a continuous line of bays, from half a mile to six miles broad, ex- 

 tends uninterruptedly, and separates the beach entirely from Long Island. 

 This Great Beach is a line of spits and islands. One of the islands is 



