22 AXEL A. OLSSON 



a stretch of sandy and rocky coast and then comes the small covelike harbor 

 of Talara. Much changed from pioneer days, Talara today is an important, 

 modern city with its refinery, shops and fine homes of the oil workers in this 

 part of Peru. About five miles south of Talara is the town of Negritos, now 

 less important than in former times, overlooking the sea with nearby Punta 

 Parinas and Punta Balcones, the most westerly points of all South America. 



Continuing southward past Punta Parinas with its light beacon perched 

 on its shoulder and the nearby Punta Balcones, another long stretch of open 

 sand beach is encountered which trends to the southeast past Portochuelo 

 and the mouth of the Chira River, and thence to Colon. The coast 

 then curves towards the west to form the next large bay "the Bay of 

 Paita", widely open to the north but affording safe anchorage opposite its 

 southern shore. The old city of Paita, founded in early colonial days, sits 

 in a small gap at the base of high cliffs at the junction point of two con- 

 trasting rock formations. To the east of the city, there are high cliffs of the 

 Chira shales capped by heavy beds of tablazo sands and coquina limestones; 

 to the west by much older slates and schists, both rock formations, in spite 

 of their great differences in hardness are planed off more or less evenly by 

 a marine sea-transgression and overlain by a variable thickness of Pleistocene 

 deposits of the Mancora tablazo forming a plain of wide extent. At this place 

 the tablazo plain is elevated about 200 feet above the sea. Collecting along 

 the shore at Paita is generally poor, but Paita is the type locality of many 

 species, for the most part, dredged in the bay outside. 



The middle bulge in the coast of northwestern Peru is that of the 

 Paita Peninsula bounded on the north by the Bay of Paita and 

 on the south by the deep Bay of Sechura. The peninsula is a broad, irregu- 

 larly shaped area, its basement formed of ancient slates, schist, seamed with 

 quartz veins and intruded by large masses of granodiorite. Near the middle 

 of this area rise the Paita Mountains, a group of small, barren peaks which 

 attain an elevation of about 400 meters above sea level. Elsewhere, the 

 general surface of the pninsula is a flat plain or tablazo, barren for the most 

 part of any vegetation. Along the west side of the peninsula, there are seg- 

 ments of Tertiary rocks infaulted between the slates and where these softer 

 beds come to the shore, they have been eroded into deep, picturesque coves 

 and small bays between the much harder slates which jut seaward in jagged, 

 rocky points. In this section is located the small village of Yasila, easily 

 accessible from Paita. Yasila is a good locality for Eocene fossils, and at 

 times may offer collecting possibilities for marine shells. The south side of 

 the peninsula is rugged, the shore lined with high cliffs of Cretaceous rocks 

 overlain by a massive bed of tablazo limestone. This is a good locality for 

 Cretaceous fossils. Nearby is the small fishing settlement of Tortuga. 



