NaNO GH Oh ee VEN N hE OF BEV ONVANT ROGKS 
IN WISCONSIN 
THERE is an outcrop of Devonian rock on the shore of Lake 
Michigan in this state, ten miles north of Port Washington and 
about a mile southeast of the little village of Lake Church, 
which has hitherto escaped the notice of geologists. The dis- 
covery of this exposure by the writer in the summer of 1896 was 
somewhat of a surprise as all the nearest outcrops of rock, to the 
north, south, and west, belong to the Niagara formation. In the 
neighborhood of Lake Church the heavy drift deposits, which 
form high bluffs on the very edge of the lake at Milwaukee and 
at Port Washington, recede quite a distance from the shore and 
take the form of a series of rolling ridges which increase in 
height towards the west. Between the lowest of these ridges 
and the lake there stretches a sort of terrace, elevated only five 
or six feet above the lake level at its eastern margin and rising 
very gradually as it recedes from the shore. The rock in ques- 
tion forms the floor of this terrace and crops out in various 
places in the neighborhood upon the beach and under the water. 
It is also uncovered in the bed of a little watercourse which 
traverses the terrace. The strata are nearly level but probably 
dip slightly towards the east. The rock is an impure limestone, 
somewhat earthy in composition and somewhat granular or 
sandy to the touch. An inconsiderable excavation has been 
made in it by the owners, disclosing a thickness of about six 
feet of Devonian strata, beneath which is a transition layer of 
bluish shaly rock, resting on a very hard, white, crystalline lime- 
stone which probably belongs to the Niagara. 
About sixty species of fossils have been obtained from the 
upper layers, all of which, with the exception of a single frag- 
mentary dental plate of Rhynchodus, are in the form of casts 
and impressions, a fact which renders their determination a matter 
of some difficulty. The fauna comprises about twenty-four 
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