CAPE COD GEOLOGY 



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long, which stands at least 9 feet above the surface of the bouldery drift. Koons 

 noted another larger boulder near by. These large boulders appear to be a 

 part of the Wisconsin drift. 



AGATE PEBBLES 



On the south coast of Naushon, west of Tarpaulin Cove, pebbles of 

 brown and white banded agate are rather common on the beach. These 

 pebbles have evidently been washed out of the morainal cliffs along the 

 coast. Similar pebbles are found on the beach on Marthas Vineyard, but 

 Tarpaulin Cove is probably about the eastern limit of their distribution in the 

 Elizabeth Islands. An occasional pebble of agate on Naushon encloses fragments 

 of a reddish shaly wall rock resembling certain phases of the Carboniferous 

 Wamsutta formation seen about Attleboro, but these agate pebbles appear 

 to have been derived from some locality south or east of Attleboro. Boulders 

 of the peculiar ilmenitic iron-ore of Cumberland Hill, in Rhode Island, some 

 5 miles northwest of North Attleboro, have been carried to Gay Head by glacial 

 action in at least one of the older Pleistocene stages of glacial invasion. The 

 general direction followed by these pebbles is S. 40° E., and Tarpaulin Cove, 

 on Naushon lies in the same direction from Diamond Hill, northwest of North 

 Attleboro. This hill includes a large mass of quartz that appears to contain 

 veins of similar agate. Other smaller veins are found near by in the red Carbon- 

 iferous rocks. Along with the agate pebbles on Naushon there are numerous 

 pebbles of white quartz that, contain small cavities beset with minute quartz 

 crystals. Possibly the source of the quartz and agate may prove to lie near 

 Diamond Hill. Similar agates have been found on the beaches on No Mans 

 Land and Block Island. 



PASQUE ISLAND 



Pasque Island lies west of Naushon and is separated from it by a narrow 

 passage, Robinson's Hole, which at its narrowest point is little more than 500 

 feet wide. The island is about a mile wide from north to south and about 1| 

 miles long from east to west. This measurement does not include the barrier 

 beaches and a small swamp and land-tied islands at the southeast end of the 

 island. Several drift-covered knolls in the eastern part of the island rise to a 

 height of about 100 feet and a middle ridge of the same height extends westward 

 toward a point exceeding a height of 120 feet, from which it is separated on the 

 north by a steep-sided glacial depression. Between the medial ridge and a lower 

 one on the north coast there is a small kettle hole containing a lakelet. Similar 



